Are free radicals involved in Ca(2+)-induced membrane damage of mitochondria?
Ca(2+)-Induced membrane damage of energized mitochondria has been proposed to be due to lipid peroxidation induced by Ca2+. To examine this possibility, we studied the effects of the radical scavenger, 3,5-di-tert-butyl-4-hydroxytoluene (BHT), and its derivative, 3,5-di-tert-butyl-4-methoxytoluene (MeO-BHT), on membrane damage of respiring mitochondria induced by Ca2+ in the presence of inorganic phosphate. Both compounds inhibited Ca(2+)-induced damage almost completely at 20 microM, and their effects were identical, although MeO-BHT had no radical scavenging ability. These results indicate that the protective effects of BHT and MeO-BHT are not due to their radical scavenging ability. Thus, free radicals are concluded not to be involved in Ca(2+)-induced membrane damage of mitochondria.
Kora
S
S
R. & D. Center, Terumo Corporation, Kanagawa, Japan.
Sado
M
M
Koike
H
H
Terada
H
H
D000818:Animals; D002084:Butylated Hydroxytoluene / Q000494:pharmacology / Q000031:analogs & derivatives; D002118:Calcium / Q000037:antagonists & inhibitors / Q000633:toxicity*; D016166:Free Radical Scavengers; D005609:Free Radicals; D066298:In Vitro Techniques; D015227:Lipid Peroxidation; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D014050:Toluene / Q000031:analogs & derivatives / Q000494:pharmacology
D016166:Free Radical Scavengers; D005609:Free Radicals; C078323:3,5-di-tert-butyl-4-methoxytoluene; D002084:Butylated Hydroxytoluene; D014050:Toluene; D002118:Calcium