Document Detail

Cardiac and peripheral vascular responses to head-up tilt during whole body thermal stress.
MedLine Citation:
PMID:  10862409     Owner:  NLM     Status:  MEDLINE    
During acute orthostatic stress, neurally mediated control of cardiac output (CO) and total peripheral vascular resistance (TPR) play an important role in the maintenance of systemic blood pressure. To examine the influence of thermal stress on the CO and TPR responses to orthostatic stress, 10 healthy male volunteers were exposed to normothermic control conditions followed by whole-body thermal stress produced by a cold or hot water-perfused suit during 5 min-70 degrees head-up tilt (HUT). HUT increased mean arterial pressure (MAP) by 3% of the pre-tilt value during normothermic control and cooling, whereas it decreased MAP by 4% of the pre-tilt value during heating. HUT decreased CO by 16-17% of the pre-tilt value under each thermal condition. The increase of TPR during HUT was exaggerated during cooling and inhibited during heating compared to normothermic control. Tilt-induced decrease of skin blood flow was greater during heating than cooling. These results suggest that the smaller increase of TPR rather than the CO change is responsible for the decreased MAP during acute orthostatic stress in hyperthermic humans. The contribution of skin vascular constriction to TPR changes during HUT is increased during heating and decreased during cooling.
F Yamazaki; K Monji; Y Sogabe; R Sone
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of UOEH     Volume:  22     ISSN:  0387-821X     ISO Abbreviation:  J. UOEH     Publication Date:  2000 Jun 
Date Detail:
Created Date:  2000-08-08     Completed Date:  2000-08-08     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  7909645     Medline TA:  J UOEH     Country:  JAPAN    
Other Details:
Languages:  eng     Pagination:  147-58     Citation Subset:  IM; S    
Department of Clinical Pathophysiology, School of Health Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
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MeSH Terms
Blood Pressure
Cardiac Output / physiology*
Hot Temperature*
Posture / physiology*
Regional Blood Flow
Skin / blood supply
Stress, Physiological
Vascular Resistance / physiology*

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

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