瘦素在糖尿病大鼠中作用机制  

Mechanism of Action of Leptin in Rats With Diabetes

作　　者：徐增康[1] 张颖[1] 王枫[2] 

机构地区：[1]陕西省疾病预防控制中心,陕西西安710054 [2]第四军医大学营养与食品卫生教研室

出　　处：《预防医学情报杂志》2009年第10期812-816,共5页Journal of Preventive Medicine Information

摘　　要：目的通过共轭亚油酸(CLA)对实验性型糖尿病大鼠干预后,观察血清中血糖、胰岛素的变化,以及胰岛细胞和脂肪组织中瘦素(leptin)表达的变化,探讨leptin在实验性型糖尿病大鼠的作用机制。方法Wistar雌性大鼠35只分成5组,正常对照组、糖尿病对照组、3组共轭亚油酸干预组(低0.4 g/Kg.bw、中0.8 g/Kg.bw、高1.6 g/Kg.bw),4组大鼠高脂高糖饮食1个月后,注射小剂量STZ(25 mg/Kg.bw),诱发大鼠糖尿病模型(血糖>10 mmol/L),共轭亚油酸干预1个月后,取动物血清,用GOD-PAP法测定血糖含量,放射免疫分析法测定血清胰岛素含量,免疫组织化学方法测定leptin在胰岛细胞中的表达,Western杂交观察大鼠脂肪组织中leptin的表达。结果CLA干预后血糖水平随着干预剂量提高而下降,胰岛素水平随着剂量增高有增高趋势。糖尿病对照组脂肪组织中leptin的表达增高,CLA干预后,leptin表达随着CLA干预剂量的增高而降低。leptin在胰岛细胞中表达阳性,而且CLA干预剂量增加,阳性率减少。结论CLA干预后,减少了脂肪组织中leptin表达,作用于胰岛细胞的leptin减少,胰岛素分泌增多,对糖尿病大鼠的血糖产生作用。Objective To investigate the mechanism of action of leptin in rats with experimental type Ⅱ diabetes by intervention of conjugated linoleic acids （CLA） to these rats and observation of their level of glucose and insulin in serum and the expression of leptin in islet cell and fatty tissue. Methods Thirty five female Wistar rats were divided into 5 groups （ 1 normal control group, 1 type II diabetes control group, 3 CLA intervention groups）. The rats in 4 groups were fed with high fat and glucose diets for 1 month, and injected with streptozoticin （ STZ, 25 mg/kg · bw） to induce hyperglycemia and type 2 diabetes （ glucose 〉 10 mmol/L）. After intervened by CLA with different dosage for 1 month, serum glucose was detected with GOD - PAP and insulin level was detected with radio immunoassay, leptin expression in islet cell was detected with immunohistochemistry assay and leptin expression in fat tissue was detected with Western blotting. Results After intervened by CLA, the level of glucose in serum decreased in dose dependent manner and the level of insulin increased in dose dependent manner too. The expression of leptin in fatty tissue and islet cell was increased in dose dependent manner in CLA intervened group compared with diabetes group（ P 〈 0.05 ）, Conclusion After intervened by CLA, ileptin expression in fatty tissue was decreased, so the leptin level in islet cells was decreased, the insulin secretion was increased, and the serum glucose was controlled.

关 键 词：瘦素 糖尿病 胰岛素 血糖 共轭亚油酸 

分 类 号：R587.1[医药卫生—内分泌]