Peritoneal mast cell hyperplasia in rats after IgE antibody-antigen interaction.

Peritoneal mast cell hyperplasia was investigated in rats after evoking IgE antibody-antigen reaction. Rats were immunized with antigen and then passively sensitized with monoclonal IgE antibody before antigen challenge. A significant increase in the number of peritoneal mast cells was observed 3 weeks after the antigen challenge in the peritoneal cavity, although the histamine content of the mast cells was decreased significantly. In rats without prior immunization, these changes were not observed. Stimulation with compound 48/80 or calcium ionophore A23187 did not affect the number of mast cells. This model may prove to be a useful tool for studying the mechanisms of mast cell hyperplasia and recruitment of mast cell precursors in vivo.