Study On The Glycometabolism Improvement By Roux-en-y Gastric Bypass Surgery In GK Rats

The study intended to explore the reasons of RYGB surgery on glucometabolismimprovement in GK rats. We selected healthy male twenty-four GK rats and eightWistar rats to perform the experiment. GK rats were randomly divided into threegroups: RYGB surgery group, sham surgery pair-feed control group and diabeticgroup, n=8; Wistar rats were set as negative diabetic control group. According to thesurgery design, eight GK rats performed RYGB gastric bypass surgery and eight GKrats performed sham surgery; The body weight and food intake of rats were measuredperiodically post surgery in each group; the results showed that the body weights ofthe RYGB surgery group rats had been well controlled post RYGB surgery; and thedata indicated the body weight of RYGB surgery was significantly lower than thesham surgery group and diabetic group (P <0.05) with equally food intake.Then we conducted oral glucose tolerance test and insulin tolerance test onemonth, three months, six months post surgery, respectively; the insulin detection andintravenous glucose tolerance test were performed six months post the operation. Theresults showed that the glucose tolerance test of RYGB surgery rats was significantlyimprovement than the control group (P <0.05). However, the insulin sensitivity ofRYGB surgery rats1month post surgery was not improved until3month post thesurgery compared to control groups.The rats were sacrificed and the tissues were extracted after all the in vivoexperiments finished; Western blot data showed the insulin action associated proteinswere activated in the liver of RYGB surgery rats. The phosphorylated insulinreceptor-β and phosphorylated protein kinase B levels were significantly increased (P<0.01); Immunostaining results indicated that islet endocrine cell distribution andsecretory function of in RYGB surgery rats were significantly improved, the detectionof β-cell release insulin level was significant improved(P <0.05). We also detected plasma free fatty acids, and triglycerides and cholesterol, and the results showed asignificant decrease in the levels of lipids in RYGB surgery GK rats (P <0.05).According to the results, the lipids reduction can significantly eases the body’sinsulin resistance, promotes the recovery of islet function and activates the expressionof insulin functionally related proteins in RYGB GK rats; which may be plays a keyrole in the glucometabolism improvement in GK rats post RYGB surgery.