SOME EFFECTS OF PURIFIED PITUITARY GROWTH HORMONE ON CARBOHYDRATE METABOLISM IN THE RAT¹

Abstract

CRUDE pituitary extracts were shown in early work to prevent the hypoglycemic action of insulin, to produce hyperglycemia and glycosuria in dogs and cats when given in excess, to increase glycogen storage and lower the respiratory quotient in rats, and to promote ketogenesis and mobilization of fat to the liver in fasting animals. Later experiments indicated that a significant proportion of these effects on carbohydrate metabolism might be mediated through the action of the adrenocortical hormones. However, adrenalectomy did not eliminate the effects of pituitary extracts on muscle glycogen maintenance in hypophysectomized rats (Russell and Bennett, 1936; Bennett and Perkins, 1945), nor the ability of these extracts to antagonize the action of insulin in rabbits (Himsworth and Scott, 1938), nor the ketogenic activity of such extracts in rats (Shipley, 1940). Similarly, diabetogenic effects were seen in partially depancreatized dogs from which the adrenals had been removed (Houssay et al., 1946).