Research On Effects Of Arsenic On Glucose Transportation Of Insulin Sensitivity

Objective:To investigate the effects of Arsentic on the glucose metabolism of insulin-dependence in 3T3-L1 adipocytes and discuss the possible mechanism.Methods; (1) The differentiation of 3T3-L1 preadipocytes was identified With rathonum red. (2) The proliferation of 3T3-L1 preadipocytes was detected by MTT. (3) The amount of glucose consumption of the 3T3-L1 adipocytes after incubation with Arsenic for 48h was determined by Glucose oxidase method. (4) Analysis of an insulin-responsive glucose transporter (GLUT4) was done by Immunofluorescence.. (5) Western blot was used to determine the protein expression of total GLUT4 and nuclear NF-κBp65. (6) The expression of IL-6, IL-8 and TNF-a in cells were evaluated by ELISA.Results:(1) The differentiation of 3T3-L1 preadipocytes was identified With rathonum red and the adipocytes was red. The amount of 3T3-L1 adipocytes was decreased (P<0.05) compared with the normal group. (2) The proliferation of 3T3-L1 preadipocytes affected with low concentration of Arsenic(≤5μmol/L) was significantly increased, but at 10,15 and 20μmol/L Arsenic, the proliferation of 3T3-L1 preadipocytes was decreased. And the viability of 3T3-L1 adipocytes was decreased incubated with Arsenic at 1,5,10,15 and 20μmol/L (p<0.05, compared with the normal group), and does-dependently. (3) Treated with Arsenic at 1,5,10,15,20μmol/L, the Glucose consumption of 3T3-L1 adipocytes was decreased (P<0.05, compared with the normal group), there was a dose-effect relationship of Arsenic in 3T3-L1 adipocytes(P<0.05); With 1μm insulin stimulation, the glucose consumption of 3T3-L1 adipocytes treated with Arsenic was much more lower than that of insulin stimulated of 3T3-L1 adipocytes (P<0.01). (4) Arsentic inhibited the translation of GLUT4 of 3T3-L1 adipocytes incubated with 1μm insulin, the strength of GLUT4 immunofluorescence was weaker than that of normal group. (5)The expression of GLUT4 was decreased in Arsenic group(P<0.05), but the expression of nuclear NF-κBp65 was increased (p<0.01); After the treatment with Arsenic at 1,5,10,15,20μmol/L for 12,24 or 48h, the expression of IL-6, IL-8 and TNF-a were increased in a dose and time dependent manner (P<0.05).Conclusion:(1) The differentiation of 3T3-L1 preadipocytes was succeed. (2) Arsenic at low concentration can increase the proliferation of 3T3-L1 preadipocytes, and Arsenic at high or low concentration can inhibit the viability of adipocytes at all. (3) Arsenic decreases insulin sensitivity and induces insulin resistance, the molecular mechanism of which might be associated with the high expression of nuclear NF-κBp65, IL-6, IL-8 and TNF-a in 3T3-L1 adipocytes.