Effects of alpha-blocker on daily testicular sperm production and sperm concentration, motility, intraluminal pressure and fluid movement in the rat epididymis.

This study was undertaken to investigate whether alpha-blocker has an effect on daily testicular sperm production and epididymal sperm parameters, intraluminal pressure and fluid movement in the rat cauda epididymal tubules. Sprague-Dawley rats were given daily oral doses 1 mg/kg, 2 mg/kg, or 10 mg/kg of Bunazosin, which was a selective alpha-blocker, for three months. Intraluminal fluids were collected from the cauda epididymidis using a micropuncture technique. Sperm concentration was determined with a sperm concentration microassay. Motility estimates were made by measurements of linear distance traveled by sperm in the diluent. Epididymal intraluminal pressure was measured through a micropunctured pipette connected to a micropressure transducer. Intraluminal fluid movement was examined by measurement of the distance which Sudan Black stained mineral oil moved along the epididymal tubules. Outside diameters of seminiferous and epididymal tubules were measured by light microscopy. Epididymal sperm concentrations were significantly increased after administration of alpha-blocker. Progressive motility of spermatozoa was not significantly altered by alpha-blocker. Intraluminal pressures were significantly reduced and intraluminal fluid movement rates were significantly increased by alpha-blocker. Daily sperm production was significantly increased by alpha-blocker. Outside diameters of seminiferous and epididymal tubules were significantly distended when treated with alpha-blocker. These results demonstrate that alpha-blocker has an effect on spermatogenesis and sperm transport in the rat testis and epididymis.