Abstract: 　Objective] To explore the apoptosis and its induction in S.japonicum. [Methods] The eggs and adult cells of S. japonicum were isolated. The adult cells were incubated with H 2O 2, dexamethasone and cyclosporin A, cyclosporin A vehicle solution, respectively in order to initiate the apoptosis. The eggs were treated at 4℃, 37℃ and 42℃, respectively for induction of apoptosis.The occurrence of apoptosis was supervised by agarose gel electrophoresis and in situ end labelling. [Results] DNA ladder band characteristic of apoptosis appeared in the cells of adult worms after incubated with H 2O 2, dexamethasone or cyclosporin A and the eggs treated at 42℃, whereas no DNA ladder band was found in other control groups. In situ end labeling revealed that the positive fluorescence could be seen in the cells incubated with H 2O 2, dexamethasone or cyclosporin A and few nuclei in the control group and cyclosporin A vehicle solution group appeared positive fluorescence. [Conclusion] Apoptosis in the cells of S.japonicum adults and eggs induced by chemical or physical agents was observed.

Key words: Schistosoma japonicum, adult cells, eggs, apoptosis, induction