胃旁路术对2型糖尿病大鼠肝脏磷酸烯醇式丙酮酸羧激酶mRNA表达的影响

目的研究胃旁路术对2型糖尿病Goto-Kakizaki（GK）大鼠降糖作用及肝脏磷酸烯醇式丙酮酸羧激酶（PEPCK）mRNA表达的影响。方法将30只12周龄的雄性GK大鼠分为手术组（胃旁路术，10只）、假手术饮食控制组（10只）及假手术空白对照组（10只），术中取各组肝脏标本用于术后对照研究。观察手术前后空腹血糖、进食量及体质量变化情况。术后8周取各组肝脏标本,用实时荧光定量PCR（real-timePCR）检测各组肝脏手术前后PEPCKmRNA的表达变化。结果术后8周。手术组空腹血糖由术前（17．6±2．1）mmol／L下降至（7．5±0．9）mmol／L；胃旁路术后PEPCKmRNA的相对表达量由术前的1．08±0．38下降至O．41±0．10（P〈0．01），与空白对照组（1．04±0．12）比较，差异具有统计学意义（P〈0．01）；饮食控制组PEPCKmRNA的表达量则由术前的1．15±0．16上升至术后8周的2．54±0．82（P〈0．01）；较手术组显著增高（P〈0．01）。结论胃旁路术降低2型糖尿病血糖的作用机制可能与降低PEPCKmRNA的表达有关。

Effect of gastric bypass surgery on mRNA expression level of hepatic phosphoenolpyruvate carboxykinase in type 2 diabetic Goto-Kakizaki rats

Objective To investigate the effects of gastric bypass surgery （GBP） on hepatic phosphoenolpyruvate earboxykinase （PEPCK） mRNA expression in type 2 diabetic Goto-Kakizaki rats. Methods Male GK rats were randomized into three groups： gastric bypass surgery （n=10）, sham operation with diet restriction（n=10）, and sham operation alone（n=lO）. Liver specimens of GK rats were collected during the intraoperative period for self-control study and 8 weeks after surgery. Fasting blood glucose, food intake, and body weight were recorded before surgery and 1, 2, 4, 8 weeks after surgery. The expression of PEPCK mRNA was measured by real-time PCR. Results The fasting plasma glucose level decreased from（17.6±2.1） mmol/L before surgery to（7.5±0.9） mmol/L 8 weeks after surgery in GBP group. The level of PEPCK mRNA decreased from 1.08±0.38 before surgery to 0.41±0.10 8 weeks after surgery, significantly lower than that in sham operation alone group （1.04±0.12）（P〈0.01 ）. The level of PEPCK mRNA in diet restriction group increased from 1.15±0.16 before surgery to 2.54±0.82 8 weeks after surgery （P〈0.01）. The expression of PEPCK mRNA in diet restriction was significantly higher than that in CBP group （P〈0.01）. Conclusions GBP can significantly improve hyperglycemia in type 2diabetic GK rat models, which may be associated with the decrease of hepatic PEPCK mRNA level.