回肠转位术对自发性糖尿病大鼠肝脏脂代谢的影响及其意义

目的探讨回肠转位术(ileal transposition,IT)对自发性糖尿病(goto-kakizaki,GK)大鼠肝脏脂代谢的影响及意义。方法 20只GK大鼠按随机数字表法分为手术组与假手术组,每组10只。手术组行回肠转位术,假手术组行末端回肠离断后原位吻合术。分别于术前,术后1、2、4周动态检测2组大鼠血液中空腹血糖、口服葡萄糖耐量试验(OGTT)2 h血糖,于术前及术后4周测定大鼠血液中空腹胰高血糖素样肽-1(glucagon-like-peptide-1,GLP-1)、游离脂肪酸(free fatty acids,FFA)、胆固醇(total cholesterol,Tch)、甘油三酯(triglyceride,TG),于术中及术后第4周获取大鼠肝脏组织行免疫组化油红O染色,观察肝脏TG沉积情况并用图形图像处理器计算平均灰阶值。结果手术组术后空腹及OGTT2 h血糖值均呈明显的下降趋势,至术后第2、4周时其血糖值显著低于术前(P<0.05);假手术组手术前后空腹及OGTT2 h血糖值无显著变化(P>0.05)。术后第4周,手术组大鼠血液中GLP-1含量较术前显著增加(P<0.05),FFA较术前显著降低(P<0.05),TG及Tch手术前后无明显变化(P>0.05);假手术组此3个指标无显著差异(P>0.05)。手术组术后第4周肝脏组织切片内TG沉积现象明显比术前改善(P<0.05),假手术组变化不明显(P>0.05)。结论回肠转位术能显著降低GK大鼠的血糖,其可能机制是手术后通过改善肝脏脂质代谢,食物过早刺激末端回肠,引起GLP-1分泌的增加,使胰岛素抵抗得到缓解。

Effect of ileal transposition on lipid metabolism in liver of goto-kakizaki rats and its significance

Objective To study the effect of ileal transposition(IT) on lipid metabolism in liver of goto-kakizaki(GK) rats.Methods Twenty GK rats were randomly divided into operation group and sham operation group according to the random digital representation method.Rats in operation group underwent IT and those in sham operation group underwent in situ anastomosis of the distal ileal after transection.Levels of fasting and 2 h OGTT glucose were measured before and 1,2,4 weeks after operation,and levels of fasting glucagon-like-peptide-1(GLP-1),free fatty acids(FFA),total cholesterol(Tch) and triglyceride(TG) were measured 4 weeks before and after operation.Liver tissue samples were taken 4 weeks before and after operation and stained with oil red O.TG sedimentation in liver was observed and its average gray-scale value was calculated with an image and graphic processor.Results The fasting and 2 h OGTT glucose levels were significantly lower in operation group 2 and 4 weeks after operation than before operation(P<0.05) with no significant difference observed in sham operation group.The GLP-1 level was significantly higher while the FFA level was significantly lower in operation group in 4 weeks after operation than before operation(P<0.05).However,no significant difference was observed in TG and Tch level between the two groups before and after operation(P>0.05).The TG sedimentation in liver tissue samples was significantly less in operation group 4 weeks after operation than before operation with no significant change observed in sham operation group(P>0.05).Conclusion IT can significantly reduce the blood glucose level in GK rats by improving the postoperative lipid metabolism in liver,and increasing GLP-1 secretion and alleviating insulin resistance due to the early arrival of food to the terminal ileum.