Hexachlorophene was reported previously to have a powerful parasiticidal effects on Clonorchis sinensis in vitro and in vivo, but the mechanism of its effect was not known. In the present report it was observed that there was an influence of hexachlorophene on the oxygen consumption, the glycolysis, the glycogenesis and the protein synthesis of C. sinensis. A hundred mg. of C. sinensis collected from the biliary tracts of the infested rabbits was incubated in 2 ml of K.R.P. medium with vavious concentration of hexachlorophene, glucose-1-C14 and glycine-1-C14 in a 25 ml incubation flask with central well. The oxygen consumption was observed by Warburg manometer, the glycogenolysis by measurement of radioactivities of extracted glycogen and protein from C. sinensis incubated with C14-glucose or C14-glycine. 1) The oxygen consumption by C. sinensis was markedly inhibited during all stages of incubation in concentration of 10-4 and 10-5g/ml of hexachlorophene, but in 10-6, slightly increased initially and gradually decreased after 3 hours of incubation. 2) Hexachlorophene inhibited the glycolysis by C. sincnsis markedly in the concentration of 10-4, 10-5, 10-6 and 10-7g/ml. 3) The protein synthesis by C. sinensis from glycine was inhibited in the concentration of 10-5, 10-6 and 10-7g/ml of hexachlorophene. 4. The glycogen synthesis by C. sinensis in each concentration of 10-4, 10-5 and 10-6g/ml of hexachlorophene was inhibited markedly. The speed of inhibition was more rapid in high concentration than in low, and in low concentration even the glycogen itself which had synthesized in their stage in their body was consumed in later stage. 5) The effects of oxygen consumption, glycolysis and glycogen synthesis were not influenced in the concentration of 10-5g/ml of chloroquine phosphate, whereas hexachlorophene and dithiazanine inhibited markedly in same concentration, and the former was more potent than the latter.
