Effects of vasectomy on intratubular hydrostatic pressure in the testes and epididymis.

Direct measurements of intratubular hydrostatic pressure in the testis and epididymis of guinea pigs and hamsters were made to determine any effect of vasectomy. In normal hamsters the pressure in the seminiferous tubules was significantly lower (P < .05) than the pressure in the caput. The pressures in the proximal and distal caudal tubules were significantly lower (P < .02) than the pressure in the caput. Linear regression showed that the pressure increased significantly from proximal to distal cauda epididymidis (P < .04). 45% of hamsters examined 2 weeks after vasectomy had formed a sperm granuloma at the operative site and were excluded from comparisons. After vasectomy the pressure in the seminiferous tubules was significantly lower (P < .04) than the mean pressure in the caput. The seminiferous tube pressure was also significantly lower than the pressure in the normal hamster (P < .01). All of the pressures in the distal epididymis were higher than the comparable values in the normal hamster and there was a progressive significant increase in pressure alone the length of the distal epididymis (P < .001). After 1 month postvasectomy 70% of hamsters had granulomas. In normal guinea pigs the pressure in the seminiferous tubule was significantly lower (P < .001) than in the caput as in the hamster. Again the pressure in the proximal cauda was significantly lower than pressure in the caput and distal cauda (P < .005). After 4 months postvasectomy the pressures in the seminferous tubules and the distal caudal tubes of guinea pigs were significantly greater (P < .01 and P < .001 respectively) than the corresponding normal controls. Pressure in the seminiferous tubules 1 year after surgery was lower than the pressure in normal tubules (P < .05) for guinea pigs.