title: Analysis of cardiovascular responses to the H2S donors Na2S and NaHS in the rat.
abstract: Hydrogen sulfide (H2S) is an endogenous gaseous molecule formed from L-cysteine in vascular tissue. In the present study, cardiovascular responses to the H2S donors Na2S and NaHS were investigated in the anesthetized rat. The intravenous injections of Na2S and NaHS 0.03-0.5 mg/kg produced dose-related decreases in systemic arterial pressure and heart rate, and at higher doses decreases in cardiac output, pulmonary arterial pressure, and systemic vascular resistance. H2S infusion studies show that decreases in systemic arterial pressure, heart rate, cardiac output, and systemic vascular resistance are well-maintained, and responses to Na2S are reversible. Decreases in heart rate were not blocked by atropine, suggesting that the bradycardia was independent of parasympathetic activation and was mediated by an effect on the sinus node. The decreases in systemic arterial pressure were not attenuated by hexamethonium, glybenclamide, N(w)-nitro-L-arginine methyl ester hydrochloride, sodium meclofenamate, ODQ, miconazole, 5-hydroxydecanoate, or tetraethylammonium, suggesting that ATP-sensitive potassium channels, nitric oxide, arachidonic acid metabolites, cyclic GMP, p450 epoxygenase metabolites, or large conductance calcium-activated potassium channels are not involved in mediating hypotensive responses to the H2S donors in the rat and that responses are not centrally mediated. The present data indicate that decreases in systemic arterial pressure in response to the H2S donors can be mediated by decreases in vascular resistance and cardiac output and that the donors have an effect on the sinus node independent of the parasympathetic system. The present data indicate that the mechanism of the peripherally mediated hypotensive response to the H2S donors is uncertain in the intact rat.
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Daniel
authors.initials: D
authors.lastname: Yoo
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Jupiter
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Pankey
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Vishwaradh G
authors.initials: VG
authors.lastname: Reddy
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Edward
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Swan
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Taylor C
authors.initials: TC
authors.lastname: Peak
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana.
authors.forename: Ricardo
authors.identifier: http://orcid.org/0000-0002-5379-0080
authors.initials: R
authors.lastname: Mostany
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana pkadowi@tulane.edu.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Kadowitz
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects*; D002302:Cardiac Output / Q000187:drug effects*; D006152:Cyclic GMP / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects*; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013440:Sulfides / Q000494:pharmacology*; D014655:Vascular Resistance / Q000187:drug effects*
chemical_list: D015221:Potassium Channels; D013440:Sulfides; D016718:Arachidonic Acid; D009569:Nitric Oxide; C025451:sodium bisulfide; D006152:Cyclic GMP; C033479:sodium sulfide; D006862:Hydrogen Sulfide
keywords: H2S donors; KATP channels; bradycardia; cardiac output; hypotension