(A) Examination of the effect of HG or LG on NO production at different time points in endothelial cells (0, 12, 24, and 48 h). (B) Examination of the effect of D-glucose on NO production at different concentrations in endothelial cells (0, 12, 24, and 48 h). (C) Examination of the effect of HG on aSMase activity at different time points (0, 4, 8, 12, and 24 h). (D) Examination of the effect of HG on ceramide content at different time points (0, 4, 8, 12, and 24 h). Data are shown as the mean ± S.E.M. with n=4–5 per group. *P<0.05 compared with the NC group. #P<0.05 compared with the HG group.