OVEREXPRESSION OF PLACENTAL LEPTIN IN DIABETIC PREGNANCY - A CRITICALROLE FOR INSULIN

Leptin, a small peptide produced by adipocytes, is implicated in an in creasing number of endocrine regulations, including adiposity, satiety , puberty, and fertility. Although the factors involved in controlling maternal and fetal weight gain during pregnancy have not been fully e lucidated, leptin has recently emerged as such a potential factor. In our study, we report the presence of high amounts of leptin mRNA and i mmunoreactive protein in the human placenta, establishing the placenta l synthesis of this hormone. A large (three-to fivefold) augmentation in leptin mRNA and protein was found in placentas from insulin-treated diabetic women. This finding was associated with increased concentrat ions of leptin and insulin in venous cord blood without modification o f maternal circulating leptin levels, These data provide evidence that the placenta is a site for regulated leptin production in utero, Insu lin is likely to play a critical role in this regulation, thus emphasi zing the importance of placental leptin signaling in diabetic pregnanc y.