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Simon Machado R, Mathias K, Joaquim L, de Quadros RW, Rezin GT, Petronilho F. Hyperoxia and brain: the link between necessity and injury from a molecular perspective. Neurotox Res 2024; 42:25. [PMID: 38619632 DOI: 10.1007/s12640-024-00702-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 11/15/2023] [Accepted: 03/25/2024] [Indexed: 04/16/2024]
Abstract
Oxygen (O2) supplementation is commonly used to treat hypoxia in patients with respiratory failure. However, indiscriminate use can lead to hyperoxia, a condition detrimental to living tissues, particularly the brain. The brain is sensitive to reactive oxygen species (ROS) and inflammation caused by high concentrations of O2, which can result in brain damage and mitochondrial dysfunction, common features of neurodegenerative disorders. Hyperoxia leads to increased production of ROS, causing oxidative stress, an imbalance between oxidants and antioxidants, which can damage tissues. The brain is particularly vulnerable to oxidative stress due to its lipid composition, high O2 consumption rate, and low levels of antioxidant enzymes. Moreover, hyperoxia can cause vasoconstriction and decreased O2 supply to the brain, posing a challenge to redox balance and neurodegenerative processes. Studies have shown that the severity of hyperoxia-induced brain damage varies with inspired O2 concentration and duration of exposure. Therefore, careful evaluation of the balance between benefits and risks of O2 supplementation, especially in clinical settings, is crucial.
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Affiliation(s)
- Richard Simon Machado
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciuma, SC, Brazil.
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil.
| | - Khiany Mathias
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciuma, SC, Brazil
| | - Larissa Joaquim
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciuma, SC, Brazil
| | | | - Gislaine Tezza Rezin
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Fabricia Petronilho
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciuma, SC, Brazil
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2
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Salvagno M, Sterchele ED, Zaccarelli M, Mrakic-Sposta S, Welsby IJ, Balestra C, Taccone FS. Oxidative Stress and Cerebral Vascular Tone: The Role of Reactive Oxygen and Nitrogen Species. Int J Mol Sci 2024; 25:3007. [PMID: 38474253 DOI: 10.3390/ijms25053007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/29/2024] [Accepted: 03/02/2024] [Indexed: 03/14/2024] Open
Abstract
The brain's unique characteristics make it exceptionally susceptible to oxidative stress, which arises from an imbalance between reactive oxygen species (ROS) production, reactive nitrogen species (RNS) production, and antioxidant defense mechanisms. This review explores the factors contributing to the brain's vascular tone's vulnerability in the presence of oxidative damage, which can be of clinical interest in critically ill patients or those presenting acute brain injuries. The brain's high metabolic rate and inefficient electron transport chain in mitochondria lead to significant ROS generation. Moreover, non-replicating neuronal cells and low repair capacity increase susceptibility to oxidative insult. ROS can influence cerebral vascular tone and permeability, potentially impacting cerebral autoregulation. Different ROS species, including superoxide and hydrogen peroxide, exhibit vasodilatory or vasoconstrictive effects on cerebral blood vessels. RNS, particularly NO and peroxynitrite, also exert vasoactive effects. This review further investigates the neuroprotective effects of antioxidants, including superoxide dismutase (SOD), vitamin C, vitamin E, and the glutathione redox system. Various studies suggest that these antioxidants could be used as adjunct therapies to protect the cerebral vascular tone under conditions of high oxidative stress. Nevertheless, more extensive research is required to comprehensively grasp the relationship between oxidative stress and cerebrovascular tone, and explore the potential benefits of antioxidants as adjunctive therapies in critical illnesses and acute brain injuries.
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Affiliation(s)
- Michele Salvagno
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1000 Brussels, Belgium
| | - Elda Diletta Sterchele
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1000 Brussels, Belgium
| | - Mario Zaccarelli
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1000 Brussels, Belgium
| | - Simona Mrakic-Sposta
- Institute of Clinical Physiology-National Research Council (CNR-IFC), 20133 Milan, Italy
| | - Ian James Welsby
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Costantino Balestra
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium
- Anatomical Research and Clinical Studies, Vrije Universiteit Brussels (VUB), 1050 Elsene, Belgium
- DAN Europe Research Division (Roseto-Brussels), 1160 Brussels, Belgium
- Motor Sciences Department, Physical Activity Teaching Unit, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
| | - Fabio Silvio Taccone
- Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), 1000 Brussels, Belgium
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3
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Leveque C, Mrakic Sposta S, Theunissen S, Germonpré P, Lambrechts K, Vezzoli A, Bosco G, Lévénez M, Lafère P, Guerrero F, Balestra C. Oxidative Stress Response Kinetics after 60 Minutes at Different (1.4 ATA and 2.5 ATA) Hyperbaric Hyperoxia Exposures. Int J Mol Sci 2023; 24:12361. [PMID: 37569737 PMCID: PMC10418619 DOI: 10.3390/ijms241512361] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/25/2023] [Accepted: 08/01/2023] [Indexed: 08/13/2023] Open
Abstract
Hyperbaric oxygen therapy (HBOT) is a therapeutical approach based on exposure to pure oxygen in an augmented atmospheric pressure. Although it has been used for years, the exact kinetics of the reactive oxygen species (ROS) between different pressures of hyperbaric oxygen exposure are still not clearly evidenced. In this study, the metabolic responses of hyperbaric hyperoxia exposures for 1 h at 1.4 and 2.5 ATA were investigated. Fourteen healthy non-smoking subjects (2 females and 12 males, age: 37.3 ± 12.7 years old (mean ± SD), height: 176.3 ± 9.9 cm, and weight: 75.8 ± 17.7 kg) volunteered for this study. Blood samples were taken before and at 30 min, 2 h, 24 h, and 48 h after a 1 h hyperbaric hyperoxic exposure. The level of oxidation was evaluated by the rate of ROS production, nitric oxide metabolites (NOx), and the levels of isoprostane. Antioxidant reactions were assessed through measuring superoxide dismutase (SOD), catalase (CAT), cysteinylglycine, and glutathione (GSH). The inflammatory response was measured using interleukine-6, neopterin, and creatinine. A short (60 min) period of mild (1.4 ATA) and high (2.5 ATA) hyperbaric hyperoxia leads to a similar significant increase in the production of ROS and antioxidant reactions. Immunomodulation and inflammatory responses, on the contrary, respond proportionally to the hyperbaric oxygen dose. Further research is warranted on the dose and the inter-dose recovery time to optimize the potential therapeutic benefits of this promising intervention.
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Affiliation(s)
- Clément Leveque
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium
- Laboratoire ORPHY, Université de Bretagne Occidentale, UFR Sciences et Techniques, 6 Avenue Le Gorgeu, 93837 Brest, France
| | - Simona Mrakic Sposta
- Institute of Clinical Physiology, National Research Council (CNR), 20162 Milan, Italy
| | - Sigrid Theunissen
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium
| | - Peter Germonpré
- DAN Europe Research Division (Roseto-Brussels), 1160 Brussels, Belgium
- Hyperbaric Centre, Queen Astrid Military Hospital, 1120 Brussels, Belgium
| | - Kate Lambrechts
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium
| | - Alessandra Vezzoli
- Institute of Clinical Physiology, National Research Council (CNR), 20162 Milan, Italy
| | - Gerardo Bosco
- Environmental Physiology & Medicine Lab, Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Morgan Lévénez
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium
| | - Pierre Lafère
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium
- DAN Europe Research Division (Roseto-Brussels), 1160 Brussels, Belgium
| | - François Guerrero
- Laboratoire ORPHY, Université de Bretagne Occidentale, UFR Sciences et Techniques, 6 Avenue Le Gorgeu, 93837 Brest, France
| | - Costantino Balestra
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium
- DAN Europe Research Division (Roseto-Brussels), 1160 Brussels, Belgium
- Anatomical Research and Clinical Studies, Vrije Universiteit Brussels (VUB), 1090 Brussels, Belgium
- Physical Activity Teaching Unit, Motor Sciences Department, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
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4
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McIlroy DR, Shotwell MS, Lopez MG, Vaughn MT, Olsen JS, Hennessy C, Wanderer JP, Semler MS, Rice TW, Kheterpal S, Billings FT. Oxygen administration during surgery and postoperative organ injury: observational cohort study. BMJ 2022; 379:e070941. [PMID: 36450405 PMCID: PMC9710248 DOI: 10.1136/bmj-2022-070941] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
OBJECTIVE To examine whether supraphysiological oxygen administration during surgery is associated with lower or higher postoperative kidney, heart, and lung injury. DESIGN Observational cohort study. SETTING 42 medical centers across the United States participating in the Multicenter Perioperative Outcomes Group data registry. PARTICIPANTS Adult patients undergoing surgical procedures ≥120 minutes' duration with general anesthesia and endotracheal intubation who were admitted to hospital after surgery between January 2016 and November 2018. INTERVENTION Supraphysiological oxygen administration, defined as the area under the curve of the fraction of inspired oxygen above air (21%) during minutes when the hemoglobin oxygen saturation was greater than 92%. MAIN OUTCOMES Primary endpoints were acute kidney injury defined using Kidney Disease Improving Global Outcomes criteria, myocardial injury defined as serum troponin >0.04 ng/mL within 72 hours of surgery, and lung injury defined using international classification of diseases hospital discharge diagnosis codes. RESULTS The cohort comprised 350 647 patients with median age 59 years (interquartile range 46-69 years), 180 546 women (51.5%), and median duration of surgery 205 minutes (interquartile range 158-279 minutes). Acute kidney injury was diagnosed in 19 207 of 297 554 patients (6.5%), myocardial injury in 8972 of 320 527 (2.8%), and lung injury in 13 789 of 312 161 (4.4%). The median fraction of inspired oxygen was 54.0% (interquartile range 47.5%-60.0%), and the area under the curve of supraphysiological inspired oxygen was 7951% min (5870-11 107% min), equivalent to an 80% fraction of inspired oxygen throughout a 135 minute procedure, for example. After accounting for baseline covariates and other potential confounding variables, increased oxygen exposure was associated with a higher risk of acute kidney injury, myocardial injury, and lung injury. Patients at the 75th centile for the area under the curve of the fraction of inspired oxygen had 26% greater odds of acute kidney injury (95% confidence interval 22% to 30%), 12% greater odds of myocardial injury (7% to 17%), and 14% greater odds of lung injury (12% to 16%) compared with patients at the 25th centile. Sensitivity analyses evaluating alternative definitions of the exposure, restricting the cohort, and conducting an instrumental variable analysis confirmed these observations. CONCLUSIONS Increased supraphysiological oxygen administration during surgery was associated with a higher incidence of kidney, myocardial, and lung injury. Residual confounding of these associations cannot be excluded. TRIAL REGISTRATION Open Science Framework osf.io/cfd2m.
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Affiliation(s)
- David R McIlroy
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Matthew S Shotwell
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Marcos G Lopez
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michelle T Vaughn
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - Joanna S Olsen
- Department of Anesthesiology, Oregon Health and Science University, Portland, OR, USA
| | - Cassandra Hennessy
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jonathan P Wanderer
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Matthew S Semler
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Todd W Rice
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sachin Kheterpal
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - Frederic T Billings
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
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Hirunpattarasilp C, Barkaway A, Davis H, Pfeiffer T, Sethi H, Attwell D. Hyperoxia evokes pericyte-mediated capillary constriction. J Cereb Blood Flow Metab 2022; 42:2032-2047. [PMID: 35786054 PMCID: PMC9580167 DOI: 10.1177/0271678x221111598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Oxygen supplementation is regularly prescribed to patients to treat or prevent hypoxia. However, excess oxygenation can lead to reduced cerebral blood flow (CBF) in healthy subjects and worsen the neurological outcome of critically ill patients. Most studies on the vascular effects of hyperoxia focus on arteries but there is no research on the effects on cerebral capillary pericytes, which are major regulators of CBF. Here, we used bright-field imaging of cerebral capillaries and modeling of CBF to show that hyperoxia (95% superfused O2) led to an increase in intracellular calcium level in pericytes and a significant capillary constriction, sufficient to cause an estimated 25% decrease in CBF. Although hyperoxia is reported to cause vascular smooth muscle cell contraction via generation of reactive oxygen species (ROS), endothelin-1 and 20-HETE, we found that increased cytosolic and mitochondrial ROS levels and endothelin release were not involved in the pericyte-mediated capillary constriction. However, a 20-HETE synthesis blocker greatly reduced the hyperoxia-evoked capillary constriction. Our findings establish pericytes as regulators of CBF in hyperoxia and 20-HETE synthesis as an oxygen sensor in CBF regulation. The results also provide a mechanism by which clinically administered oxygen can lead to a worse neurological outcome.
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Affiliation(s)
- Chanawee Hirunpattarasilp
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Anna Barkaway
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Harvey Davis
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Thomas Pfeiffer
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
| | - Huma Sethi
- Division of Neurosurgery, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - David Attwell
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
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6
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Siwicka-Gieroba D, Robba C, Gołacki J, Badenes R, Dabrowski W. Cerebral Oxygen Delivery and Consumption in Brain-Injured Patients. J Pers Med 2022; 12:1763. [PMID: 36573716 PMCID: PMC9698645 DOI: 10.3390/jpm12111763] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 12/30/2022] Open
Abstract
Organism survival depends on oxygen delivery and utilization to maintain the balance of energy and toxic oxidants production. This regulation is crucial to the brain, especially after acute injuries. Secondary insults after brain damage may include impaired cerebral metabolism, ischemia, intracranial hypertension and oxygen concentration disturbances such as hypoxia or hyperoxia. Recent data highlight the important role of clinical protocols in improving oxygen delivery and resulting in lower mortality in brain-injured patients. Clinical protocols guide the rules for oxygen supplementation based on physiological processes such as elevation of oxygen supply (by mean arterial pressure (MAP) and intracranial pressure (ICP) modulation, cerebral vasoreactivity, oxygen capacity) and reduction of oxygen demand (by pharmacological sedation and coma or hypothermia). The aim of this review is to discuss oxygen metabolism in the brain under different conditions.
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Affiliation(s)
- Dorota Siwicka-Gieroba
- Department of Anaesthesiology and Intensive Care, Medical University in Lublin, 20-954 Lublin, Poland
| | - Chiara Robba
- Department of Anesthesiology and Intensive Care, San Martino Policlinico Hospital, IRCCS for Oncology and Neurosciences, 16132 Genoa, Italy
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, 16132 Genoa, Italy
| | - Jakub Gołacki
- Department of Anaesthesiology and Intensive Care, Medical University in Lublin, 20-954 Lublin, Poland
| | - Rafael Badenes
- Department of Anesthesiology and Surgical-Trauma Intensive Care, Hospital Clinic Universitari, University of Valencia, 46010 Valencia, Spain
| | - Wojciech Dabrowski
- Department of Anaesthesiology and Intensive Care, Medical University in Lublin, 20-954 Lublin, Poland
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7
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Machado RS, Tenfen L, Joaquim L, Lanzzarin EVR, Bernardes GC, Bonfante SR, Mathias K, Biehl E, Bagio É, Stork SDS, Denicol T, de Oliveira MP, da Silva MR, Danielski LG, de Quadros RW, Rezin GT, Terra SR, Balsini JN, Gava FF, Petronilho F. Hyperoxia by short-term promotes oxidative damage and mitochondrial dysfunction in rat brain. Respir Physiol Neurobiol 2022; 306:103963. [PMID: 36041716 DOI: 10.1016/j.resp.2022.103963] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/29/2022] [Accepted: 08/21/2022] [Indexed: 11/17/2022]
Abstract
Oxygen (O2) therapy is used as a therapeutic protocol to prevent or treat hypoxia. However, a high inspired fraction of O2 (FIO2) promotes hyperoxia, a harmful condition for the central nervous system (CNS). The present study evaluated parameters of oxidative stress and mitochondrial dysfunction in the brain of rats exposed to different FIO2. Male Wistar rats were exposed to hyperoxia (FIO2 40 % and 60 %) compared to the control group (FIO2 21 %) for 2 h. Oxidative stress, neutrophilic infiltration, and mitochondrial respiratory chain enzymes were determined in the hippocampus, striatum, cerebellum, cortex, and prefrontal cortex after O2 exposure. The animals exposed to hyperoxia showed increased lipid peroxidation, formation of carbonyl proteins, N/N concentration, and neutrophilic infiltration in some brain regions, like hippocampus, striatum, and cerebellum being the most affected. Furthermore, CAT activity and activity of mitochondrial enzyme complexes were also altered after exposure to hyperoxia. Rats exposed to hyperoxia showed increase in oxidative stress parameters and mitochondrial dysfunction in brain structures.
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Affiliation(s)
- Richard Simon Machado
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Leonardo Tenfen
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Larissa Joaquim
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Everton Venicius Rosa Lanzzarin
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Gabriela Costa Bernardes
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Sandra Regina Bonfante
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Khiany Mathias
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Erica Biehl
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Érick Bagio
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Solange de Souza Stork
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Tais Denicol
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Mariana Pacheco de Oliveira
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Mariella Reinol da Silva
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Lucinéia Gainski Danielski
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Criciuma, SC, Brazil
| | | | - Gislaine Tezza Rezin
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Silvia Resende Terra
- Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Jairo Nunes Balsini
- Laboratory of Neurobiology of Inflammatory and Metabolic Processes, Graduate Program in Health Sciences, Health Sciences Unit, University of South Santa Catarina, Tubarão, SC, Brazil
| | - Fernanda Frederico Gava
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Criciuma, SC, Brazil
| | - Fabricia Petronilho
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina, Criciuma, SC, Brazil.
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8
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Horn AG, Kunkel ON, Schulze KM, Baumfalk DR, Weber RE, Poole DC, Behnke BJ. Supplemental oxygen administration during mechanical ventilation reduces diaphragm blood flow and oxygen delivery. J Appl Physiol (1985) 2022; 132:1190-1200. [PMID: 35323060 PMCID: PMC9054262 DOI: 10.1152/japplphysiol.00021.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/04/2022] [Accepted: 03/18/2022] [Indexed: 11/22/2022] Open
Abstract
During mechanical ventilation (MV), supplemental oxygen (O2) is commonly administered to critically ill patients to combat hypoxemia. Previous studies demonstrate that hyperoxia exacerbates MV-induced diaphragm oxidative stress and contractile dysfunction. Whereas normoxic MV (i.e., 21% O2) diminishes diaphragm perfusion and O2 delivery in the quiescent diaphragm, the effect of MV with 100% O2 is unknown. We tested the hypothesis that MV supplemented with hyperoxic gas (100% O2) would increase diaphragm vascular resistance and reduce diaphragmatic blood flow and O2 delivery to a greater extent than MV alone. Female Sprague-Dawley rats (4-6 mo) were randomly divided into two groups: 1) MV + 100% O2 followed by MV + 21% O2 (n = 9) or 2) MV + 21% O2 followed by MV + 100% O2 (n = 10). Diaphragmatic blood flow (mL/min/100 g) and vascular resistance were determined, via fluorescent microspheres, during spontaneous breathing (SB), MV + 100% O2, and MV + 21% O2. Compared with SB, total diaphragm vascular resistance was increased, and blood flow was decreased with both MV + 100% O2 and MV + 21% O2 (all P < 0.05). Medial costal diaphragmatic blood flow was lower with MV + 100% O2 (26 ± 6 mL/min/100 g) versus MV + 21% O2 (51 ± 15 mL/min/100 g; P < 0.05). Second, the addition of 100% O2 during normoxic MV exacerbated the MV-induced reductions in medial costal diaphragm perfusion (23 ± 7 vs. 51 ± 15 mL/min/100 g; P < 0.05) and O2 delivery (3.4 ± 0.2 vs. 6.4 ± 0.3 mL O2/min/100 g; P < 0.05). These data demonstrate that administration of supplemental 100% O2 during MV increases diaphragm vascular resistance and diminishes perfusion and O2 delivery to a significantly greater degree than normoxic MV. This suggests that prolonged bouts of MV (i.e., 6 h) with hyperoxia may accelerate MV-induced vascular dysfunction in the quiescent diaphragm and potentially exacerbate downstream contractile dysfunction.NEW & NOTEWORTHY This is the first study, to our knowledge, demonstrating that supplemental oxygen (i.e., 100% O2) during mechanical ventilation (MV) augments the MV-induced reductions in diaphragmatic blood flow and O2 delivery. The accelerated reduction in diaphragmatic blood flow with hyperoxic MV would be expected to potentiate MV-induced diaphragm vascular dysfunction and consequently, downstream contractile dysfunction. The data presented herein provide a putative mechanism for the exacerbated oxidative stress and diaphragm dysfunction reported with prolonged hyperoxic MV.
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Affiliation(s)
- Andrew G Horn
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Olivia N Kunkel
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Kiana M Schulze
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Dryden R Baumfalk
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Ramona E Weber
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - David C Poole
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas
| | - Bradley J Behnke
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
- Johnson Cancer Research Center, Kansas State University, Manhattan, Kansas
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9
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Fan JL, Sayegh ALC, Kaur M, Dawes M, Paton JFR, Fisher JP. Effects of hypoxia and hyperoxia on venous capacity and compliance in healthy men and women. Am J Physiol Regul Integr Comp Physiol 2022; 322:R445-R453. [PMID: 35319299 DOI: 10.1152/ajpregu.00319.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/03/2022] [Accepted: 03/18/2022] [Indexed: 11/22/2022]
Abstract
Blood oxygen is an important modulator of arterial function, but its impact on peripheral venous function is incompletely understood. Herein, we sought to determine the effect of hypoxia and hyperoxia on venous capacity and compliance in the lower limb. In 16 healthy individuals (7 women; age: 28.3 ± 7.6 yr, mean ± SD), we assessed peripheral oxygen saturation ([Formula: see text]), the cross-sectional area (CSA) of the great saphenous vein (GSV; Doppler ultrasound), and calf volume (strain-gauge plethysmography) during a standard 60 mmHg thigh cuff inflation-deflation protocol. Separate trials were undertaken during breathing of room air, hypoxia [fraction in inspired oxygen ([Formula: see text]): 0.10], and hyperoxia ([Formula: see text]: 0.50), according to a single-blinded, randomized design. Lower limb pressure-CSA and pressure-volume relationships were modeled using a quadratic regression equation and compliance derived. [Formula: see text] was decreased by hypoxia (83.6 ± 5.6%) and increased by hyperoxia (98.7 ± 0.5%) compared with room air (96.4 ± 1.0%, P < 0.001). Compared with room air (17.0 ± 7.9 mm2), hypoxia decreased GSV CSA (13.4 ± 5.7 mm2, P < 0.001), whereas no change was observed with hyperoxia (17.1 ± 8.7 mm2, P = 0.883). GSV compliance derived from the pressure-CSA relationships was elevated approximately twofold with hyperoxia (-0.0061 ± 0.0046 a.u.) when compared with room air (-0.0029 ± 0.002 a.u., P = 0.027) and hypoxia (-0.0030 ± 0.0032 a.u., P = 0.007). No differences were observed in calf pressure-volume parameters with either hypoxia or hyperoxia (P > 0.05). Our data indicate that GSV capacity is reduced by hypoxia, and that GSV compliance is increased by hyperoxia, thus highlighting the often overlooked role of oxygen in the regulation of venous circulation.
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Affiliation(s)
- Jui-Lin Fan
- Manaaki Manawa, The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
| | - Ana Luiza C Sayegh
- Manaaki Manawa, The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
| | - Manpreet Kaur
- Manaaki Manawa, The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
| | - Mathew Dawes
- Department of Medicine, University of Auckland, Auckland, New Zealand
| | - Julian F R Paton
- Manaaki Manawa, The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
| | - James P Fisher
- Manaaki Manawa, The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
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10
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Theunissen S, Balestra C, Bolognési S, Borgers G, Vissenaeken D, Obeid G, Germonpré P, Honoré PM, De Bels D. Effects of Acute Hypobaric Hypoxia Exposure on Cardiovascular Function in Unacclimatized Healthy Subjects: A "Rapid Ascent" Hypobaric Chamber Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095394. [PMID: 35564787 PMCID: PMC9102089 DOI: 10.3390/ijerph19095394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022]
Abstract
Background: This study aimed to observe the effects of a fast acute ascent to simulated high altitudes on cardiovascular function both in the main arteries and in peripheral circulation. Methods: We examined 17 healthy volunteers, between 18 and 50 years old, at sea level, at 3842 m of hypobaric hypoxia and after return to sea level. Cardiac output (CO) was measured with Doppler transthoracic echocardiography. Oxygen delivery was estimated as the product of CO and peripheral oxygen saturation (SpO2). The brachial artery’s flow-mediated dilation (FMD) was measured with the ultrasound method. Post-occlusion reactive hyperemia (PORH) was assessed by digital plethysmography. Results: During altitude stay, peripheral oxygen saturation decreased (84.9 ± 4.2% of pre-ascent values; p < 0.001). None of the volunteers presented any hypoxia-related symptoms. Nevertheless, an increase in cardiac output (143.2 ± 36.2% of pre-ascent values, p < 0.001) and oxygen delivery index (120.6 ± 28.4% of pre-ascent values; p > 0.05) was observed. FMD decreased (97.3 ± 4.5% of pre-ascent values; p < 0.05) and PORH did not change throughout the whole experiment. Τhe observed changes disappeared after return to sea level, and normoxia re-ensued. Conclusions: Acute exposure to hypobaric hypoxia resulted in decreased oxygen saturation and increased compensatory heart rate, cardiac output and oxygen delivery. Pre-occlusion vascular diameters increase probably due to the reduction in systemic vascular resistance preventing flow-mediated dilation from increasing. Mean Arterial Pressure possibly decrease for the same reason without altering post-occlusive reactive hyperemia throughout the whole experiment, which shows that compensation mechanisms that increase oxygen delivery are effective.
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Affiliation(s)
- Sigrid Theunissen
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium;
- Correspondence: (S.T.); (C.B.)
| | - Costantino Balestra
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium;
- Physical Activity Teaching Unit, Motor Sciences Department, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
- DAN Europe Research Division (Roseto-Brussels), 1160 Brussels, Belgium
- Correspondence: (S.T.); (C.B.)
| | - Sébastien Bolognési
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1160 Brussels, Belgium;
| | - Guy Borgers
- Hypobaric Centre, Queen Astrid Military Hospital, 1120 Brussels, Belgium; (G.B.); (D.V.)
| | - Dirk Vissenaeken
- Hypobaric Centre, Queen Astrid Military Hospital, 1120 Brussels, Belgium; (G.B.); (D.V.)
| | - Georges Obeid
- Military Hospital Queen Elizabeth, 1120 Brussels, Belgium; (G.O.); (P.G.)
| | - Peter Germonpré
- Military Hospital Queen Elizabeth, 1120 Brussels, Belgium; (G.O.); (P.G.)
| | - Patrick M. Honoré
- Department of Intensive Care Medicine, CHU-Brugmann, 1020 Brussels, Belgium; (P.M.H.); (D.D.B.)
| | - David De Bels
- Department of Intensive Care Medicine, CHU-Brugmann, 1020 Brussels, Belgium; (P.M.H.); (D.D.B.)
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11
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Levenez M, Lambrechts K, Mrakic-Sposta S, Vezzoli A, Germonpré P, Pique H, Virgili F, Bosco G, Lafère P, Balestra C. Full-Face Mask Use during SCUBA Diving Counters Related Oxidative Stress and Endothelial Dysfunction. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19020965. [PMID: 35055791 PMCID: PMC8776018 DOI: 10.3390/ijerph19020965] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 12/29/2022]
Abstract
Impaired flow mediated dilation (FMD), an index of vascular stress, is known after SCUBA diving. This is related to a dysfunction of nitric oxide (NO) availability and a disturbance of the redox status, possibly induced by hyperoxic/hyperbaric gas breathing. SCUBA diving is usually performed with a mask only covering “half face” (HF) and therefore forcing oral breathing. Nasal NO production is involved in vascular homeostasis and, as consequence, can significantly reduce NO possibly promoting vascular dysfunction. More recently, the utilization of “full-face” (FF) mask, allowing nasal breathing, became more frequent, but no reports are available describing their effects on vascular functions in comparison with HF masks. In this study we assessed and compared the effects of a standard shallow dive (20 min at 10 m) wearing either FF or a HF mask on different markers of vascular function (FMD), oxidative stress (ROS, 8-iso-PGF2α) and NO availability and metabolism (NO2, NOx and 3-NT and iNOS expression). Data from a dive breathing a hypoxic (16% O2 at depth) gas mixture with HF mask are shown allowing hyperoxic/hypoxic exposure. Our data suggest that nasal breathing might significantly reduce the occurrence of vascular dysfunction possibly due to better maintenance of NO production and bioavailability, resulting in a better ability to counter reactive oxygen and nitrogen species. Besides the obvious outcomes in terms of SCUBA diving safety, our data permit a better understanding of the effects of oxygen concentrations, either in normal conditions or as a strategy to induce selected responses in health and disease.
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Affiliation(s)
- Morgan Levenez
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (M.L.); (K.L.); (P.G.); (H.P.); (P.L.)
| | - Kate Lambrechts
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (M.L.); (K.L.); (P.G.); (H.P.); (P.L.)
| | - Simona Mrakic-Sposta
- Institute of Clinical Physiology, National Research Council (IFC-CNR), Piazza dell’Ospedale Maggiore, 20162 Milano, Italy; (S.M.-S.); (A.V.)
| | - Alessandra Vezzoli
- Institute of Clinical Physiology, National Research Council (IFC-CNR), Piazza dell’Ospedale Maggiore, 20162 Milano, Italy; (S.M.-S.); (A.V.)
| | - Peter Germonpré
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (M.L.); (K.L.); (P.G.); (H.P.); (P.L.)
- Hyperbaric Centre, Queen Astrid Military Hospital, 1120 Brussels, Belgium
- DAN Europe Research Division, Contrada Padune, 64026 Roseto, Italy
| | - Hadrien Pique
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (M.L.); (K.L.); (P.G.); (H.P.); (P.L.)
| | - Fabio Virgili
- Council for Agricultural Research and Economics—Food and Nutrition Research Centre (CREA-AN), Via Ardeatina 548, 00187 Rome, Italy
- Correspondence: (F.V.); (C.B.)
| | - Gerardo Bosco
- Environmental Physiology & Medicine Laboratory, Department of Biomedical Sciences, University of Padova, 35122 Padova, Italy;
| | - Pierre Lafère
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (M.L.); (K.L.); (P.G.); (H.P.); (P.L.)
- DAN Europe Research Division, Contrada Padune, 64026 Roseto, Italy
| | - Costantino Balestra
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (M.L.); (K.L.); (P.G.); (H.P.); (P.L.)
- DAN Europe Research Division, Contrada Padune, 64026 Roseto, Italy
- Physical Activity Teaching Unit, Motor Sciences Department, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
- Correspondence: (F.V.); (C.B.)
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12
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Yu Y, Yao RQ, Zhang YF, Wang SY, Xi W, Wang JN, Huang XY, Yao YM, Wang ZN. Is oxygen therapy beneficial for normoxemic patients with acute heart failure? A propensity score matched study. Mil Med Res 2021; 8:38. [PMID: 34238369 PMCID: PMC8268364 DOI: 10.1186/s40779-021-00330-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 06/01/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The clinical efficiency of routine oxygen therapy is uncertain in patients with acute heart failure (AHF) who do not have hypoxemia. The aim of this study was to investigate the association between oxygen therapy and clinical outcomes in normoxemic patients hospitalized with AHF using real-world data. METHODS Normoxemic patients diagnosed with AHF on ICU admission from the electronic ICU (eICU) Collaborative Research Database were included in the current study, in which the study population was divided into the oxygen therapy group and the ambient-air group. Propensity score matching (PSM) was applied to create a balanced covariate distribution between patients receiving supplemental oxygen and those exposed to ambient air. Linear regression and logistic regression models were performed to assess the associations between oxygen therapy and length of stay (LOS), and all-cause in-hospital as well as ICU mortality rates, respectively. A series of sensitivity and subgroup analyses were conducted to further validate the robustness of our findings. RESULTS A total of 2922 normoxemic patients with AHF were finally included in the analysis. Overall, 42.1% (1230/2922) patients were exposed to oxygen therapy, and 57.9% (1692/2922) patients did not receive oxygen therapy (defined as the ambient-air group). After PSM analysis, 1122 pairs of patients were matched: each patient receiving oxygen therapy was matched with a patient without receiving supplemental oxygen. The multivariable logistic model showed that there was no significant interaction between the ambient air and oxygen group for all-cause in-hospital mortality [odds ratio (OR) 1.30; 95% confidence interval (CI) 0.92-1.82; P = 0.138] or ICU mortality (OR 1.39; 95% CI 0.83-2.32; P = 0.206) in the post-PSM cohorts. In addition, linear regression analysis revealed that oxygen therapy was associated with prolonged ICU LOS (OR 1.11; 95% CI 1.06-1.15; P < 0.001) and hospital LOS (OR 1.06; 95% CI 1.01-1.10; P = 0.009) after PSM. Furthermore, the absence of an effect of supplemental oxygen on mortality was consistent in all subgroups. CONCLUSION Routine use of supplemental oxygen in AHF patients without hypoxemia was not found to reduce all-cause in-hospital mortality or ICU mortality.
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Affiliation(s)
- Yue Yu
- Department of Cardiothoracic Surgery, Changzheng Hospital, Naval Medical University, 415 Fengyang Road, Huangpu District, Shanghai, 200003, China
| | - Ren-Qi Yao
- Trauma Research Center, Fourth Medical Center and Medical Innovation Research Department of the Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing, 100048, China.,Department of Burn Surgery, Changhai Hospital, Naval Medical University, Shanghai, 200433, China
| | - Yu-Feng Zhang
- Department of Cardiothoracic Surgery, Changzheng Hospital, Naval Medical University, 415 Fengyang Road, Huangpu District, Shanghai, 200003, China
| | - Su-Yu Wang
- Department of Cardiothoracic Surgery, Changzheng Hospital, Naval Medical University, 415 Fengyang Road, Huangpu District, Shanghai, 200003, China
| | - Wang Xi
- Department of Cardiothoracic Surgery, Changzheng Hospital, Naval Medical University, 415 Fengyang Road, Huangpu District, Shanghai, 200003, China
| | - Jun-Nan Wang
- Department of Cardiothoracic Surgery, Changzheng Hospital, Naval Medical University, 415 Fengyang Road, Huangpu District, Shanghai, 200003, China.,Medical Research Center of War Injuries and Trauma, Changzheng Hospital, Naval Medical University, Shanghai, 200003, China
| | - Xiao-Yi Huang
- Department of Pathology, Changhai Hospital, Naval Medical University, Shanghai, 200433, China
| | - Yong-Ming Yao
- Trauma Research Center, Fourth Medical Center and Medical Innovation Research Department of the Chinese PLA General Hospital, 51 Fucheng Road, Haidian District, Beijing, 100048, China.
| | - Zhi-Nong Wang
- Department of Cardiothoracic Surgery, Changzheng Hospital, Naval Medical University, 415 Fengyang Road, Huangpu District, Shanghai, 200003, China.
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13
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Platonova TF, Zhilyaev SY, Alekseeva OS, Nikitina ER, Demchenko IT. Blockade of Brain Adrenoreceptors
Delays Seizure Development during Hyperbaric Oxygen Breathing. J EVOL BIOCHEM PHYS+ 2020. [DOI: 10.1134/s0022093020050051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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14
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Yan S, Resta TC, Jernigan NL. Vasoconstrictor Mechanisms in Chronic Hypoxia-Induced Pulmonary Hypertension: Role of Oxidant Signaling. Antioxidants (Basel) 2020; 9:E999. [PMID: 33076504 PMCID: PMC7602539 DOI: 10.3390/antiox9100999] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/06/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023] Open
Abstract
Elevated resistance of pulmonary circulation after chronic hypoxia exposure leads to pulmonary hypertension. Contributing to this pathological process is enhanced pulmonary vasoconstriction through both calcium-dependent and calcium sensitization mechanisms. Reactive oxygen species (ROS), as a result of increased enzymatic production and/or decreased scavenging, participate in augmentation of pulmonary arterial constriction by potentiating calcium influx as well as activation of myofilament sensitization, therefore mediating the development of pulmonary hypertension. Here, we review the effects of chronic hypoxia on sources of ROS within the pulmonary vasculature including NADPH oxidases, mitochondria, uncoupled endothelial nitric oxide synthase, xanthine oxidase, monoamine oxidases and dysfunctional superoxide dismutases. We also summarize the ROS-induced functional alterations of various Ca2+ and K+ channels involved in regulating Ca2+ influx, and of Rho kinase that is responsible for myofilament Ca2+ sensitivity. A variety of antioxidants have been shown to have beneficial therapeutic effects in animal models of pulmonary hypertension, supporting the role of ROS in the development of pulmonary hypertension. A better understanding of the mechanisms by which ROS enhance vasoconstriction will be useful in evaluating the efficacy of antioxidants for the treatment of pulmonary hypertension.
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Affiliation(s)
| | | | - Nikki L. Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA; (S.Y.); (T.C.R.)
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15
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Ma Y, Mazerolle EL, Cho J, Sun H, Wang Y, Pike GB. Quantification of brain oxygen extraction fraction using QSM and a hyperoxic challenge. Magn Reson Med 2020; 84:3271-3285. [DOI: 10.1002/mrm.28390] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 05/19/2020] [Accepted: 06/01/2020] [Indexed: 12/24/2022]
Affiliation(s)
- Yuhan Ma
- Department of Biomedical Engineering and McConnell Brain Imaging Centre McGill University Montréal Quebec Canada
| | - Erin L. Mazerolle
- Department of Radiology and Hotchkiss Brain Institute University of Calgary Calgary Alberta Canada
| | - Junghun Cho
- Department of Biomedical Engineering Cornell University Ithaca New York USA
| | - Hongfu Sun
- Department of Radiology and Hotchkiss Brain Institute University of Calgary Calgary Alberta Canada
- School of Information Technology and Electrical Engineering University of Queensland Brisbane Australia
| | - Yi Wang
- Department of Biomedical Engineering Cornell University Ithaca New York USA
- Department of Radiology Weill Cornell Medical College New York New York USA
| | - G. Bruce Pike
- Department of Biomedical Engineering and McConnell Brain Imaging Centre McGill University Montréal Quebec Canada
- Department of Radiology and Hotchkiss Brain Institute University of Calgary Calgary Alberta Canada
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16
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Mutch WAC, El-Gabalawy R, Ryner L, Puig J, Essig M, Kilborn K, Fidler K, Graham MR. Brain BOLD MRI O 2 and CO 2 stress testing: implications for perioperative neurocognitive disorder following surgery. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2020; 24:76. [PMID: 32131878 PMCID: PMC7057494 DOI: 10.1186/s13054-020-2800-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/18/2020] [Indexed: 12/17/2022]
Abstract
Background Mechanical ventilation to alter and improve respiratory gases is a fundamental feature of critical care and intraoperative anesthesia management. The range of inspired O2 and expired CO2 during patient management can significantly deviate from values in the healthy awake state. It has long been appreciated that hyperoxia can have deleterious effects on organs, especially the lung and retina. Recent work shows intraoperative end-tidal (ET) CO2 management influences the incidence of perioperative neurocognitive disorder (POND). The interaction of O2 and CO2 on cerebral blood flow (CBF) and oxygenation with alterations common in the critical care and operating room environments has not been well studied. Methods We examine the effects of controlled alterations in both ET O2 and CO2 on cerebral blood flow (CBF) in awake adults using blood oxygenation level-dependent (BOLD) and pseudo-continuous arterial spin labeling (pCASL) MRI. Twelve healthy adults had BOLD and CBF responses measured to alterations in ET CO2 and O2 in various combinations commonly observed during anesthesia. Results Dynamic alterations in regional BOLD and CBF were seen in all subjects with expected and inverse brain voxel responses to both stimuli. These effects were incremental and rapid (within seconds). The most dramatic effects were seen with combined hyperoxia and hypocapnia. Inverse responses increased with age suggesting greater risk. Conclusions Human CBF responds dramatically to alterations in ET gas tensions commonly seen during anesthesia and in critical care. Such alterations may contribute to delirium following surgery and under certain circumstances in the critical care environment. Trial registration ClincialTrials.gov NCT02126215 for some components of the study. First registered April 29, 2014.
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Affiliation(s)
- W Alan C Mutch
- Department of Anesthesiology, Perioperative and Pain Medicine, Max Rady College of Medicine, University of Manitoba, 2nd Floor, Harry Medovy House, 671 William Ave., Winnipeg, MB, R3E 0Z2, Canada. .,Canada North Concussion Network, .
| | - Renée El-Gabalawy
- Department of Anesthesiology, Perioperative and Pain Medicine, Max Rady College of Medicine, University of Manitoba, 2nd Floor, Harry Medovy House, 671 William Ave., Winnipeg, MB, R3E 0Z2, Canada.,Department of Clinical Health Psychology, University of Manitoba, Winnipeg, Canada
| | - Lawrence Ryner
- Canada North Concussion Network.,Department of Radiology, University of Manitoba, Winnipeg, Canada.,Department of Physics, University of Manitoba, Winnipeg, Canada
| | - Josep Puig
- Department of Radiology, University of Manitoba, Winnipeg, Canada
| | - Marco Essig
- Canada North Concussion Network.,Department of Radiology, University of Manitoba, Winnipeg, Canada
| | - Kayla Kilborn
- Department of Anesthesiology, Perioperative and Pain Medicine, Max Rady College of Medicine, University of Manitoba, 2nd Floor, Harry Medovy House, 671 William Ave., Winnipeg, MB, R3E 0Z2, Canada
| | - Kelsi Fidler
- Department of Anesthesiology, Perioperative and Pain Medicine, Max Rady College of Medicine, University of Manitoba, 2nd Floor, Harry Medovy House, 671 William Ave., Winnipeg, MB, R3E 0Z2, Canada
| | - M Ruth Graham
- Department of Anesthesiology, Perioperative and Pain Medicine, Max Rady College of Medicine, University of Manitoba, 2nd Floor, Harry Medovy House, 671 William Ave., Winnipeg, MB, R3E 0Z2, Canada.,Canada North Concussion Network
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17
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López HV, Vivas MF, Ruiz RN, Martínez JR, Navaridas BGV, Villa MG, Lázaro CL, Rubio RJ, Ortiz AM, Lacal LA, Diéguez AM. Association between post-procedural hyperoxia and poor functional outcome after mechanical thrombectomy for ischemic stroke: an observational study. Ann Intensive Care 2019; 9:59. [PMID: 31127402 PMCID: PMC6534627 DOI: 10.1186/s13613-019-0533-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 05/15/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The actual effects of oxygen therapy on patients who have suffered a stroke are still unknown, and its recommendation as a routine measure in emergency services remains controversial. The aim of this study is to determine the effect of hyperoxia in functional recovery in patients with ischemic stroke who underwent intra-arterial mechanical thrombectomy (IAMT). METHODS A prospective observational cohort study that included all adult patients consecutively admitted to the intensive care unit (ICU) due to an ischemic stroke in the anterior cerebral circulation and following an IAMT intervention, between 2010 and 2015. All patients were intubated and connected to mechanical ventilation for the intra-arterial therapy, receiving supplementary oxygen to achieve saturations above 94%. Two groups were established regarding oxygen partial pressure (paO2) reached. It was based on a single ICU admission blood gas analysis. The hyperoxia group was defined as paO2 > 120 mmHg. We measured functional recovery in each of the groups according to the modified Rankin scale after 90 days. RESULTS For the analysis, a total of 333 patients were included. High levels of paO2 were mostly related to higher scores in modified Rankin scale (mRS) after 90 days. There were 60.6% cases with mRS ≥ 4 and 70.6% with mRS ≥ 3 in the hyperoxia group, compared to 43.0% and 56.1% in the paO2 ≤ 120 group, p < 0.01, respectively. Mortality was higher in the hyperoxia group, 28.6% vs 18.7%, p = 0.04. After regression adjustment by confounding factors, poor functional outcome was still significantly higher in the hyperoxia group, for both mRS ≥ 4 and mRS ≥ 3: OR 2.2.7, IC 95%, 1.22-4.23, p = 0.01 and OR 2.07, IC 95%, 1.05-4.029, p = 0.04, respectively. Both the National Institute of Health Stroke Scale Score (NIHSS) values at 24 h after the IAMT and the days of ICU stay were significantly higher in the hyperoxia group. CONCLUSIONS In patients with ischemic stroke in the anterior cerebral circulation treated with IAMT, we found an association between admission PaO2 > 120 mmHg and worse functional outcome 90 days after ischemic stroke, but this association needs further confirmation by other studies.
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Affiliation(s)
- Héctor Vargas López
- Department of Intensive Care, Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain.
| | - Miguel Fernández Vivas
- Department of Intensive Care, Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
| | - Rafael Núñez Ruiz
- Department of Intensive Care, Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
| | - José Ros Martínez
- Department of Intensive Care, Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
| | | | - Manuel García Villa
- Department of Intensive Care, Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
| | - Cristina Llamas Lázaro
- Department of Intensive Care, Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
| | - Rubén Jara Rubio
- Department of Intensive Care, Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
| | - Ana Morales Ortiz
- Department of Neurology, Biomedical Research Institute of Murcia (IMIB), Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
| | - Laura Albert Lacal
- Department of Neurology, Biomedical Research Institute of Murcia (IMIB), Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
| | - Antonio Moreno Diéguez
- Department of Neuroradiology, Virgen de la Arrixaca, Clinical University Hospital, Murcia, Spain
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18
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Ni YN, Wang YM, Liang BM, Liang ZA. The effect of hyperoxia on mortality in critically ill patients: a systematic review and meta analysis. BMC Pulm Med 2019; 19:53. [PMID: 30808337 PMCID: PMC6390560 DOI: 10.1186/s12890-019-0810-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 02/11/2019] [Indexed: 02/05/2023] Open
Abstract
Background Studies investigating the role of hyperoxia in critically ill patients have reported conflicting results. We did this analysis to reveal the effect of hyperoxia in the patients admitted to the intensive care unit (ICU). Methods Electronic databases were searched for all the studies exploring the role of hyperoxia in adult patients admitted to ICU. The primary outcome was mortality. Random-effect model was used for quantitative synthesis of the adjusted odds ratio (aOR). Results We identified 24 trials in our final analysis. Statistical heterogeneity was found between hyperoxia and normoxia groups in patients with mechanical ventilation (I2 = 92%, P < 0.01), cardiac arrest(I2 = 63%, P = 0.01), traumatic brain injury (I2 = 85%, P < 0.01) and post cardiac surgery (I2 = 80%, P = 0.03). Compared with normoxia, hyperoxia was associated with higher mortality in overall patients (OR 1.22, 95% CI 1.12~1.33), as well as in the subgroups of cardiac arrest (OR 1.30, 95% CI 1.08~1.57) and extracorporeal life support (ELS) (OR 1.44, 95% CI 1.03~2.02). Conclusions Hyperoxia would lead to higher mortality in critically ill patients especially in the patients with cardiac arrest and ELS. Electronic supplementary material The online version of this article (10.1186/s12890-019-0810-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yue-Nan Ni
- Department of Respiratory and Critical Care, West China School of Medicine and West China Hospital, Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, China
| | - Yan-Mei Wang
- Department of Respiratory Medicine, Sichuan Second Hospital of Traditional Chinese Medicine, Chengdu, 610031, Sichuan, China
| | - Bin-Miao Liang
- Department of Respiratory and Critical Care, West China School of Medicine and West China Hospital, Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, China.
| | - Zong-An Liang
- Department of Respiratory and Critical Care, West China School of Medicine and West China Hospital, Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, China
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Mattos JD, Campos MO, Rocha MP, Mansur DE, Rocha HNM, Garcia VP, Batista G, Alvares TS, Oliveira GV, Souza MV, Videira RLR, Rocha NG, Secher NH, Nóbrega ACL, Fernandes IA. Human brain blood flow and metabolism during isocapnic hyperoxia: the role of reactive oxygen species. J Physiol 2018; 597:741-755. [PMID: 30506968 DOI: 10.1113/jp277122] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/16/2018] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS It is unknown whether excessive reactive oxygen species (ROS) production drives the isocapnic hyperoxia (IH)-induced decline in human cerebral blood flow (CBF) via reduced nitric oxide (NO) bioavailability and leads to disruption of the blood-brain barrier (BBB) or neural-parenchymal damage. Cerebral metabolic rate for oxygen (CMR O 2 ) and transcerebral exchanges of NO end-products, oxidants, antioxidants and neural-parenchymal damage markers were simultaneously quantified under IH with intravenous saline and ascorbic acid infusion. CBF and CMR O 2 were reduced during IH, responses that were followed by increased oxidative stress and reduced NO bioavailability when saline was infused. No indication of neural-parenchymal damage or disruption of the BBB was observed during IH. Antioxidant defences were increased during ascorbic acid infusion, while CBF, CMR O 2 , oxidant and NO bioavailability markers remained unchanged. ROS play a role in the regulation of CBF and metabolism during IH without evidence of BBB disruption or neural-parenchymal damage. ABSTRACT To test the hypothesis that isocapnic hyperoxia (IH) affects cerebral blood flow (CBF) and metabolism through exaggerated reactive oxygen species (ROS) production, reduced nitric oxide (NO) bioavailability, disturbances in the blood-brain barrier (BBB) and neural-parenchymal homeostasis, 10 men (24 ± 1 years) were exposed to a 10 min IH trial (100% O2 ) while receiving intravenous saline and ascorbic acid (AA, 3 g) infusion. Internal carotid artery blood flow (ICABF), vertebral artery blood flow (VABF) and total CBF (tCBF, Doppler ultrasound) were determined. Arterial and right internal jugular venous blood was sampled to quantify the cerebral metabolic rate of oxygen (CMR O 2 ), transcerebral exchanges (TCE) of NO end-products (plasma nitrite), antioxidants (AA and AA plus dehydroascorbic acid (AA+DA)) and oxidant biomarkers (thiobarbituric acid-reactive substances (TBARS) and 8-isoprostane), and an index of BBB disruption and neuronal-parenchymal damage (neuron-specific enolase; NSE). IH reduced ICABF, tCBF and CMR O 2 , while VABF remained unchanged. Arterial 8-isoprostane and nitrite TCE increased, indicating that CBF decline was related to ROS production and reduced NO bioavailability. AA, AA+DA and NSE TCE did not change during IH. AA infusion did not change the resting haemodynamic and metabolic parameters but raised antioxidant defences, as indicated by increased AA/AA+DA concentrations. Negative AA+DA TCE, unchanged nitrite, reductions in arterial and venous 8-isoprostane, and TBARS TCE indicated that AA infusion effectively inhibited ROS production and preserved NO bioavailability. Similarly, AA infusion prevented IH-induced decline in regional and total CBF and re-established CMR O 2 . These findings indicate that ROS play a role in CBF regulation and metabolism during IH without evidence of BBB disruption or neural-parenchymal damage.
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Affiliation(s)
- João D Mattos
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | - Monique O Campos
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | - Marcos P Rocha
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | - Daniel E Mansur
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | - Helena N M Rocha
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | - Vinicius P Garcia
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | - Gabriel Batista
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | | | | | | | | | - Natalia G Rocha
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | - Niels H Secher
- Department of Anaesthesia, The Copenhagen Muscle Research Centre, Rigshospitalet, University of Copenhagen, Denmark
| | - Antonio C L Nóbrega
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil
| | - Igor A Fernandes
- Laboratory of Exercise Sciences, Fluminense Federal University, Niterói, Brazil.,NeuroVASQ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brazil
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20
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Hyperbaric oxygen and aerobic exercise in the long-term treatment of fibromyalgia: A narrative review. Biomed Pharmacother 2018; 109:629-638. [PMID: 30399600 DOI: 10.1016/j.biopha.2018.10.157] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/13/2018] [Accepted: 10/25/2018] [Indexed: 12/20/2022] Open
Abstract
Chronic pain is one of the most common clinical presentations in the primary care settings. In the US, Fibromyalgia (FM) affects about 1-3% of adults and commonly occurs in adults between the ages of 40-50 years. FM causes widespread muscular pain and tenderness with hyperalgesia and allodynia and may be associated with other somatic complaints. Hyperbaric oxygen therapy (HBOT) has been utilized and has recently shown promising effects in the management of FM and other chronic pain disorders. In HBOT, the intermittent breathing of 100% oxygen in a pressurized chamber where the pressure is higher than 1 atmosphere absolute (ATA) has been utilized. HBOT exhibits a significant anti-inflammatory effect through reducing production of glial cells and inflammatory mediators which results in pain alleviation in different chronic pain conditions. HBOT can also influence neuroplasticity and affects the mitochondrial mechanisms resulting in functional brain changes. In addition to that, HBOT stimulates nitric oxide (NO) synthesis which helps in alleviating hyperalgesia and NO-dependent release of endogenous opioids which seemed to be the primary HBOT mechanism of antinociception. Moreover, aerobic exercise and meditative movement therapies (MMT) have gained attention for their role in pain alleviation through different anti-inflammatory and antioxidant mechanisms. In this review, we aim to elucidate the different mechanisms of HBOT and aerobic exercise in attenuating pain as adjuvant therapy in the multidisciplinary treatment strategy of chronic pain, and more particularly fibromyalgia.
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21
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Xing P, Ma K, Li L, Wang D, Hu G, Long W. The protection effect and mechanism of hyperbaric oxygen therapy in rat brain with traumatic injury. Acta Cir Bras 2018; 33:341-353. [PMID: 29768537 DOI: 10.1590/s0102-865020180040000006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 03/23/2018] [Indexed: 12/18/2022] Open
Abstract
PURPOSE To investigate the effect of hyperbaric oxygen therapy (HBOT) on traumatic brain injury (TBI) outcome. METHODS The modified Marmarou's weight drop device was used to generate non-lethal moderate TBI rat model, and further developed in vitro astrocytes culturing system. Then, we analyzed the expression changes of interested genes and protein by quantitative PCR and western blot. RESULTS Multiple HBO treatments significantly reduced the expression of apoptosis promoting genes, such as c-fos, c-jun, Bax and weakened the activation of Caspase-3 in model rats. On the contrary, HBOT alleviated the decrease of anti-apoptosis gene Bcl-2 and promoted the expression of neurotrophic factors (NTFs), such as NGF, BDNF, GDNF and NT-3 in vivo. As a consequent, the neuropathogenesis was remarkably relied with HBOT. Astrocytes from TBI brain or those cultured with 21% O2 density expressed higher NTFs than that of corresponding controls, from sham brain and cultured with 7% O2, respectively. The NTFs expression was the highest in astrocytes form TBI brain and cultured with 21% O2, suggesting a synergistic effect existed between TBI and the following HBO treatment in astrocytes. CONCLUSION Our findings provided evidence for the clinical usage of HBO treating brain damages.
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Affiliation(s)
- Pengcheng Xing
- MD, Department of Emergency and Intensive Care Unit, Shanghai Sixth People's Hospital East, China. Acquisition, analysis and interpretation of data; manuscript preparation
| | - Ke Ma
- MD, Department of Emergency and Intensive Care Unit, Shanghai Sixth People's Hospital East, China. Conception and design of the study, manuscript preparation, final approval
| | - Lijuan Li
- MD, Physician, Department of Geriatrics, Shanghai Sixth People's Hospital East, China. Acquisition of data, technical procedures
| | - Donglian Wang
- MD, Physician, Department of Emergency and Intensive Care Unit, Shanghai Sixth People's Hospital East, China. Technical procedures
| | - Guoyong Hu
- MD, Physician, Department of Emergency and Intensive Care Unit, Shanghai Sixth People's Hospital East, China. Technical procedures
| | - Wei Long
- MD, Physician, Department of Geriatrics, Shanghai Sixth People's Hospital East, China. Technical procedures
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22
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Terraneo L, Samaja M. Comparative Response of Brain to Chronic Hypoxia and Hyperoxia. Int J Mol Sci 2017; 18:ijms18091914. [PMID: 28880206 PMCID: PMC5618563 DOI: 10.3390/ijms18091914] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/01/2017] [Accepted: 09/03/2017] [Indexed: 12/25/2022] Open
Abstract
Two antithetic terms, hypoxia and hyperoxia, i.e., insufficient and excess oxygen availability with respect to needs, are thought to trigger opposite responses in cells and tissues. This review aims at summarizing the molecular and cellular mechanisms underlying hypoxia and hyperoxia in brain and cerebral tissue, a context that may prove to be useful for characterizing not only several clinically relevant aspects, but also aspects related to the evolution of oxygen transport and use by the tissues. While the response to acute hypoxia/hyperoxia presumably recruits only a minor portion of the potentially involved cell machinery, focusing into chronic conditions, instead, enables to take into consideration a wider range of potential responses to oxygen-linked stress, spanning from metabolic to genic. We will examine how various brain subsystems, including energetic metabolism, oxygen sensing, recruitment of pro-survival pathways as protein kinase B (Akt), mitogen-activated protein kinases (MAPK), neurotrophins (BDNF), erythropoietin (Epo) and its receptors (EpoR), neuroglobin (Ngb), nitric oxide (NO), carbon monoxide (CO), deal with chronic hypoxia and hyperoxia to end-up with the final outcomes, oxidative stress and brain damage. A more complex than expected pattern results, which emphasizes the delicate balance between the severity of the stress imposed by hypoxia and hyperoxia and the recruitment of molecular and cellular defense patterns. While for certain functions the expectation that hypoxia and hyperoxia should cause opposite responses is actually met, for others it is not, and both emerge as dangerous treatments.
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Affiliation(s)
- Laura Terraneo
- Department of Health Science, University of Milan, I-20142 Milano, Italy.
| | - Michele Samaja
- Department of Health Science, University of Milan, I-20142 Milano, Italy.
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Ciarlone GE, Dean JB. Normobaric hyperoxia stimulates superoxide and nitric oxide production in the caudal solitary complex of rat brain slices. Am J Physiol Cell Physiol 2016; 311:C1014-C1026. [PMID: 27733362 DOI: 10.1152/ajpcell.00160.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/05/2016] [Indexed: 12/25/2022]
Abstract
Central CO2-chemosensitive neurons in the caudal solitary complex (cSC) are stimulated not only by hypercapnic acidosis, but by hyperoxia as well. While a cellular mechanism for the CO2 response has yet to be isolated, previous data show that a redox-sensitive mechanism underlies neuronal excitability to hyperoxia. However, it remains unknown how changes in Po2 affect the production of reactive oxygen and nitrogen species (RONS) in the cSC that can lead to increased cellular excitability and, with larger doses, to cellular dysfunction and death. To this end, we used fluorescence microscopy in real time to determine how normobaric hyperoxia increases the production of key RONS in the cSC. Because neurons in the region are CO2 sensitive, we also examined the potential effects of CO2 narcosis, used during euthanasia before brain slice harvesting, on RONS production. Our findings show that normobaric hyperoxia (0.4 → 0.95 atmospheres absolute O2) increases the fluorescence rates of fluorogenic dyes specific to both superoxide and nitric oxide. Interestingly, different results were seen for superoxide fluorescence when CO2 narcosis was used during euthanasia, suggesting long-lasting changes in superoxide production and/or antioxidant activity subsequent to CO2 narcosis before brain slicing. Further research needs to distinguish whether the increased levels of RONS reported here are merely increases in oxidative and nitrosative signaling or, alternatively, evidence of redox and nitrosative stress.
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Affiliation(s)
- Geoffrey E Ciarlone
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Jay B Dean
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, University of South Florida, Tampa, Florida
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24
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Rostain JC, Lavoute C. Dopamine, Neurochemical Processes, and Oxygen Toxicity at Pressure. Compr Physiol 2016; 6:1339-44. [PMID: 27347895 DOI: 10.1002/cphy.c140025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
All mammals, including man, exposed to breathing gas mixtures at high pressures exhibit central nervous system disturbances, which differ according to the gas used. With the use of compressed air, the increased oxygen partial pressure induces hyperoxic disturbances that consist of epileptic seizures that occur, on average, after 30 min exposure to 2.8 ATA in man or to 5 ATA in rats. Increased oxygen partial pressure induces reactive oxygen species and reactive nitrogen species production that could be related to neurotransmitter changes reported for the preepileptic phase or at pressures that produce epileptic seizures. In rats, oxygen pressures lower than 5 ATA induce a decrease of dopamine release in the stratum that could be due to disturbances of neurotransmitter regulatory processes that are different from those implicated for hyperbaric oxygen-induced epileptic seizures. © 2016 American Physiological Society. Compr Physiol 6:1339-1344, 2016.
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Affiliation(s)
- Jean-Claude Rostain
- UMR-MD2, Disoxie et suractivité, Aix-Marseille University, Faculté de Médecine Nord, Marseille, France
| | - Cécile Lavoute
- UMR-MD2, Disoxie et suractivité, Aix-Marseille University, Faculté de Médecine Nord, Marseille, France
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25
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Karri VVSR, Kuppusamy G, Talluri SV, Yamjala K, Mannemala SS, Malayandi R. Current and emerging therapies in the management of diabetic foot ulcers. Curr Med Res Opin 2016; 32:519-42. [PMID: 26643047 DOI: 10.1185/03007995.2015.1128888] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Diabetic foot ulcers are one of the major causes of mortality in diabetic patients. Very few drugs and therapies have regulatory approval for this indication and several agents from diverse pharmacological classes are currently in various phases of clinical trials for the management of diabetic foot ulcers. SCOPE The purpose of this review is to provide concise information of the drugs and therapies which are approved and present in clinical trials. REVIEW METHODS This review was carried out by systematic searches of relevant guidelines, patents, published articles, reviews and abstracts in PubMed/Medline, Web of Science, clinicaltrials.gov, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Google Scholar of all English language articles up to 1 March 2015. The following search terms were used: diabetes, diabetic foot, diabetic foot ulcer, diabetic wound, diabetic foot infections, wound management, randomized controlled trials, approved treatments, new treatments and clinical trials. CONCLUSIONS The various drugs and therapies for the management of diabetic foot ulcers comprise antibiotics, neuropathic drugs, wound dressings, skin substitutes, growth factors and inflammatory modulators. The majority of these therapies target the treatment of diabetic foot ulcers to address the altered biochemical composition of the diabetic wound. However, no single treatment can be definitively recommended for the treatment of diabetic foot ulcers.
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Affiliation(s)
| | - Gowthamarajan Kuppusamy
- a a Department of Pharmaceutics, JSS College of Pharmacy, Ootacamund , JSS University , Mysore , India
| | | | - Karthik Yamjala
- b b Department of Pharmaceutical Analysis, JSS College of Pharmacy, Ootacamund , JSS University , Mysore , India
| | - Sai Sandeep Mannemala
- b b Department of Pharmaceutical Analysis, JSS College of Pharmacy, Ootacamund , JSS University , Mysore , India
- c c Department of Pharmacy, Faculty of Engineering and Technology , Annamalai University , Annamalai Nagar, Tamil Nadu , India
| | - Rajkumar Malayandi
- d d Pharmacokinetic Research and Development, Sun Pharmaceutical Industries Ltd , Baroda , India
- e e JSS College of Pharmacy, Ootacamund , JSS University , Mysore , India
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26
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Jung JY. Airway management of patients with traumatic brain injury/C-spine injury. Korean J Anesthesiol 2015; 68:213-9. [PMID: 26045922 PMCID: PMC4452663 DOI: 10.4097/kjae.2015.68.3.213] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 11/26/2022] Open
Abstract
Traumatic brain injury (TBI) is usually combined with cervical spine (C-spine) injury. The possibility of C-spine injury is always considered when performing endotracheal intubation in these patients. Rapid sequence intubation is recommended with adequate sedative or analgesics and a muscle relaxant to prevent an increase in intracranial pressure during intubation in TBI patients. Normocapnia and mild hyperoxemia should be maintained to prevent secondary brain injury. The manual-in-line-stabilization (MILS) technique effectively lessens C-spine movement during intubation. However, the MILS technique can reduce mouth opening and lead to a poor laryngoscopic view. The newly introduced video laryngoscope can manage these problems. The AirWay Scope® (AWS) and AirTraq laryngoscope decreased the extension movement of C-spines at the occiput-C1 and C2-C4 levels, improving intubation conditions and shortening the time to complete tracheal intubation compared with a direct laryngoscope. The Glidescope® also decreased cervical movement in the C2-C5 levels during intubation and improved vocal cord visualization, but a longer duration was required to complete intubation compared with other devices. A lightwand also reduced cervical motion across all segments. A fiberoptic bronchoscope-guided nasal intubation is the best method to reduce cervical movement, but a skilled operator is required. In conclusion, a video laryngoscope assists airway management in TBI patients with C-spine injury.
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Affiliation(s)
- Jin Yong Jung
- Department of Anesthesiology and Pain Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea
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27
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Silva H, Ferreira H, Bujan MJ, Rodrigues LM. Regarding the quantification of peripheral microcirculation--Comparing responses evoked in the in vivo human lower limb by postural changes, suprasystolic occlusion and oxygen breathing. Microvasc Res 2015; 99:110-7. [PMID: 25872021 DOI: 10.1016/j.mvr.2015.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 04/05/2015] [Accepted: 04/06/2015] [Indexed: 11/25/2022]
Abstract
The human skin is an interesting model to explore microcirculation, particularly if using noninvasive technologies such as LDF (Laser Doppler Flowmetry) and tc (transcutaneous) gasimetry and methods as near as possible from the normal physiological state. In this study, we combined those technologies with three classical approaches--leg raising from supine, suprasystolic occlusion (in the ankle), and normobaric oxygen breathing to explore distal peripheral circulation in the foot. These methods are often cited, but a comparative assessment has not been done. The goal of this study was to identify relevant flow related descriptors, method-related advantages and pitfalls, and eventually, to find the best experimental approach. Volunteers (both genders, 22.1 ± 3.7 years old) were subjected to these methods and variables registered during basal, challenge and stabilization phases. Descriptive and comparative statistics were obtained, adopting a 95% confidence level. All flow-related quantitative descriptors potentially useful for the analysis were identified and compared. As expected, male patients consistently showed higher LDF levels and transepidermal water loss (TEWL) and lower tcpO2 values. However, lower results were recorded in the supine position, suggesting a postural dependence. Both leg raising and suprasystolic occlusion produced a hyperemic response after provocation, although different in magnitude, significantly reducing LDF and tcpO2 during provocation. The oxygen breathing method provided the most patient-friendly protocol, consistently reducing LDF (potentially by the inhibition of production of local vasodilators). TEWL increased during the provocation phase in all protocols, although not significantly. Baseline tcpO2 was found to correlate positively with the peak tcpO2 during oxygen breathing and basal LDF with peak flow during leg raising and suprasystolic occlusion. No statistical correlation between TEWL and LDF could be demonstrated under the current experimental conditions. We conclude that although equally useful considering the purpose, these methods involve very different practicalities and do not provide the same information. Also noteworthy, LDF is a highly sensitive indicator that could be further explored to look deeper into blood flow regulating mechanisms.
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Affiliation(s)
- Henrique Silva
- CBIOS - Universidade Lusófona's Research Center for Biosciences and Health Technologies, Lisboa, Portugal; Pharmacol. Sc Depart - Universidade de Lisboa, Faculty of Pharmacy, Lisboa, Portugal
| | - Hugo Ferreira
- IBEB - Biophysics and Biomedical Engineering Institute, Universidade de Lisboa Faculty of Sciences, Lisboa, Portugal
| | - Ma Julia Bujan
- Dept Medicine and Medical Specialities, CIBER-BBN Alcalá de Henares, Madrid, Spain
| | - Luis Monteiro Rodrigues
- CBIOS - Universidade Lusófona's Research Center for Biosciences and Health Technologies, Lisboa, Portugal; Pharmacol. Sc Depart - Universidade de Lisboa, Faculty of Pharmacy, Lisboa, Portugal.
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Ranadive SM, Joyner MJ, Walker BG, Taylor JL, Casey DP. Effect of vitamin C on hyperoxia-induced vasoconstriction in exercising skeletal muscle. J Appl Physiol (1985) 2014; 117:1207-11. [PMID: 25237186 DOI: 10.1152/japplphysiol.00073.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Hyperoxia can cause substantial reductions in peripheral and coronary blood flow at rest and during exercise, which may be caused by reactive oxygen species (ROS) generated during hyperoxia. The aim of this study was to investigate the role of ROS in hyperoxia-induced reductions in skeletal muscle blood flow during forearm exercise. We hypothesized that infusion of vitamin C would abolish the effects of hyperoxia on the forearm blood flow (FBF) responses to exercise. Twelve young healthy adults performed rhythmic forearm handgrip exercise (10% of maximum voluntary contraction for 5 min) during normoxia and hyperoxia. For each condition, two trials were conducted with intra-arterial administration of saline or vitamin C. FBF was measured using Doppler ultrasound. During hyperoxia with saline, FBF and forearm vascular conductance (FVC) were 86.3 ± 5.1 and 86.8 ± 5.2%, respectively, of the normoxic values (100%) (P < 0.05). During vitamin C, hyperoxic FBF and FVC responses were 90.9 ± 4.2 and 90.9 ± 4.1%, respectively, of the normoxic values (P = 0.57 and 0.59). Subjects were then divided into three subgroups based on their percent decrease in FBF (>20, 10-20, and <10%) during hyperoxia. In the subgroup that demonstrated the greatest hyperoxia-induced changes (>20%), FBF and FVC during hyperoxia were 67.1 ± 4.0 and 66.8 ± 3.6%, respectively, of the normoxic values. Vitamin C abolished these effects on FBF and FVC with values that were 102.0 ± 5.2 and 100.8 ± 6.1%, respectively. However, vitamin C had no effect in the other two subgroups. This analysis is consistent with the idea that ROS generation blunts the FBF responses to exercise in the subjects most affected by hyperoxia.
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Affiliation(s)
| | - Michael J Joyner
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and
| | - Branton G Walker
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and
| | - Jennifer L Taylor
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa
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Theunissen S, Schumacker J, Guerrero F, Tillmans F, Boutros A, Lambrechts K, Mazur A, Pieri M, Germonpré P, Balestra C. Dark chocolate reduces endothelial dysfunction after successive breath-hold dives in cool water. Eur J Appl Physiol 2014; 113:2967-75. [PMID: 24078211 DOI: 10.1007/s00421-013-2732-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 09/16/2013] [Indexed: 01/22/2023]
Abstract
OBJECTIVE The aim of this study is to observe the effects of dark chocolate on endothelial function after a series of successive apnea dives in non-thermoneutral water. METHODS Twenty breath-hold divers were divided into two groups: a control group (8 males and 2 females) and a chocolate group (9 males and 1 female). The control group was asked to perform a series of dives to 20 m adding up to 20 min in the quiet diving pool of Conflans-Ste-Honorine (Paris, France), water temperature was 27 °C. The chocolate group performed the dives 1 h after ingestion of 30 g of dark chocolate. Flow-mediated dilatation (FMD), digital photoplethysmography, nitric oxide (NO), and peroxynitrite ONOO−) levels were measured before and after each series of breath-hold dives. RESULTS A significant decrease in FMD was observed in the control group after the dives (95.28 ± 2.9 % of pre-dive values, p < 0.001) while it was increased in the chocolate group (104.1 ± 2.9 % of pre-dive values, p < 0.01). A decrease in the NO level was observed in the control group (86.76 ± 15.57 %, p < 0.05) whereas no difference was shown in the chocolate group (98.44 ± 31.86 %, p > 0.05). No differences in digital photoplethysmography and peroxynitrites were observed between before and after the dives. CONCLUSION Antioxidants contained in dark chocolate scavenge free radicals produced during breath-hold diving. Ingestion of 30 g of dark chocolate 1 h before the dive can thus prevent endothelial dysfunction which can be observed after a series of breath-hold dives.
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Golub AS, Pittman RN. Bang-bang model for regulation of local blood flow. Microcirculation 2014; 20:455-83. [PMID: 23441827 DOI: 10.1111/micc.12051] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 02/19/2013] [Indexed: 11/27/2022]
Abstract
The classical model of metabolic regulation of blood flow in muscle tissue implies the maintenance of basal tone in arterioles of resting muscle and their dilation in response to exercise and/or tissue hypoxia via the evoked production of vasodilator metabolites by myocytes. A century-long effort to identify specific metabolites responsible for explaining active and reactive hyperemia has not been successful. Furthermore, the metabolic theory is not compatible with new knowledge on the role of physiological radicals (e.g., nitric oxide, NO, and superoxide anion, O2 (-) ) in the regulation of microvascular tone. We propose a model of regulation in which muscle contraction and active hyperemia are considered the physiologically normal state. We employ the "bang-bang" or "on/off" regulatory model which makes use of a threshold and hysteresis; a float valve to control the water level in a tank is a common example of this type of regulation. Active bang-bang regulation comes into effect when the supply of oxygen and glucose exceeds the demand, leading to activation of membrane NADPH oxidase, release of O2 (-) into the interstitial space and subsequent neutralization of the interstitial NO. Switching arterioles on/off when local blood flow crosses the threshold is realized by a local cell circuit with the properties of a bang-bang controller, determined by its threshold, hysteresis, and dead-band. This model provides a clear and unambiguous interpretation of the mechanism to balance tissue demand with a sufficient supply of nutrients and oxygen.
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Affiliation(s)
- Aleksander S Golub
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA, USA.
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Golub AS, Song BK, Pittman RN. Muscle contraction increases interstitial nitric oxide as predicted by a new model of local blood flow regulation. J Physiol 2014; 592:1225-35. [PMID: 24445318 DOI: 10.1113/jphysiol.2013.267302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The prevailing metabolic theory of local blood flow regulation suggests the dilatation of arterioles in response to tissue hypoxia via the emission of multiple metabolic vasodilators by parenchymal cells. We have proposed a mechanism of regulation, built from well-known components, which assumes that arterioles are normally dilated in metabolically active tissues, due to the emission of NO by the endothelium of microvessels. Regulation of local blood flow aims at preventing an excessive supply of oxygen (O2) and glucose to the tissue and thus provides an adequate supply, in contrast to the metabolic regulation theory which requires permanent hypoxia to generate the metabolic vasodilators. The mediator of the restrictive signal is superoxide anion (O2(-)) released by membrane NAD(P)H oxidases into the interstitial space, where it neutralizes NO at a diffusion-limited rate. This model predicts that the onset of muscle contraction will lead to the cessation of O2(-) production, which will cause an elevation of interstitial NO concentration and an increase in fluorescence of the NO probe DAF-FM after its conversion to DAF-T. The time course of DAF-T fluorescence in contracting muscle is predicted by also considering the washout from the muscle of the interstitially loaded NO indicator. Experiments using pulse fluorimetry confirmed an increase in the interstitial concentration of NO available for reaction with DAF-FM during bouts of muscle contraction. The sharp increase in interstitial [NO] is consistent with the hypothesis that the termination of the neutralizing superoxide flow into the interstitium is associated with the activation of mitochondria and a reduction of the interstitial oxygen tension. The advantage of the new model is its ability to explain the interaction of metabolic activity and local blood flow through the adequate delivery of glucose and oxygen.
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Affiliation(s)
- Aleksander S Golub
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, 1101 E. Marshall Street, PO Box 980551, Richmond, VA 23298-0551, USA.
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Impact of gas delivery systems on imaging studies of human cerebral blood flow. Radiol Res Pract 2013; 2013:694803. [PMID: 24392225 PMCID: PMC3874307 DOI: 10.1155/2013/694803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 11/08/2013] [Accepted: 11/13/2013] [Indexed: 11/30/2022] Open
Abstract
Purpose. To compare a semiopen breathing circuit with a non-rebreathing (Hudson mask) for MRI experiments involving gas delivery. Methods and Materials. Cerebral blood flow (CBF) was measured by quantitative phase contrast angiography of the internal carotid and basilar arteries in 18 volunteers (20–31 years). In 8 subjects, gases were delivered via a standard non-rebreathing (Hudson mask). In 10 subjects, gases were delivered using a modified “Mapleson A” semiopen anesthetic gas circuit and mouthpiece. All subjects were given 100% O2, medical air, and carbogen gas (95% O2 and 5% CO2) delivered at 15 L/min in a random order. Results. The Hudson mask group showed significant increases in CBF in response to increased FiCO2 compared to air (+9.8%). A small nonsignificant reduction in CBF (−2.4%) was seen in response to increased inspired concentrations of oxygen (FiO2). The Mapleson A group showed significantly larger changes in CBF in response to both increased inspired concentrations of carbon dioxide (FiCO2) (+32.2%, P < 0.05) and FiO2 (−14.6%, P < 0.01). Conclusions. The use of an anaesthetic gas delivery circuit avoids entrainment of room air and rebreathing effects that may otherwise adversely affect the experimental results.
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Affiliation(s)
- Aleksander S Golub
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia
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Muller MD, Drew RC, Cui J, Blaha CA, Mast JL, Sinoway LI. Effect of oxidative stress on sympathetic and renal vascular responses to ischemic exercise. Physiol Rep 2013; 1. [PMID: 24098855 PMCID: PMC3787721 DOI: 10.1002/phy2.47] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Reactive oxygen species (ROS), produced acutely during skeletal muscle contraction, are known to stimulate group IV muscle afferents and accentuate the exercise pressor reflex (EPR) in rodents. The effect of ROS on the EPR in humans is unknown. We conducted a series of studies using ischemic fatiguing rhythmic handgrip to acutely increase ROS within skeletal muscle, ascorbic acid infusion to scavenge free radicals, and hyperoxia inhalation to further increase ROS production. We hypothesized that ascorbic acid would attenuate the EPR and that hyperoxia would accentuate the EPR. Ten young healthy subjects participated in two or three experimental trials on separate days. Beat-by-beat measurements of heart rate (HR), mean arterial pressure (MAP), muscle sympathetic nerve activity (MSNA), and renal vascular resistance index (RVRI) were measured and compared between treatments (saline and ascorbic acid; room air and hyperoxia). At fatigue, the reflex increases in MAP (31 ± 3 versus 29 ± 2 mmHg), HR (19 ± 3 versus 20 ± 3 bpm), MSNA burst rate (21 ± 4 versus 23 ± 4 burst/min), and RVRI (39 ± 12 versus 44 ± 13%) were not different between saline and ascorbic acid. Relative to room air, hyperoxia did not augment the reflex increases in MAP, HR, MSNA, or RVRI in response to exercise. Muscle metaboreflex activation and time/volume control experiments similarly showed no treatment effects. While contrary to our initial hypotheses, these findings suggest that ROS do not play a significant role in the normal reflex adjustments to ischemic exercise in young healthy humans.
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Affiliation(s)
- Matthew D Muller
- Pennsylvania State University College of Medicine, Penn State Hershey Heart and Vascular Institute, 500 University Drive, Hershey, PA 17033
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Effect of a single, open-sea, air scuba dive on human micro- and macrovascular function. Eur J Appl Physiol 2013; 113:2637-45. [DOI: 10.1007/s00421-013-2676-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 05/31/2013] [Indexed: 11/26/2022]
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Demchenko IT, Zhilyaev SY, Moskvin AN, Krivchenko AI, Piantadosi CA, Allen BW. Baroreflex-mediated cardiovascular responses to hyperbaric oxygen. J Appl Physiol (1985) 2013; 115:819-28. [PMID: 23823147 DOI: 10.1152/japplphysiol.00625.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The cardiovascular system responds to hyperbaric hyperoxia (HBO2) with vasoconstriction, hypertension, bradycardia, and reduced cardiac output (CO). We tested the hypothesis that these responses are linked by a common mechanism-activation of the arterial baroreflex. Baroreflex function in HBO2 was assessed in anesthetized and conscious rats after deafferentation of aortic or carotid baroreceptors or both. Cardiovascular and autonomic responses to HBO2 in these animals were compared with those in intact animals at 2.5 ATA for conscious rats and at 3 ATA for anesthetized rats. During O2 compression, hypertension was greater after aortic or carotid baroreceptor deafferentation and was significantly more severe if these procedures were combined. Similarly, the hyperoxic bradycardia observed in intact animals was diminished after aortic or carotid baroreceptor deafferentation and replaced by a slight tachycardia after complete baroreceptor deafferentation. We found that hypertension, bradycardia, and reduced CO--the initial cardiovascular responses to moderate levels of HBO2--are coordinated through a baroreflex-mediated mechanism initiated by HBO2-induced vasoconstriction. Furthermore, we have shown that baroreceptor activation in HBO2 inhibits sympathetic outflow and can partially reverse an O2-dependent increase in arterial pressure.
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Affiliation(s)
- Ivan T Demchenko
- Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina
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Casey DP, Joyner MJ, Claus PL, Curry TB. Vasoconstrictor responsiveness during hyperbaric hyperoxia in contracting human muscle. J Appl Physiol (1985) 2012; 114:217-24. [PMID: 23154993 DOI: 10.1152/japplphysiol.01197.2012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Large increases in systemic oxygen content cause substantial reductions in exercising forearm blood flow (FBF) due to increased vascular resistance. We hypothesized that 1) functional sympatholysis (blunting of sympathetic α-adrenergic vasoconstriction) would be attenuated during hyperoxic exercise and 2) α-adrenergic blockade would limit vasoconstriction during hyperoxia and increase FBF to levels observed under normoxic conditions. Nine male subjects (age 28 ± 1 yr) performed forearm exercise (20% of maximum) under normoxic and hyperoxic conditions. Studies were performed in a hyperbaric chamber at 1 atmosphere absolute (ATA; sea level) while breathing 21% O(2) and at 2.82 ATA while breathing 100% O(2) (estimated change in arterial O(2) content ∼6 ml O(2)/100 ml). FBF (ml/min) was measured using Doppler ultrasound. Forearm vascular conductance (FVC) was calculated from FBF and blood pressure (arterial catheter). Vasoconstrictor responsiveness was determined using intra-arterial tyramine. FBF and FVC were substantially lower during hyperoxic exercise than normoxic exercise (∼20-25%; P < 0.01). At rest, vasoconstriction to tyramine (% decrease from pretyramine values) did not differ between normoxia and hyperoxia (P > 0.05). During exercise, vasoconstrictor responsiveness was slightly greater during hyperoxia than normoxia (-22 ± 3 vs. -17 ± 2%; P < 0.05). However, during α-adrenergic blockade, hyperoxic exercise FBF and FVC remained lower than during normoxia (P < 0.01). Therefore, our data suggest that although the vasoconstrictor responsiveness during hyperoxic exercise was slightly greater, it likely does not explain the majority of the large reductions in FBF and FVC (∼20-25%) during hyperbaric hyperoxic exercise.
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Affiliation(s)
- Darren P Casey
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Lott MEJ, Slocomb JE, Shivkumar V, Smith B, Gabbay RA, Quillen D, Gardner TW, Bettermann K. Comparison of retinal vasodilator and constrictor responses in type 2 diabetes. Acta Ophthalmol 2012; 90:e434-41. [PMID: 22682034 DOI: 10.1111/j.1755-3768.2012.02445.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE The retinal blood vessels provide a unique way to directly examine the human microvasculature, which is frequently damaged in individuals with diabetes. Previous studies have demonstrated that retinal flickering light-induced vasodilation and hyperoxia-induced vasoconstriction may operate by enhancing or reducing similar vasoregulatory factor(s), but a comparison between these two provocative stimuli in individuals with diabetes has not been studied. The purpose of the study was to examine the association between retinal flickering light-induced vasodilation and retinal hyperoxia-induced vasoconstriction in type 2 diabetic subjects and in healthy controls. METHODS Twenty men and women with type 2 diabetes and 10 men and women without diabetes between 21 and 75 years of age were recruited. Changes in retinal artery and vein diameters to flickering light and during hyperoxia (100% oxygen) stimuli were measured on the same visit using a noninvasive retinal imaging device (Dynamic Vessel Analyzer, Imedos Inc., Germany). RESULTS Compared with controls, diabetic subjects had impaired arterial vasodilator and vasoconstrictor responses to both flickering light and hyperoxia, respectively (both p<0.001). Merging both groups, an inverse correlation (r=-0.56; p=0.003) between the retinal artery's responses to flickering light-induced vasodilation and hyperoxia-induced vasoconstriction was demonstrated independent of glucose or insulin levels. CONCLUSION This suggests that both responses are attenuated to a similar degree in diabetic subjects and that the attenuation to both stimuli can be observed in retinal arteries and veins. This would suggest that similar vasoregulatory factor(s) might in part help to explain the retinal diameter responses between the two stimuli. One suggested common vasoregulator of vascular tone is nitric oxide; however, other factor(s) may be involved, which contribute to this association and require further research.
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Affiliation(s)
- Mary E J Lott
- Penn State Hershey Medical Center, Heart and Vascular Institute, Department of Neurology, Hershey, PA 17033-2390, USA.
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Wagner M, Magerkurth J, Volz S, Jurcoane A, Singer OC, Neumann‐Haefelin T, Zanella FE, Deichmann R, Hattingen E. T2′‐ and PASL‐based perfusion mapping at 3 Tesla: influence of oxygen‐ventilation on cerebral autoregulation. J Magn Reson Imaging 2012; 36:1347-52. [DOI: 10.1002/jmri.23777] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 07/20/2012] [Indexed: 11/07/2022] Open
Affiliation(s)
- Marlies Wagner
- Institute of Neuroradiology, University Hospital, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Jörg Magerkurth
- Institute of Neuroradiology, University Hospital, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Steffen Volz
- Brain Imaging Center, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Alina Jurcoane
- Institute of Neuroradiology, University Hospital, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Oliver C. Singer
- Department of Neurology, University Hospital, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Tobias Neumann‐Haefelin
- Department of Neurology, University Hospital, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Friedhelm E. Zanella
- Institute of Neuroradiology, University Hospital, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Ralf Deichmann
- Brain Imaging Center, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Elke Hattingen
- Institute of Neuroradiology, University Hospital, Goethe University Frankfurt am Main, Frankfurt am Main, Germany
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Abstract
Cell-free hemoglobin (Hb) has been blamed for a spectrum of problems, including vasoconstriction pancreatitis, myocardial infarction, and pulmonary hypertension in hemolytic anemia, malaria, and sickle cell anemia, and from Hb-based oxygen carriers (HBOCs). Toxicities have been attributed to scavenging of nitric oxide (NO). However, while NO scavenging may explain many in vitro effects, and some effects in animal models and clinical trials with HBOCs, key inconsistencies in the theory require alternative explanations. This review considers the hypothesis that cell-free Hb oversupplies oxygen to tissues, leading to oxygen-related toxicity, possibly through formation of reactive oxygen species and local destruction of NO. Evidence for this hypothesis comes from various sources, establishing that tissue oxygen levels are maintained over very narrow (and low) levels, even at high oxygen consumption. Tissue is normally protected from excessive oxygen by its extremely low solubility in plasma, but introduction of cell-free Hb, even at low concentration, greatly augments oxygen supply, engaging protective mechanisms that include vasoconstriction and ischemia. The requirement to limit oxygen supply by cell-free Hb suggests novel ways to modify it to overcome vasoconstriction, independent of the intrinsic reaction of Hb with NO. This control is essential to the design of a safe and effective cell-free HBOC.
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Affiliation(s)
- Robert M Winslow
- Department of Bioengineering, University of California, San Diego, USA
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Atochin DN, Huang PL. Role of endothelial nitric oxide in cerebrovascular regulation. Curr Pharm Biotechnol 2012; 12:1334-42. [PMID: 21235451 DOI: 10.2174/138920111798280974] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Revised: 07/01/2010] [Accepted: 08/08/2010] [Indexed: 11/22/2022]
Abstract
Endothelial nitric oxide (NO) plays important roles in the vascular system. Animal models that show vascular dysfunction demonstrate the protective role of endothelial NO dependent pathways. This review focuses on the role of endothelial NO in the regulation of cerebral blood flow and vascular tone. We will discuss the importance of NO in cerebrovascular function using animal models with altered endothelial NO production under normal, ischemic and reperfusion conditions, as well as in hyperoxia. Pharmacological and genetic manipulations of the endothelial NO system demonstrate the essential roles of endothelial NO synthase in maintenance of vascular tone and cerebral perfusion under normal and pathological conditions.
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Affiliation(s)
- Dmitriy N Atochin
- Cardiovascular Research Center and Cardiology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA.
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Casey DP, Joyner MJ. Local control of skeletal muscle blood flow during exercise: influence of available oxygen. J Appl Physiol (1985) 2011; 111:1527-38. [PMID: 21885800 DOI: 10.1152/japplphysiol.00895.2011] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Reductions in oxygen availability (O(2)) by either reduced arterial O(2) content or reduced perfusion pressure can have profound influences on the circulation, including vasodilation in skeletal muscle vascular beds. The purpose of this review is to put into context the present evidence regarding mechanisms responsible for the local control of blood flow during acute systemic hypoxia and/or local hypoperfusion in contracting muscle. The combination of submaximal exercise and hypoxia produces a "compensatory" vasodilation and augmented blood flow in contracting muscles relative to the same level of exercise under normoxic conditions. A similar compensatory vasodilation is observed in response to local reductions in oxygen availability (i.e., hypoperfusion) during normoxic exercise. Available evidence suggests that nitric oxide (NO) contributes to the compensatory dilator response under each of these conditions, whereas adenosine appears to only play a role during hypoperfusion. During systemic hypoxia the NO-mediated component of the compensatory vasodilation is regulated through a β-adrenergic receptor mechanism at low-intensity exercise, while an additional (not yet identified) source of NO is likely to be engaged as exercise intensity increases during hypoxia. Potential candidates for stimulating and/or interacting with NO at higher exercise intensities include prostaglandins and/or ATP. Conversely, prostaglandins do not appear to play a role in the compensatory vasodilation during exercise with hypoperfusion. Taken together, the data for both hypoxia and hypoperfusion suggest NO is important in the compensatory vasodilation seen when oxygen availability is limited. This is important from a basic biological perspective and also has pathophysiological implications for diseases associated with either hypoxia or hypoperfusion.
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Affiliation(s)
- Darren P Casey
- Dept. of Anesthesiology, Mayo Clinic, Rochester, MN 55905, USA.
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Iscoe S, Beasley R, Fisher JA. Supplementary oxygen for nonhypoxemic patients: O2 much of a good thing? Crit Care 2011; 15:305. [PMID: 21722334 PMCID: PMC3218982 DOI: 10.1186/cc10229] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Supplementary oxygen is routinely administered to patients, even those with adequate oxygen saturations, in the belief that it increases oxygen delivery. But oxygen delivery depends not just on arterial oxygen content but also on perfusion. It is not widely recognized that hyperoxia causes vasoconstriction, either directly or through hyperoxia-induced hypocapnia. If perfusion decreases more than arterial oxygen content increases during hyperoxia, then regional oxygen delivery decreases. This mechanism, and not (just) that attributed to reactive oxygen species, is likely to contribute to the worse outcomes in patients given high-concentration oxygen in the treatment of myocardial infarction, in postcardiac arrest, in stroke, in neonatal resuscitation and in the critically ill. The mechanism may also contribute to the increased risk of mortality in acute exacerbations of chronic obstructive pulmonary disease, in which worsening respiratory failure plays a predominant role. To avoid these effects, hyperoxia and hypocapnia should be avoided, with oxygen administered only to patients with evidence of hypoxemia and at a dose that relieves hypoxemia without causing hyperoxia.
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Affiliation(s)
- Steve Iscoe
- Department of Physiology, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - Richard Beasley
- Medical Research Institute of New Zealand, Level 7, CSB Building, Wellington Hospital, Private Bag 7902, Wellington 6242, New Zealand
| | - Joseph A Fisher
- Department of Anesthesiology, Toronto General Hospital, 3EN 200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
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Casey DP, Joyner MJ, Claus PL, Curry TB. Hyperbaric hyperoxia reduces exercising forearm blood flow in humans. Am J Physiol Heart Circ Physiol 2011; 300:H1892-7. [PMID: 21421819 DOI: 10.1152/ajpheart.00165.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxia during exercise augments blood flow in active muscles to maintain the delivery of O(2) at normoxic levels. However, the impact of hyperoxia on skeletal muscle blood flow during exercise is not completely understood. Therefore, we tested the hypothesis that the hyperemic response to forearm exercise during hyperbaric hyperoxia would be blunted compared with exercise during normoxia. Seven subjects (6 men/1 woman; 25 ± 1 yr) performed forearm exercise (20% of maximum) under normoxic and hyperoxic conditions. Forearm blood flow (FBF; in ml/min) was measured using Doppler ultrasound. Forearm vascular conductance (FVC; in ml·min(-1)·100 mmHg(-1)) was calculated from FBF and blood pressure (in mmHg; brachial arterial catheter). Studies were performed in a hyperbaric chamber with the subjects supine at 1 atmospheres absolute (ATA) (sea level) while breathing normoxic gas [21% O(2), 1 ATA; inspired Po(2) (Pi(O(2))) ≈ 150 mmHg] and at 2.82 ATA while breathing hyperbaric normoxic (7.4% O(2), 2.82 ATA, Pi(O(2)) ≈ 150 mmHg) and hyperoxic (100% O(2), 2.82 ATA, Pi(O(2)) ≈ 2,100 mmHg) gas. Resting FBF and FVC were less during hyperbaric hyperoxia compared with hyperbaric normoxia (P < 0.05). The change in FBF and FVC (Δ from rest) during exercise under normoxia (204 ± 29 ml/min and 229 ± 37 ml·min(-1)·100 mmHg(-1), respectively) and hyperbaric normoxia (203 ± 28 ml/min and 217 ± 35 ml·min(-1)·100 mmHg(-1), respectively) did not differ (P = 0.66-0.99). However, the ΔFBF (166 ± 21 ml/min) and ΔFVC (163 ± 23 ml·min(-1)·100 mmHg(-1)) during hyperbaric hyperoxia were substantially attenuated compared with other conditions (P < 0.01). Our data suggest that exercise hyperemia in skeletal muscle is highly dependent on oxygen availability during hyperoxia.
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Affiliation(s)
- Darren P Casey
- Dept. of Anesthesiology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905.
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Santos RM, Lourenço CF, Pomerleau F, Huettl P, Gerhardt GA, Laranjinha J, Barbosa RM. Brain nitric oxide inactivation is governed by the vasculature. Antioxid Redox Signal 2011; 14:1011-21. [PMID: 20712398 DOI: 10.1089/ars.2010.3297] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The mechanisms underlying nitric oxide ((•)NO) synthesis and inactivation in the brain are essential determinants of (•)NO neuroactivity. Although (•)NO production is well characterized, the pathways of inactivation in vivo remain largely unknown. Here, we characterize the kinetics and the major mechanism of (•)NO inactivation in the rat brain cortex and hippocampus in vivo by measuring locally applied (•)NO with carbon-fiber microelectrodes (CFMs) and ceramic-based microelectrode arrays (MEAs). An apparent first-order clearance was observed in both brain regions, with decay rate constants (k) of (•)NO signals of 0.67 to 0.84 per second, significantly higher than the k obtained in agarose gel (0.099 per second), used as a (•)NO diffusion-control medium. (•)NO half-life in vivo, estimated by mathematical modeling, was 0.42 to 0.75 s. Experiments using MEAs support that the (•)NO diffusion radius is heterogeneous and related to local metabolic activity and vascular density. After global ischemia, k decreased to control values of diffusion in gel, but during anoxia, k decreased only 21%. Additionally, k in brain slices was threefold to fivefold lower than that in vivo, and hemorrhagic shock induced a 53% decrease in k. Overall, the results support that (•)NO scavenging by circulating erythrocytes constitutes the major (•)NO-inactivation pathway in the brain.
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Affiliation(s)
- Ricardo M Santos
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
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Hyperoxia suppresses excessive superoxide anion radical generation in blood, oxidative stress, early inflammation, and endothelial injury in forebrain ischemia/reperfusion rats: laboratory study. Shock 2011; 34:299-305. [PMID: 20016404 DOI: 10.1097/shk.0b013e3181ceeeec] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study used an electrochemical O2. sensor to investigate the effects of hyperoxia on generation of the superoxide radical (O2.) in the jugular vein during forebrain I/R in rats. Twenty-eight male Wistar rats were allocated to a sham group (n = 7; sham-treated rats with inspired oxygen fraction [FiO2] of 0.4), a hemorrhagic shock and reperfusion (HS/R) group (n = 7; HS without carotid artery occlusion and reperfusion with FiO2 of 0.4), a normoxia group (n = 7; forebrain ischemia produced by bilateral carotid arteries occlusion with HS and reperfusion with FiO2 of 0.4), and a hyperoxia group (n = 7; forebrain ischemia with FiO2 of 0.4 and reperfusion with FiO2 of 1.0). The jugular venous O2. current was measured for 10 min during forebrain ischemia and for 120 min after reperfusion. The O2. current increased gradually during forebrain ischemia in the three groups other than the sham group. Immediately after reperfusion, the current showed a marked increase in the normoxia group and a pronounced decrease in the hyperoxia group. Levels of brain and plasma malondialdehyde, high-mobility group box 1 protein, and intercellular adhesion molecule 1 were significantly attenuated in the hyperoxia group relative to those in the normoxia group. In conclusion, hyperoxia suppressed jugular venous O2. generation and malondialdehyde, high-mobility group box 1, and intercellular adhesion molecule 1 in the brain and plasma in the acute phase of cerebral I/R. Thus, the administration of 100% oxygen immediately after reperfusion suppresses oxidative stress and early inflammation in cerebral I/R.
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Xu X, Wang Z, Li Q, Xiao X, Lian Q, Xu W, Sun X, Tao H, Li R. Endothelial nitric oxide synthase expression is progressively increased in primary cerebral microvascular endothelial cells during hyperbaric oxygen exposure. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2011; 2:7-13. [PMID: 20046639 PMCID: PMC2763225 DOI: 10.4161/oxim.2.1.7697] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 12/20/2008] [Accepted: 12/22/2008] [Indexed: 11/19/2022]
Abstract
Exposure to hyperbaric oxygen (HBO) can lead to seizures. Many studies have demonstrated that there exist a very close relationship between the alteration of cerebral blood flow (CBF) and the onset of seizures. Nitric oxide (NO) may play a key role in the change of CBF during exposure, and modulation of endothelial nitric oxide synthase (eNOS)-derived NO by HBO is responsible for early vasoconstriction, whereas late HBO-induced vasodilation depends upon a large amount of NO from both eNOS and neuronal nitric oxide synthase (nNOS). To investigate the effect of HBO on the activity and expression of eNOS in cerebral microvascular endothelial cells (CMEC) in vitro, primarily cultured CMEC from neonatal rats were exposed to oxygen at 500 kPa [5 atmosphere absolute (ATA)] for 10, 20, 30, 60 and 120 minutes (min), then eNOS activity, protein and mRNA contents in cells were detected. Our results showed that immediately after exposure, 30, 60 and 120 min HBO exposures did not alter NOS activity. When detected no matter immediately or six hours (h) after exposure, these exposures also did not alter eNOS protein and mRNA levels. However, when detected 24 h after exposure, 30, 60 and 120 min exposures upregulated eNOS protein content by 39%, 60% and 40% respectively. 10 and 20 min exposures upregulated eNOS mRNA content by about 15%, while 30, 60 and 120 min exposures upregulated it by about 20-30%. The increased eNOS protein and mRNA contents at 24 h after exposure may reflect new protein synthesis for eNOS. Our studies showed that with the exposing protocols we used, HBO did induce eNOS expression increase in CMEC. However, compared with the decrease of CBF in vivo, which occurred in a relative short time after rat was exposed to HBO above 4 ATA, the responses of eNOS in CMEC in vitro were a little slow. Thus we considered that for the vasodilation in the late period of HBO exposure before seizure, the effect of NO produced by eNOS was limited.
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Affiliation(s)
- Xiongfei Xu
- Department of Diving Medicine, Faculty of Naval Medicine, Changhai Hospital, Second Military Medical University, Shanghai, China
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Edwards ML. Hyperbaric oxygen therapy. Part 2: application in disease. J Vet Emerg Crit Care (San Antonio) 2010; 20:289-97. [DOI: 10.1111/j.1476-4431.2010.00535_1.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Davis DP, Meade W, Sise MJ, Kennedy F, Simon F, Tominaga G, Steele J, Coimbra R. Both Hypoxemia and Extreme Hyperoxemia May Be Detrimental in Patients with Severe Traumatic Brain Injury. J Neurotrauma 2009; 26:2217-23. [DOI: 10.1089/neu.2009.0940] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Daniel P. Davis
- Univeristy of California–San Diego, Department of Emergency Medicine, San Diego, California
| | - William Meade
- Univeristy of California–San Diego, Department of Emergency Medicine, San Diego, California
| | | | | | - Fred Simon
- Scripps Memorial Hospital, San Diego, California
| | | | | | - Raul Coimbra
- Division of Trauma, University of California–San Diego, San Diego, California
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Abstract
An association between major surgery in the elderly and precipitation of Alzheimer's disease has been reported. As 100% oxygen (hyperoxia) is commonly administered after surgery, we exposed cognitively unimpaired Alzheimer's transgenic mice to hyperoxia typical of human exposure in a hospital setting. Three-hour hyperoxia treatments to young adult Alzheimer's transgenic mice: (i) triggered cognitive impairment that was not otherwise present at that age, (ii) increased aberrant brain synaptophysin staining, and (iii) increased brain levels of isofurans (products of lipid peroxidation sensitive to hyperoxia). Thus, hyperoxia-induced synaptic dysfunction and brain oxidative stress are likely the triggering mechanisms of cognitive dysfunction in Alzheimer's mice. These results may suggest that exposure of elderly patients to excessive amounts of oxygen perioperatively hastens the development of Alzheimer's disease.
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