title: Sulfur dioxide: a physiologic endothelium-derived relaxing factor.
abstract: The gasotransmitter nitric oxide was classified as the first endothelium-derived relaxant factor, and opened a new era in cardiovascular research. Another small gas, sulfur dioxide (SO₂), can also be generated endogenously in mammals. Recent studies have shown that SO₂ may play important roles in the cardiovascular system. At low concentrations, the vasodilatory effect of SO₂ is endothelium-dependent. The vasodilation induced by an endothelium-derived relaxant factor is achieved by the opening of potassium channels, and hyperpolarization of the membranes of vascular smooth muscle cells. This feature is in accordance with that of SO₂. The vasodilatory effect of SO₂ is related to the opening of adenosine triphosphate-sensitive potassium channels and high-conductance calcium-activated potassium channels. The 3'-5'-cyclic guanosine monophosphate pathway and activation of nitric oxide synthase are also involved in the endothelium-derived relaxant factor effect of SO₂. The vasodilatory effect of gaseous SO₂ is much stronger than that of its derivatives (bisulfite and sulfite). It is suggested that SO₂ may be a candidate endothelium-derived relaxant factor, which could lead to a new era of research into cardiovascular disease in mammals.
authors.affiliation: Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Xin-Bao
authors.initials: XB
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, Beijing Friendship Hospital, Capital Medical University, Beijing, PR China. cuihongl00@sina.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Cui
authors.affiliation: Department of Pediatrics, Peking University First Hospital, Beijing, PR China.
authors.forename: Jun-Bao
authors.initials: JB
authors.lastname: Du
mesh_terms: D000818:Animals; D004730:Endothelium, Vascular / Q000378:metabolism*; D045462:Endothelium-Dependent Relaxing Factors / Q000378:metabolism*; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D013458:Sulfur Dioxide / Q000378:metabolism*; D014664:Vasodilation / Q000502:physiology*
chemical_list: D045462:Endothelium-Dependent Relaxing Factors; D013458:Sulfur Dioxide