Herkunft und Bedeutung von Leptin und Neuropeptid Y (NPY) im Fruchtwasser zwischen der 14. - 18. Schwangerschaftswoche

Abstract

Leptin and neuropeptide Y (NPY) play important roles in the regulation of food intake, energy expenditure, hematopoesis and reproduction. The biological functions of leptin and NPY in fetal development, and their regulation during pregnancy by fetal and maternal factors remain poorly understood. From 55 women undergoing diagnostic amniocentesis between the 14th and 18th weeks of gestation samples of amniotic fluid were collected. In accord with the circadian rhythm of leptin secretion all amniocenteses were performed between 8.00 and 12.00 a. m. The concentrations of leptin and NPY in amniotic fluid were analysed using commercially available RIA's. The amniotic fluid samples of 32 male and 23 female fetuses were determined and demonstrated no gender-dependent differences in leptin and NPY levels. No correlation was found between leptin/NPY and the maternal body mass index. NPY concentrations are lower in advanced gestational age pregnancies. Leptin levels revealed no differences with respect to gestational age. Leptin and NPY levels were independent of fetal gender and maternal BMI. This provides clues for alternative regulatory mechanisms in leptin and NPY secretion. Compared to the data of adults, our findings show high leptin concentrations in the amniotic fluid in the presence of only minor amounts of white adipose tissues which might include the placenta. Our data including the observation of lower levels of NPY in more advanced gestational age support the idea of specific factors regulating leptin and NPY secretion into the amniotic fluid.