Protection by beta-blocking agents against free radical-mediated sarcolemmal lipid peroxidation.

摘要: The effects of beta-blocking and class I antiarrhythmic agents on free radical-mediated sarcolemmal lipid peroxidation were examined. Highly purified canine myocytic membranes pretreated with 10-800 microM selected (propranolol, pindolol, metoprolol, atenolol, or sotalol) (quinidine, lidocaine, procainamide, diphenylhydantoin) at 37 degrees C for 10 minutes. Subsequently, a superoxide radical (derived from dihydroxyfumarate) driven, Fe3+-ADP catalyzed generating system was added incubated up to 45 Lipid sarcolemma determined by malondialdehyde formation. Pretreatment the five beta-blockers resulted in various (20-95%) inhibition concentration- time-dependent manner. All less effective (less than 20% inhibition). order potency propranolol greater pindolol metoprolol atenolol sotalol appeared relate their degree lipophilicity. Propranolol, most potent agent, achieved half-maximal about 100 significance (p 0.01) 20 microM. At pH 6.0, efficacy diminished 30-50% compared 7.2, but remained unchanged. Since increased production may occur during myocardial ischemia/reperfusion injury, above findings suggest that lipophilic provide additional antiperoxidative protection ischemic tissue.