Epinephrine Deficiency Potentiates Cortisol Elevation of Glucose Turnover in the Dog

Abstract

Daily injection of cortisol at 0.8–1.2 mg/kg restores to normal a number of abnormalities of carbohydrate metabolism exhibited by the adrenalectomized dog. The influence of this dosage regimen of cortisol on glucose turnover was studied in normal, adrenalectomized and hypophysectomized dogs. Rates of glucose turnover were determined in the postabsorptive state, using ¹⁴C-glucose. In the normal dog this amount of cortisol (and also doses up to 5.5 mg/kg per day) had no effect on glucose turnover. In the hypophysectomized dog, which has a markedly diminished glucose turnover rate, the replacement regimen of cortisol restored the turnover rate to normal. In the adrenalectomized dog, which exhibits no significant reduction in glucose turnover, the replacement regimen of cortisol elevated glucose turnover to 1½ times the normal rate. Adrenal demedullation of the dog also produced an elevation of glucose turnover to nearly 1½ times the normal rate; this increase in turnover was abolished by the removal of the remaining adrenal cortex. Epinephrine deficiency potentiates the effect of endogenous or administered glucocorticoids to increase glucose turnover in the dog. (Endocrinology93: 1336, 1973)