Abstract

In a study of several diuretic drugs on erythropoietin production, meralluride, mercaptomerin, benzydroflumethiazide and triamterene were found to be potent inhibitors of cobalt induced erythropoietin production in rats. Acetazolamide and chlorothiazide were also studied and did not significantly alter erythropoietin formation after the cobalt stimulus. Meralluride was also found to inhibit erythropoietin production in dogs in which bleeding was used as the stimulus. Additional studies are reported on urinary excretion of cobalt after treatment with the diuretic drugs which show that enhanced cobalt excretion is not a likely explanation for the blocking action of these compounds. The mercurial contained in the plasma administered to the assay animal was also studied and did not interfere with the response of the recipient animal to plasma erythropoietin. It is postulated that the drugs effective in blocking erythropoietin production probably act by interfering with some essential renal tubular enzyme which is necessary for erythropoietin production.