Accession Number : ADA189387

Title :   Plasma Cortisol, Renin and Aldosterone during an Intense Heat Acclimation Program,

Corporate Author : ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Personal Author(s) : Armstrong, Lawrence E ; Francesconi, Ralph P ; Kraemer, William J ; Leva, Natalie ; DeLuca, Jane P

PDF Url : ADA189387

Report Date : Sep 1987

Pagination or Media Count : 20

Abstract : The effects of an intense, intermittent heat acclimation (HA) regimen on stress and fluid balance hormones responses were examined in 13 unacclimated male volunteers. Venous blood samples were collected before (PRE) and after (POST) exercise and analyzed for plasma renin activity (PRA), aldosterone (ALD), cortisol (PC), plasma volume shifts (delta PV%), sodium (Na+) and potassium (K+). Subjects exhibited physiological adaptions typical of HA decreased heart rate, rectal temperature, skin temperature, and improved defense of PV. While plasma Na+ demonstrated no change during daily exercise, K+, PC, PRA, and ALD increased more than delta PV% accounted for. PRA and ALD did not change as a result of HA, but PRE vs POST PC responses were attenuated. The dissociation of PRA and ALD levels on day 4 of HA (POST) may be explained by differences in splanchnic clearance mechanisms. It was concluded that during an intense HA regimen, electrolyte and hormonal responses to exercise in the heat are modulated by the acquisition of acclimation. Keywords: Plasma volume, Rectal temperature, Heat rate, Skin temperature.

Descriptors :   *ACCLIMATIZATION, *ALDOSTERONE, *CORTISOL, *EXERCISE(PHYSIOLOGY), *RENIN, *HEAT STRESS(PHYSIOLOGY), BALANCE, BLOOD ANALYSIS, BLOOD PLASMA, BLOOD VOLUME, BODY TEMPERATURE, DAILY OCCURRENCE, DISSOCIATION, ELECTROLYTES, FLUIDS, HEART RATE, HEAT, HORMONES, INTENSITY, POTASSIUM, RATES, RECTUM, RESPONSE(BIOLOGY), SAMPLING, SHIFTING, SODIUM

Subject Categories : Stress Physiology
      Biochemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE