title: The effects of vitamin C and nitric oxide synthase inhibition on coronary flow and oxidative stress markers in isolated rat heart.
abstract: The aim of this study was to assess the effects of vitamin C (ascorbic acid) on coronary flow and oxidative stress markers with or without non-specific inhibition of nitric oxide synthase by N(ω)-nitro-L-arginine monomethyl ester (L-NAME) in isolated rat hearts. The hearts of male Wistar albino rats (n = 12, age 8 weeks, body mass 180-200 g) were retrograde perfused according to the Langendorff technique at gradually increased constant perfusion pressure (40-120 cm H2O). Coronary flow, nitrite outflow, superoxide anion production, and index of lipid peroxidation (by measuring thiobarbituric acid reactive substances) in coronary effluent were determined. The experiments were performed during control conditions and in presence of vitamin C (100 µM) alone or vitamin C (100 µM) + L-NAME (30 µM). Administration of vitamin C induced only increase of nitrite levels, while vitamin C + L-NAME induced significant decrease of coronary flow above autoregulatory range, i.e. especially at higher coronary perfusion pressure (CPP) values, accompanied with similar dynamic in nitrite outflow. Vitamin C + L-NAME also induced significant decrease in TBARS production. The results of our study show no significant effects of vitamin C administration either on ROS levels or on coronary flow in isolated rat heart.
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Kragujevac, Serbia. drvladakgbg@yahoo.com
authors.forename: Vladimir Lj
authors.initials: VLj
authors.lastname: Jakovljevic
authors.forename: Dusica Z
authors.initials: DZ
authors.lastname: Djordjevic
authors.forename: Dragan M
authors.initials: DM
authors.lastname: Djuric
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D003326:Coronary Circulation / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006321:Heart / Q000502:physiology; D008297:Male; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D009573:Nitrites / Q000737:chemistry; D018384:Oxidative Stress; D051381:Rats; D017382:Reactive Oxygen Species; D013481:Superoxides / Q000737:chemistry; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D009573:Nitrites; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D013481:Superoxides; D019001:Nitric Oxide Synthase; D001205:Ascorbic Acid; D019331:NG-Nitroarginine Methyl Ester