Abstract
The effects of averufin on both succinate-and NAD-linked respiratory chain were compared using rat liver mitochondria and electron transport particles (ETP). Averufin was found to exert a strong inhibition on both systems, showing somewhat stronger inhibition on the NAD- than on succinate-linked respiratory chains. Neither succinate nor NADH-dehydrogenase activity was affected by averufin. Both succinate- and HADH-cyto-chrome c reductases were markedly inhibited by averufin. These results in combination with our previous finding (no inhibition on cytochrome c oxidase by averufin) imply that the complex III of the respiratory chain is the site of action by averufin. A result was obtained which suggested that averufin interfered with membrane transport system of the inner membrane against organic anions in TCA cycle, in addition to the inhibitory effect on the respiratory chain.
