THE ROLE OF GROWTH HORMONE IN CALORIGENESIS AND THYROID FUNCTION1

Experimental evidence is presented which demonstrates that growth hormone intensifiesthe characteristic action of thyrotrophin on calorigenesis in hypophysectomized rats, presumably through augmentation of thyroid function as measured by thyroid weight, morphology and I131 uptake.Growth hormone also magnifies the calorigenic action of thyroxine in hypophysectomized rats indicating that the enhancement of calorigenesis by growth hormone is partly peripheral. Excessive heat production in hypophysectomized rats resulting from the administration of high levels of either thyrotrophin or thyroxine with growth hormone is not compatible with life in the absence of adrenal glucocorticoids.