Lipoperoxidation associated with mitochondrial membrane permeabilization in the presence of Ca2+.
Lipoperoxidation was investigated as a step for membrane protein thiol oxidation of rat liver mitochondria incubated in the presence of Ca2+ and t-butylhydroperoxide, by the determination of thiobarbituric acid reactive substances. Lipoperoxidation occurred only when the incubation medium contained 125 microM t-butylhydroperoxide (t-buOOH) in the presence of Ca2+ and phosphate (Pi). No lipoperoxidation was observed when acetate replaced Pi as permeant anion, or when the oxidant was omitted, even at high Ca2+ and Pi concentrations (up to 120 microM Ca2+ and 5 mM Pi), conditions under which the mitochondria are fully permeabilized. In both cases, ADP protected efficiently against permeabilization, indicating the possible involvement of the ADP/ATP carrier in the earlier stages of the process.
Nepomuceno
M F
MF
Departamento de Bioquímica, Universidade Estadual de Campinas, Brasil.
Macedo
D V
DV
Pereira-da-Silva
L
L
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002463:Cell Membrane Permeability; D015227:Lipid Peroxidation; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D010758:Phosphorus / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D010758:Phosphorus; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D002118:Calcium