Abstract: Leptin is mainly an adipocyte-secreted , obese gene encoded hormone with 16 KD molecular weight. It is a 167 amino acid protein whose amino terminal signal sequence is cleaved during secretion. It circulates as a 146 amino acid peptide in mouse and human plasma. Leptin has a broader role in the regulation of body weight , sexual maturation and reproduction , immunity and glucose metabolism. Much evidence showed that leptin is not only an adipocyte-secreted hormone , but also a neuroendocrine regulator. In this paper , we reviewed the roles of leptin in the regulation of body weight , reproduction and immunity. It includes the following aspects : seasonal change of leptin levels in serum; the effect of environmental factors such as photoperiod , temperature, and food composition on serum leptin levels ; the interactions between leptin and uncoupling proteins , hypothalamus neuropeptide Y, insulin , and thyroid in the regulation of body weight and thermogenesis ; and the roles of leptin in reproduction and immunity.

Key words: Leptin, Energy balance, Body weight, Reproduction, Immunity

摘要： 瘦素(Leptin) 主要是由白色脂肪细胞分泌的、肥胖基因编码的、分子量为16 KD 的蛋白类激素。其N 端具有信号肽序列, 引导蛋白质进入分泌途径, 信号肽被切除后成为有生物学功能的成熟蛋白质。瘦素在动物的体重调节、发育与生殖、免疫和糖代谢等方面有重要作用。瘦素已经不仅仅是脂肪细胞分泌的蛋白类激素, 而是一个在许多方面发挥作用的神经内分泌调节因子。本文综述了瘦素在哺乳动物体重调节、繁殖和免疫中的作用及其调控机制, 主要包括: 动物血清瘦素浓度的季节性变化; 光周期、温度和食物等环境因子对瘦素浓度的影响; 瘦素与解偶联蛋白(Uncoupling proteins , UCPs) 在能量代谢和产热中的互作; 瘦素与下丘脑神经肽Y (Hypothalamus neuropeptide Y, NPY) 在体重调节和产热作用中的拮抗; 瘦素与甲状腺激素和胰岛素在能量代谢中的互作以及瘦素在生殖和免疫中的作用。

关键词: 瘦素, 能量平衡, 体重, 生殖, 免疫