A Research About The Hypoglycemic Effect And Mechanism Of GIP For The Duodenal-proximal Jejunal Bypass On The GK Rats

Objective: By detcting the change of blood glucose and GIP blood levels, GIPmRNAand GIP protein expression levels after the duodenal-proximal jejunal bypassprocedure,Observe the mechanisms and procedures for the treatment.Methods: Male rats(20GK mice and20SD mice) randomly underwent one of thefollowing procedures:GK operation(n=10),GK sham operation(n=10) or SDoperation(n=10),SD sham operation (n=10).GK operation group and SD operation groupunderwent the duodenal-proximal jejunal bypass procedure. Fasting plasma glucose andoral glucose tolerance(OGTT) were measured pre-and postoperative1,2,4,12weeks.Insulin sensitivity(ITT), plasma GIP levels,GIPmRNA and GIP protein expression levelswere detected pre-and postoperative12weeksResults:1. Compared with GK sham-operation group and its preoperative ones, thefasting plasma glucose levels of GK operation group were significant lower Sincepostoperative2week(P<0.05).2. Compared with GK sham-operation group and its preoperative ones, oral glucosetolerance(OGTT) levels of GK operation group were significant lower Since postoperative2week(P<0.05).3. Compared with GK sham-operation group,the Insulin sensitivity(ITT) of GKopration group was significant higher during the same time after the surgery(P<0.05).4. In GK operation group, plasma GIP levels were significant lower after theduodenal-proximal jejunal bypass procedure(P<0.05).5. Immunohistochemistry showed that all four groups had GIP positive or strongpositive expression.In SD opration group and SD sham-operation group,no strong positiveexpression of GIP.In GK sham-opration group,GIP positive expression rate was 12.5%(1/8),in which strong positive expression rate of87.5%(7/8). In GK oprationgroup,GIP positive expression rate was66.6%(6/9),in which strong positive expression rateof33.3%(3/9).6. Compared with GK operation group,the expression of GIP mRNA in GKsham-operation group were much higher with RT-PCR(P<0.05).The expression of GIPmRNA in SD operation and SD sham-operation group were much lower than in GKsham-operation group (p<0.05),but there was no significant difference between SDoperation and SD sham-operation group(p>0.05).Conclusions:The duodenal-proximal jejunal bypass operation can significantlydecrease the blood glucose level of GK rats,and the mechanism may be that the operationcan avoiding the stimulus from food on the duodenum and upper jejunum. BothGIPmRNA and GIP protein expression levels decrease correspondingly,and improve thesymptoms of diabetes finally.