Studies on ferrous ion-induced lipid peroxidation of rat liver mitochondria. II. Relationship to incubation temperature.

Ferrous ion-induced lipid peroxidation in rat liver mitochondria has a lag in the induction period. The characteristics of the lag were investigated under various conditions. This lag period lengthened proportionally to increased temperature (4 degrees approximately 37 degrees C). In the presence of inorganic phosphate the lag period lengthened, reaching a maximum at about 20 degrees C, and then shortened with increased temperatute. Elongated lag periods were shown in heat-treated or protein digested mitochondria. Shortened lag periods were shown in snake venom-treated mitochondria. On the other hand, almost no lag was observed in the peroxidation of the lipid extracted from mitochondria. The lag period also varied with incubation temperature. The results suggested that certain factors, which determined lag of the induction period in membrane lipid peroxidation associate with reaction-temperature and the lipo-protein structure in mitochondrial membranes.