Reversed anaphylaxis with anti-IgE on mouse and rat mast cells.

Peritoneal mast cells of four inbred strains of mice (BABL/c, 129, C3H/A, C57BL/6J) and F1 hybrids of August and Wistar rats were studied for their sensitivity to the action of anti-IgE antibody for histamine release. The mast cells of normal mice from four mouse strains tested showed different abiltiy to release histamine after challenge with several dilutions of anti-IgE; mast cells of BALB/c mice showed the lowest reaction to anti-IgE. After active sensitization of mice and rats their mast cells release histamine after challenge with specific antigen, however, the detectable changes in their sensitivity to anti-IgE were not observed. After passive sensitization of mice the mast cells of three out of four strains tested show slightly enhanced sensitivity to anti-IgE for histamine release. Thus, the sensitization of mast cells not always stimulates their sensitivity to anti-IgE in reversed anaphylaxis.