To determine the role of As-IV and P38 MAPK in high glucose-induced endothelial dysfunction, we pretreated the thoracic aortic rings with As-IV and the p38 MAPK specific inhibitor SB203580 for 48 h in the presence or absence of high glucose (to mimic the chronic hyperglycemia environment of diabetes). This evidence concerns the gene MAPK14 and diabetes mellitus.