Effect of a heme-peptide derived from cytochrome-c on lipid peroxidation. II. Experiments with liver microsomes.
ADP-Fe2+ stimulated, NADPH dependent lipid peroxidation of liver microsomes (as measured by malondialdehyde formation) was not inhibited by c-heme-nonapeptide, unlike the same process in brain microsomes. However, in the presence of 5 mM aminopyrine (causing partial inhibition) or SKF-525A (a specific inhibitor of cytochrome P450) the residual activity of lipid peroxidation of liver microsomes was markedly inhibited by c-heme-nonapeptide. Further, c-heme-nonapeptide itself prevented the transient accumulation of lipid hydroperoxides during ADP-Fe2+ stimulated lipid peroxidation. These results led us to suggest two different pathways of lipid peroxidation. The first route involves cytochrome P450. The second pathway, which can be inhibited by c-heme-nonapeptide, appears to be more important physiologically.
D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000632:Aminopyrine / Q000494:pharmacology; D000818:Animals; D003574:Cytochrome c Group / Q000494:pharmacology*; D045304:Cytochromes c; D066298:In Vitro Techniques; D008054:Lipid Peroxides / Q000096:biosynthesis*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D051379:Mice; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology*; D011335:Proadifen / Q000494:pharmacology
D003574:Cytochrome c Group; D008054:Lipid Peroxides; D010446:Peptide Fragments; C029936:adenosine diphosphate-ferric chelate; C046027:heme nonapeptide; D000632:Aminopyrine; D008315:Malondialdehyde; D000244:Adenosine Diphosphate; D045304:Cytochromes c; D011335:Proadifen