Señarís R, Garcia-Caballero T, Casabiell X, Gallego R, Castro R, Considine R V, Dieguez C, Casanueva F F
Department of Physiology, University of Santiago de Compostela, Spain.
Endocrinology. 1997 Oct;138(10):4501-4. doi: 10.1210/endo.138.10.5573.
Gender-based differences in serum leptin levels have been reported in umbilical cord blood, and leptin has been detectedin human amniotic fluid. In order to understand if leptin may be directly synthesized by human placentae an analysis made up of several steps was performed. First at all RT-PCR analysis from placenta-derived RNA was used to detect human leptin mRNA. The leptin-like immunoradioactivity detected in placentae extracts was identical to human leptin according to the criteria of charge, immunorecognition, SDS-PAGE analysis and blotting, indicating that intact leptin was found and no variants in size, charge or immunoactivity were present in the placentae. Finally an immunohistochemical analysis showed the presence of leptin in the cytoplasm of syncytiotrophoblast cells but not in the core of villi.
leptin is synthesized as a single molecular variant identical to human recombinant leptin in human placentae at delivery.
已有报道称脐带血中存在基于性别的血清瘦素水平差异，并且在人羊水中检测到了瘦素。为了了解瘦素是否可能由人胎盘直接合成，进行了由几个步骤组成的分析。首先，使用从胎盘来源的RNA进行的RT-PCR分析来检测人瘦素mRNA。根据电荷、免疫识别、SDS-PAGE分析和印迹标准，在胎盘提取物中检测到的瘦素样免疫放射性与人瘦素相同，表明发现了完整的瘦素，且胎盘中不存在大小、电荷或免疫活性的变体。最后，免疫组织化学分析显示合体滋养层细胞的细胞质中存在瘦素，但绒毛核心中不存在。
分娩时人胎盘中合成的瘦素是一种与重组人瘦素相同的单一分子变体。
