Antigen-indued histamine release from peritoneal mast cells of mice producing reagin-like antibody.

The time course of production in the mouse circulation, after different schemes of immunization, of reagin-like and γ antibodies, as measured by the ability of the antisera to induce thermolabile long-latence and thermostable short-latence PCA reactions, has been studied. γ antibody was obtained in all schemes of immunization and its amount in antiserum increased with time. Reagin-like antibody appeared on the 7th day after immunization with sufficient dose of ovalbumin and adjuvant, and on later days with less efficient antigens such as DNP—BSA and DNP—BGG. Maximal amounts of the reagin-like antibody were reached in the early days after immunization and its presence in the circulation had a somewhat transient character; however, it persisted in the circulation for periods of more than 60 days, on occasion. The time course of antigen-induced histamine release from washed peritoneal mast cells of the immunized mice was also studied. A correlation was observed between the histamine release and the production of reagin-like antibody. It is suggested that the antigen-induced histamine release from washed peritoneal mast cells may be taken as an indication of the production of reagin-like antibody. Some quantitative aspects of the PCA and histamine release reactions were also studied. PCA reactions were affected similarly by varying either dilution or volume of the antiserum intradermally injected. Histamine release from peritoneal mast cells did not seem to be affected specifically by excess of antigen.