assessment of morphological and functional changes in the mouse testis and epididymal sperms following busulfan treatment

busulfan, a cytotoxic drug, which is currently used as a chemotherapeutic agent, has many side effects on different body organs. in this research, the effects of busulfan on sperm parameters and microstructure of mouse testis were investigated. methods: busulfan was injected intrapretoneally at 10, 20, 30, 40 and 50 mg/kg and testes were removed after 4, 6 and 8 weeks, weighed and processed for light microscopic examination. transverse and cross section diameters of testes, seminiferous tubules diameters, percentage of different types of tubules, epithelium thickness, spermatogenic cell numbers and capsule thickness as well as the sperm parameters in epididymis were measured. results: there was a significant decline in sperm numbers and marked changes in testes structures. almost 8 weeks after the injection of drug, some of the changes are reversed. accordingly, the changes in percent of normal tubules without sperm, abnormal tubules and capsule thickness were increased until 6 weeks of drug administration, the changes declined thereafter. conclusion: in general, busulfan caused a decrease in all analyzed parameters (except capsule thickness, normal tubules without sperm and abnormal tubules), probably due to the arrest of spermatogenesis. our results also revealed that some of the changes are reversible and dose dependent.