Experimental Study Of The Effect Of Roux-en-Y Gastric Bypass Surgery Upon Hepatic Glycometabolism Of GK Rats

Purpose:This study was conducted to spontaneous type2diabetic Goto-Kakizaki (GK) rats, rats in experimental implementation of Roux-en-Y gastric bypass (Roux-en-Y gastric bypass surgery, RYGB), were observed before and after operation of rat blood glucose, weight, HbA1c, fasting insulin, insulin resistance index and hepatic key enzymes of glucose metabolism, G-6-P PEPCK and GSK3beta changes, discuss RYGB operation on hepatic glucose metabolism influence and significance to the operation type, clinical treatment of type2diabetes and provide a theoretical basis.Methods:In line with type2diabetes diagnostic standard40GK rats were randomly divided into Roux-en-Y group (gastric bypass in resection of the stomach volume2/3, at a distance of about10cm cut the ligament of Treitz jejunum, the distal jejunum with gastric side to side anastomosis, proximal jejunum in gastrointestinal anastomosis. About10cm line jejunum side anastomosis, group A), sham operation group (from the ligament of Treitz10cm area around the cut end to end anastomosis of jejunum, in situ, group B).In preoperative and postoperative first,2,4weeks line dynamic glucose tolerance test (OGTT), fasting insulin, and according to the records of the body weight and insulin resistance index.In addition, in the preoperative and postoperative fourth weeks were measured in two groups of rats glycosylated hemoglobin (HbAIc) level.After fourth weeks of animal death, obtaining liver tissue, using reverse transcriptase polymerase chain reaction (RT-PCR) and Western hybridization in the detection of liver gluconeogenesis enzymes--glucose6phosphatase (G-6-P), phosphoenol pyruvate kinase (PEPCK) and glycogen synthesis key enzymes--glycogen synthase kinase3beta (beta GSK3). MRNA relative expression and protein content.In addition, the liver tissue paraffin-embedded sections, line glycogen staining, understanding of liver glycogen deposition.Results:compared with the preoperative, gastric bypass rats blood glucose, glycosylated hemoglobin, insulin resistance index and weight were significantly reduced (P<0.05) fourth weeks after operation, with the most significant, fasting insulin did not change significantly (P>0.05); while the false operation group rats, blood glucose glycated hemoglobin, insulin resistance index was progressively increased (P<0.05), while the weight of progressively decreasing trend (P<0.05), fasting insulin levels also showed no significant change (P>0.05).Compared with the sham operation group, gastric bypass after first,2,4weeks in rat body weight, blood glucose, insulin resistance index and fourth weeks after operation of glycosylated hemoglobin were at the same time points were significantly reduced (P<0.05), and fasting insulin levels showed no significant change (P>0.05); postoperative gastric bypass in groups of rats after fourth weeks of liver G-6-P, PEPCK and GSK3beta protein expression compared with sham operation group was significantly lower (P<0.05).Further testing revealed, gastric bypass after fourth weeks of liver G-6-P, PEPCK and GSK3beta mRNA relative expression than in sham operation group were decreased by25.9%, 21%and18.9%(P<0.05).In addition, the gastric bypass group fourth weeks after operation of liver tissue section staining revealed hepatic glycogen deposition compared with sham operation group increased significantly.Conclusion:Roux-en-Y gastric bypass operation can significantly decrease the GK rats blood sugar.Meanwhile, the gastric bypass postoperative hepatic key enzymes of glucose metabolism (G-6-P, PEPCK and GSK3beta) mRNA and protein abnormal expression of hepatic gluconeogenesis, leading to decreased, liver glycogen synthesis is increased, thereby improving the rat postoperative hepatic insulin resistance, which leads to the hypoglycemic effect, a series of this causal association may be gastric bypass operation has obvious hypoglycemic effect of one of the important mechanisms.