[Protective effect of nitric oxide synthase inhibitor (L-NAME) on germ cell apoptosis in experimentally cryptorchid rats].

OBJECTIVE: To explore the protective effect of nitric oxide synthase inhibitor (L-NAME) on the germ cell apoptosis in the rat cryptorchid. METHODS: Immature rats (22 day-old Sprague Dawley) were subjected to unilateral cryptorchid. Thirty rats were divided into three groups: sham operation group (testes still in the scrotum after operation); operation group; operation + L-NAME group(given L-NAME 10 mg/kg after operation, dip). Seven days after operation germ cell apoptosis was detected by terminal-deoxynucleotidyl transferase mediated-dUTP nick end labeling(TUNEL). Biochemical parameters (NO, NOS) were evaluated with spectrophotometric determination. RESULTS: At the 7th day after the operation, compared with the control, the number of apoptotic germ cells in the cryptorchid testis was increased significantly, but the testis weight was decreased predominantly(P < 0.01). The levels of NO and NOS in the cryptorchid were significantly higher than the control. CONCLUSIONS: The levels of NO and NOS might be involved in the germ cell apoptosis in the cryptorchid; L-NAME could protect the germ cell from apoptosis in experimentally cryptorchid rats by reducing the activity of NOS and reducing the level of NO in the testis.