EFFECT OF THYROTROPIN ON ADRENOCORTICAL FUNCTION*

Abstract

THIS study is concerned with the effect of thryrotropin administration on adrenocortical function in the hypothyroid and in the euthyroid subject. As reported previously (1) evidences of decreased adrenocortical function are encountered not only in instances of hypothyroidism secondary to adenohypophysial disease but also in patients or experimental animals with primary thyroidal deficiency. In the former group the administration of desiccated thyroid may precipitate adrenocortical insufficiency. In the latter subjects, however, following therapy with desiccated thyroid, various indices of adrenocortical function reflect increased physiologic activity of the adrenal gland. The present study demonstrates the effect of thyroid stimulation on the urinary excretion of adrenal steroids in subjects with panhypopituitarism. These observations are contrasted with the results obtained following thyrotropin administration to the euthyroid subject and to the patient with primary hypothyroidism. MATERIAL AND METHODS The investigations were conducted on 2 subjects with euthyroidism, 3 with primary hypothyroidism, and 4 with hypothyroidism secondary to hypopituitarism. Following a control observation period, thyrotropin (TSH) was administered in a daily dosage of 25 to 50 mg. (10 to 20 international units) in one or two daily injections for periods of six to twentyone days. Serial measurements were made of the basal metabolic rate (BMR), the serum level of protein-bound iodine (SPI), the 24-hour urinary excretion of the neutral 17-ketosteroids and of the “formaldehydogenic” corticoids (“11-oxygenated steroids”) and the degree of exophthalmos. Serial skin biopsies were also performed and the findings in the latter study will form the subject of a separate report.