[Effects of bushen tongmai recipe on insulin signaling in insulin resistant rats].
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Institute of Integrated Traditional and Western Medicine, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030.
Dong-mei
DM
Huang
Fuer
F
Lu
Guang-ying
GY
Huang
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism*; D055504:Insulin Receptor Substrate Proteins; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D010750:Phosphoproteins / Q000187:drug effects; D010766:Phosphorylation; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D011972:Receptor, Insulin / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D014443:Tyrosine / Q000378:metabolism
D001786:Blood Glucose; D004365:Drugs, Chinese Herbal; D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; C526296:Irs1 protein, rat; D010750:Phosphoproteins; D014443:Tyrosine; D011972:Receptor, Insulin