肥胖患者外周脂肪组织中瘦素受体水平的研究

Leptin Receptor in Peripheral Adipose Tissues of Obesity Subjects

通过对肥胖患者外周脂肪组织中瘦素 (leptin)受体表达的研究 ,进一步探讨肥胖发生发展的机制。用放射配基竞争试验的方法 ,对 71例受检者 (其中肥胖 32例 ,超重 19例 ,正常人 2 0名 )外周脂肪组织leptin受体的密度进行检测。结果显示 ,随着体重指数 (BMI)的增加 ,瘦素受体密度肥胖组和超重组与正常组比较差异十分显著 (P <0 .0 1) ,肥胖组与超重组比较有显著性差异 (P <0 .0 1) ;而受体与瘦素结合的能力没有显著性差异 (P >0 .0 5 )。三组间的解离常数 (Kd)值无差异 ,表明瘦素受体与配基结合的能力与BMI无关。从散点分布图可以看出 ,体重指数越大leptin受体的密度就越小 ,BMI与Bmax呈显著负相关 (r =- 0 .76 ,P <0 .0 1)。结论 :肥胖患者外周脂肪组织中leptin受体的表达减少与BMI密切相关 ,这提示体内存在着leptin受体水平下调而造成leptin耐受 。

To investigate the relationship between leptin receptor and obesity by studying the leptin receptor density B max and dissociation constant K d value in peripheral adipose tissues with different body weight mass index(BMI), leptin receptor density B max and K d value were assayed via radioligand competition method from 71 cases, including 32 classified as obesity, 19 weight excess and 20 normal controls. With the elevation of BMI, the leptin receptor density was significantly higher in obese and weight excess group than that in normal controls (both P <0.01), and there was also statistical difference between the obese and weight excess group ( P <0.01). While for K d value, there were no differences among all three groups, suggesting no correlation between the binding ability of leptin to its receptor and BMI. There was negative correlation between BMI and B max ( r =-0.76, P <0.01). Conclusion: Leptin receptor density correlated with the BMI in obese cases and it suggested that the down-regulation of leptin receptor may contribute to occurrence of leptin resistance and obesity afterwards.