Adrenocortical Activity and Metabolism of 17-Hydroxycorticosteroids in Thyroidectomized Dogs

¹ From the Departments of Biological Chemistry and Anatomy, University of Utah College of Medicine, Salt Lake City, Utah

Low or zero levels of plasma 17-hydroxycorticosteroids and a reduced adrenocortical capacity were found in dogs at the 7th day following thyroidectomy. The daily administration of l-thyroxine to thyroidectomized dogs restored normal adrenocortical function. Low but measurable levels of plasma 17-hydroxycorticosteroids were present in dogs 30 days after thyroidectomy, whereas an apparent normal removal rate of intravenously given cortisol (compound F), was present both at the 7th and at the 30th day after thyroidectomy. Since sham operations or other ‘stress’ forms were not associated with reduced adrenocortical function either on the 7th or on the 30th day post ‘stress,’ a thyroid-adrenal metabolic interaction is postulated.