A Micropuncture Study of Transepithelial Water Reabsorption in Rat Ductuli Efferentes

Micropuncture techniques were used to study transepithelial water reabsorption in single tubular sections of rat ductuli efferentes in vivo and in situ. Fluid reabsorption was found to be secondary to an electrolyte transport process. It was completely abolished by intraluminal application of 10−4M amiloride and by an elevated local temperature of 38°C. The fluid reabsorption rate was modified by the intraluminal electrolyte concentration, whereas various local temperatures from 37°C to room temperature had no effect. This finding led to the conclusion that the function of the ductuli efferentes may require temperatures lower than body temperature, which is in accordance with the well-known behavior of mammalian testes. It was further suggested that the described fluid reabsorption leads to concentrations of spermatozoa and of substrates which spermatozoa may need to develop and mature.