THE EXPRESSION OF LEPTIN AND ITS RECEPTORS IN PREOVULATORY HUMAN FOLLICLES

The expression of leptin and its receptors was examined by reverse tra nscriptase-polymerase chain reaction and immunofluorescence in granulo sa and cumulus cells of pre-ovulatory follicles and in meiotically mat ure oocytes obtained from women undergoing in-vitro fertilization, Lep tin concentrations were measured in newly aspirated follicular fluids and in maternal serum before and after the administration of an ovulat ory dose of human chorionic gonadotrophin, The findings demonstrate le ptin expression at the mRNA and protein levels by granulosa and cumulu s cells, and the presence of leptin in mature human oocytes. While an association between follicular leptin concentration and embryo develop ment was not observed, a postovulatory increase in serum leptin concen tration was associated with implantation potential. The results are di scussed with respect to possible roles of leptin in early human develo pment.