THE CURVES OF THYROXINE DECAY IN MYXEDEMA AND OF IODINE RESPONSE IN THYROTOXICOSIS: THEIR SIMILARITY AND ITS POSSIBLE SIGNIFICANCE

Abstract

The basal metabolic rate curve of thyroid hormone decay is shown to be closely similar to that of iodinization in spontaneous thyrotoxicosis in the following respects. Iodinization and subtotal thyroidectomy without iodinization cause similar metabolic responses. The composite iodine response curve of thyrotoxic persons forms a segment of the same curve as that traced by thyroxine decay in myxedematous persons. In a single person identical metabolic curves were produced by iodinization when the subject was spontaneously thyrotoxic and by withdrawal of thyroid when she was artificially thyrotoxic. On the basis of these facts the theory is advanced that iodine response in spontaneous thyrotoxicosis is in fact due to thyroxine decay; that the flooding of the system with iodine under such circumstances causes an interruption for a time of the delivery of new hormone from gland to body at large, and that hormone previously delivered decays at the same rate as in the thyroidless subject.