IGE AND IGGA ANTIBODY-MEDIATED RELEASE OF HISTAMINE FROM RAT PERITONEAL CELLS

Abstract

The existence, in several species, of two major types of homocytotropic antibodies has been recognized and reviewed previously (1). In the preceding paper (2) conditions were described for studying in vitro the antigen-induced release of histamine in the rat IgE and IgGa antibody-mediated systems. The present paper further characterizes the properties of the IgGa antibodymediated reaction and presents evidence that homologous IgGa and IgE antibodies utilize the same cellular receptors in the pathway leading to the release of histamine. Materials and MethodsThe media, antigen, and antibody preparations used in this study were the same as those previously described (2). Except where specifically indicated, the conditions of the experiments were those found to yield optimum results in the previous study (2).

IGE AND IGGA ANTIBODY-MEDIATED RELEASE OF HISTAMINE FROM RAT PERITONEAL CELLS

“…The transient nature of the binding of IgGa antibody to target cells as evidenced by the apparent failure to survive washing of the cells will be discussed in the subsequent paper (11). Further, although the optimum conditions for release of histamine are identical for the two systems, the two reactions differ in the time course of release of histamine.…”

“…To date there have been no direct in vitro comparisons of antigen-induced histamine release from target cells prepared with the two types of homocytotropic antibody in a single species of animal; the present studies describe and compare the experimental conditions for the in vitro preparation of mixed rat peritoneal cells, or their mast cell fraction, with rat IgE or IgGa antibodies. A second paper (11) describes the interactions of these two types of antibodies and the target cell.…”

Antiallergic action of 6-ethyl-3-(1h-tetrazol-5-yl) chromone (aa-344) on immediate hypersensitivity reaction in rats

“…Furthermore, a common receptor or closely interacting receptors have been suggested as such would interfere with each other in the rat PCA reaction and in the mediator release from the sensitized rat peritoneal mast cell provoked by antigen (30,31). In the present study, AA-344, like DSCG, suppressed partially the rat 3-hr PCA induced by anti serum containing IgGa, although 100 times the dose of AA-344 was required to inhibit the IgE-mediated 72-hr PCA.…”

INHIBITORY ACTION OF 6-ETHYL-3-(lH-TETRAZOL-5-YL)CHROMONE (AA-344) ON IgE-, IgGa- OR CHEMICAL AGENT-INDUCED HISTAMINE RELEASE FROM ISOLATED RAT MAST CELLS

“…On the other hand, the IgGa-mediated PCA in rats was inhibited by the injection of IgE antibody at the same site, suggesting a competition for the IgE receptor of mast cells (26,27). Moreover, the anaphylactic release of histamine from the isolated rat mast cells was mediated not only by IgE but also by IgGa (28).…”

“…Moreover, the anaphylactic release of histamine from the isolated rat mast cells was mediated not only by IgE but also by IgGa (28). These observations led to the proposal that both rat IgE and IgGa may utilize the same receptor on the mast cell or some common process leading to histamine release (26)(27)(28)(29). However, differences between IgE and IgGa in the period for sensitization and an affinity to the binding site have also been observed (28).…”