THE CALORIGENIC EFFICIENCY OF THYROID MATERIAL IN RELATION TO THYRQXINE AND TO IODINE CONTENT

Abstract

ALTHOUGH thyroxine possesses most, if not all, of the physiological effects on organisms, that are obtained with whole thyroid gland, the general}lmpression prevails that crude thyroid material, when administered orally, exerts an action that is not quantitatively in agreement with its thyroxine content and possibly even qualitatively of a more or less different character. Thyroxine content of glandular material of standard iodine content (U.S.P. 0.2÷ iodine) is subject to wide variations, and consequently no physiological uniformity can be expected unless one rejects the theory that the thyroxine is of any outstanding significance in thyroid action. In fact, Salter, Lerman and Means (I) claimed that clinically the total iodine rather than the thyroxine content of thyroid substance was the better index of its ability to relieve myxedema. JjEowever, since Thompson, et 1.