Role of sulfur-containing gaseous substances in the cardiovascular system.

Gaseous mediators are important signaling molecules with properties that differ from other, larger signaling molecules. Small gaseous mediators readily cross cell membranes and can access sites on target molecules that would be inaccessible to bulkier molecules. They have a variety of signaling mechanisms, some well understood, some not. The family of gasotransmitters is growing, well known members include nitric oxide (NO) and carbon monoxide (CO). Newer candidates include the sulfur containing gases hydrogen sulfide (H2S), which has been shown to have a wide range of physiological functions, and more recently sulfur dioxide (SO2) has been studied as a potential new gasotransmitter. This review explores the production, regulation and role of the sulfur-containing gases H2S and SO2 at the level of the endothelial and vascular smooth muscle cells as well as the broader effects on the cardiovascular system under both physiological and pathophysiological conditions.