title: Insulin Control of Blood Glucose and GLUT4 Expression in the Skeletal Muscle of Septic Rats.
abstract: BACKGROUND
  Insulin resistance is common in septic patients. The level at which the serum glucose should be maintained using insulin infusions for optimal utilization by skeletal muscles is not yet established.
  
  
  OBJECTIVE
  The objective of the present study was to compare glucose transporter 4 (GLUT4) mRNA and GLUT4 expression and glucose utilization at the recommended glucose levels of 6-8 mmol/L (110-140 mg/dL) and 8-10 mmol/L (140-180 mg/dL) in septic rats.
  
  
  METHODS
  This was a prospective randomized study using 44 Sprague-Dawley rats (260-330 g). Rats were anaesthetized with gaseous diethyl ether. Catheters were implanted into the jugular vein and artery. Following a laparotomy, rats in the experimental group (n = 36) were rendered septic by standard caecal ligation and puncture (CLP) and intraperitoneal lipopolysaccharide (LPS) infusion (O111:[B4], 1 mg/kg). Control animals (n = 8) underwent laparotomy, but no caecal ligation or puncture and no LPS injection. Four experimental groups were studied: sham-operated control, sepsis treated with fluid maintenance only, sepsis treated with fluid and insulin infusion controlling blood glucose concentration at 6-8 mmol/L and sepsis treated with fluid and insulin infusion controlling blood glucose concentration at 8-10 mmol/L. Hyperinsulinaemic-euglycaemic clamp experiment was done before fluid maintenance and insulin treatment to calculate average glucose infusion rate.
  
  
  RESULTS
  All septic rats were markedly hyperglycaemic compared with sham-operated controls two hours after operation. Glucose infusion rate during hyperinsulinaemic-euglycaemic clamp experiment was slower in septic rats, suggesting that they were insulin resistant. At the 12th and 24th hour, skeletal muscle was taken to observe pathological change and analyse the GLUT4 mRNA and GLUT4 levels. There were more inflammatory cells, less GLUT4 mRNA and GLUT4 expression in the skeletal muscles of septic rats. Insulin increased the expression of GLUT4 mRNA and GLUT4 in the skeletal muscle of septic rats. Among all septic rats, the expression of GLUT4 mRNA and GLUT4 was more in the 8-10 mmol/L group.
  
  
  CONCLUSIONS
  Blood glucose concentration of 8-10 mmol/L results in more glucose utilization than 6-8 mmol/L in the skeletal muscle of septic rats during insulin therapy.
authors.affiliation: Division of Pediatric Emergency Medicine and Critical Care Medicine, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102, PR China.
authors.forename: G P
authors.initials: GP
authors.lastname: Lu
authors.affiliation: Division of Pediatric Emergency Medicine and Critical Care Medicine, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102, PR China.
authors.forename: P
authors.initials: P
authors.lastname: Cui
authors.affiliation: Division of Pediatric Emergency Medicine and Critical Care Medicine, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102, PR China.
authors.forename: Y
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Division of Pediatric Emergency Medicine and Critical Care Medicine, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102, PR China.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Lu
authors.affiliation: Division of Pediatric Emergency Medicine and Critical Care Medicine, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai 201102, PR China.
authors.forename: L E
authors.initials: LE
authors.lastname: Zhang
authors.affiliation: The University of British Columbia and the BC Children's Hospital, 4480 Oak Street, Room B245, Vancouver, BC V6H 3V4, Canada. nkissoon@cw.bc.ca.
authors.forename: N
authors.initials: N
authors.lastname: Kissoon