Abstract
Alterations in liver microsomal drug-metabolizing enzymes and phospholipids following oral administration of chloroquine to rats for 14 days were investigated. An increase in cytochrome P450 and cytochrome b5 contents and an increase in the activities of NADPH cytochrome c reductase and NADH microsomal cytochrome reductase were observed. A decrease in cholesterol and an increase in phospholipids were noted in the microsomal membranes, which altered the membrane fluidity, which may be of importance in controlling different membrane functions. The increase in different fractions of microsomal phospholipid is probably due to an increased incorporation of acetate into phospholipids.