Stimulation of HCO3- excretion in frog skin by urinary and adrenal cortical extracts

1. There is a substance extractable from human urine which stimulates frog skin to excrete bicarbonate. The response to this extract is delayed, taking 4-9 hr, depending upon the dosage. 2. The amount of this substance varies with the bicarbonate intake of the urine donor. 3. This is a reasonable dose-response curve to the extract. 4. A substance with the same solubility characteristics, and which stimulates bicarbonate excretion with a similar time response is present in adrenal cortical extracts.