Role of endothelial nitric oxide synthase gene in vascular diseases

The endothelial nitric oxide synthase (eNOS or NOS 3) is expressed in the endothelium where it produces Nitric Oxide (NO) from L-arginine. NO a powerful short lived vascular substance, plays a key role to maintain vascular homeostasis. Association of endothelial nitric oxide synthase gene variants and nitric oxide has been found in many vascular diseases chiefly stroke, coronary artery disease and hypertension. The variants have been associated with low plasma nitric oxide concentrations and reduced vascular reactivity, however difficulties in measuring those phenotypes implicates that their functions remain unclear. While a large no of studies report the association of NOS3 gene with vascular diseases, a few are contradictory to such reports. So a need for large scale genetic association studies using tagging polymorphisms to confirm or refute the role of NOS3 gene in vascular diseases is strongly warranted.