Evidence for a pathogenic role of xanthine oxidase in the stunned myocardium

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:5993911

Charlat, M L; O'Neill, P G; Egan, J M; Abernethy, D R; Michael, L H; Myers, M L; Roberts, R; Bolli, R

Recent evidence suggests that postischemic myocardial dysfunction (or myocardial stunning) may be mediated by oxygen free radicals, but the mechanism for their production remains unknown. To explore the role of xanthine oxidase as a potential source of free radicals, open-chest dogs undergoing a 15-min occlusion of the left anterior descending coronary artery (LAD) followed by 4 h of reperfusion (REP) received intravenously either allopurinol or saline. The two groups were similar with respect to occluded bed size (postmortem perfusion) and collateral flow (radioactive microspheres). In controls, the transcardiac difference in plasma uric acid increased 199 +/- 70% (means +/- SE) during ischemia and remained elevated for 5 min after REP; no increase was observed in treated dogs. Regional myocardial function was assessed by measuring systolic wall thickening with an epicardial Doppler probe. The two groups exhibited comparable systolic thickening under base-line conditions and similar degrees of dyskinesis during ischemia. Following REP, however, recovery of contractile function (expressed as percent of preocclusion values) was considerably greater in allopurinol-treated as compared with control dogs. These differences could not be ascribed to hemodynamic factors. The results suggest that xanthine oxidase is a source of the oxygen free radicals responsible for myocardial stunning following a brief episode of reversible regional ischemia.

• Research Organization: Baylor College of Medicine, Houston, TX
• OSTI ID: 5993911
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:3; ISSN AJPHA
• Country of Publication: United States
• Language: English

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62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
AROMATICS
AZAARENES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
BLOOD FLOW
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DISEASES
DOGS
DYNAMIC FUNCTION STUDIES
ENZYME ACTIVITY
ENZYME INHIBITORS
ENZYMES
HEART
HETEROCYCLIC COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISCHEMIA
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MICROSPHERES
MUSCLES
MYOCARDIUM
NIOBIUM 95
NIOBIUM ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
OXIDOREDUCTASES
PURINES
RADICALS
RADIOISOTOPES
REACTION KINETICS
SUPEROXIDE RADICALS
TRACER TECHNIQUES
VASCULAR DISEASES
VERTEBRATES
XANTHINES