title: Inhibition by ebselen on nitric oxide mediated relaxations in the rat anococcygeus muscle.
abstract: The effect of 2-phenyl-1,2-benzisoselenazol-3(2H)-one (ebselen) on nitric oxide (NO) mediated responses and NO generation from NO donors were studied in vitro. In precontracted rat isolated anococcygeus muscles, relaxations induced by NO donors, electrical field stimulation and 5-[1-(phenylmethyl)-1H-indazole-3-yl]-2-furanmethanol (YC-1) were significantly inhibited by ebselen (100 microM), whereas responses elicited by papaverine and theophylline were not affected; those by 8-bromo-cyclic-guanosine-monophosphate (8-Br-cGMP) were slightly enhanced. NO generation from NO gas aqueous solution or acidified nitrite was not affected, but that from S-nitroso-N-acetyl-penicillamine (SNAP) was attenuated by ebselen, and the attenuation was reserved by glutathione. Both glutathione and cupric sulphate altered the ultraviolet spectrum of ebselen. These findings suggest that ebselen at high concentrations nonselectively inhibited NO-mediated responses, possibly through inhibiting soluble guanylate cyclase. Ebselen does not appear to directly interact with NO, but it may inhibit NO release from nitrosothiols by a thiol- and/or copper-dependent mechanism.
authors.affiliation: Division of Biosciences, School of Medical Sciences, RMIT University, GPO Box 71, Bundoora, Victoria 3083, Australia.
authors.forename: Yan
authors.initials: Y
authors.lastname: Che
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Rand
authors.forename: Chun Guang
authors.initials: CG
authors.lastname: Li
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D001393:Azoles / Q000737:chemistry / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004730:Endothelium, Vascular / Q000502:physiology; D020536:Enzyme Activators / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005978:Glutathione / Q000494:pharmacology; D066298:In Vitro Techniques; D007191:Indazoles / Q000494:pharmacology; D054833:Isoindoles; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology; D016566:Organoselenium Compounds / Q000737:chemistry / Q000494:pharmacology*; D010208:Papaverine / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013056:Spectrophotometry, Ultraviolet; D014664:Vasodilation / Q000187:drug effects
chemical_list: D001393:Azoles; D016861:Cyclooxygenase Inhibitors; D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D007191:Indazoles; D054833:Isoindoles; D020030:Nitric Oxide Donors; D016566:Organoselenium Compounds; D010726:Phosphodiesterase Inhibitors; C110881:S-nitro-N-acetylpenicillamine; C090937:3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole; D009599:Nitroprusside; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; C042986:ebselen; D003300:Copper; D010208:Papaverine; D019001:Nitric Oxide Synthase; D005978:Glutathione; D010396:Penicillamine; D006152:Cyclic GMP; D019331:NG-Nitroarginine Methyl Ester