ABSTRACT
Doxepin is a serotonin and norepinephrine reuptake inhibitor. Considering the importance of this drug in treating some nervous diseases, its side effects seem to be important on the endocrine axis. In this study, the effects of doxepin on the concentration of testosterone, FSH and LH level and spermatogenesis were studied. This experimental study was done on 40 male Wistar rats that were divided into 5 groups of 8. The control group received nothing. The sham group was given distilled water as a solvent. The experimental groups were injected 35, 70 and 140 mg/kg of the drug orally for 21 days, respectively. The blood samples were taken at 22[th] day and the concentration of testosterone, FSH and LH were measured by RIA method. In addition, at the 22[th] day, the testes were separated and histological changes were studied among experimental, sham and control groups. The results were evaluated by using ANOVA and Duncan tests. The results showed that 140 mg/kg of doxepin reduced serum testosterone level, while it increased FSH and LH levels [p<0.05]. Histological investigations of the testes showed a decline on spermatogenesis chain in dose of 140 mg/kg of the drug. This study showed that doxepin decreases the concentration of testosterone level and the number of spermatogenic cells and increases FSH and LH levels at high doses. Therefore, it may weaken the function of reproductive activity