Abstract
The rate of fluid reabsorption was studied in the rat isolated caudal epididymal sac in vitro. Part of the fluid reabsorption was found to be dependent on intraluminal Na+. Amiloride (0.1 mm) completely inhibited this component of fluid reabsorption. The log dose‐inhibition curve to amiloride was sigmoid and the IC50 value was found to be 1.6 μm.