The Effect of Surgical Stress on Insulin Resistance in Rats / 대한내분비학회지

ABSTRACT

BACKGROUND: It has been reported that surgical stress increased insulin resistance in human. However, there was no research about insulin resistance induced by surgical sttess in Korea. Catheters needed to be inserted in carotid artery and jugular vein of male Sprague Dawley rats to perform euglycemic hyperinsulinemic clamp procedures. The insertion of catheters in rats is a major surgery, which may increase insulin resistance. The purpose of the study is to determine whether surgical stress influence the insulin resistance. METHODS: The euglycemic hyperinsulinemie clamp procedures were performed 5 hours and 7 days after insertion of catheter in carotid artery and jugular vein. A continuous intravenous infusion of insulin was started at a rate of 12 mU/kg/minute and continued for 2 hours. Twenty-five percent glucose solution was infused through the venous line at a various rate to maintain blood glucose at 5.0-5.6 mmol/L and calculated the glucose disposal rate. Blood was collected from arterious line every 5 minutes and measured serum glucose and insulin levels. RESULTS: Prior to the clamp procedures, serum glucose levels of 5 hours and 7 days after catheter insertion were 29.8 +/- 9.8 and 7.8 +/- 0.9mmol/L, respectively. However, basal serum insulin levels were not different between 5 hours and 7 days after surgery. The glucose disposal rates were remarkably higher in rats who recovered from the surgery (22.0 +/- 7.8 mg/kg/minute) than those who did not (2.2 +/- 2.7 mg/kg/minute). Thus, surgical stress increased insulin resistance in male Sprague Dawley rats. CONCLUSION: Since surgery of catheter insertion increased insulin resistance about 10 times, euglycemic hyperinsulinemic clamp study should be performed in rats who completely recovered from the surgical stress.