1) By immunizing rabbits with inactivated Vibrio cholerae, the occurence of a factor inhibiting the crisis of cholera, termed cholera crisis-inhibiting factor (CCIF), was recognized in the small intestines of the rabbits. This CCIF could be found only in the small intestine of immunized rabbits, and not in any other organs, or the serum of immunized rabbits, and in the small intestine of non-immunized rabbits. 2) The occurence of CCIF with immunization was clearly distinguished from the formation of an antibody in the blood, the difference in the period of their formation, and by the fact that the serum antibody titer cannot be recognized in the case of CCIF. 3) Two active fractions, S-1 and S-4, were obtained by successive purification, such as by column chromatography on DEAE-cellulose, gel filtration on Sephadex G-100, and column chromatography on carboxymethyl cellulose (CMC), after extracting with Triton X-100, but it did not result in complete purification to obtain a single component. 4) S-1 is a glycoprotein with a molecular weight of about 300000 anb contains immunoglobulins such as IgA and IgG. S-4 is a new protein with a molecular weight of about 300000 and does not contain any immunoglobulins. 5) Further examinations are required to find the essential nature of CCIF, whether the activity of S-1 is related to the local antibody system and whether the activity of S-4 is related to inhibition of the intestinal permeability.
