The effect of CTX on the expression of occludin at tight junction between Sertoli cells

Cyclophosphamide(CTX) has been associated with impaired spermatogenesis, but the mechanisms are still unclear. Tight junction and occludin play important roles in spermatogenesis. The present study is focused on toxicological effects of CTX on the expression of occludin at tight junction in adult mice testes. Male mouse were injected intraperitoneally with the CTX (100mg?kg-1) once a day for 5 days as experimental groups. Control groups were injected with isochoric physiological saline. The animals were sacrificed after 24 hour, 1st, 2nd and 4th week of last injection. The testes were removed, cleared of the adhering tissues, rinsed with ice-cold physiological saline, frozen for the assays of immunohistochemistry staining, RT-PCR and Western blot. After the injection of CTX, the expression of occludin showed decline, and there was a number of gaps in the closed barrier formed by occludin compared with the control groups. In the 24 hour, 1st week, 2nd week and 4th week experimental groups, the expression of occludin was in recovery gradually, not to the normal level. We indicated that CTX impaired spermatogenesis as a result of reduction of expression of occludin. These changes provide important information about the mechanisms underlying the effects of CTX on male mice reproduction.