Environmental tobacco smoke exposure during intrauterine period promotes granulosa cell apoptosis: a prospective, randomized study.

ABSTRACT

OBJECTIVE: To evaluate the intrauterine effect of cigarette smoke on cell death and DNA damage in follicular cells of fetal ovarian tissue. METHODS: A prospective, randomized study was conducted with 25 female wistar-albino rats. The rats were randomized to be exposed either to cigarette smoke or to room air, initiating from proestrous period and during pregnancy. Newborn female rats were categorized as Group 1 (n = 24) that had been exposed to cigarette smoke during intrauterine life and Group 2 (n = 7) that had been exposed to room air during intrauterine life. Bilateral ooferectomies were performed on the 2nd week of their life. TUNEL (in-situ Terminal Deoxynucleotidyl-Transferase Mediated dUTP-Nick-End Labeling) immunofluorescent staining and immunohistochemical analyses with caspase-3 were used for detection of DNA damage and apoptosis. Primary outcomes were apoptotic index and immunohistochemical scores (HSCORE). Secondary outcomes were ovarian follicle counts and birth weights of newborn rats. RESULTS: There was a significant increase of HSCORE and apoptotic index in Group 1. Increased immunofluorescent staining; evaluating DNA damage, with TUNEL method was observed in granulosa cells in Group 1. CONCLUSIONS: Intrauterine exposure to cigarette smoke diminishes ovarian reserve of female offspring, raising the concern about the generational impact of maternal smoking on ovarian function in the human.