INFLUENCE OF CHRONIC HEAT EXPOSURE AND PROLONGED FOOD DEPRIVATION ON EXCRETION OF MAGNESIUM, PHOSPHORUS, CALCIUM, H+, AND KETONES.
Final rept., 1952-59,
SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX
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The study was concerned with the interplay of two stressors, chronic heat exposure and prolonged food deprivation. Laboratory rats were studied after 8 months residence in quarters in which air temperature remained at either 25 or 35C. Urinary and fecal determinations were made over a 6-day period, the first 3 days of which constituted the control prefast period and the last 3 days, the experimental fasting period. Chronic heat exposure had modifying influence on the fasting-induced changes in a body weight, b fecal constituents magnesium, phosphorus, and calcium, and c urinary functions volume, specific gravity, pH, titratable acid, ketones, magnesium, phosphorus, and calcium. Heat and fasting acted synergistically with respect to urinary ketone output and specific gravity and antagonistically with respect to urinary titratable acid. Heat augmented the fasting-induced changes in a urinary and fecal magnesium, b urinary and fecal phosphorus, and c fecal calcium. The fasting-induced change in urinary calcium was not modified by chronic heat exposure. These results suggest that the heat-fasting interplay may involve neuroendocrine mechanisms. Author
- Anatomy and Physiology
- Stress Physiology