eNOS catalyzes the formation of NO from L-arginine in many cell types including vascular endothelium, bronchiolar epithelium, cardiac myocytes, spleen, and kidney.{2667,1475,1895} Although eNOS was initially characterized as a constitutive enzyme, expression of eNOS mRNA is altered by many factors including shear stress, fibroblast growth factor, hypoxia, and LPS.{5570,2841,3439} eNOS is myristoylated and palmitoylated at the N-terminus, modifications which are required for localization to the plasmalalemmal caveolae of endothelial cells.{6977,4849,6355,2923,3214} Additionally, eNOS is phosphorylated on Ser1179 by protein kinase Akt resulting in an increase in NOS activity.{4020,7156,4863}