effect of supraphysiological dose of nandrolone decanoate on the testis and testosterone concentration in mature and immature male rats: a time course study

background: most studies on anabolic-androgenic steroids abuse have been done in adult rats, but few data are available to immature. objective: this study was conducted to assay the effect of nandrolone decanoate (nd) on the testis and testosterone concentration in male immature rats compare with mature ones in short and long time. materials and methods: 40 mature rats were divided into 4 groups: group a (short term) and group b (long-term) received 10 mg/kg/day nd interaperitoneally for 35 and 70 days, respectively. group c (control) without any treatment, and group d (vehicle) received dimethyl sulfoxide (dmso) solution in two periods 35 and 70 days. 40 immature rats were divided into 4 groups same as mature ones. after surgery body weight, testis size, histomorphometry of testis, and serum testosterone level were evaluated. results: our results showed that nd decreased the number of leydig cells in group b (39.9 ±. 919), group a (43.4 ±. 120), and long term (40.6 ±. 299) immature rats, which could result in a reduction of testosterone concentration significantly in all experimental groups except short term mature group. number of sertoli cells, testis size, and diameter of seminiferous tubules decreased in the long-term immature group. eventually, the number of sperm was decreased in mature and immature groups, but a severe depletion of sperm was occurred in both mature and immature in long time  in comparison to the control group  (p< 0.05). conclusion: this time course study showed that supraphysiological dose of nd may negatively affect the number of leydig cells, sperm cell, and testosterone concentration of immature rats in the same matter of mature rats. however, the number of sertoli cell, testis size, and seminferous diameter were decreased only in the long immature rats.