Regulation of vascular tone homeostasis by NO and HS: Implications in hypertension.

Nitric oxide (NO) and hydrogen sulfide (HS) are two gasotransmitters that are produced in the vasculature and contribute to the regulation of vascular tone. NO and HS are synthesized in both vascular smooth muscle and endothelial cells; NO functions primarily through the sGC/cGMP pathway, and HS mainly through activation of the ATP-dependent potassium channels; both leading to relaxation of vascular smooth muscle cells. A deficit in the NO/HS homeostasis is involved in the pathogenesis of various cardiovascular diseases, especially hypertension. It is now becoming increasingly clear that there are important interactions between NO and HS and that have a profound impact on vascular tone and this may provide insights into the new therapeutic interventions. The aim of this review is to provide a better understanding of individual and interactive roles of NO and HS in vascular biology. Overall, available data indicate that both NO and HS contribute to vascular (patho)physiology and in regulating blood pressure. In addition, boosting NO and HS using various dietary sources or donors could be a hopeful therapeutic strategy in the management of hypertension.