山茱萸乙醇提取液对NIDDM大鼠骨骼肌GLUT4表达影响的实验研究

目的 :在明确山茱萸降糖、促进胰岛增生和增加胰岛素分泌作用的基础上 ,研究山茱萸乙醇提取液对非胰岛素依赖型糖尿病 (NIDDM)大鼠骨骼肌GLUT4mRNA和蛋白表达的影响 ,探讨其降糖作用的分子机制。方法 :制备NIDDM大鼠模型。将动物分为 3组 ,每组 6只 :①正常对照组 ,②NIDDM模型组 ,③NIDDM模型 +山茱萸乙醇提取液给药组。动物每天灌胃一次 ,连续给药一个月。用Northernblot方法检测骨骼肌组织中GLUT4mRNA表达量 ,Westernblot方法检测骨骼肌组织GLUT4蛋白表达。结果:NIDDM大鼠骨骼肌GLUT4 mRNA表达显著减少 ,用山茱萸乙醇提取液治疗后 ,GLUT4 mRNA表达明显上调;GLUT4蛋白的表达变化与其mRNA表达变化一致。结论 :山茱萸通过促进NIDDM大鼠胰岛修复增生 ,增加进食后胰岛素的分泌 ,使骨骼肌等外周组织GLUT4mRNA和蛋白表达增加 ,发挥快速转运葡萄糖的作用。

Effect of Alcohol Extract of Cornus officinalis Sieb.et Zucc on GLUT4 Expression in Skeletal Muscle in Type 2 (non-insulin-Dependent) Diabetic Mellitus Rats

OBJECTIVE: Based on its effects of decreasing postprandial plasma glucose and increasing insulin level in non-insulin-dependent diabetic mellitus (NIDDM) rats, we studied the effects of Alcohol extract of Cornus officinalis Sieb. et Zucc on the GLUT4 expression in NIDDM model rats. METHOD: The rat model of NIDDM was made. The animals were divided into three groups(six for each group): group I: control; group II: NIDDM model; group III: NIDDM model + Cornus officinalis Sieb. et Zucc. The drug was given orally to animals one time a day, uninterrupted for a month. The GLUT4 mRNA and its protein expression in skeletal muscle were observed with Northern blot and Western blot method, respectively. RESULT: The GLUT4 mRNA expression in skeletal muscle was decreased remarkably in NIDDM rats (P < 0.01, compared to control group). Alcohol extract of Cornus officinalis Sieb. et Zucc increased GLUT4 mRNA expression in NIDDM rats(P < 0.01), compared to NIDDM model group). The result of GLUT4 protein expression was similar to GLUT4 mRNA expression. CONCLUSION: This experiment demonstrated that alcohol extract of Cornus officinalis Sieb. et Zucc can increase GLUT4 mRNA and its protein expression in NIDDM rats through promoting proliferation of islet and increasing postprandial secretion of insulin and therefore accelerate glucose transport.