RESUMO
Objective To investigate mRNA expression of hepatic phosphoenolpyruvate carboxykinase (PEPCK) after gastric bypass surgery (GBS) in rats with type 2 diabetes mellitus (T2DM).Methods 36 male Goto-Kakizaki rats,aged 12 weeks,were randomly divided into GBS,sham operation with diet restriction (SO),and sham operation alone(control) groups(n=12 per group).The blood lipid levels and fasting plasma glucose (FPG)levels in rats before and 8 weeks after surgery were measured and compared.The insulin sensitivity index (ISI)was calculated.Real-time polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of PEPCK mRNA and protein in hepatocytes at 8 weeks after operation.Results 8 weeks after operation,the blood lipid levels [TC(1.25±0.08) mmol/L,TG (0.93±0.10) mmol/L,FFA(0.88±0.12) mmoUL] in GBS group were significantly lower than those before operation [TC (2.31 ±0.52) mmol/L,TG(1.44±0.27) mmol/L,FFA (1.08±0.06) mmol/L] (P＜0.05).The fasting blood glucose levels in GBS decreased from (11.73±0.37) mmol/L to (5.13±0.22) mmol/L (P＜0.05),and ISI in GBS group increased from (-5.78±0.10) to (-4.64±0.15) (P＜0.05).PEPCKmR-NA (3.97±0.30) and protein (1.60±0.31) expression significantly reduced (P＜0.05).Conclusion GBS can reduce blood glucose in T2DM rats while improving glucose tolerance and hyperglycemia,and the mechanism appears to be associated with a decrease of hepatic PEPCK mRNA and protein expression.
RESUMO
Objective To investigate the expression of hepatic glucose transporter-2 ( GLUT-2 ) and glu-cokinase(GCK)after gastric bypass(GBP)in type 2 diabetes mellitus(T2DM)GK rats and to discuss the mecha-nism of GBP improving insulin resistance .Methods 30 male GK rats aged 8 weeks were randomly divided into 3 groups:the operation group(10 rats), the sham operation group(10 rats)and the diet control group(10 rats), and 10 male SD rats aged 8 weeks were made as blank control group .The levels of fasting plasma glucose ( FPG) and fasting insulin(FINS)were measured and compared among the 4 groups before and 1,2 and 4 weeks after the operation and then the rats were sacrificed to retrieve the liver .The expressions of GLUT-2 and GCK mRNA and protein were detected by PT-PCR and Western blot respectively .Results As for GK operation group ,FPG levels at the 1st, 2nd,and 4th week after surgery ((11.06 ±0.52) mmol/L,(7.49 ±0.34) mmol/L,(5.20 ±0.08) mmol/L)respectively)were all lower than that before surgery (all P<0.05),and FINS level at the 4th week after surgery increased from(11.90 ±0.75)mmol/L to(14.20 ±1.23)mmol/L(P<0.05).The expressions of GLUT-2 and GCK mRNA and protein significantly increased in GK operation group 4 weeks after surgery ( P<0.01 ) . Conclusion The expressions of hepatic GLUT-2 and GCK in insulin signal transmission in T2DM rats are up-regu-lated after GBP , which enhance the signal transmission of insulin receptor , and improves the insulin sensibility .