An Update on Hydrogen Sulfide and Nitric Oxide Interactions in the Cardiovascular System

Hydrogen sulfide (H₂S) and nitric oxide (NO) are now recognized as important regulators in the cardiovascular system, although they were historically considered as toxic gases. As gaseous transmitters, H₂S and NO share a wide range of physical properties and physiological functions: they penetrate into the membrane freely; they are endogenously produced by special enzymes, they stimulate endothelial cell angiogenesis, they regulate vascular tone, they protect against heart injury, and they regulate target protein activity via posttranslational modification. Growing evidence has determined that these two gases are not independent regulators but have substantial overlapping pathophysiological functions and signaling transduction pathways. H₂S and NO not only affect each other's biosynthesis but also produce novel species through chemical interaction. They play a regulatory role in the cardiovascular system involving similar signaling mechanisms or molecular targets. However, the natural precise mechanism of the interactions between H₂S and NO remains unclear. In this review, we discuss the current understanding of individual and interactive regulatory functions of H₂S and NO in biosynthesis, angiogenesis, vascular one, cardioprotection, and posttranslational modification, indicating the importance of their cross-talk in the cardiovascular system.