Fig. 3.

a Oxidation reduction and formation of nitrotyrosine by homocysteine. b Homocysteine causes reduction of thioredoxin and increases superoxide production by inducing NAD(P)H oxidase. Homocysteine also induces eNOS and iNOS to produce NO. Reaction of NO and tyrosine forms peroxynitrite and causes nitrosylation of protein tyrosine residues, such as actin and myosin. This leads to impairment of contractility and resulting in hypertension. H2S scavenges superoxide; therefore, reduces hypertension