Intratubular hydrostatic pressure in testis and epididymis before and after vasectomy

A method is described for the measurement of intratubular hydrostatic pressure in the testis, caput epididymidis, and cauda epididymidis of the golden hamster. Pressures in these locations in normal animals ranged from 3 to 6 cmH2O. Mean pressure in the tubules of the caput was significantly higher than that in the seminiferous tubules (P smaller than 0.05) and in the proximal caudal tubules (P smaller than 0.02). There was a small, significant increase in pressure from the proximal cauda to the distal cauda (P smaller than 0.04). Two weeks after vasectomy, the mean pressure in the seminiferous tubules of 3.3 cmH2O was significantly lower (P smaller than 0.004) than the mean pressure in the normal seminiferous tubules of 4.4 cmH2O. Pressures in the cauda at 2 wk of 10-18 cmH2O were significantly greater than normal (P smaller than 0.0005) and reflected the accumulation of sperm and fluid. The high incidence of spermatic granuloma formation and/or rupture of the epididymis observed after vasectomy emphasized that there are definite limits to both distensibility and reabsorptive capacity of the epididymis in some species. Pressures at 1 mo after vasectomy were similar to those at 2 wk in animals that were still obstructed and comparable to normal in animals with granulomas and/or large epididymal leaks. Testicular weight was slightly but significantly decreased 2 wk after vasectomy. At 4 wk, there was no detectable effect of vasectomy on the weights of the testes.