OBJECTIVETo investigate the content and expression of the urokinase plasminogen activator (uPA) in the ornidazole-induced asthenospermia animal model, and to probe the mechanism of ornidazole inducing asthenospermia and the possibility of using uPA for the prevention and treatment of asthenospermia.

METHODSForty-eight male rats were equally randomized into 5 medication groups (1 d, 5 d, 10 d, 15 d and 20 d) and a blank control group, and ornidazole (200 mg/kg) was given intragastrically every day to the former five while 0.5% carboxymethylcellulose Na (CMC-Na) to the latter for 20 successive days. Then the rats were sacrificed by intraperitoneal injection of pentobarbital at 1, 5, 10, 15 and 20 days respectively and the epididymides and testes harvested. The integrity of the sperm cell membrane was detected by hypoosmotic swelling experiments, the uPA expression in the testicular and epididymal tissues dynamically observed by immunohistochemistry and the level of uPA mRNA in the testis determined by RT-PCR.

RESULTSThe integrity of the sperm cell membrane was reduced at 10 days and remained low till the end of the medication, but with no statistic significance. Compared with the blank controls, the uPA expression and mRNA content in the testicular and epididymal tissues showed no conspicuous difference in the 1 d and 5 d groups, decreased insignificantly in the 10 d group, but significantly in the 15 d and 20 d groups (P < 0.05).

CONCLUSIONThe defect of sperm cell membrane and decrease of sperm motility go in parallel with the reduced expression and content of uPA, which may be one of the factors for the development of asthenospermia.