PTGS2 and endothelial dysfunction: Prior work with the Zucker and ZDF rats have shown impaired endothelial dependent relaxation of the coronary and mesenteric vascular beds that is exacerbated with increased age (Oltman et al., 2006) and the endothelial dysfunction in ZDF rats is related to increased inflammation and cyclooxygenase-2 derivatives (Vessieres et al., 2013).