Improvement Of Glycometabolism After The Operation Which Resects The Inferior Segment Of Small Intestine With The Terminal Ileum Retained In A Type2Diabetes Rat Model And The Preliminary Investigate Of Its Mechanism

Objective:Surgical operations which shorten the intestinal tract between the stomach and the terminal ileum result in an early improvement in type2diabetes, and one possible explanation is the arrival of undigested food in the terminal ileum. This study was designed to evaluate the role of the distal ileum in the improvement of glucose control in type2diabetic rat model who underwent thid kind of surgery and to investigate its mechanism.Methods:The operation which resects the inferior segment of small intestine with the terminal ileum retained was performed in type2diabetic rat model which was setuped by injecting8weeks old SD rats with streptozotocin (STZ)30mg/kg after it had been given high calorie for8weeks. The operation was compared to sham-operated diabetic rats and a control group of diabetic rats. Fasting glycemia、food intake and body weight were measured. An oral glucose tolerance test (OGTT) was performed1weeks before the operation and4weeks and8weeks after the surgery while insulin and GLP-1were measured during the OGTT30min.Results:Fasting plasma glucose and glucose tolerance improved significantly in the operation group compared with both the sham-operation group and control group after the surgery (P<0.05). No differences were noted between the three groups in terms of insulin levels (P<0.05). Food intake in the operation group and the sham-operation group had declined significantly compared with the control group1week after surgery (P<0.05), and no differences had been recorded between the three groups since2weeks after surgery (P>0.05).The weight increment in the operation group was obviously less than that in both the sham-operation group and control group (P<0.05). GLP-1levels were significantly higher in the operation group compared with the sham-operated rats (P<0.05).Conclusions:The operation which resects the inferior segment of small intestine with the terminal ileum retained is effective in inducing an improvement in fasting plasma glucose and glucose tolerance in type2diabetes rats. The possible mechanism underlying the early improvement of diabetes after this surgery may be due to the increased GLP-1secretion, and the terminal ileum may play an important role in this process. Results of our study support the hypothesis that the contact of undigested food in the terminal ileum ahead of time can control type2diabetes.