Effect of an acute increase in central blood volume on cerebral hemodynamics
| Autor: | Jun Sugawara, Ai Hirasawa, Thomas Rebuffat, Shigehiko Ogoh, Hervé Normand, Peter B. Raven, Romain Lericollais, Pierre Denise |
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| Přispěvatelé: | Toyo University, University of North Texas Health Science Center [Fort Worth], Hôpital Côte de Nacre [CHU Caen], CHU Caen, Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN)-Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN), Université de Caen Normandie - UFR Santé (UNICAEN Santé), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU), Mobilités : Vieillissement, Pathologie, Santé (COMETE), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Caen Normandie (UNICAEN), Ibaraki University, Cognition, Mobilités, Temporalité (COMETE), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM) |
| Rok vydání: | 2015 |
| Předmět: |
Adult
Male Mean arterial pressure Physiology [SDV]Life Sciences [q-bio] [SHS.PSY]Humanities and Social Sciences/Psychology Hemodynamics Blood Pressure Pressoreceptors Blood volume 030204 cardiovascular system & hematology Cerebral autoregulation Young Adult 03 medical and health sciences 0302 clinical medicine Physiology (medical) medicine.artery medicine Animals Humans Cardiac Output Cerebrum ComputingMilieux_MISCELLANEOUS Arterial pulse pressure Blood Volume Weightlessness business.industry [SCCO.NEUR]Cognitive science/Neuroscience Blood pressure Cerebral blood flow Anesthesia Middle cerebral artery business 030217 neurology & neurosurgery circulatory and respiratory physiology |
| Zdroj: | AJP-Regulatory, Integrative and Comparative Physiology AJP-Regulatory, Integrative and Comparative Physiology, American Physiological Society, 2015, 309 (8), pp.R902-R911. ⟨10.1152/ajpregu.00137.2015⟩ |
| ISSN: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.00137.2015 |
| Popis: | Systemic blood distribution is an important factor involved in regulating cerebral blood flow (CBF). However, the effect of an acute change in central blood volume (CBV) on CBF regulation remains unclear. To address our question, we sought to examine the CBF and systemic hemodynamic responses to microgravity during parabolic flight. Twelve healthy subjects were seated upright and exposed to microgravity during parabolic flight. During the brief periods of microgravity, mean arterial pressure was decreased (−26 ± 1%, P < 0.001), despite an increase in cardiac output (+21 ± 6%, P < 0.001). During microgravity, central arterial pulse pressure and estimated carotid sinus pressure increased rapidly. In addition, this increase in central arterial pulse pressure was associated with an arterial baroreflex-mediated decrease in heart rate ( r = −0.888, P < 0.0001) and an increase in total vascular conductance ( r = 0.711, P < 0.001). The middle cerebral artery mean blood velocity (MCA Vmean) remained unchanged throughout parabolic flight ( P = 0.30). During microgravity the contribution of cardiac output to MCA Vmean was gradually reduced ( P < 0.05), and its contribution was negatively correlated with an increase in total vascular conductance ( r = −0.683, P < 0.0001). These findings suggest that the acute loading of the arterial and cardiopulmonary baroreceptors by increases in CBV during microgravity results in acute and marked systemic vasodilation. Furthermore, we conclude that this marked systemic vasodilation decreases the contribution of cardiac output to CBF. These findings suggest that the arterial and cardiopulmonary baroreflex-mediated peripheral vasodilation along with dynamic cerebral autoregulation counteracts a cerebral overperfusion, which otherwise would occur during acute increases in CBV. |
| Databáze: | OpenAIRE |
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