Objective To explore the effect of pH on the mutagenic potency of ICR-170 in the reproductive gland of female Schistosoma japonicum.Methods Mice of Kunming strain were infected with S.japonicum cercariae which were previously treated with acridine mutagen ICP-170 at various pH values(pH7.2-8.0) for 30 min or 45 min. Results The pH of the solution had significant effects on the mutagenic potency of ICR-170 in female S.japonicum. When the pH value increased from pH 7.2 to pH 8.0,the percent of mutation of female reproductive organs decreased. The highest mutagenic rate of ICR-170 occurred at pH 7.2,which was 13 times of that at pH 7.8 in the group of 10 ?g/ml 45 min,6 times in the group of 15 ?g/ml 30 min. However,pH value had lower effect on recovery of adult warms compared with mutagenicity. Conclusion The mutagenic potency of ICR-170 is strongly pH-dependent in the reproductive glands of female S.japonicum.

Mice of Kunming strain were infected with Schistosoma japonicum cercariae previously incubated with various concentrations of acridine mutagen ICR-170 for different time durations. At 6 weeks after infection, the mice were autopsied. The results showed that 24 out of 28(85. 7%) adult female worms had deformed or lacked ovaries and vitelline glands when the cercariae were treated with the agent at a concentration of 10?g/ml and incubated at 30. 5℃ for 30min. No apparnet changes were observed in the male worms inhabiting the mesenteric and portal veins with the females worms in their gynecophoral canals. The mutagenized female schistosomes obtained from the present experiment might be served as another form of attenuated worms for the induction of protective immunity.