Post-space flight orthostatic hypotension/intolerance occurs in 25 to 66 percent of crew members upon returning to a 1 G environment. The mechanism(s) causing this response are not completely understood. Identification of countermeasures to reduce the incidence of orthostatic intolerance associated with space flight is paramount to NASA's mission. One such countermeasure may be skin surface cooling. In light of this, three specific objectives will be accomplished by the proposal work: 1) Identify an optimal skin surface cooling paradigm that causes the largest increase in autonomic responses (i.e. stroke volume, blood pressure, sympathetic nerve activity, etc.) without causing shivering or altering motor function. 2) Identify the mechanisms by which skin surface cooling increases the aforementioned autonomic responses resulting in improved tolerance to orthostatic stress. 3) Identify whether skin surface cooling is an effective countermeasure to improve orthostatic tolerance in men and women following simulated microgravity exposure using the head-down tilt bed rest model. Upon completion of the proposed studies important information will be provided that will be beneficial for both operational and safety concerns for astronauts, as well as to individuals who suffer from idiopathic orthostatic intolerance.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL067422-03
Application #
6690032
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Program Officer
Velletri, Paul A
Project Start
2002-01-01
Project End
2005-12-31
Budget Start
2004-01-01
Budget End
2004-12-31
Support Year
3
Fiscal Year
2004
Total Cost
$263,000
Indirect Cost
Name
University of Texas Sw Medical Center Dallas
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
800771545
City
Dallas
State
TX
Country
United States
Zip Code
75390
Brothers, R M; Pecini, Redi; Dalsgaard, M et al. (2014) Beneficial effects of elevating cardiac preload on left-ventricular diastolic function and volume during heat stress: implications toward tolerance during a hemorrhagic insult. Am J Physiol Regul Integr Comp Physiol 307:R1036-41
Schlader, Zachary J; Seifert, Thomas; Wilson, Thad E et al. (2013) Acute volume expansion attenuates hyperthermia-induced reductions in cerebral perfusion during simulated hemorrhage. J Appl Physiol (1985) 114:1730-5
Wilson, Thad E; Crandall, Craig G (2011) Effect of thermal stress on cardiac function. Exerc Sport Sci Rev 39:12-7
Keller, David M; Low, David A; Davis, Scott L et al. (2011) Skin surface cooling improves orthostatic tolerance following prolonged head-down bed rest. J Appl Physiol (1985) 110:1592-7
Shibasaki, Manabu; Wilson, Thad E; Bundgaard-Nielsen, Morten et al. (2011) Modelflow underestimates cardiac output in heat-stressed individuals. Am J Physiol Regul Integr Comp Physiol 300:R486-91
Bundgaard-Nielsen, M; Wilson, T E; Seifert, T et al. (2010) Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans. J Physiol 588:3333-9
Wilson, T E; Brothers, R M; Tollund, C et al. (2009) Effect of thermal stress on Frank-Starling relations in humans. J Physiol 587:3383-92
Low, David A; Wingo, Jonathan E; Keller, David M et al. (2008) Cerebrovascular responsiveness to steady-state changes in end-tidal CO2 during passive heat stress. J Appl Physiol 104:976-81
Crandall, Craig G (2008) Heat stress and baroreflex regulation of blood pressure. Med Sci Sports Exerc 40:2063-70
Crandall, C G; Wilson, T E; Marving, J et al. (2008) Effects of passive heating on central blood volume and ventricular dimensions in humans. J Physiol 586:293-301

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