The effects of cyclosporin (Cs), azathioprine (AZP) and mizoribine (MZR) on male reproduction in rats were examined.
Each drug was orally administered every day for 14 days at the following doses; Cs, 10, 20, 40, or 80 mg/kg body weight; AZP, 5, 10, or 20 mg; and MZR, 2.5, 5, 10, or 20 mg.
In the sperm count in the cauda epididymis, two weeks after the discontinuation of administration, a ... [Show full abstract] significant decrease was observed only in the 80 mg/kg dose group among the Cs-treated groups and in the 5 mg/kg and 20 mg/kg dose groups among the AZP-treated groups. At the end of the administration, a significant dose-dependent decrease was observed in the MZR-treated groups. The degree of the decrease was smaller after Cs administration compared with the other 2 drugs. Sperm motility was significantly decreased in each Cs-treated group immediately after the oral administration of Cs and improved gradually, but was not changed in AZP- and MZR-treated groups. Significant dose-dependent damage of the seminiferous tubules was noted 6 weeks after administration of Cs, AZP and MZR. The serum levels of luteinizing hormone and follicle-stimulating hormone remained the same throughout the experiment. The serum level of testosterone was significantly low immediately after the oral administration of AZP, but was not changed by that of Cs and MZR.
Cs, AZP and MZR injured the spermatogenesis in rat. However, changes in the sperm count in the cauda epididymis suggested that the degree of impairment by Cs is relatively small, but only Cs injured epididymal function as well.