Leptin modulates lipid metabolism in human term placenta

V. WHITE, E. GONZÁLEZ, E. CAPOBIANCO, M.C. PUSTOVRH, N. MARTÍNEZ, A. JAWERBAUM.

Buenos Aires, Argentina

Workshop; I Taller de Intracción Materno-Fetal: De la fisiología a la patología; 2005

CEFYBO-CONICET-UBA

Leptin has significant effects on appetite, energy expenditure, lipid mobilization and reproduction. Leptin and its receptor are expressed in human placenta suggesting  autocrine/paracrine functions of this hormone. The aim of the present study was to evaluate the role of leptin in lipid metabolism in human placenta. Methodology: Human placental explants were obtained after delivery and incubated for 3 h either with or without leptin additions (1-30 nM). Lipid levels were assessed by thin layer chromatography and revealed with iodine. Lipid synthesis was evaluated by 14C-acetate incorporation on the distinct lipid species. Lipid catabolism was analyzed by quantification of glycerol release. Results:  Leptin diminished triglycerides (51%, p<0.01) and cholesterol placental levels (26%,p<0.001), but did not modify the cholesteryl esters and phospholipids levels. Leptin additions did not modify incorporation of 14C-acetate to any of the lipids evaluated. When we tested leptin effects on placental lipid catabolism we found that leptin increased glycerol release (93%, p<0.01). Conclusions: In human placenta, leptin decreases in  lipid mass may be due to a stimulatory effect on lipid catabolism but not to modulation of the de novo lipid synthesis. These findings provide evidence of a role of leptin in lipid metabolism, a placental function that may condition the transfer of nutrients to the developing fetus.