Nitric Oxide (NO) and Hydrogen Sulfide (H₂S): Molecular Targets for Vascular Muscle Relaxation

Nitric oxide (NO) is produced in endothelial cells by nitric oxide synthase. This NO plays an important role in normal pathophysiology and homeostasis of human body. NO exerts a surfeit of biological effects in the cardiovascular system. Hydrogen sulphide (H₂S) is synthesized naturally in the body from L-cysteine mainly by the activity of two enzymes, cystathionine-γ-lyase and cystathionine-β-synthetase. The H₂S plays a vital role in vasorelaxation. Both NO and H₂S works by different mechanism to produce the effect of vascular muscle relaxation. The present review focuses on the molecular enzymatic targets for NO and H₂S for producing vascular muscle relaxation with recent advances and studies.