Non-enzymatic lipid peroxidation of microsomes and mitochondria isolated from liver and heart of pigeon and rat

ANA M. GUTIÉRREZ ; GUILLERMO R. REBOREDO; CESAR J. ARCEMIS; ANGEL CATALA

INTERNATIONAL JOURNAL OF BIOCHEMISTRY AND CELLULAR BIOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2000 vol. 32 p. 73 - 79

1357-2725

Studies were carried out to determine the level of ascorbate±Fe2+ dependent lipid peroxidation of mitochondria and microsomes isolated from liver and heart of rat and pigeon. Measurements of chemiluminescence indicate that the lipid peroxidation process was more e?ective in mitochondria and microsomes from rat liver than in the same organelles obtained from pigeon. In both mitochondria and microsomes from liver of both species a signi®cant decrease of arachidonic acid was observed during peroxidation. The rate C18:2 n6/C20:4 n6 was 4.5 times higher in pigeon than in rat liver. This observation can explain the di?erences noted when light emission and unsaturation index of both species were analysed. A signi®cant decrease of C18:2 n6 and C20:4 n6 in pigeon liver mitochondria was observed when compared with native organelles whereas in pigeon liver microsomes only C20:4 n6 diminished. In rat liver mitochondria only arachidonic acid C20:4 n6 showed a signi®cant decrease whereas in rat liver microsomes C20:4 n6 and C22:6 n3 decreased signi®cantly. However changes were not observed in the fatty acid pro®le of mitochondria and microsomes isolated from pigeon heart. In the heart under our peroxidation conditions the fatty acid pro®le does not appear to be responsible for the di?erent susceptibility to the lipid peroxidation process. The lack of a relationship between fatty acid unsaturation and sensitivity to peroxidation observed in heart suggest that other factor/s may be involved in the protection to lipid peroxidation in microsomes and mitochondria isolated from heart. # 1999 Elsevier Science Ltd. All rights reserved.