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Marques SM, Naves LM, Silva TDME, Cavalcante KVN, Alves JM, Ferreira-Neto ML, de Castro CH, Freiria-Oliveira AH, Fajemiroye JO, Gomes RM, Colombari E, Xavier CH, Pedrino GR. Medullary Noradrenergic Neurons Mediate Hemodynamic Responses to Osmotic and Volume Challenges. Front Physiol 2021; 12:649535. [PMID: 33967822 PMCID: PMC8103169 DOI: 10.3389/fphys.2021.649535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/04/2021] [Indexed: 11/16/2022] Open
Abstract
Despite being involved in homeostatic control and hydro-electrolyte balance, the contribution of medullary (A1 and A2) noradrenergic neurons to the hypertonic saline infusion (HSI)-induced cardiovascular response after hypotensive hemorrhage (HH) remains to be clarified. Hence, the present study sought to determine the role of noradrenergic neurons in HSI-induced hemodynamic recovery in male Wistar rats (290–320 g) with HH. Medullary catecholaminergic neurons were lesioned by nanoinjection of antidopamine-β-hydroxylase–saporin (0.105 ng·nl−1) into A1, A2, or both (LES A1; LES A2; or LES A1+A2, respectively). Sham rats received nanoinjections of free saporin in the same regions (SHAM A1; SHAM A2; or SHAM A1+A2, respectively). After 15 days, rats were anesthetized and instrumented for cardiovascular recordings. Following 10 min of stabilization, HH was performed by withdrawing arterial blood until mean arterial pressure (MAP) reaches 60 mmHg. Subsequently, HSI was performed (NaCl 3 M; 1.8 ml·kg−1, i.v.). The HH procedure caused hypotension and bradycardia and reduced renal, aortic, and hind limb blood flows (RBF, ABF, and HBF). The HSI restored MAP, heart rate (HR), and RBF to baseline values in the SHAM, LES A1, and LES A2 groups. However, concomitant A1 and A2 lesions impaired this recovery, as demonstrated by the abolishment of MAP, RBF, and ABF responses. Although lesioning of only a group of neurons (A1 or A2) was unable to prevent HSI-induced recovery of cardiovascular parameters after hemorrhage, lesions of both A1 and A2 made this response unfeasible. These findings show that together the A1 and A2 neurons are essential to HSI-induced cardiovascular recovery in hypovolemia. By implication, simultaneous A1 and A2 dysfunctions could impair the efficacy of HSI-induced recovery during hemorrhage.
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Affiliation(s)
- Stefanne Madalena Marques
- Department of Physiology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil
| | - Lara Marques Naves
- Department of Physiology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil
| | - Talita de Melo E Silva
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | | | - Juliana Milan Alves
- Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Brazil
| | - Marcos Luiz Ferreira-Neto
- Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Brazil
| | - Carlos Henrique de Castro
- Department of Physiology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil
| | | | | | - Rodrigo Mello Gomes
- Department of Physiology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, Brazil
| | - Carlos Henrique Xavier
- Department of Physiology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil
| | - Gustavo Rodrigues Pedrino
- Department of Physiology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil
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McKinley MJ, Pennington GL, Ryan PJ. The median preoptic nucleus: A major regulator of fluid, temperature, sleep, and cardiovascular homeostasis. Handb Clin Neurol 2021; 179:435-454. [PMID: 34225980 DOI: 10.1016/b978-0-12-819975-6.00028-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Located in the midline lamina terminalis of the anterior wall of the third ventricle, the median preoptic nucleus is a thin elongated nucleus stretching around the rostral border of the anterior commissure. Its neuronal elements, composed of various types of excitatory glutamatergic and inhibitory GABAergic neurons, receive afferent neural signals from (1) neighboring subfornical organ and organum vasculosum of the lamina terminalis related to plasma osmolality and hormone concentrations, e.g., angiotensin II; (2) from peripheral sensors such as arterial baroreceptors and cutaneous thermosensors. Different sets of these MnPO glutamatergic and GABAergic neurons relay output signals to hypothalamic, midbrain, and medullary regions that drive homeostatic effector responses. Included in the effector responses are (1) thirst, antidiuretic hormone secretion and renal sodium excretion that subserve osmoregulation and body fluid homeostasis; (2) vasoconstriction or dilatation of skin blood vessels, and shivering and brown adipose tissue thermogenesis for core temperature homeostasis; (3) inhibition of hypothalamic and midbrain nuclei that stimulate wakefulness and arousal, thereby promoting both REM and non-REM sleep; and (4) activation of sympathetic pathways that drive vasoconstriction and heart rate to maintain arterial pressure and the perfusion of vital organs. The small size of MnPO belies its massive homeostatic significance.
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Affiliation(s)
- Michael J McKinley
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia; Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia.
| | - Glenn L Pennington
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Philip J Ryan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
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Mohebbati R, Hosseini M, Khazaei M, Shafei MN. Cardiovascular Effect of Cuneiform Nucleus During Hemorrhagic Hypotension. Basic Clin Neurosci 2020; 11:251-259. [PMID: 32963718 PMCID: PMC7502186 DOI: 10.32598/bcn.11.2.84.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/10/2018] [Accepted: 11/10/2019] [Indexed: 12/19/2022] Open
Abstract
Introduction: The underlying mechanism responsible for the cardiovascular response to Hemorrhage (HEM) is still unknown; however, several brain areas, such as the Cuneiform nucleus (CnF) have shown to be involved. In this study, the cardiovascular effect of the CnF during HEM was evaluated. Methods: The animals were divided into the following groups: 1. Vehicle; 2. HEM; 3. Cobalt chloride (CoCl2); 4. CoCl2+saline; and 5. CoCl2+HEM. Catheterization of the left and right femoral artery was performed to record blood pressure and blood withdrawal, respectively. Saline and CoCl2 were microinjected into the CnF nucleus, and then blood withdrawal was done for HEM induction. Cardiovascular regulation throughout the experiments was recorded and changes (Δ) in the Systolic Blood Pressure (SBP), Mean Arterial Pressure (MAP) and Heart Rate (HR) were calculated over time and compared with those treated with saline and HEM, using repeated-measures ANOVA. Results: HEM significantly reduced ΔSBP and ΔMAP and augmented ΔHR than the vehicle group. CoCl2 did not significantly affect basic ΔSBP, ΔMAP, and ΔHR compared with the vehicle group. However, injection of CoCl2 into the CnF before HEM (CoCl2+HEM group) significantly decreased ΔSBP, ΔMAP, and tachycardia, induced by HEM. Conclusion: Our results indicated that blockade of the CnF by CoCl2 significantly reduced the hypotension and tachycardia, induced by HEM indicating the involvement of CnF in cardiovascular regulation during HEM.
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Affiliation(s)
- Reza Mohebbati
- Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahmoud Hosseini
- Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Majid Khazaei
- Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Naser Shafei
- Neurogenic Inflammation Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran
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