Journal of

Introduction: Tamoxifen is a nonsteroidal drug which mainly treats breast cancer. It is also applied for stimulation of ovulation and remedy of infertility. Regarding the tamoxifen binding to estrogen receptors and the possible role of estrogens in spermatogenesis, the present study aimed to histologically evaluate spermatogenesis in the seminiferous ducts of mice, whose mothers had received tamoxifen during pregnancy.

Methods: In the present study, 30 female and 15 male mice of NMRI race were selected for mating. Since 13^th day of pregnancy, the experimental group received tamoxifen with the dosage of 5 mg/kg intra-peritoneally for 7 days, wherease the control group received normal saline. After childbirth of the mated mice, male infants were selected and monitored in the standard laboratory conditions. After reaching the age of puberty (6-8Weeks), adult mice were sacrificed by the cervical dislocation, and the testes were removed for histological evaluation of spermatogenesis. After routine histological processing, the samples were studied by the light microscope.

Results: Histological studies showed that spermatogenic and Sertoli cells in the seminiferous tubules in control and experimental groups were significantly different, though no difference was observed in the number of Leydig cells in the both groups.

Conclusion: The findings of the present study showed that tamoxifen exposure during development can cause histological changes in the seminiferous tubules, which can lead to infertility in the male rat.