Effect of chloroquine on rat liver mitochondria.

Chloroquine causes an increase in phospholipid and a decrease in cholesterol in liver mitochondria. A significant decrease in the activities of mitochondrial inner membrane enzymes such as NADH dehydrogenase, succinate dehydrogenase and cytochrome c oxidase is observed. Decrease in cytochrome contents and respiratory control ratio, shown by a decrease in state 3(+ADP) and an increase in state 4 (-ADP), implies decreased ATP synthesis following chloroquine administration. The results confirm drug-induced inhibition of mitochondrial respiration, thereby impairing availability and utilisation of energy.