title: Preoperative oral carbohydrate improved postoperative insulin resistance in rats through the PI3K/AKT/mTOR pathway.
abstract: BACKGROUND
  Preoperative oral carbohydrate (OCH) improves postoperative insulin resistance (PIR) and insulin sensitivity. However, the exact mechanisms involved in the improvement of PIR with respect to preoperative OCH are still not clear. The aim of this study was to investigate the involvement of preoperative OCH and PI3K/AKT/mTOR pathway in reducing PIR in rats.
  
  
  METHODS
  Forty male Sprague-Dawley rats were randomly assigned to PreOp, glucose, saline, and fasting groups. Rats in the PreOp, glucose, and saline groups received OCH, 5% glucose solution, and saline, respectively. Rats in the fasting group did not receive anything but were fasted 3 h before surgery. Blood glucose, insulin and leucine levels, and insulin resistance, secretion, and sensitivity indexes were measured before and after surgery. mRNA and protein (total and phosphorylated) levels of mTOR, IRS-1, PI3K, PKB/AKT, and GlUT4 were measured using real-time polymerase chain reaction and Western blot in skeletal muscles.
  
  
  RESULTS
  In the PIR experiment, blood glucose, serum insulin, insulin resistance, and serum leucine levels were all significantly lower in the PreOp group than in the other 3 groups (P<0.05) after surgery. HOMA-ISI were higher in the PreOp group vs the other 3 groups after surgery (P<0.05), and HOMA-b in the PreOp group was higher than that in the other 3 groups at 30 and 120 min after surgery. Additionally, post-operative phosphorylated IRS-1, PI3K, and AKT protein levels were significantly higher in the PreOp group than in the other 3 groups (P<0.05), but no significant differences were observed in their respective protein levels (P>0.05).
  
  
  CONCLUSIONS
  OCH decreases postoperative insulin resistance and improves postoperative insulin sensitivity in skeletal muscles through the PI3K/AKT/mTOR pathway.
authors.affiliation: Department of General Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, Shanghai, China (mainland).
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Library, Second Military Medical University, Shanghai, China (mainland).
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of General Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, Shanghai, China (mainland).
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of General Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, Shanghai, China (mainland).
authors.forename: Canping
authors.initials: C
authors.lastname: Ruan
authors.affiliation: Department of Thoracic Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, Shanghai, China (mainland).
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.affiliation: Department of General Surgery, Shanghai Zhabei Central Hospital, Shanghai, China (mainland).
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, Shanghai, China (mainland).
authors.forename: Zhiqian
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of General Surgery, Tenth People's Hospital of Tongji University, Shanghai, China (mainland).
authors.forename: Huanlong
authors.initials: H
authors.lastname: Qin
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D015153:Blotting, Western; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D013505:Digestive System Surgical Procedures / Q000379:methods*; D005947:Glucose / Q000008:administration & dosage; D007328:Insulin / Q000097:blood; D055504:Insulin Receptor Substrate Proteins / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D007421:Intestine, Small / Q000601:surgery*; D007930:Leucine / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011184:Postoperative Period; D011300:Preoperative Care / Q000379:methods*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D005947:Glucose; D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; D007930:Leucine; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; C526296:Irs1 protein, rat; C546845:mTOR protein, rat