The mechanisms of free-radical lipids and antioxidant heart protection in experimental ischaemia and infarction.
Free-radical lipid peroxidation (FRLP) during experimental myocardial ischaemia and infarction was studied on the first author's model using coronary occlusion in more than 1500 albino rats. FRLP was tested at various intervals after coronary occlusion (from the 20th minute to 14--30 days) in myocardial lipid extracts using various methods: 1) chemiluminescent method determining the intensity of free radical reactions, 2) diene conjugate production, 3) malone dialdehyde reaction, 4) Schiff bases fluorometric determination. The severity of ischaemia and infarction was assessed according to electrocardiographic, light and electron microscopic findings and morphometry of the damaged area. Intensified FRLP was registered in all four indicators at most tests performed within the first 14 days after production of ischaemia and infarction. The severity of ischaemic lesion could be reduced by FRLP inhibition using antioxidative agents of sharply differing chemical nature (sodium selenite, alpha-tocopherol a.o.). The authors conclude that FRLP intensification plays a role in the pathogenesis of myocardial ischaemia and infarction, and recommend to include antioxidative drugs in comprehensive heart protection.