CYTOGENETIC EFFECTS OF CAFFEINE DURING IN-VIVO MOUSE OOCYTE MATURATION

Numerous investigators have studied the reproductive and genetic toxic ity of caffeine. Caffeine has also been reported to retard meiotic pro gression and induce aneuploidy in hamster oocytes in vitro, However, t he ability of caffeine to induce aneuploidy in mammalian oocytes in vi vo has not been reported. The objective of this study was to test the hypothesis that chemical-induced perturbations during in vivo oocyte m eiotic maturation (OM) predispose oocytes to chromosome missegregation , Caffeine inhibits cAMP phosphodiesterase, which is needed for dephos phorylating p34(cdc2) kinase and initiating OM, Following superovulati on, a dose of 150 mg/kg caffeine was administered to Institute of Canc er Research (ICR) female mice at various times prior to metaphase I(MI ). Ovulated oocytes were collected from the oviducts and processed for cytogenetic analysis. Statistical analyses of the frequencies of hype rploid, MI, diploid, premature centromere separation and single chroma tids revealed nonsignificant (P > 0.05) differences between the contro ls and each of the caffeine groups. Structural chromosome aberrations were not found, Under our experimental conditions, we rejected the hyp othesis and concluded that caffeine neither retarded the rate of OM no r increased the incidence of aneuploidy in mouse oocytes. The factors responsible for the different in vivo and in vitro responses require i nvestigation.