THE INFLUENCE OF THYROID HORMONE ON HYDROCORTISONE PRODUCTION AND METABOLISM*

Abstract

The metabolism of endogenously produced and exogenous tracer doses of labeled hydrocortisone was studied in euthyroid subjects, in spontaneous hyperthyroidism, in myxedema, and following administration of triiodothyronine. It was found that an elevated level of thyroid hormone caused pronounced alteration in the metabolism of hydrocortisone toward 11-ketonic metabolites, together with an absolute increase in the endogenous production of the adrenal hormone. In hypothyroidism the converse of these effects was found, in that the metabolism of hydrocortisone was shifted toward the production of 11-hydroxy metabolites together with a decreased formation of hydrocortisone from endogenous sources. A mechanism is suggested for these changes in the production and metabolism of hydrocortisone.