关键词: 瘦素, 能量平衡, 体重, 生殖, 免疫

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