Short Communication

Abstract

Mitochondriale H^Oz-Bildung an "Site //" Zusammenfassung: In Mitochondrien wird H2O2 gebildet. Die Bildungsrate von mitochondrialem Ü2O2 ist unabhängig vom Redoxzustand der Cytochrome 6562 und ci. Ein Block des Elektronentransportes durch Cytochrome-c-Extraktion induziert keine meßbare H2O2-Bildung. Antimycin reduziert unter diesen Bedingungen spezifisch Cytochrome 6566 und parallel dazu induziert es die Bildung von HfeOa. In Membranfragmenten von RinderherzmitochondrienIt was shown recently that mitochondria have to be regarded as a novel source of cellular H2O2 production d-4]t As detected either by the psroxidase-linked oxidation of the fluorescent dye scopoletint 1 · 4 ! or by the formation of enzyme-substrate complex by the cytochrome c peroxidase [2 -3] it was shown that tightly coupled mitochondria in state 4^ produce H2O2 when supplemented with succinate. The sensitivity of the rate of H2Ü2 formation towards inhibitors of respiration and uncouplers of oxidative phosphorylation identified the mitochondrial respiratory chain as the source of its formation. In our previous communication^ we discussed the possibility that the flavin moiety in the succinate dehydrogenase complex might be responsible for mitochondrial H2Ü2 generation. The obvious dependency of Ü2O2