匙羹藤对胰岛素抵抗小鼠脂肪组织蛋白激酶B 的影响

目的：观察匙羹藤对胰岛素抵抗（IR）KKAy 小鼠脂肪组织中蛋白激酶B 表达及磷酸化的影响以及调节机制。方法：将18只胰岛素抵抗KKAy小鼠按体质量随机分为模型组（DM）和匙羹藤水提物组（GS），并选取9只C57BL/6J小鼠为正常对照组（NC），连续灌胃给药8周。实验结束后取血测定空腹血糖（FPG），空腹血清胰岛素（Fins），并计算胰岛素敏感指数（ISI），测定附睾脂肪组织中磷酸激酶依赖的激酶1（PDK1）、蛋白激酶B（PKB）、P-PKB（Ser473），P-PKB（Thr308）蛋白相对含量，及磷酸酶和张力蛋白同源物基因（PTEN）mRNA 相对含量。结果：与DM 组相比，GS组小鼠FPG、Fins降低，ISI升高，P-PKB（Ser473）蛋白相对含量及其磷酸化水平升高，P-PKB（Thr308）蛋白相对含量升高，PDK1蛋白相对含量降低，PTENmRNA表达量降低。结论：匙羹藤可通过增加脂肪组织中P-PKB（Ser473）蛋白相对含量，增强Ser473位点磷酸化水平，以及增加P-PKB（Thr308）蛋白相对含量激活PKB，进而改善IR。

Effect of Gymnema Sylvestre on Protein Kinase B in Adipose Tissues of Insulin Resistance Mice

This article was aimed to study effects and mechanisms of Gymnema sylvestre on protein kinase B (PKB) and its phosphorylation in adipose tissues of KKAy mice which were mainly characterized by insulin resistance (IR). A total of 18 KKAy mice were randomly divided into the diabetes model (DM) group and Gymnema sylvestre (GS) group according to body weight levels. And 9 normal C57BL/6J mice were used as the normal control (NC) group. Intragastric administration of medication was given to mice for 8 weeks. At the end of the experiment, all animals were tested for fasting plasma glucose (FPG) and fasting insulin level (Fins) for evaluation of insulin sensitivity index (ISI). Expressions of phosphoinositide-dependent kinase-1 (PDK1), PKB, P-PKB (Ser473), P-PKB (Thr 308) in adipose tissues of epididymis were determined. The expression of phosphatase and tensin homolog (PTEN) mRNA was also determined. The results showed that compared with the DM group, the GS group showed lower FPG and Fins, higher ISI. The expression of P-PKB (Ser473) phosphorylation and P-PKB (Thr 308) were increased, and the PDK1 and PTEN mRNA were decreased. It was concluded that GS can improve insulin sensitivity of KKAy mice through activating PKB by up-regulate the expression of P- PKB (Ser473) and its phosphorylation ratio and P- PKB (Thr308) in adipose tissues.