Physiological Control of Growth Hormone in the Rabbit

Abstract

All experiments utilized blood samples obtained bychronic right atrial catheters. Growth hormone measurements, made by specific radioimmunoassay, showed that fasting and estrogen ad-ministration result in increased growth hormone secretion in the rabbit, although physical stress and exposure to cold do not. Insulin-induced hypoglycemia after fasting caused a decline in plasma growth hormone, and arginine infusion in the estrogen-primed rabbit resulted in an initial depression of plasma growth hormone followed by a renewed secretory phase. Electrical stimulation in the vicinity of the ventromedial nucleus of the hypothalamus caused an abrupt rise in serum growth hormone.