These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Protective effects of preconditioning of the ischaemic myocardium involve cyclo-oxygenase products.
    Author: Vegh A, Szekeres L, Parratt JR.
    Journal: Cardiovasc Res; 1990 Dec; 24(12):1020-3. PubMed ID: 2129022.
    Abstract:
    STUDY OBJECTIVE: The aim was to determine whether short (preconditioning) occlusions of a coronary artery protect against the arrhythmias occurring during a subsequent more prolonged occlusion and to examine whether the observed protection is mediated by the release of a product of the cyclo-oxygenase pathway of arachidonic acid metabolism. DESIGN: The effects were examined of two short (5 min) coronary artery occlusions, in chloralose-urethane anaesthetised dogs, on a subsequent prolonged (25 min) occlusion; analysis of ischaemia and reperfusion induced arrhythmias and of epicardial ST segment changes was performed. EXPERIMENTAL MATERIAL: 46 anaesthetised mongrel dogs in a restricted body weight range were used. MEASUREMENTS AND MAIN RESULTS: Preconditioning reduced the incidence and severity of ischaemic arrhythmias during a 25 min occlusion. Ventricular premature beats (VPB) reduced from 445 (SEM 140) to 96(22) (p less than 0.01), ventricular fibrillation (VF) from 4/10 to 0/20 (p less than 0.05), and ventricular tachycardia from 9/10 to 6/20 (p less than 0.05). VF following reperfusion was reduced from 6/6 to 6/10 (p less than 0.05). Preconditioning thus increased survival from the prolonged ischaemia-reperfusion insult from 0% to 40%. The protective effect of preconditioning was lost in the presence of the cyclo-oxygenase inhibitor sodium meclofenamate (2 mg.kg-1), eg, VPBs 367(95), VF during occlusion 1/9 and during reperfusion 8/8, survival 0%. CONCLUSIONS: Short, preconditioning periods of myocardial ischaemia protect the myocardium against the arrhythmogenic effects of a more prolonged occlusion. That this protection is lost if the cyclo-oxygenase pathway is blocked suggests a protective role for prostanoids, most likely prostacyclin, as endogenous myocardial protective substances.
    [Abstract] [Full Text] [Related] [New Search]