Metabolic Effects of Thyroid Hormones and Cortisone in the Hypophysectomized Rat

Abstract

1. The hypophysectomized rat does not exhibit any especially prompt or extensive metabolic response to single doses of 3,5,3\m='\-triiodothyronine(T3) or 3,5,3\m='\-triiodothyroacetic acid.2. The hypophysectomized rat is less sensitive than the thyroidectomized one to oxygen consumption effects of thyroxine (T4) or T3 by repeated injection.3. In contrast, injection of cortisone produces two or three times as great a rise in the metabolic rate of hypophysectomized animals as in that of normal, thyroidectomized or adrenalectomized-thyroidectomized ones.4. In all animals, stimulation of oxygen consumption by cortisone plus T4 or cortisone plus T3 was the same as the simple additive action of each component.