Influence of acute erythrocythemia on temperature regulation during exercise-heat stress

Conference · Sat Mar 01 00:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5318804

Sawka, M N; Gonzalez, R R; Dennis, R C; Young, A J; Muza, S R; Martin, J W; Francesconi, R P; Pandolf, K B; Valeri, C R

We studied the effects of acute erythrocythemia on temperature regulation responses during exercise in the heat. In a double blind study, 6 subjects (Ss) received a 700-ml solution of autologous red blood cells at a 60% Hct, and 3 Ss (control) received a 700-ml saline solution. All Ss attempted a Heat Stress Test (HST) two weeks prior to and 48-h post-transfusion during summer months. After 30 min of rest in a 20/sup 0/C antechamber, the HST consisted of a 120-min exposure (two repeats of 15-min rest and 45-min treadmill walk) in a 35/sup 0/C, 45% rh environment while euhydrated. Maximal oxygen uptake (VO/sub 2/ max) and red cell volume (RCV, /sup 51/Cr) were measured approximately 24 h before each HST. For experimental Ss, an increase in RCV (11%, P < 0.01) and VO/sub 2/ max (11%, P < 0.05) was found following transfusion, whereas, differences were not observed in the control Ss. During the HSTs for experimental Ss, metabolic rate as well as steady state rectal and esophageal temperatures were similar, but heat storage tended (P = 0.13) to be lower post-transfusion. Steady state local arm (R + C) was reduced (P < 0.05) with no change in total body sweating rate or local arm evaporative heat loss post-transfusion. For control Ss, thermoregulatory responses were generally not altered post-transfusion. Erythrocythemia may improve steady state sensible heat exchange by allowing a greater volume of blood to be directed to the cutaneous vasculature.

• Research Organization: Boston Univ. School of Medicine, MA
• OSTI ID: 5318804
• Report Number(s): CONF-8604222-; TRN: 86-028520
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
HYPERTHERMIA
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BODY TEMPERATURE
CHROMIUM 51
ERYTHROCYTES
EXERCISE
OXYGEN
TRACER TECHNIQUES
TRANSFUSIONS
BETA DECAY RADIOISOTOPES
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ELEMENTS
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INTERMEDIATE MASS NUCLEI
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550901* - Pathology- Tracer Techniques