Document Detail

Regional difference of blood flow in anesthetized rats during reduced gravity induced by parabolic flight.
MedLine Citation:
PMID:  16081624     Owner:  NLM     Status:  MEDLINE    
To examine a hypothesis that change in regional blood flow due to decreased hydrostatic pressure gradient and redistribution of blood during reduced gravity (rG) is different between organs, changes in cerebrocortical blood flow (CBF) and blood flow in the temporal muscle (MBF) with exposure to rG were measured in anesthetized rats in head-up tilt and flat positions during parabolic flight. Carotid arterial pressure (CAP), jugular venous pressure (JVP), and abdominal aortic pressure were also measured simultaneously. In the head-up tilt group, CBF increased by 15 +/- 3% within 3 s of entry into rG and rapidly recovered during rG. MBF also increased, but the change was significantly greater than that of CBF. JVP increased by 1.8 +/- 0.5 mmHg, probably due to loss of hydrostatic pressure gradient, since the measuring point of JVP was 2-3 cm above the hydrostatic indifference point. CAP and abdominal aortic pressure increased by 16.7 +/- 2 and 7.7 +/- 2 mmHg, respectively, compared with the 1-G condition. Muscle vascular resistance [(CAP-JVP)/MBF] decreased on entry into rG, but no significant change was observed in cerebrocortical vascular resistance [(CAP-JVP)/CBF]. In the flat group, no significant change was observed in all the variables. The results indicate that arteriolar vasodilatation occurs in the temporal muscle but not in the cerebral cortex. Thus the blood flow control mechanism at the onset of rG is different between intra- and extracranial organs.
Kunihiko Tanaka; Taro M Gotoh; Chihiro Awazu; Hironobu Morita
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2005-08-04
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  99     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2005 Dec 
Date Detail:
Created Date:  2005-11-18     Completed Date:  2006-01-05     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2144-8     Citation Subset:  IM    
Dept. of Physiology, Gifu University, Graduate School of Medicine, Gifu, Japan.
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MeSH Terms
Adaptation, Physiological / physiology
Blood Flow Velocity / physiology*
Cerebrovascular Circulation / physiology*
Rats, Sprague-Dawley
Regional Blood Flow / physiology*
Temporal Muscle / blood supply*,  physiology*
Weightlessness Simulation / methods*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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