胃转流术后血糖与胰升血糖素样肽-1改变的实验研究

Experimental study on the SD rats to observe the change of glucose and GLP-1 levels after gastric bypass

目的探讨胃转流手术(GBP)后糖代谢与胰升血糖素样肽-1(GLP-1)的变化规律。方法选取GK大鼠30只,随机分为5组,术后4周时检测OGTT,ELISA检测血浆总GLP-1的表达。结果与Ⅰ组术前相比,各组术后OGTT各时间点血糖水平均明显下降(P<0.05);与Ⅱ组术前相比,Ⅲ～Ⅴ组术后血糖水平差异无统计学意义(P>0.05);与Ⅰ组[空腹(42.7±4.9)pmol/L,餐后(47.5±7.9)pmol/L]相比,Ⅱ～Ⅴ组空腹和餐后30min血浆总GLP-1值上升(P<0.05);与Ⅱ组[空腹(54.0±6.5)pmol/L,餐后(75.1±13.8)pmol/L]相比,Ⅲ～Ⅴ组空腹和餐后30 min血浆总GLP-1值均呈上升趋势,餐后30min血浆总GLP-1表达明显上升(P分别为0.01、0.000、0.000);与Ⅲ组[空腹(54.0±6.5)pmol/L,餐后(75.1±13.8)pmol/L]相比,随着转流肠襻长度的增加,Ⅳ、Ⅴ组空腹和餐后30min血浆总GLP-1表达逐渐升高,Ⅴ组餐后30min血浆总GLP-1表达明显上升(P=0.01)。结论肠道GLP-1表达的最佳效应区域位于小肠中段,GBP对T2DM的治疗作用与术后血浆GLP-1水平上调相关,是手术治疗糖尿病的机制之一。

Objective To establish the stomach-preserving Roux-en-Y gastric bypass model in SD rats and investigate the changing laws of glucose metabolism and glucagon-like peptide-1（GLP-1） level after surgery.Methods Thirty SD rats were randomized into five groups： group I（sham operation）,groupⅡ（traditional bypass）,group Ⅲ（duodenum bypass）,group Ⅳ（jejunum bypass）,group Ⅴ（ileum bypass）.OGTT and total plasma GLP-1 expression were evaluated before and 4 weeks after operation for observation.Results Compared with group I,the blood glucose level in the experimental groups dropped significantly at all OGTT time points after surgery.Compared with group Ⅱ,the change in blood glucose level in the group Ⅲ,Ⅳ,and Ⅴ was not statistically significant after surgery（P0.05）.Compared with the total plasma GLP-1 expression in group I [fasting（42.7±4.9） pmol/L,after meal（47.5±7.9） pmol/L],the total plasma GLP-1 expression in group Ⅱ,Ⅲ,Ⅳ,and Ⅴ increased at fasting and 30 min after meal（P0.05）.Comparing with the total plasma GLP-1 expression in group Ⅱ [fasting（54.0±6.5） pmol/L,after meal（75.1±13.8） pmol/L],the total plasma GLP-1 expression in group Ⅲ,Ⅳ,and Ⅴ increased at fasting and 30 min after meal,especially in 30 min after meal（P=0.01,0.000,and 0.000 respectively）.Comparing with the total plasma GLP-1 expression in group Ⅲ [fasting（54.0±6.5） pmol/L,after meal（75.1±13.8） pmol/L],the total plasma GLP-1 expression in group Ⅳ and Ⅴ increased gradually at fasting and 30 min after meal owing to the increased length of intestinal loop,especially in group Ⅴ at 30 min after meal（P=0.01）.Conclusion The effective section of GLP-1 expression in gut locates in the middle part of small intestine,and the remission effect of GBP on T2DM is associated with increased GLP-1 expression,being one of the mechanisms of operative treatment for diabetes.