EFFECT OF CHLOROQUINE ON RAT-LIVER MICROSOMES

Alterations in liver microsomal drug-metabolizing enzymes and phosphol ipids following oral administration of chloroquine to rats for 14 days were investigated. An increase in cytochrome P450 and cytochrome b(5) contents and an increase in the activities of NADPH cytochrome c redu ctase and NADH microsomal cytochrome reductase were observed. A decrea se in cholesterol and an increase in phospholipids were noted in the m icrosomal membranes, which altered the membrane fluidity, which may be of importance in controlling different membrane functions. The increa se in different fractions of microsomal phospholipid is probably due t o an increased incorporation of acetate into phospholipids.