The proposal deals with the problem of reentry orthostatic intolerance that follows spaceflight. The main hypothesis is that microgravity induces a generalized reduction in the function of vascular smooth muscle and the innervating sympathetic and/or sensory nerve terminals. Also reviewed in this study are the characteristics of hindlimb unweighted (HU) rat model of microgravity. Since HU treatment has shown different effects on arterial and venous vasoconstrictor mechanisms, this suggests that HU treatment itself, and not some non-specific factors such as stress, was responsible for observed effects. Further studies will compare the effect of HU vs. control treatment in rat abdominal aorta and femoral vein and characterize mechanisms underlying the effects of HU on arterial and venous function.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31HL009725-03
Application #
2838873
Study Section
Special Emphasis Panel (ZRG2-PSF (04))
Project Start
1998-12-01
Project End
Budget Start
1998-12-01
Budget End
1999-11-30
Support Year
3
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Pharmacology
Type
Schools of Medicine
DUNS #
161202122
City
Irvine
State
CA
Country
United States
Zip Code
92697
Sangha, D S; Han, S; Purdy, R E (2001) Simulated microgravity upregulates an endothelial vasoconstrictor prostaglandin. J Appl Physiol 91:789-96
Sangha, D S; Vaziri, N D; Ding, Y et al. (2000) Vascular hyporesponsiveness in simulated microgravity: role of nitric oxide-dependent mechanisms. J Appl Physiol 88:507-17