Autologous Red Blood Cell Reinfusion: Effects on Stress and Fluid Regulatory Hormones during Exercise-Heat Stress,
Abstract
This study assessed the effects of induced erythrocythemia on stress and fluid regulatory hormones during exercise in the heat. Six unacclimated male subjects received approximately 600 ml of a sterile saline solution containing 50% v/v of autologous erythrocytes. Three heat stress tests (HST's) were attempted: one approximately 2 weeks prior to the reinfusion procedure, a second 48 h after the reinfusion procedure, and a third 1 wk later corresponding to 9 d subsequent to reinfusion. Each HST comprised three consecutive exercise and rest intervals of 45/15 min, respectively (VO2 approx. 2.0 L/min, 1.56 m/s, 6% incline, 35 C, 45% rh). Blood was withdrawn before the HST and 30 min into each exercise (EX) bout. In all 3 HST's plasma cortisol (PC) levels were significantly (p<.01) reduced during the first exercise bout when compared to pre-exercise levels, and then progressively increased during the second and third exercise intervals during HST 1. During HST 2 (48h post-infusion), however, PC levels were same blood samples from HST-1 (pre-infusion). Plasma renin activity (PRA) and aldosterone (ALD) were significantly (p<.01) increased by the exercise/heat stress, but were unaffected by erythrocythemia either 48 h or 9 d subsequent to reinfusion. PRA and ALD were correlated (r=0.84, p<.001) under all conditions. We concluded from this study that acutely induced erythropcythemia reduced the stress response to consecutive exercise/heat intervals as manifested in PC responses during HST 2.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1986
- Accession Number
- ADA172545
Entities
People
- Aaron J. Young
- Michael N. Sawka
- R. C. Dennis
- R. R. Gonzalez
- Ralph P. Francesconi
Organizations
- United States Army Research Institute of Environmental Medicine