Initiation of lipid peroxidation in submitochondrial particles: effect of respiratory inhibitors.
Initiation of lipid peroxidation in the inner mitochondrial membrane was investigated using respiratory substrates and inhibitors and various iron chelates. An iron chelate was required for initiation of lipid peroxidation in the presence of either NADH or NADPH. The two nicotinamide nucleotides exhibited different activities in initiating lipid peroxidation with regard to concentration and to the effects of rotenone and rhein. Succinate and both nicotinamide nucleotides supported lipid peroxidation in the presence of thenoyl trifluoroacetone (TTFA), without a requirement for exogenously added iron. ADP stimulated lipid peroxidation in the case of NAD(P)H and TTFA, but inhibited it in the case of succinate and TTFA. Lipid peroxidation is thought to be enzymatically induced in both the NADH and the succinate dehydrogenase regions of the respiratory chain, and evidence is presented for a novel pathway of NADPH oxidation that may also be involved. Possible initiation mechanisms are discussed.
Glinn
M
M
Department of Biochemistry, Wayne State University School of Medicine, Detroit, Michigan 48201.
Ernster
L
L
Lee
C P
CP
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D000880:Anthraquinones / Q000494:pharmacology; D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D002417:Cattle; D066298:In Vitro Techniques; D007501:Iron / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism; D009243:NAD / Q000494:pharmacology; D009249:NADP / Q000378:metabolism / Q000494:pharmacology; D010084:Oxidation-Reduction; D013367:Submitochondrial Particles / Q000187:drug effects / Q000378:metabolism*; D013386:Succinates / Q000494:pharmacology; D019802:Succinic Acid; D013804:Thenoyltrifluoroacetone / Q000494:pharmacology
D000880:Anthraquinones; D013386:Succinates; D009243:NAD; C032456:antimycin; D013804:Thenoyltrifluoroacetone; D009249:NADP; D000244:Adenosine Diphosphate; D000968:Antimycin A; D019802:Succinic Acid; D007501:Iron; C020491:rhein