Comparison of the cardioprotective efficacy of superoxide dismutase in a single and a repetitive coronary occlusion model in rabbit hearts.
The effects of exogenous superoxide dismutase (SOD) on acute myocardial ischemia (MI) was investigated in isolated electrically-driven rabbit hearts (Langendorff, constant pressure: 70 cm H2O, Tyrode solution, Ca++ 1.8 mmol/l, 37 degrees C). Acute regional ischemia (MI) was induced by occlusion of a coronary artery branch (CAO) and quantitated from epicardial NADH-fluorescence photography. SOD (48 U/ml) was applied either 30 min after CAO in a single coronary occlusion model (treatment) or 30 min before the 2nd CAO in a repetitive coronary occlusion model (pre-treatment). SOD had no significant influence on the left ventricular pressure or the global coronary flow (p > 0.05). MI was significantly diminished in hearts pre-treated with SOD before CAO (-25%)(p < 0.05), but remained unaffected when SOD was applied after CAO (p > 0.05). The results suggest that superoxide anion radicals contribute to ischemic tissue injury. SOD shows cardioprotective properties only if present in the ischemic zone, requiring the application of SOD before CAO in poorly collateralised rabbit hearts.
Rump
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Institut für Pharmakologie, Universität Köln, Cologne, Germany.
Klaus
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W
D000818:Animals; D003097:Collateral Circulation / Q000502:physiology; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000503:physiopathology / Q000517:prevention & control*; D003331:Coronary Vessels / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D008856:Microscopy, Fluorescence; D017202:Myocardial Ischemia / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D011817:Rabbits; D013482:Superoxide Dismutase / Q000008:administration & dosage / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects; D017725:Ventricular Pressure / Q000187:drug effects
D009243:NAD; D013482:Superoxide Dismutase