Steroid excretion by guinea pigs exposed to cold for prolonged periods

Abstract

Guinea pigs were exposed to cold at a temperature of 2°–4°C for a period of 92 days. With daily cabbage supplementation mortality was low although growth rate was impaired. Urinary corticoid excretion increased markedly being more than doubled initially and averaged approximately 1.8 times that of unexposed control animals. Ketosteroid excretion increased moderately initially but values did not differ appreciably for unexposed controls in subsequent periods. The ratio ketosteroids/corticoids remained remarkably constant throughout the period of exposure. Statistically significant negative correlations were observed between the increment in weight and increment in creatinine excretion with the average corticoid excretion values over a 2-month period whether the animals were maintained at room temperature or in the cold. Similar positive correlations were observed with the ratio ketosteroids/corticoids. Following return to room temperature steroid excretion values fell abruptly although the adrenals were markedly hypertrophic. The animals which had been cold exposed exhibited greater corticoid excretion values after a standard dose of ACTH than did unexposed controls.