Studies on metabolism of lung flukes of the genus Paragonimus. VI. Succinoxidase system in homogenates of eggs, larvae, and adults

The present study was concerned with the succinoxidase system in Paragonimus westermani, Paragonimus ohirai, and Paragonimus miyazakii. Potassium cyanide inhibited the motility of larval and adult forms. Succinate stimulated the reduction of methylene blue by homogenates of embryonated eggs, larvae, and adults, while malonate inhibited the reduction. Reduced cytochrome c was oxidized by the 1,000g supernatant from homogenates of embryonated eggs, larvae, and adults. The supernatant prepared from unembryonated eggs did not oxidize reduced cytochrome c. Succinate stimulated oxygen consumption by the homogenate of adult worms. Oxygen consumption markedly increased in the homogenate of adults when both succinate and cytochrome c were added as substrate to the reaction mixture, while malonate and cyanide inhibited oxygen consumption.