title: [Effect of gastric bypass operation on expressions of adipic insulin receptor and insulin receptor substrate-1 in rats with type 2 diabetes mellitus].
abstract: OBJECTIVE
  To investigate the expressions of adipic insulin receptor β(IR-β) and insulin receptor substrate-1 (IRS-1) after gastric bypass (GBP) operation in spontaneous rats with type 2 diabetes mellitus(GK rats) and to elucidate the mechanisms of GBP in improving insulin resistance.
  
  
  METHODS
  Thirty male GK rats aged 8 weeks were randomly divided into 3 groups according to the table of random number: the operation group (GBP, 10 rats), the sham operation group (the same sites were cut off as GBP and end to end anastomosis was performed in site, 10 rats) and the diet pairing group (the same kind and weight dieting as the operation group, 10 rats), besides 10 male SD rats aged 8 weeks were used as blank control group (free eating and drinking). Four weeks before and after operation, levels of fasting blood glucose(FPG) and fasting insulin(FINS) were measured, HOMA-IR was calculated respectively, and compared among 4 groups. Then rats were decapitated to retrieve the omentum. Expressions of adipic IR-β and IRS-1 protein were detected by Western blot.
  
  
  RESULTS
  Compared with the preoperative levels, the FPG and HOMA-IR decreased significantly 4 weeks after surgery in operation group [(5.13±0.22) vs. (11.73±0.37) mmol/L, 2.16±0.18 vs. 5.10±0.29, P<0.05), reaching the level of blank control group(P>0.05). FINS showed no obvious change in these 4 groups after operation(all P>0.05). Expressions of IR-β and IRS-1 were significantly higher in operation group than those in other 3 groups 4 weeks after the operation(all P<0.05).
  
  
  CONCLUSIONS
  Expressions of adipic IR-β and IRS-1 in insulin signal transmission of rats with type 2 diabetes mellitus after GBP are up-regulated, meanwhile insulin resistance can be improved and insulin sensibility increases.
authors: Department of Hepatobiliary Laparoscopic Surgery, ZhongShan Hospital, DaLian University, Dalian 116001, China. doctorxujian@163.com.
authors: Jian
authors: J
authors: Xu
authors: Shan
authors: S
authors: Lin
authors: Jiajun
authors: J
authors: Yin
mesh_terms: D000818:Animals; D001835:Body Weight; D003924:Diabetes Mellitus, Type 2; D015390:Gastric Bypass; D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; D007333:Insulin Resistance; D008297:Male; D051381:Rats; D011972:Receptor, Insulin; D015854:Up-Regulation
chemical_list: D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; C526296:Irs1 protein, rat; D011972:Receptor, Insulin