title: Effect of sodium and potassium concentrations and pH on the maintenance of motility of rabbit and rat epididymal spermatozoa.
abstract: Spermatozoa were collected from the caput and cauda epididymidis of rabbits and rats and diluted in Hank's solution containing BSA, with various concentrations of Na+ and K+. Ionic strength and osmolarity were kept constant. Motility was assessed at various intervals during incubation at 25 degrees C. In the pH range 7.05--7.20, the motility of rabbit spermatozoa was not affected by changes in the ratio of K+ to Na+. Similarly, the motility of rat cauda spermatozoa was not altered, but that of caput spermatozoa was slightly depressed by a high K+/Na+ ratio. In the pH range 5.45--5.85, rabbit cauda and caput spermatozoa had much greater motility in media with a high K+/Na+ ratio. The reverse result was obtained for the rat. These findings indicate that the motility of epididymal spermatozoa is influenced by external Na+ and K+ concentrations and that this phenomenon is pH-dependent.
mesh_terms: D000818:Animals; D004822:Epididymis / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D008297:Male; D009994:Osmolar Concentration; D011188:Potassium / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D012964:Sodium / Q000494:pharmacology*; D013081:Sperm Motility / Q000187:drug effects*
chemical_list: D012964:Sodium; D011188:Potassium