THE TOXIC EFFECT OF PRIMAQUINE ON THE HEARTS OF LABORATORY ANIMALS-A HISTOLOGICAL AND ULTRASTRUCTURAL INVESTIGATION
He Dehua, et alDepartment of Pathologic Anatomy
It has been known that quinoline antimalariai drugs may cause inhibition of heart conduction or Adamsstokes syndrome. Its morphologic bases were obscure, We observed the histological and ultrastructural features of dogs, monkey and rats, in the toxic experiments of primaquine, with the stress on the heart. Myo-cardial granular degeneration, eosinophilic degeneration, coaggulation necrosis,vacuolar degeneration and colliguative myocytolysis were found in most of the intoxicated dogs. The heart conduction systems of dogs also showed above mentioned lesions. Electro-microsopically the myocardial cells of intoxicated dogs showed swelling of mitochondria, dilatation of transvers tubules and sarcoplasmic reticulum, fusion or dissolution of myofibrils, deformity of nuclei, clumping of chromatin,and evertually cell necrosis. The severities of lesions were parallel to the doses of the drug used.These lesions were supposed to be the morpholoic bases of the intoxication symptoms and signs caused by primaquine. A few experimental rats also revealed myocardial eosinophilic degeneration, No important cardiac lesion was found in the experimental monkeys, but the pathologic changes in the liver were obv :ous. Different Species of laboratory animals showed different sensitivitiss to primaquine, but the heart lesions should be considered an important toxic effect of primaquine.