title: Nitroglycerine effects on portal vein mechanics and oxidative stress in portal hypertension.
abstract: OBJECTIVE
  Тo examine the effects of nitroglycerine on portal vein haemodynamics and oxidative stress in patients with portal hypertension.
  
  
  METHODS
  Thirty healthy controls and 39 patients with clinically verified portal hypertension and increased vascular resistance participated in the study. Liver diameters, portal diameters and portal flow velocities were recorded using color flow imaging/pulsed Doppler detection. Cross-section area, portal flow and index of vascular resistance were calculated. In collected blood samples, superoxide anion radical (O(2) (-)), hydrogen peroxide (H(2)O(2)), index of lipid peroxidation (measured as TBARS) and nitric oxide (NO) as a marker of endothelial response (measured as nitrite-NO(2) (-)) were determined. Time-dependent analysis was performed at basal state and in 10th and 15th min after nitroglycerine (sublingual 0.5 mg) administration.
  
  
  RESULTS
  Oxidative stress parameters changed significantly during the study. H(2)O(2) decreased at the end of study, probably via O(2) (-) mediated disassembling in Haber Weiss and Fenton reaction; O(2) (-) increased significantly probably due to increased diameter and tension and decreased shear rate level. Consequently O(2) (-) and H(2)O(2) degradation products, like hydroxyl radical, initiated lipid peroxidation. Increased blood flow was to some extent lower in patients than in controls due to double paradoxes, flow velocity decreased, shear rate decreased significantly indicating non Newtonian characteristics of portal blood flow.
  
  
  CONCLUSIONS
  This pilot study could be a starting point for further investigation and possible implementation of some antioxidants in the treatment of portal hypertension.
authors.affiliation: Andreja Vujanac, Vladimir Jakovljevic, Dusica Djordjevic, Vladimir Zivkovic, Department of Physiology, Faculty of Medicine, University of Kragujevac, 34000 Kragujevac, Serbia.
authors.forename: Andreja
authors.initials: A
authors.lastname: Vujanac
authors.forename: Vladimir
authors.initials: V
authors.lastname: Jakovljevic
authors.forename: Dusica
authors.initials: D
authors.lastname: Djordjevic
authors.forename: Vladimir
authors.initials: V
authors.lastname: Zivkovic
authors.forename: Mirjana
authors.initials: M
authors.lastname: Stojkovic
authors.forename: Dragan
authors.initials: D
authors.lastname: Celikovic
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Andjelkovic
authors.forename: Aleksandra Jurisic
authors.initials: AJ
authors.lastname: Skevin
authors.forename: Dragan
authors.initials: D
authors.lastname: Djuric
mesh_terms: D000328:Adult; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D006975:Hypertension, Portal / Q000503:physiopathology*; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism; D005996:Nitroglycerin / Q000494:pharmacology*; D016877:Oxidants / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D010865:Pilot Projects; D011169:Portal Vein / Q000187:drug effects* / Q000502:physiology*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D016877:Oxidants; D017392:Thiobarbituric Acid Reactive Substances; D014665:Vasodilator Agents; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D005996:Nitroglycerin