OBJECTIVETo explore the antifertility effect and safety of 30% ethanol retro-injection into the vas deferens of the rat.

METHODSThirty Sprague-Dawley male rats, 3 m of age and (200 +/- 20) g in weight, were equally randomized into an experimental group and a control group. The former received 30% ethanol (0.5 ml) and the latter 0.9% sodium chloride (0.5 ml), both retro-injected into the vas deferens. Pregnancy rates were obtained through pregnancy tests with 60 Sprague-Dawley female adult rats 1.5 m and 3 m after the injection. All the male rats were sacrificed three months later, and tests were done for the rates of sperm motility and deformity as well as for the apoptosis of spermatogenic cells with TUNEL.

RESULTSThe 1.5 m pregnancy rate was 0 and the 3 m sperm motility and pregnancy rates were (0.32 +/- 1.12)% and (0.58 +/- 1.27)%, significantly decreased (P < 0.05) as compared with those of the control group, which were (80.62 +/- 2.68)%, (70.68 +/- 1.62)% and (86.62 +/- 1.68)%, respectively. While the 3 m sperm deformity rate in the experimental group was (78.26 +/- 1.08)%, increased significantly (P < 0.05), and the apoptosis index (AI) of spermatogenic cells was (7.63 +/- 1.16)% as compared with (5.62 +/- 1.32)% of the control group, with no significant difference between the two groups (P > 0.05).

CONCLUSIONRetro-injection of 30% ethanol into the vas deferens of the rat produces significant antifertility effect on rats, but has no significant influence on their spermatogenic cells.