Prepubal hyperandrogen exposure induces reproductive changes in adult female rats / 医学研究生学报

ABSTRACT

Objective Androgen is an important precursor for the synthesis of estrogen in vivo and is involved in the regulation of female reproductive function.In this study, we explored the influence of different lengths of prepubertal exposure to hyperandrogen on the reproductive function of adult female rats. Methods Twenty-five 23-day-old female rats were equally randomized into five groupsoil control, 2-wk dehydroepiandrosterone (DHEA), 4-wk DHEA, 6-wk DHEA, and 8-wk DHEA, injected with oil or DHEA daily for 2, 4, 6, and 8 weeks respectively, and mated at 80 days old.We detected serum concentrations of total testosterone (tT), estradiol (E2), follicle-stimulating hormone ( FSH) and luteinizing hormone ( LH) by ELISA, observed the time of vaginal opening and changes of the estrous cycle, and recorded the rates of mating and pregnancy, the number of the offspring and their survival rate. Results The tT lev-el was elevated after 2 weeks of DHEA injection, fell to normal after drug withdrawal in the 2-wk and 4-wk DHEA groups, and remained at a high level in the 6-wk group.The E2 level was markedly increased in at 2 and 4 weeks but showed a falling trend at 6 and 8 weeks. DHEA injection did not change the level of FSH significantly but re-markably lifted that of LH with the increased concentration of tT.The vaginal opening time was significantly advanced in the 2-wk DHEA group as compared with the controls ([26.60 ±0.89] d vs [35.20 ± 2.49] d, P0.05). Conclusion Prepubertal expo-sure to hyperandrogen may advance adrenarche and gonadarche and affect the initiation of the sexual gland function in female rats.Impro-ving the hyperandrogen status in the early pubertal stage can reverse the disorder of the estrous cycle, while long-term exposure to DHEA may significantly reduce the fecundity at the childbearing age.