Benoit Stephen C, Clegg Deborah J, Seeley Randy J, Woods Stephen C
Department of Psychiatry, University of Cincinnati Medical Center, Cincinnati, Ohio 45267, USA.
Recent Prog Horm Res. 2004;59:267-85. doi: 10.1210/rp.59.1.267.
There is now considerable consensus that the adipocyte hormone leptin and the pancreatic hormone insulin are important regulators of food intake and energy balance. Leptin and insulin fulfill many of the requirements to be putative adiposity signals to the brain. Plasma leptin and insulin levels are positively correlated with body weight and with adipose mass in particular. Furthermore, both leptin and insulin enter the brain from the plasma. The brain expresses both insulin and leptin receptors in areas important in the control of food intake and energy balance. Consistent with their roles as adiposity signals, exogenous leptin and insulin both reduce food intake when administered locally into the brain in a number of species under different experimental paradigms. Additionally, central administration of insulin antibodies increases food intake and body weight. Recent studies have demonstrated that both insulin and leptin have additive effects when administered simultaneously. Finally, we recently have demonstrated that leptin and insulin share downstream neuropeptide signaling pathways. Hence, insulin and leptin provide important negative feedback signals to the central nervous system, proportional to peripheral energy stores and coupled with catabolic circuits.
目前已形成相当多的共识，即脂肪细胞激素瘦素和胰腺激素胰岛素是食物摄入和能量平衡的重要调节因子。瘦素和胰岛素满足了作为向大脑传递假定肥胖信号的许多要求。血浆瘦素和胰岛素水平与体重呈正相关，尤其与脂肪量相关。此外，瘦素和胰岛素都能从血浆进入大脑。大脑在控制食物摄入和能量平衡的重要区域表达胰岛素和瘦素受体。与它们作为肥胖信号的作用一致，在不同实验范式下，将外源性瘦素和胰岛素局部注射到多种物种的大脑中时，都会减少食物摄入。此外，中枢注射胰岛素抗体可增加食物摄入量和体重。最近的研究表明，胰岛素和瘦素同时给药时具有相加作用。最后，我们最近证明瘦素和胰岛素共享下游神经肽信号通路。因此，胰岛素和瘦素向中枢神经系统提供重要的负反馈信号，与外周能量储备成比例，并与分解代谢回路相关联。
