Increased Reactivity of Schistosoma japonicum Eggs in the Circumoval Precipitin Test after Hydrochloric Acid Treatment

摘要

The effect of a hydrochloric acid solution on the circumoval precipitin (COP) reactivity of Schistosoma japonicum eggs was studied. When eggs, recovered by trypsin digestion from tissues of an 8 week-infected rabbit, were treated with a pepsin HCl solution, they had significantly higher reactivity than the saline-treated eggs (control). A similar effect was obtained with HCl solution (0.008 N), alone. In contrast, a sodium hydroxide solution (0.05 N) decreased the reactivity. Treatment with different concentrations of HCl (0.01 to 6N) for 2 days revealed that the reactivity was highest at 0.1 N, and was diminished by the higher concentrations (3 and 6N). Preservation in an HCl solution (0.01N) yielded a peak reactivity at 2 days. While the exact role of the HCl solution was not studied, this study contributes to the preparation of egg specimens and to our understanding of the low reactivity of eggs.