NOS3 and endothelial dysfunction: Recent clinical studies have demonstrated the ability of taurine to induce vasodilation in patients with endothelial dysfunction [181,182], which may be attributed to its ability to influence mechanisms of endothelium-dependent relaxation, such as upregulating endothelial nitric oxide synthase (eNOS) expression, increasing NO levels and bioavailability, and enhancing eNOS activity by augmenting phosphorylation at site Ser1177 [183,184,185,186].