title: Hydrogen sulfide and endothelium-dependent vasorelaxation.
abstract: In addition to nitric oxide and carbon monoxide, hydrogen sulfide (H2S), synthesized enzymatically from l-cysteine or l-homocysteine, is the third gasotransmitter in mammals. Endogenous H2S is involved in the regulation of many physiological processes, including vascular tone. Although initially it was suggested that in the vascular wall H2S is synthesized only by smooth muscle cells and relaxes them by activating ATP-sensitive potassium channels, more recent studies indicate that H2S is synthesized in endothelial cells as well. Endothelial H2S production is stimulated by many factors, including acetylcholine, shear stress, adipose tissue hormone leptin, estrogens and plant flavonoids. In some vascular preparations H2S plays a role of endothelium-derived hyperpolarizing factor by activating small and intermediate-conductance calcium-activated potassium channels. Endothelial H2S signaling is up-regulated in some pathologies, such as obesity and cerebral ischemia-reperfusion. In addition, H2S activates endothelial NO synthase and inhibits cGMP degradation by phosphodiesterase 5 thus potentiating the effect of NO-cGMP pathway. Moreover, H2S-derived polysulfides directly activate protein kinase G. Finally, H2S interacts with NO to form nitroxyl (HNO)-a potent vasorelaxant. H2S appears to play an important and multidimensional role in endothelium-dependent vasorelaxation.
authors.affiliation: Department of Pathophysiology, Medical University, 20-150 Lublin, Poland. jerzy.beltowski@lublin.pl.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Bełtowski
authors.affiliation: Department of Neurology, Medical University, 20-090 Lublin, Poland. ajamroz@wp.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Jamroz-Wiśniewska
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000187:drug effects / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism*; D045462:Endothelium-Dependent Relaxing Factors / Q000494:pharmacology*; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism / Q000494:pharmacology*; D020738:Leptin; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D045462:Endothelium-Dependent Relaxing Factors; D020738:Leptin; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D017869:Cyclic GMP-Dependent Protein Kinases; D006152:Cyclic GMP; D006862:Hydrogen Sulfide