Introduction: Testicular tissue is susceptible to environmental risk factors. Structural and functional alterations in spermatogenesis are the most important factors involved in fertility complications. Methylphenidate is amphetamine derivatives. This drug can approve for treatment of attention-deficit/hyperactivity disorder (ADHD), tachycardia syndrome, narcolepsy, depression. There is a little data about the effects of methylphenidate on testicular tissue. In this study, time dependent effects of methylphenidate were evaluated on testicular tissue in microscopic and ultrastructural levels.

Materials & methods: 30 adult Wistar rats were divided into three groups as control, short-term methylphenidate (10 mg/kg/day) treated for two weeks and long-term methylphenidate (10 mg/kg/day) treated for eight weeks. Histomorphological and ultrastructural assessments were prepared on testicular tissue through routine histologic and electron microscopic methods.

Findings: Some alterations such as tubular atrophy and transformation and disarrangement of spermatogenic cells were observed in testicular tissue following time dependent administration of methylphenidate. Deformation of mitochondria, increment of collagen fibers and basement membrane thickness, were the main cellular and structural alterations observed in ultrastructural level.

Discussion & conclusions: The results of this study indicated that the process of spermatogenesis reduces temporary following short term administration of methylphenidate; however, it seems that repeated administration of methylphenidate progressively leads to some degrees of tissue habitation and resistance.