Effects of C-peptide on Expression of eNOS by Cultured Human Umbilical Vein Endothelial Cells in Hyperglycemia

Objective:To investigate the effects of C-peptide on expression of endothelium nitric oxide synthase(eNOS)by cultured human umbilical vein endothelial cells(HUVEC)in hyperglycemia.Methods:HUVEC were incubated at different concentrations of glucose and C-peptide for72hours.Using semi-quantitative RT-PCR techniques,the expression of eNOS mRNA in HUVEC was measured.Results:In physiologic concentration of glucose(5.5mmol/L),low concentration of C-peptide(0.3nmol/L)reduced the expression of eNOS mRNA,and physiologic(3nmol/L)and high(30nmol/L)concentration of C-peptide could increase it(P0.01).In high concentration of glucose(33.3mmol/L),the expression of eNOS mRNA was decreased(P0.01),and the expression of eNOS mRNA increased after added physiological and high concentration of C-peptide(P0.01).Conclusion:C-peptide can affect the expression of eNOS mRNA in HUVEC.Physiological and high concentration of C-peptide can reduce the inhibition of high glucose on exˉpression of eNOS in HUVEC.This suggests that C-peptide can be important on the treatment of diabetic macrovascular diseases.