The Effects Of GLP-1 To The Expression Of Glycogen Synthetase And The Study With MAPK Cell Signalling Pathway In Muscle Cells

Objective:1.L6 muscle cells were incubated in the medium in the presence of glucagons-like peptide-1(GLP-1) for some time,to observe the effects to the expression of glycogen synthetase.2.Utilized UO126(MAPK inhibitor) to block the MAPK pathway,and then to detect the effects to the expression of glycogen synthetase from GLP-1,thereby explore the pathways of glycogen synthesis in muscle cells mediated by GLP-1.3.To supply theory foundation for the insulin-like effects mediated by GLP-1 in extrapancreatic tissues and correlated mechanism.Method:1.Revived L6 muscle cells,to observe the contion of growth and increment by inverted microscope.2.L6 muscle cells were equally divided into 6 groups:A:control group;B:GLP-1 (10^-9mol/L) group;C:GLP-1(l0^-9mol/L) +UO126(10μmol/L) group;D:insulin(10 (-9)mol/L) group;E:insulin(10^-9mol/L)+UO126(10μmol/L) group;F:GLP-1(10⁹ mol/L)+insulin(10^-9mol/L) group.A,B,C,D,E and F 6 group were incubated separately for 3min,30 min,A,B,D and F group were incubated for 24 hourso3.Utilized Western Blot and immunohistochemistry to detect the expression of glycogen synthase in muscle cells.Result:1.Expression of glycogen synthase of GLP-1(10^-9mol/L) group were all significantly higher than control group at 3min,30min and 24 hour(were 1997.33±115.47vs 1444.00±94.64,P＜0.05;1465.33±86.00 vs1267.33±66.46,P＜0.05;1426.67±24.54vsl326.33±18.84,P＜0.05 respectively,n=3).2.Expression of glycogen synthase of GLP-l(10^-9mol/L)+insulin(10^-9mol/L) group were all significantly higher than control group at 3 min,30min and 24 hour (were 2209.33±186.18vs 1444±94.64,P＜0.05;1565.00±15.39 vsl267.33±66.46,P ＜0.05;1428.00±36.51 vsl326.33±18.84,P＜0.05,respectively,n=3)。3.Expression of glycogen synthase of GLP-1(10^-9mol/L) +UO126(10μmol/L) group were significantly lower than GLP-1(10^-9mol/L) group at 3 min and 30min (were 1752.67±198.65 vsl997.33±115.47,P＜0.05;1395.33±78.21 vsl465.33±86.00,P＜0.05,respectively,n=3),however,were significantly higher than control group at 30 min(1395.33±78.21 vsl267.33±66.46,P＜0.05,n=3).Conclusion:Our results in vitro study demonstrated that GLP-1 can directly up-regulate the expression of glycogen synthase in muscle cells,and this effect can maintain for a long time.MAPK inhibitor can inhibite the up-regulation effect to glycogen synthesis expression mediated by GLP-1 in muscle cells,indicate that MAPK pathway can be important to the up-regulation with glycogen synthesis expression mediated by GLP-1 in muscle cells.