Effect of Tamoxifen on Fertility in Female Rats

Tamoxifen is a nonstroidal antiestrogen agent, which is prescribed for treatment of breast cancer. The aim of this study was to investigate the effect of tamoxifen on estradiol concentration and structure of ovary in female Wistar rats. One group of rats (45 days old and 90 g body weight) received 800 µg/kg b.w tamoxifen dissolved in solvent (consisted of ethanol (60%) and physiological solution) for 10 consecutive days. The sham group received the solvent and controls did not receive any thing or solvent. After treatment period, blood serum estrogen was measured by ELISA method and 5µm thickness sections from ovaries stained with Haematoxylin & Eosin method. Results showed that estradiol concentration in serum decreased significantly in group which received tamoxifen, compared with control group. (P<0.05) The significant decrease in body weight, diameter of ovary, number of primordial follicles, primary follicles, growing follicles, Graafian follicles, corpus luteui and corpus luteal cells, were observed in animals received tamoxifen. The diameter of primary oocyte, corpus luteum, corpus luteal cells and thickness of granulosa layer in intact Graafian follicles, decreased significantly. (P<0.05) These findings showed that tamoxifen decreased fertility in female Wistar rats which received it in immature stage.