Effects of bushen tongmai recipe on insulin signaling in insulin resistant rats / 中国中西医结合杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of Bushen Tongmai recipe (BSTMR) on the tyrosine phosphorylation of insulin receptor (InsR) and insulin receptor substrate-1 (IRS-1) after insulin stimulation in muscle and fat tissues of insulin resistant (IR) rats induced by high-fat forage.</p><p><b>METHODS</b>Male Wistar rats were randomly divided into normal group (normal forage), model group (high fat forage, in which 61% calories were supplied by fat) and treated group (same forage as model group and treated with BSTMR). All animals were fed for 8 weeks, fasting blood glucose (FBG), blood glucose (BG) levels 1- and 2-hrs after glucose loading were determined routinely, serum fasting insulin (Ins) was determined with radioimmunoassay (RIA) and tyrosine phosphorylation level of InsR and IRS-1 in fatty and muscular tissues was measured by immunoprecipitation and Western blot.</p><p><b>RESULTS</b>Compared with the model group, FBG in the treated group changed insignificantly, but level of Fins decreased markedly (P < 0.01), so the insulin sensitivity index was significantly elevated in the treated group (P < 0.01), levels of BG 1- and 2-hrs after glucose loading in the treated group were greatly improved in comparison with those in the model group (P < 0.05 and P < 0.01 respectively). Meanwhile, the density of electrophoresis bands of tyrosine phosphorylated InsR and IRS-1 proteins in muscular and fatty tissues in the treated group increased obviously.</p><p><b>CONCLUSION</b>BSTMR could attenuate the insulin resistance in rats, its pharmaceutical mechanisms might be closely related with the elevation of the tyrosine phosphorylation levels of InsR and IRS-1 in muscular and fatty tissues after insulin stimulation, and improvement of insulin signal transduction in target tissues.</p>