Action of Thyroxin on Tissue Metabolism.

Magnus-Levy 1 showed that the thyroid gland increased metabolism. The manner in which this effect is brought about is still a matter for discussion. 2 , 3 Adler 4 stated that thyroid action persisted after ergotamine and concluded a peripheral action. However, Abderhalden and Wertheimer 5 found that ergotamine inhibited the effect of a previous thyroid injection. The great amount of work done on the direct effect of thyroxin on tissue metabolism has served to complicate rather than to clarify matters. Fleischmann, 6 Rothschild, 7 Simon, 8 Paasch and Reinwein, 9 Anselmino, 10 Ellinger, 11 obtain negative results with the thyroid principle, while Wohlgemuth and Klopstock, 12 Weil, 13 and Ahlgren 14 find an increase in metabolism.

The method used in this work consists in placing (alligator) blood (6 to 10 cc.) in duplicate tonometers containing air under alveolar tensions (CO₂ 3%, O₂ 17%, in the alligator) and measuring by direct analysis of the pair, the O₂ and CO₂ contents at the beginning and end of a test period, maintaining the tonometers in a constant temperature bath. The gas phase was analyzed by the Haldane apparatus, the liquid phase by the Van Slyke manometric method of blood gas analysis. Calculating the volumes of oxygen consumed and carbon dioxide liberated, under standard conditions of temperature and pressure, allows the expression of the metabolism of the blood in terms of small calories∗ per hour per 1000 cc. of blood (with 500,000 red cells per cu. mm.).