The Effect of Thyroxin Upon the Metabolism of Isolated Normal and Malignant Tissue

Abstract

In the course of an extended study of the influence of the internal secretions upon tissue metabolism, the thyroid influence seemed particularly significant. Here, therefore, is presented a detailed report of its effect not only upon a parasitic tumor tissue, but also upon the liver tissue of the host.The effect of the hormones upon tumor growth has been investigated extensively by others but the effect upon the metabolism of the tumor has received little or no attention. Several reports of the effect of thyroxin upon the metabolism of various normal isolated tissues have been made since 1924, but the results have been somewhat contradictory. Ahlgren (1) reported that thyroxin increased the metabolic rate of tissues of frogs in vitro as measured by acceleration of the reduction of methylene blue. In 1925 he reported that thyroxin increased the oxygen consumption of thyroid-deprived muscle, and pituitrin in proper concentration acted similarly. Reinwein and Singer (2) found an increase in the oxygen consumption of surviving liver cells after addition in vitro of thyroid extract but Paasch and Reinwein (3) found no effect upon the surviving diaphragm of the rat. Wohlgemuth and Klopstock (4) noted very striking increases in the oxygen consumption of skin with inhibition of anaerobic glycolysis after administration in vitro of thyroid. Hopping (5) reported increase in the metabolism of alligator blood of 150 to 190 per cent after injection of thyroxin but no effect from the direct addition of this substance to the blood.Fleischmann (6) found slight increase in the glycolysis of leukocytes in exudate of animals but unchanged respiration after administration in vitro of thyroxin. Anselmino, Eichler and Schlossmann (7) noted maximum effects of injected thyroxin upon isolated kidney tissues at the end of 72 hours. This effect was chiefly an increase in the anaerobic glycolysis. They discerned no significant increase in the oxygen consumption of liver or spleen and only slight increase in the oxygen consumption of kidney. The anaerobic glycolysis in the liver and spleen was not increased. Dresel (8), however, a year before, reported somewhat different results in isolated rat tissues after injection of thyroxin. He noted an increase in the oxygen consumption of liver as great as 200 per cent on the third day after the injection with slight decrease in the anaerobic glycolysis. The oxygen con-723