[Effect of chronic chloroquine poisoning on the cardiac binding sites of calcium inhibitors in the rat].

Among the antimalarial drugs, chloroquine (CLQ) and 4-aminoquinoline derivatives display important interferences with biological membranes. The present study reports the effects of CLQ on dihydropyridine binding sites, measured in the heart of rats intoxicated with the drug. Acute intoxication does not entail any modification of the sites. On the other hand, binding sites were dramatically decreased by a chronic intoxication realized twice a week. In such a case, this decrease may be directly related to CLQ concentration in the heart. The regulation mechanisms involved are discussed.