Nandrolone decanoate–induced hypogonadism in male rats: Dose‐ and time‐dependent effects on pituitary and testicular hormonal functions

Abstract Anabolic‐androgenic steroids (AASs) impairment of reproduction has been reported. We investigated dose‐ and time‐dependent effects of Nandrolone decanoate (ND) on reproductive system in comparison with Testosterone enanthate (TE). Male Wistar rats were administrated with 1, 3, and 9 mg/kg/weeks ND or 1 and 3 mg/kg/weeks TE for 8 weeks, and testicular phenotype and reproductive hormones were assessed at 4 and 8 weeks post‐treatments. AASs × treatment period interaction was significant for gonadosomatic index (GSI), testosterone (T), 17β‐estradiol (E2), and luteinizing hormone (LH). At 4 weeks post‐treatment, GSI was decreased in rats treated with 3 mg/kg/weeks ND and T was decreased in all ND‐treated groups, while no significant changes in LH levels were observed. At 8 weeks post‐treatment, GSI was decreased in rats treated with 1 and 3 mg/kg/weeks ND and with 3 mg/kg/weeks TE, T was decreased in all groups, and E2 and LH were increased and decreased, respectively, in rats treated with 9 mg/kg/weeks ND and with 3 mg/kg/weeks TE. The testes showed histopathological defects in both ND‐ and TE‐treated rats suggesting a delay in seminiferous cycle. This study shows AASs‐induced hypogonadism at low‐dose that coincided with inhibition of T biosynthesis and disruption of T feedback on pituitary.