SYNTHESIS OF LEPTIN IN HUMAN PLACENTA

Gender-based differences in serum leptin levels have been reported in umbilical cord blood, and leptin has been detected in human amniotic f luid. In order to understand if leptin may be directly synthesized by human placentae an analysis made up of several steps was performed. Fi rst at all RT-PCR analysis from placenta-derived RNA was used to detec t human leptin mRNA. The leptin-like immunoradioactivity detected in p lacentae extracts was identical to human leptin according to the crite ria of charge, immunorecognition, SDS-PAGE analysis and blotting, indi cating that intact leptin was found and no variants in size, charge or immunoactivity were present in the placentae. Finally an immunohistoc hemical analysis showed the presence of leptin in the cytoplasm of syn cytiotrophoblast cells but not in the core of villi. In conclusion: le ptin is synthesized as a single molecular variant identical to human r ecombinant leptin in human placentae at delivery.