SPECIFIC RENAL FUNCTIONS IN HYPERTHYROIDISM AND MYXEDEMA

Abstract

Observations of specific renal functions in 2 patients suffering from hyperthyroidism, 1 treated by subtotal thyroidectomy, and the other with thiouracil, indicate that this condition is not associated with a significant renal vasodilation or with an increase in tubular secretory capacity for diodrast which is proportionate to the elevation of the basal metabolic rate. Observations in 2 patients suffering from myxedema and treated with desiccated thyroid demonstrate before treatment reductions of renal blood flow, glomerular filtration and tubular secretory capacity. Treatment results in restoration of these functions towards normal. The changes thus induced in renal blood flow and glomerular filtration rate reflect a decrease in afferent vascular resistance. The depression of tubular secretory capacity in myxedema is excessive in relation to the reduction of basal metabolic rate in this condition and to the changes observed in this function during hyperthyroidism. It is suggested that the renal functional depression present in myxedema is in part a reflection of depression of anterior hypophyseal function rather than a direct renal lack of thyroidal hormone.