1
|
Mester JR, Bazzigaluppi P, Dorr A, Beckett T, Burke M, McLaurin J, Sled JG, Stefanovic B. Attenuation of tonic inhibition prevents chronic neurovascular impairments in a Thy1-ChR2 mouse model of repeated, mild traumatic brain injury. Am J Cancer Res 2021; 11:7685-7699. [PMID: 34335958 PMCID: PMC8315057 DOI: 10.7150/thno.60190] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 06/04/2021] [Indexed: 12/24/2022] Open
Abstract
Rationale: Mild traumatic brain injury (mTBI), the most common type of brain trauma, frequently leads to chronic cognitive and neurobehavioral deficits. Intervening effectively is impeded by our poor understanding of its pathophysiological sequelae. Methods: To elucidate the long-term neurovascular sequelae of mTBI, we combined optogenetics, two-photon fluorescence microscopy, and intracortical electrophysiological recordings in mice to selectively stimulate peri-contusional neurons weeks following repeated closed-head injury and probe individual vessel's function and local neuronal reactivity. Results: Compared to sham-operated animals, mTBI mice showed doubled cortical venular speeds (115 ± 25%) and strongly elevated cortical venular reactivity (53 ± 17%). Concomitantly, the pericontusional neurons exhibited attenuated spontaneous activity (-57 ± 79%) and decreased reactivity (-47 ± 28%). Post-mortem immunofluorescence revealed signs of peri-contusional senescence and DNA damage, in the absence of neuronal loss or gliosis. Alteration of neuronal and vascular functioning was largely prevented by chronic, low dose, systemic administration of a GABA-A receptor inverse agonist (L-655,708), commencing 3 days following the third impact. Conclusions: Our findings indicate that repeated mTBI leads to dramatic changes in the neurovascular unit function and that attenuation of tonic inhibition can prevent these alterations. The sustained disruption of the neurovascular function may underlie the concussed brain's long-term susceptibility to injury, and calls for development of better functional assays as well as of neurovascularly targeted interventions.
Collapse
|
2
|
Prasad GL. Steroids for delayed cerebral edema after traumatic brain injury. Surg Neurol Int 2021; 12:46. [PMID: 33654549 PMCID: PMC7911208 DOI: 10.25259/sni_756_2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/15/2021] [Indexed: 11/04/2022] Open
Abstract
Background Brain edema is a common phenomenon after traumatic brain injury (TBI) resulting in increased intracranial pressure and subsequent neurological deterioration. Experimental studies have proven that brain edema is biphasic (cytotoxic followed by vasogenic). Till date, all studies, including the corticosteroid randomization after significant head injury (HI) trial, have used high-dose steroids in the acute period during which the edema is essentially cytotoxic in nature. No clinical data exist pertaining to delayed cerebral edema (vasogenic) and steroids. Methods Patients who had received steroids for delayed cerebral edema after TBI were retrospectively analyzed over a 2-year period. Steroid dose, timing of steroid prescription, time to improvement of symptoms, and complications were noted. Results There were six males and three females. Mean age was 41.1 years. There were no severe HI cases. All subjects had cerebral contusions on imaging. Dexamethasone was the preferred steroid starting with 12 mg/day and tapered in 5-7 days. The mean interval to steroid administration after trauma was 7 days. The mean duration of steroid prescription was 6.3 days. All patients had complete symptomatic improvement. The mean time to symptom resolution was 3.8 days. No patients experienced any complications pertinent to steroid usage. Conclusion This is the first study to document efficacy of steroids for delayed cerebral edema after TBI, at least in mild/moderate head injuries. The timing of steroid usage and dose of steroids is key aspects that might determine its efficacy in TBI which was the drawbacks of the previous studies. Future prospective trials with the above factors in consideration may confirm/refute above findings.
Collapse
Affiliation(s)
- G Lakshmi Prasad
- Department of Neurosurgery, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
| |
Collapse
|
3
|
Faroqi AH, Lim MJ, Kee EC, Lee JH, Burgess JD, Chen R, Di Virgilio F, Delenclos M, McLean PJ. In Vivo Detection of Extracellular Adenosine Triphosphate in a Mouse Model of Traumatic Brain Injury. J Neurotrauma 2020; 38:655-664. [PMID: 32935624 PMCID: PMC7898407 DOI: 10.1089/neu.2020.7226] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Traumatic brain injury (TBI) is traditionally characterized by primary and secondary injury phases, both contributing to pathological and morphological changes. The mechanisms of damage and chronic consequences of TBI remain to be fully elucidated, but synaptic homeostasis disturbances and impaired energy metabolism are proposed to be a major contributor. It has been proposed that an increase of extracellular (eATP) adenosine triphosphate (ATP) in the area immediately surrounding impact may play a pivotal role in this sequence of events. After tissue injury, rupture of cell membranes allows release of intracellular ATP into the extracellular space, triggering a cascade of toxic events and inflammation. ATP is a ubiquitous messenger; however, simple and reliable techniques to measure its concentration have proven elusive. Here, we integrate a sensitive bioluminescent eATP sensor known as pmeLUC, with a controlled cortical impact mouse model to monitor eATP changes in a living animal after injury. Using the pmeLUC probe, a rapid increase of eATP is observed proximal to the point of impact within minutes of the injury. This event is significantly attenuated when animals are pretreated with an ATP hydrolyzing agent (apyrase) before surgery, confirming the contribution of eATP. This new eATP reporter could be useful for understanding the role of eATP in the pathogenesis in TBI and may identify a window of opportunity for therapeutic intervention.
Collapse
Affiliation(s)
- Ayman H Faroqi
- Department of Neuroscience, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA.,Neuroscience PhD Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA
| | - Melina J Lim
- Department of Neuroscience, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA
| | - Emma C Kee
- Department of Neuroscience, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA
| | - Jannifer H Lee
- Department of Neuroscience, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA.,Neuroscience PhD Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA
| | - Jeremy D Burgess
- Department of Neuroscience, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA.,Neuroscience PhD Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA
| | - Ridong Chen
- APT Therapeutics, Inc., St. Louis, Missouri, USA
| | - Francesco Di Virgilio
- Department of Morphology Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Marion Delenclos
- Department of Neuroscience, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA
| | - Pamela J McLean
- Department of Neuroscience, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA.,Neuroscience PhD Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida, USA
| |
Collapse
|
4
|
Bodnar CN, Roberts KN, Higgins EK, Bachstetter AD. A Systematic Review of Closed Head Injury Models of Mild Traumatic Brain Injury in Mice and Rats. J Neurotrauma 2019; 36:1683-1706. [PMID: 30661454 PMCID: PMC6555186 DOI: 10.1089/neu.2018.6127] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mild TBI (mTBI) is a significant health concern. Animal models of mTBI are essential for understanding mechanisms, and pathological outcomes, as well as to test therapeutic interventions. A variety of closed head models of mTBI that incorporate different aspects (i.e., biomechanics) of the mTBI have been reported. The aim of the current review was to compile a comprehensive list of the closed head mTBI rodent models, along with the common data elements, and outcomes, with the goal to summarize the current state of the field. Publications were identified from a search of PubMed and Web of Science and screened for eligibility following PRISMA guidelines. Articles were included that were closed head injuries in which the authors classified the injury as mild in rats or mice. Injury model and animal-specific common data elements, as well as behavioral and histological outcomes, were collected and compiled from a total of 402 articles. Our results outline the wide variety of methods used to model mTBI. We also discovered that female rodents and both young and aged animals are under-represented in experimental mTBI studies. Our findings will aid in providing context comparing the injury models and provide a starting point for the selection of the most appropriate model of mTBI to address a specific hypothesis. We believe this review will be a useful starting place for determining what has been done and what knowledge is missing in the field to reduce the burden of mTBI.
Collapse
Affiliation(s)
- Colleen N. Bodnar
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| | - Kelly N. Roberts
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| | - Emma K. Higgins
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| | - Adam D. Bachstetter
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| |
Collapse
|
5
|
Farfara D, Feierman E, Richards A, Revenko AS, MacLeod RA, Norris EH, Strickland S. Knockdown of circulating C1 inhibitor induces neurovascular impairment, glial cell activation, neuroinflammation, and behavioral deficits. Glia 2019; 67:1359-1373. [PMID: 30882931 DOI: 10.1002/glia.23611] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 02/11/2019] [Accepted: 02/19/2019] [Indexed: 12/20/2022]
Abstract
The cross-talk between blood proteins, immune cells, and brain function involves complex mechanisms. Plasma protein C1 inhibitor (C1INH) is an inhibitor of vascular inflammation that is induced by activation of the kallikrein-kinin system (KKS) and the complement system. Knockout of C1INH was previously correlated with peripheral vascular permeability via the bradykinin pathway, yet there was no evidence of its correlation with blood-brain barrier (BBB) integrity and brain function. In order to understand the effect of plasma C1INH on brain pathology via the vascular system, we knocked down circulating C1INH in wild-type (WT) mice using an antisense oligonucleotide (ASO), without affecting C1INH expression in peripheral immune cells or the brain, and examined brain pathology. Long-term elimination of endogenous C1INH in the plasma induced the activation of the KKS and peritoneal macrophages but did not activate the complement system. Bradykinin pathway proteins were elevated in the periphery and the brain, resulting in hypotension. BBB permeability, extravasation of plasma proteins into the brain parenchyma, activation of glial cells, and elevation of pro-inflammatory response mediators were detected. Furthermore, infiltrating innate immune cells were observed entering the brain through the lateral ventricle walls and the neurovascular unit. Mice showed normal locomotion function, yet cognition was impaired and depressive-like behavior was evident. In conclusion, our results highlight the important role of regulated plasma C1INH as it acts as a gatekeeper to the brain via the neurovascular system. Thus, manipulation of C1INH in neurovascular disorders might be therapeutically beneficial.
Collapse
Affiliation(s)
- Dorit Farfara
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, New York
| | - Emily Feierman
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, New York
| | - Allison Richards
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, New York
| | - Alexey S Revenko
- Department of Antisense Drug Discovery, IONIS Pharmaceuticals Inc., Carlsbad, California
| | - Robert A MacLeod
- Department of Antisense Drug Discovery, IONIS Pharmaceuticals Inc., Carlsbad, California
| | - Erin H Norris
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, New York
| | - Sidney Strickland
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, New York
| |
Collapse
|
6
|
Saunders NR, Dziegielewska KM, Møllgård K, Habgood MD. Markers for blood-brain barrier integrity: how appropriate is Evans blue in the twenty-first century and what are the alternatives? Front Neurosci 2015; 9:385. [PMID: 26578854 PMCID: PMC4624851 DOI: 10.3389/fnins.2015.00385] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/05/2015] [Indexed: 11/18/2022] Open
Abstract
In recent years there has been a resurgence of interest in brain barriers and various roles their intrinsic mechanisms may play in neurological disorders. Such studies require suitable models and markers to demonstrate integrity and functional changes at the interfaces between blood, brain, and cerebrospinal fluid. Studies of brain barrier mechanisms and measurements of plasma volume using dyes have a long-standing history, dating back to the late nineteenth-century. Their use in blood-brain barrier studies continues in spite of their known serious limitations in in vivo applications. These were well known when first introduced, but seem to have been forgotten since. Understanding these limitations is important because Evans blue is still the most commonly used marker of brain barrier integrity and those using it seem oblivious to problems arising from its in vivo application. The introduction of HRP in the mid twentieth-century was an important advance because its reaction product can be visualized at the electron microscopical level, but it also has limitations. Advantages and disadvantages of these markers will be discussed together with a critical evaluation of alternative approaches. There is no single marker suitable for all purposes. A combination of different sized, visualizable dextrans and radiolabeled molecules currently seems to be the most appropriate approach for qualitative and quantitative assessment of barrier integrity.
Collapse
Affiliation(s)
- Norman R Saunders
- Laboratory of Developmental Neurobiology and Neurotrauma, Department of Pharmacology and Therapeutics, University of Melbourne Parkville, VIC, Australia
| | - Katarzyna M Dziegielewska
- Laboratory of Developmental Neurobiology and Neurotrauma, Department of Pharmacology and Therapeutics, University of Melbourne Parkville, VIC, Australia
| | - Kjeld Møllgård
- Department of Cellular and Molecular Medicine, University of Copenhagen Copenhagen, Denmark
| | - Mark D Habgood
- Laboratory of Developmental Neurobiology and Neurotrauma, Department of Pharmacology and Therapeutics, University of Melbourne Parkville, VIC, Australia
| |
Collapse
|
7
|
Lopez-Rodriguez AB, Acaz-Fonseca E, Viveros MP, Garcia-Segura LM. Changes in cannabinoid receptors, aquaporin 4 and vimentin expression after traumatic brain injury in adolescent male mice. Association with edema and neurological deficit. PLoS One 2015; 10:e0128782. [PMID: 26039099 PMCID: PMC4454518 DOI: 10.1371/journal.pone.0128782] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 04/30/2015] [Indexed: 12/21/2022] Open
Abstract
Traumatic brain injury (TBI) incidence rises during adolescence because during this critical neurodevelopmental period some risky behaviors increase. The purpose of this study was to assess the contribution of cannabinoid receptors (CB1 and CB2), blood brain barrier proteins (AQP4) and astrogliosis markers (vimentin) to neurological deficit and brain edema formation in a TBI weight drop model in adolescent male mice. These molecules were selected since they are known to change shortly after lesion. Here we extended their study in three different timepoints after TBI, including short (24h), early mid-term (72h) and late mid-term (two weeks). Our results showed that TBI induced an increase in brain edema up to 72 h after lesion that was directly associated with neurological deficit. Neurological deficit appeared 24 h after TBI and was completely recovered two weeks after trauma. CB1 receptor expression decreased after TBI and was negatively correlated with edema formation and behavioral impairments. CB2 receptor increased after injury and was associated with high neurological deficit whereas no correlation with edema was found. AQP4 increased after TBI and was positively correlated with edema and neurological impairments as occurred with vimentin expression in the same manner. The results suggest that CB1 and CB2 differ in the mechanisms to resolve TBI and also that some of their neuroprotective effects related to the control of reactive astrogliosis may be due to the regulation of AQP4 expression on the end-feet of astrocytes.
Collapse
Affiliation(s)
- Ana Belen Lopez-Rodriguez
- Department of Animal Physiology (II), Biology Faculty, Complutense University of Madrid, Madrid, Spain
- Instituto Cajal, Consejo Superior de Investigaciones Cientificas (CSIC), Madrid, Spain
- * E-mail:
| | - Estefania Acaz-Fonseca
- Department of Animal Physiology (II), Biology Faculty, Complutense University of Madrid, Madrid, Spain
| | - Maria-Paz Viveros
- Instituto Cajal, Consejo Superior de Investigaciones Cientificas (CSIC), Madrid, Spain
| | - Luis M. Garcia-Segura
- Department of Animal Physiology (II), Biology Faculty, Complutense University of Madrid, Madrid, Spain
| |
Collapse
|
8
|
Li Z, Shu Q, Li L, Ge M, Zhang Y. Sequential expression of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor in rat hippocampal neurons after fluid percussion injury. Neural Regen Res 2014; 9:978-85. [PMID: 25206921 PMCID: PMC4146214 DOI: 10.4103/1673-5374.133151] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2014] [Indexed: 01/09/2023] Open
Abstract
Traumatic brain injury causes gene expression changes in different brain regions. Occurrence and development of traumatic brain injury are closely related, involving expression of three factors, namely cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. However, little is known about the correlation of these three factors and brain neuronal injury. In this study, primary cultured rat hippocampal neurons were subjected to fluid percussion injury according to Scott's method, with some modifications. RT-PCR and semi-quantitative immunocytochemical staining was used to measure the expression levels of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. Our results found that cyclooxygenase-2 expression were firstly increased post-injury, and then decreased. Both mRNA and protein expression levels reached peaks at 8 and 12 hours post-injury, respectively. Similar sequential changes in glutamate receptor 2 were observed, with highest levels mRNA and protein expression at 8 and 12 hours post-injury respectively. On the contrary, the expressions of platelet activating factor receptor were firstly decreased post-injury, and then increased. Both mRNA and protein expression levels reached the lowest levels at 8 and 12 hours post-injury, respectively. Totally, our findings suggest that these three factors are involved in occurrence and development of hippocampal neuronal injury.
Collapse
Affiliation(s)
- Zhiqiang Li
- Second Department of Medicine, Inner Mongolia Corps Hospital, Chinese People's Armed Police Forces, Huhhot, Inner Mongolia Autonomous Region, China
| | - Qingming Shu
- Department of Pathology, General Hospital of Chinese People's Armed Police Forces, Beijing, China
| | - Lingzhi Li
- Section of Pharmaceutical Chemistry, Department of Rescue Medicine, Logistics University of Chinese People's Armed Police Force, Tianjin, China
| | - Maolin Ge
- Second Department of Surgery, Inner Mongolia Corps Hospital, Chinese People's Armed Police Forces, Huhhot, Inner Mongolia Autonomous Region, China
| | - Yongliang Zhang
- Training Department, Logistics University of Chinese People's Armed Police Force, Tianjin Key Laboratory for Biomarkers of Occupational and Environmental Hazard, Tianjin, China
| |
Collapse
|
9
|
Tohme S, Delhumeau C, Zuercher M, Haller G, Walder B. Prehospital risk factors of mortality and impaired consciousness after severe traumatic brain injury: an epidemiological study. Scand J Trauma Resusc Emerg Med 2014; 22:1. [PMID: 24393519 PMCID: PMC3892077 DOI: 10.1186/1757-7241-22-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/28/2013] [Indexed: 12/03/2022] Open
Abstract
Background Severe traumatic brain injury (TBI) is a significant health concern and a major burden for society. The period between trauma event and hospital admission in an emergency department (ED) could be a determinant for secondary brain injury and early survival. The aim was to investigate the relationship between prehospital factors associated with secondary brain injury (arterial hypotension, hypoxemia, hypothermia) and the outcomes of mortality and impaired consciousness of survivors at 14 days. Methods A multicenter, prospective cohort study was performed in dedicated trauma centres of Switzerland. Adults with severe TBI (Abbreviated Injury Scale score of head region (HAIS) >3) were included. Main outcome measures were death and impaired consciousness (Glasgow Coma Scale (GCS) ≤13) at 14 days. The associations between risk factors and outcome were assessed with univariate and multivariate regression models. Results 589 patients were included, median age was 55 years (IQR 33, 70). The median GCS in ED was 4 (IQR 3-14), with abnormal pupil reaction in 167 patients (29.2%). Median ISS was 25 (IQR 21, 34). Three hundred seven patients sustained their TBI from falls (52.1%) and 190 from a road traffic accidents (32.3%). Median time from Out-of-hospital Emergency Medical Service (OHEMS) departure on scene to arrival in ED was 50 minutes (IQR 37-72); 451 patients had a direct admission (76.6%). Prehospital hypotension was observed in 24 (4.1%) patients, hypoxemia in 73 (12.6%) patients and hypothermia in 146 (24.8%). Prehospital hypotension and hypothermia (apart of age and trauma severity) was associated with mortality. Prehospital hypoxemia (apart of trauma severity) was associated with impaired consciousness; indirect admission was a protective factor. Conclusion Mortality and impaired consciousness at 14 days do not have the same prehospital risk factors; prehospital hypotension and hypothermia is associated with mortality, and prehospital hypoxemia with impaired consciousness.
Collapse
Affiliation(s)
| | | | | | | | - Bernhard Walder
- Division of Anaesthesiology, University Hospitals of Geneva, Geneva, Switzerland.
| |
Collapse
|
10
|
Najafipour H, Siahposht Khachaki A, Khaksari M, Shahouzehi B, Joukar S, Poursalehi HR. Traumatic brain injury has not prominent effects on cardiopulmonary indices of rat after 24 hours: hemodynamic, histopathology, and biochemical evidence. IRANIAN BIOMEDICAL JOURNAL 2014; 18:225-31. [PMID: 25326021 PMCID: PMC4225062 DOI: 10.6091/ibj.13222.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 03/09/2014] [Accepted: 03/11/2014] [Indexed: 11/23/2022]
Abstract
BACKGROUND Accidents are the second reason for mortality and morbidity in Iran. Among them, brain injuries are the most important damage. Clarification of the effects of brain injuries on different body systems will help physicians to prioritize their treatment strategies. In this study, the effect of pure brain trauma on the cardiovascular system and lungs 24 hours post trauma was assessed. METHODS Male Wistar rats (n = 32) were divided into sham control and traumatic brain injury (TBI) groups. In TBI animals, under deep anesthesia, a blow to the head was induced by the fall of a 450 g weight from 2 m height. Twenty four hours later, heart electrocardiogram and functional indices, cardiac troponin I, IL-6, TNF-, IL-I in tissue and serum, and the histopathology of heart and lung were assessed. RESULTS The results showed that none of the functional, biochemical, inflammatory, and histopathology indices was statistically different between the two groups at 24 hours post TBI. Indices of impulse conduction velocity in atrium (P wave duration and P-R interval) were significantly longer in the TBI group. CONCLUSION Overall, no important functional and histopathologic disturbances were found in heart and lung of TBI group after 24 hours. If the data is reproduced in human studies, the medical team could allocate their priority to treatment of brain disorders of the victim in the first 24 hours of pure TBI and postpone extensive assessment of heart and lung health indices to later time, thus reducing patient and health system expenditures.
Collapse
Affiliation(s)
- Hamid Najafipour
- Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran;
| | | | - Mohammad Khaksari
- Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran;
| | - Beydolah Shahouzehi
- Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran;
| | - Siyavash Joukar
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Hamid Reza Poursalehi
- Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran;
| |
Collapse
|
11
|
Intranasal delivery of nerve growth factor attenuates aquaporins-4-induced edema following traumatic brain injury in rats. Brain Res 2013. [DOI: 10.1016/j.brainres.2012.11.028] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
12
|
Effects of selective and non-selective cyclooxygenase inhibition against neurological deficit and brain oedema following closed head injury in mice. Brain Res 2013; 1491:78-87. [DOI: 10.1016/j.brainres.2012.10.049] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 11/23/2022]
|
13
|
Quantitative immunohistochemical analysis of human brain basic fibroblast growth factor, glial fibrillary acidic protein and single-stranded DNA expressions following traumatic brain injury. Forensic Sci Int 2012; 221:142-51. [DOI: 10.1016/j.forsciint.2012.04.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 02/29/2012] [Accepted: 04/25/2012] [Indexed: 11/22/2022]
|
14
|
Thal SC, Heinemann M, Luh C, Pieter D, Werner C, Engelhard K. Pioglitazone reduces secondary brain damage after experimental brain trauma by PPAR-γ-independent mechanisms. J Neurotrauma 2012; 28:983-93. [PMID: 21501066 DOI: 10.1089/neu.2010.1685] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inflammatory and ischemic processes contribute to the development of secondary brain damage after mechanical brain injury. Recent data suggest that thiazolidinediones (TZDs), a class of drugs approved for the treatment of non-insulin-dependent diabetes mellitus, effectively reduces inflammation and brain lesion by stimulation of the peroxisome proliferator-activated receptor-γ (PPAR-γ). The present study investigates the influence of the TZD pioglitazone and rosiglitazone on inflammation and secondary brain damage after experimental traumatic brain injury (TBI). A controlled cortical impact (CCI) injury was induced in male C57BL/6 mice to investigate following endpoints: (1) mRNA expression of PPAR-γ and PPAR-γ target genes (LPL, GLT1, and IRAP/Lnpep), and inflammatory markers (TNF-α, IL-1β, IL-6, and iNOS), at 15 min, 3 h, 6 h, 12 h, and 24 h post-trauma; (2) contusion volume, neurological function, and gene expression after 24 h in mice treated with pioglitazone (0.5 and 1 mg/kg) or rosiglitazone (5 and 10 mg/kg IP at 30 min post-trauma); and (3) the role of PPAR-γ to mediate protection was determined in animals treated with pioglitazone, the PPAR-γ inhibitor T0070907, and a combination of both. Inflammatory marker genes, but not PPAR-γ gene expression, was upregulated after trauma. Pioglitazone reduced the histological damage and inflammation in a dose-dependent fashion. In contrast, rosiglitazone failed to suppress inflammation and histological damage. PPAR-γ and PPAR-γ target gene expression was not induced by pioglitazone and rosiglitazone. In line with these results, pioglitazone-mediated protection was not reversed by T0070907. The results indicate that the neuroprotective effects of pioglitazone are not solely related to PPAR-γ-dependent mechanisms.
Collapse
Affiliation(s)
- Serge C Thal
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Mainz, Germany.
| | | | | | | | | | | |
Collapse
|
15
|
Kenne E, Erlandsson A, Lindbom L, Hillered L, Clausen F. Neutrophil depletion reduces edema formation and tissue loss following traumatic brain injury in mice. J Neuroinflammation 2012; 9:17. [PMID: 22269349 PMCID: PMC3292978 DOI: 10.1186/1742-2094-9-17] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 01/23/2012] [Indexed: 12/24/2022] Open
Abstract
Background Brain edema as a result of secondary injury following traumatic brain injury (TBI) is a major clinical concern. Neutrophils are known to cause increased vascular permeability leading to edema formation in peripheral tissue, but their role in the pathology following TBI remains unclear. Methods In this study we used controlled cortical impact (CCI) as a model for TBI and investigated the role of neutrophils in the response to injury. The outcome of mice that were depleted of neutrophils using an anti-Gr-1 antibody was compared to that in mice with intact neutrophil count. The effect of neutrophil depletion on blood-brain barrier function was assessed by Evan's blue dye extravasation, and analysis of brain water content was used as a measurement of brain edema formation (24 and 48 hours after CCI). Lesion volume was measured 7 and 14 days after CCI. Immunohistochemistry was used to assess cell death, using a marker for cleaved caspase-3 at 24 hours after injury, and microglial/macrophage activation 7 days after CCI. Data were analyzed using Mann-Whitney test for non-parametric data. Results Neutrophil depletion did not significantly affect Evan's blue extravasation at any time-point after CCI. However, neutrophil-depleted mice exhibited a decreased water content both at 24 and 48 hours after CCI indicating reduced edema formation. Furthermore, brain tissue loss was attenuated in neutropenic mice at 7 and 14 days after injury. Additionally, these mice had a significantly reduced number of activated microglia/macrophages 7 days after CCI, and of cleaved caspase-3 positive cells 24 h after injury. Conclusion Our results suggest that neutrophils are involved in the edema formation, but not the extravasation of large proteins, as well as contributing to cell death and tissue loss following TBI in mice.
Collapse
Affiliation(s)
- Ellinor Kenne
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | | | | | | |
Collapse
|
16
|
Protective effect of tert-butylhydroquinone on cerebral inflammatory response following traumatic brain injury in mice. Injury 2011; 42:714-8. [PMID: 21466884 DOI: 10.1016/j.injury.2011.03.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 02/21/2011] [Accepted: 03/07/2011] [Indexed: 02/02/2023]
Abstract
AIM Antioxidant transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) has been shown in our previous studies to play a crucial role in protection against TBI induced inflammatory response in the brain. The objective of this study was to test whether tert-butylhydroquinone (tBHQ), a novel Nrf2 activator, can protect mice brain against TBI-induced inflammatory damage. METHODS Adult male ICR mice were randomly divided into three groups: (1) sham+vehicle group; (2) TBI+vehicle group; and (3) TBI+tBHQ group (n=12 per group). Closed head injury was adopted using Hall's weight-dropping method. We measured Nrf2 and nuclear factor kappa B (NF-κB) binding activities by electrophoretic mobility shift assay (EMSA), concentrations of tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) by enzyme-linked immunosorbent assay (ELISA), brain oedema by wet/dry weight method, and cortical apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) analysis. RESULTS Induction of the Nrf2 activity by tBHQ markedly decreased NF-κB activation and inflammatory cytokine production in the injured brain. Administration of tBHQ also significantly attenuated TBI-induced brain oedema and cortical apoptosis. CONCLUSION Pre-treatment with tBHQ could attenuate the cerebral inflammatory response after TBI.
Collapse
|
17
|
Zheng PP, Romme E, van der Spek PJ, Dirven CMF, Willemsen R, Kros JM. Glut1/SLC2A1 is crucial for the development of the blood-brain barrier in vivo. Ann Neurol 2011; 68:835-44. [PMID: 21194153 DOI: 10.1002/ana.22318] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVE The overall permeability of the blood-brain barrier (BBB) is regulated by specialized cerebral endothelial cells and their junctional complexes, consisting of adherens junctions (AJs) and tight junctions (TJs). Among the members of the glucose transporters (Glut), Glut1 is a unique molecule expressed in the cerebral endothelial cells. Glut1 and the junctional proteins are concomitantly downregulated in situations in which breakdown of the BBB has taken place. We hypothesized that the expression of Glut1 may play a significant role in the development of the cerebral microvasculature with BBB properties. To date, there is no information on the role of Glut1 during the development of BBB. In the present study, the in vivo effects of Glut1 knockdown on the cerebral vascular development were investigated. METHODS Zebrafish was used as a model organism. We confirmed that the structure of the zebrafish homologue of Glut1 is highly similar to the human Glut1 and that the function of the Glut1-mediated cerebral uptake of glucose is evolutionally conserved. RESULTS In the Glut1 knockdown model, we observed loss of the cerebral endothelial cells, with concomitant downregulation of the junctional proteins important for intactness of the AJs/TJs and impaired cerebral circulation. The resulting leaky BBB caused vasogenic brain edema. INTERPRETATION The data suggest a crucial role of Glut1 in the development of the cerebral endothelial cells with BBB properties in vivo. The findings suggest that modulation of Glut1 expression and function may open new directions of research for therapeutic strategies to prevent vasogenic brain edema.
Collapse
Affiliation(s)
- Ping-Pin Zheng
- Department of Pathology, Erasmus Medical Center, Rotterdam, the Netherlands
| | | | | | | | | | | |
Collapse
|
18
|
Comparison Evans Blue injection routes: Intravenous versus intraperitoneal, for measurement of blood-brain barrier in a mice hemorrhage model. J Neurosci Methods 2010; 195:206-10. [PMID: 21168441 DOI: 10.1016/j.jneumeth.2010.12.013] [Citation(s) in RCA: 179] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 12/08/2010] [Accepted: 12/09/2010] [Indexed: 01/24/2023]
Abstract
AIMS Intracerebral hemorrhage is one of the most devastating subtypes of stroke, leaving survivors with severe neurological deficits. Disruption of the blood brain barrier (BBB) following hemorrhage results in the development of vasogenic brain edema, a most life-threatening event after such events as intracerebral hemorrhage (ICH). The Evans Blue assay is a popular method for the quantification of BBB disruption. Although this method is in common use, there are several protocols of the assay in the literature which vary in the route of administration, as well as the circulation time of the stain. In this study, we compared the amounts of accumulated stain in brain tissue following intraperitoneal versus intravenous injection at 0.5, 3 and 24h of circulation time. METHODS 58 CD-1 mice were used. Animals were divided into ICH (N=42), sham groups (N=6) and naïve (N=10). ICH animals received stereotactic injection of collagenase type VII into the right basal ganglia. Sham animals received only needle trauma. Evans Blue stain was injected 24h after collagenase injection or needle trauma. The consistency of ICH produced was characterized by estimation of hematoma volume via hemoglobin assay and neurological evaluation. RESULTS The produced hematoma and neurological deficits were well comparable between different experimental groups. There was no statistically significant difference in the results of the Evans Blue assay with regard to administration route. CONCLUSIONS The amount of Evans Blue stain accumulated in the brains of mice after ICH produced by collagenase injection was independent of the stain administration route.
Collapse
|
19
|
Homsi S, Piaggio T, Croci N, Noble F, Plotkine M, Marchand-Leroux C, Jafarian-Tehrani M. Blockade of Acute Microglial Activation by Minocycline Promotes Neuroprotection and Reduces Locomotor Hyperactivity after Closed Head Injury in Mice: A Twelve-Week Follow-Up Study. J Neurotrauma 2010; 27:911-21. [DOI: 10.1089/neu.2009.1223] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Shadi Homsi
- Laboratoire de Pharmacologie de la Circulation Cérébrale (EA 2510), Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Tomaso Piaggio
- Laboratoire de Pharmacologie de la Circulation Cérébrale (EA 2510), Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Nicole Croci
- Laboratoire de Pharmacologie de la Circulation Cérébrale (EA 2510), Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Florence Noble
- Laboratoire de Neuropsychopharmacologie des addictions (INSERM U705, CNRS UMR 7157), Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Michel Plotkine
- Laboratoire de Pharmacologie de la Circulation Cérébrale (EA 2510), Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Catherine Marchand-Leroux
- Laboratoire de Pharmacologie de la Circulation Cérébrale (EA 2510), Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Mehrnaz Jafarian-Tehrani
- Laboratoire de Pharmacologie de la Circulation Cérébrale (EA 2510), Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| |
Collapse
|
20
|
Homsi S, Federico F, Croci N, Palmier B, Plotkine M, Marchand-Leroux C, Jafarian-Tehrani M. Minocycline effects on cerebral edema: relations with inflammatory and oxidative stress markers following traumatic brain injury in mice. Brain Res 2009; 1291:122-32. [PMID: 19631631 DOI: 10.1016/j.brainres.2009.07.031] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 07/10/2009] [Accepted: 07/14/2009] [Indexed: 01/27/2023]
Abstract
One of the severe complications following traumatic brain injury (TBI) is cerebral edema and its effective treatment is of great interest to prevent further brain damage. This study investigated the effects of minocycline, known for its anti-inflammatory properties, on cerebral edema and its respective inflammatory markers by comparing different dose regimens, on oxidative stress and on neurological dysfunction following TBI. The weight drop model was used to induce TBI in mice. The brain water content was measured to evaluate cerebral edema. Inflammatory markers were detected by ELISA (IL-1beta), zymography and Western blot (MMP-9). The oxidative stress marker (glutathione levels) and neurological function were measured by Griffith technique and string test, respectively. Minocycline was administered i.p. once (5 min), twice (5 min and 3 h) or triple (5 min, 3 h and 9 h) following TBI. The first dose of minocycline only varied (45 or 90 mg/kg), whereas the following doses were all at 45 mg/kg. The single and double administrations of minocycline reduced the increase of inflammatory markers at 6 h post-TBI. Minocycline also reduced cerebral edema at this time point, only after double administration and at the high dose regimen, although with no effect on the TBI-induced oxidized glutathione increase. The anti-edematous effect of minocycline persisted up to 24 h, upon a triple administration, and accompanied by a neurological recovery. In conclusion, we reported an anti-edematous effect of minocycline after TBI in mice according to a specific treatment regimen. These findings emphasize that the beneficial effects of minocycline depend on the treatment regimen following a brain injury.
Collapse
Affiliation(s)
- Shadi Homsi
- Laboratoire de Pharmacologie de la Circulation Cérébrale (EA 2510), Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, 4, avenue de l'Observatoire, 75006 Paris, France
| | | | | | | | | | | | | |
Collapse
|
21
|
Rhinn H, Marchand-Leroux C, Croci N, Plotkine M, Scherman D, Escriou V. Housekeeping while brain's storming Validation of normalizing factors for gene expression studies in a murine model of traumatic brain injury. BMC Mol Biol 2008; 9:62. [PMID: 18611280 PMCID: PMC2500043 DOI: 10.1186/1471-2199-9-62] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 07/08/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Traumatic brain injury models are widely studied, especially through gene expression, either to further understand implied biological mechanisms or to assess the efficiency of potential therapies. A large number of biological pathways are affected in brain trauma models, whose elucidation might greatly benefit from transcriptomic studies. However the suitability of reference genes needed for quantitative RT-PCR experiments is missing for these models. RESULTS We have compared five potential reference genes as well as total cDNA level monitored using Oligreen reagent in order to determine the best normalizing factors for quantitative RT-PCR expression studies in the early phase (0-48 h post-trauma (PT)) of a murine model of diffuse brain injury. The levels of 18S rRNA, and of transcripts of beta-actin, glyceraldehyde-3P-dehydrogenase (GAPDH), beta-microtubulin and S100beta were determined in the injured brain region of traumatized mice sacrificed at 30 min, 3 h, 6 h, 12 h, 24 h and 48 h post-trauma. The stability of the reference genes candidates and of total cDNA was evaluated by three different methods, leading to the following rankings as normalization factors, from the most suitable to the less: by using geNorm VBA applet, we obtained the following sequence: cDNA(Oligreen); GAPDH > 18S rRNA > S100beta > beta-microtubulin > beta-actin; by using NormFinder Excel Spreadsheet, we obtained the following sequence: GAPDH > cDNA(Oligreen) > S100beta > 18S rRNA > beta-actin > beta-microtubulin; by using a Confidence-Interval calculation, we obtained the following sequence: cDNA(Oligreen) > 18S rRNA; GAPDH > S100beta > beta-microtubulin > beta-actin. CONCLUSION This work suggests that Oligreen cDNA measurements, 18S rRNA and GAPDH or a combination of them may be used to efficiently normalize qRT-PCR gene expression in mouse brain trauma injury, and that beta-actin and beta-microtubulin should be avoided. The potential of total cDNA as measured by Oligreen as a first-intention normalizing factor with a broad field of applications is highlighted. Pros and cons of the three methods of normalization factors selection are discussed. A generic time- and cost-effective procedure for normalization factor validation is proposed.
Collapse
|
22
|
Ongali B, Hellal F, Rodi D, Plotkine M, Marchand-Verrecchia C, Pruneau D, Couture R. Autoradiographic Analysis of Mouse Brain Kinin B1 and B2 Receptors after Closed Head Trauma and Ability of Anatibant Mesylate to Cross the Blood–Brain Barrier. J Neurotrauma 2006; 23:696-707. [PMID: 16689671 DOI: 10.1089/neu.2006.23.696] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The potent non-peptide B2 receptor (R) antagonist, Anatibant mesylate (Ms) (LF 16-0687 Ms), reduces brain edema and improves neurological function recovery in various focal and diffuse models of traumatic brain injury in rodents. In the present study, alteration of kinin B1 and B2R after closed head trauma (CHT) and in vivo binding properties of Anatibant Ms (3 mg/kg, s.c.) injected 30 min after CHT were studied in mice by autoradiography using the radioligands [125I]HPP-Hoe 140 (B2R), and [125I]HPP-des-Arg10-Hoe 140 (B1R). Whereas B1R is barely detected in most brain regions, B2R is extensively distributed, displaying the highest densities in the hindbrain. CHT was associated with a slight increase of B1R and a decrease of B2R (10-50%) in several brain regions. Anatibant Ms (Ki = 22 pM) displaced the B2R radioligand from its binding sites in several areas of the forebrain, basal ganglia and hindbrain. Displacement was achieved in 1 h and persisted at 4 h post-injection. The inhibition did not exceed 50% of the total specific binding in non-injured mice. After CHT, the displacement by Anatibant Ms was higher and almost complete in the cortex, caudate putamen, thalamus, hippocampus, medial geniculate nucleus, ventral tegmental area, and raphe. Evans blue extravasation in brain tissue at 4 h after CHT was abolished by Anatibant Ms. It appeared that Anatibant Ms penetrated into the brain in sufficient amounts, particularly after disruption of the blood-brain barrier, to account for its B2R-mediated neuro- and vascular protective effects. The diminished binding of B2R after CHT may reflect the occupancy or internalization of B2R following the endogenous production of bradykinin (BK).
Collapse
Affiliation(s)
- Brice Ongali
- Département de Physiologie, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | | | | | | | | | | | | |
Collapse
|