EFFECT OF DIURETICS ON RENAL IODIDE EXCRETION BY RATS AND DOGS

¹ Departments of Physiology and of Pharmacology and Therapeutics, University of Florida, College of Medicine, Gainesville, Florida

Diuretic studies were performed on rats and dogs after acute administration of hydrochlorothiazide, aminophylline, ethacrynic acid, methazolamide and benzolamide. All chioruretic agents studied increased the rate of urinary excretion of iodide. A significant correlation was noted between the logarithms of the rates of chloride and iodide excretion by rats and dogs both prior to and during drug administration. Apparently, drug administration does not alter tubular discrimination between these two anions. The carbonic anhydrase inhibitors, methazolamide and benzolamide, increased bicarbonate, but not chloride, excretion rate and had no significant effect on urinary iodide excretion rate. The increased iodide loss accompanying administration of hydrochlorothiazide and chlorothiazide to rats may explain the goitrogenic effect of these drugs reported earlier.