糖尿病大鼠胃旁路手术前后抑胃肽水平的检测及其意义

Detection of gastric inhibitory polypeptide levels of diabetic rats before and after gastric bypass surgery and its significance

目的:检测糖尿病大鼠胃旁路手术(GBP)前后抑胃肽(GIP)水平的变化,探讨GBP治疗2型糖尿病的可能机制。方法:将40只8周龄的Wistar大鼠腹腔内注射链脲佐菌素(STZ)制作糖尿病大鼠模型,并随机分为对照组、饮食控制组、假手术组和手术组,每组10只。对照组大鼠自由进食,饮食控制组控制大鼠进食量为15g.d-1,假手术组大鼠行GBP后行原位端端吻合,手术组大鼠行GBP;分别于术前及术后1、2、4、8周检测各组大鼠空腹、餐后血糖和胰岛素及GIP水平。结果:与术前比较,手术组大鼠术后空腹和餐后血糖显著下降并低于其他各组的相应时间点(P<0.01);空腹和餐后血清胰岛素水平显著升高,且明显高于其他各组的相应时间点(P<0.01);术后第4和8周手术组大鼠空腹、餐后血清GIP水平明显低于其他各组相应时间点(P<0.01);术后1周,手术组及假手术组大鼠平均进食量均减少,之后均逐渐增加。手术组大鼠平均进食量自术后第2周起再次减少,术后第3周至实验结束少于假手术组和对照组(P<0.05)。与术前比较,术后1周内手术组、假手术组、饮食控制组大鼠体质量均明显下降(P<0.05)。结论:糖尿病大鼠施行GBP后血糖及血清GIP水平下降,其机制可能与GIP分泌减少和解除周围组织胰岛素抵抗有关。

Objective To measure the changes of gastric inhibitory polypeptide（GIP） of the diabetic rats before and after gastric bypass surgery（GBP） and to discuss the possible mechanism of GBP in treatment of type 2 diabetes mellitus.Methods The animal models with diabetes mellitus were established in 40 eight weeks old Wistar rats by intraperitoneal injection with STZ,then all the rats were randomly divided into control,diet control,sham operation and operation groups.The rats in control group took food freely,the rats in diet control group were controlled with food intake at 15 g·d-1,the rats in sham operation group underwent in situ anastomosis after GBP,and the rats in operation group received GBP.Results Compared with before operation the fasting and postprandial plasma glucose levels in operation group 4 and 8 weeks after operation were significantly lower than those in the other 3 groups at the corresponding time points（P0.01）;the mean fasting and postprandial serum insulin levels were significantly higher than those in the other groups at the corresponding time points（P0.01）.Compared with before operation,the serum GIP levels in operation group 4 and 8 weeks after operation were decreased significantly（P0.01）,and the fasting and postprandial serum GIP levels in operation group were significantly lower than those in the other groups at the corresponding time points（P0.01）.1 week after operation,the average intakes in operation group and sham operation group were decreased and then increased.The average intake in operation group was decreased again from the second postoperative week and was less than those in sham operation group and control group till the experiment ended（P0.05）.Compared with before operation,the body mass of the rats in operation group,shame operation group and diet control group were decreased significantly 1 week after operation（P0.05）.Conclusion The blood glucose and the serum GIP levels of the diabetic rats after GBP are decreased,and its mechanism may be related to decreasing GIP secretion and lifting the peripheral tissue insulin resistance.