Abstract
Cholera crisis-inhibiting factors (CCIF) and immunoglobulines were isolated from the intestines of rabbits immunized with inactivated vibrio cholerae and also from non-immunized intestines, and they were purified. From the immunized intestines, four fractions possessing cholera crisis inhibiting activity, PL, PS, IgA, and IgM were obtained. The cholea crisis-inhibiting activity of fraction PL appeared at a dose of 0.05 μg/mouse, the specific activity of which was the same as those of fractions IgA and IgM, but the cholera-crisis inhibiting activity of fraction PS appeared at a dose of 0.005 μg/head and the activity of fraction PS was the highest. From non-immunized intestines, three fractions possessing cholera crisis-inhibiting activity, NL, IgA, and IgM, were obtained. Activity of each of these fractions was lower than those obtained from the immunized intestines, and especially, fraction NS did not show any activity. A thin-layer electrophoresis of fraction PL showed a wide band. The fraction PL was found to be a high molecular glycoprotein containing IgA, IgM, and IgG. The activity of fraction PL seems to be due to the non-specific activity of immunoglobulin, the activity of which may be strengthened by further immunization. A thin-layer electrophoresis of fraction PS showed almost a single band, but its disc electrophoresis did not prove it to be a single component. This product is a novel active substance produced by immunization and is a low molecular glycoprotein, which contains hexose, hexosamine, and methylpentose, but does not contain sialic acid and immunoglobulin. The property of this product is different from that of fraction PL. Cholera crisis-inhibiting factors are produced by immunization of pigs as well as rabbits with vibrio cholerae or crude exotoxin.
