[Mechanisms of the initiation of lipid peroxidation in the synaptosomes of marine teleosts].

The initial rates of NAD- and NADPH-dependent enzymic and Fe+-ascorbic acid-dependent nonenzymic lipid peroxidation have been measured in synaptosomes from the brain of 4 teleost species. The rates of peroxidation were compared with lipid composition and fatty acid composition of total lipids in order to reveal factors accounting for the intensity of peroxidation in the excitable membranes from the brain of ectotherms. The data obtained indicate that the rates of enzymic lipid peroxidation do not correlate with lipid and fatty acid compositions, depending on the efficiency of production of oxygen in the active form by pyridine nucleotide-dependent enzymic systems. Activation of lipid peroxidation during adaptation of animals to the environment may be considered as one of the mechanisms which account for compensatory changes in fatty acid composition of the membrane lipids.