Effects of coenzyme Q(10) on changes in the membrane potential and rate ofgeneration of reactive oxygen species in hydrazine- and chloramphenicol-treated rat liver mitochondria

Effects of CoQ(10) and cycloheximide (CHX) on hydrazine- and chloramphenico l (CP)-induced morphological and some functional changes of mitochondria us ing cultured rat hepatocytes and effects on the process of recovery from CP intoxication using mouse liver were examined. Results obtained are summari zed as follows: (1) The formation of megamitochondria induced in the hepato cytes cultured for 22 h in the presence of 2 mM hydrazine or CP (300 mu g/m l) was suppressed by pretreatment of hepatocytes with CoQ(10) (1 mu M) or C HX (0.5 mu g/ml). This was proved by electron microscopic analysis of mitoc hondria. (2) Treatment of hepatocytes with hydrazine for 48 h or longer cau sed decreases in the membrane potential of mitochondria, which were suppres sed by CoQ(10). (3) Treatment of hepatocytes with hydrazine for 22 h or lon ger caused remarkable increases in intracellular levels of reactive oxygen species in hepatocytes, which were suppressed by CoQ(10). (4) The process o f recovery from the CP-induced changes of mitochondria in mouse liver was a ccelerated by CoQ(10) and CHX. (C) 1999 Academic Press.