Old and new gasotransmitters in the cardiovascular system: focus on the role of nitric oxide and hydrogen sulfide in endothelial cells and cardiomyocytes.

The functional relevance of nitric oxide (NO) in the cardiovascular system is well established since the end of the 80', when it was firstly proposed as a key controller of vasodilation. More recent evidences, still debated and partly conflicting, point to a role of NO in the angiogenic progression. On the other hand hydrogen sulfide is a new entry as a gasotransmitter in the cardiovascular system. The variety of its biological functions seems to grow day after day. The first to be described is surely its reversible and poisoning binding of the cytochrome c oxidase that leads to impairment of the respiratory chain in mitochondria. However, sub-toxic concentrations have been later proved to be essential to maintain fundamental physiological functions in several tissues. The basal production of H2S is determined by the activity of, at least, three constitutively expressed enzymes (CBS, CSE, and 3-MPT) with tissue specificity for CBS and CSE in the central nervous and cardiovascular system, respectively. The assumption of a pivotal role of H2S in regulating physiological function is supported by the demonstration that reduced production of this gaseous molecule by CSE induces hypertension in mice. The increasing number of studies showing the regulatory functions of H2S reveals that maintaining the normal blood pressure levels is only one of its multiple biological actions. In this review, we would like to explore the recent literature on NO and H2S roles on cardiovascular system and to elucidate potential outcomes in the use of pharmacological drugs interfering with their metabolism.