title: Decreased vasoconstrictor responses in remote cerebral arteries after focal brain ischemia and reperfusion in the rat, in vitro.
abstract: The effects of brain ischemia and reperfusion on smooth muscle function in remote cerebral and peripheral arteries are hardly known. Maximum vasoconstrictions (E(max)) caused by 120mmol/l KCl and 5-HT in endothelium-denuded ring preparations were measured in ischemic and control cerebral arteries of rats after a 1-h right middle cerebral artery occlusion followed by 0-min (I/NR) or 2-3-min (I/SR) reperfusion, and in peripheral arteries after I/SR. Surprisingly, vasoconstrictions to 5-HT and 120mmol/lK(+) were attenuated in remote brain vessels after I/SR, i.e. in the contralateral middle cerebral artery and the basilar artery, while I/NR depressed E(max) of 5-HT and high KCl only in the ischemic middle cerebral artery. Pretreatment with N-(2-mercaptopropionyl) glycine (MPG, 100mg/kg i.p.), a free radical scavenger, fully prevented the impairment of vasomotor function in the middle cerebral artery on both sides after I/SR. Moreover, vasomotor functions were normal in the coronary, renal and pulmonary arteries after I/SR. In conclusion, focal cerebral ischemia and reperfusion impaired vasoconstrictor responses in remote brain arteries of rats by a mechanism involving free radicals. The lack of similar effects in peripheral vessels indicates poor defence of brain arteries against remote injury caused by reactive oxygen species-dependent mechanisms.
authors.affiliation: EGIS Pharmaceuticals PLC, Division of Preclinical Research, 1106 Keresztúri út 30-38, Budapest, Hungary.
authors.forename: Anikó
authors.initials: A
authors.lastname: Kovács
authors.forename: Krisztina
authors.initials: K
authors.lastname: Móricz
authors.forename: Mihály
authors.initials: M
authors.lastname: Albert
authors.forename: Angéla
authors.initials: A
authors.lastname: Benedek
authors.forename: László G
authors.initials: LG
authors.lastname: Hársing
authors.forename: Gábor
authors.initials: G
authors.lastname: Szénási
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000209:etiology / Q000503:physiopathology*; D002536:Cerebral Arteries / Q000503:physiopathology; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D020244:Infarction, Middle Cerebral Artery / Q000150:complications; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000150:complications; D012701:Serotonin / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000494:pharmacology*; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D016166:Free Radical Scavengers; C110658:N-(2-mercaptoproprionyl)-glycine; D013438:Sulfhydryl Compounds; D012701:Serotonin; D011189:Potassium Chloride; D005998:Glycine