Inhibition of the Release of Slow-Reacting Substance of Anaphylaxis in the Rat with Diethylcarbamazine ∗

Summary

The immunologic release of SRS-A_rat with intravenously administered antigen is described. Hetrazan effectively inhibits the antigen-induced release of SRS-A_rat in a dose of 20 mg/kg iv. In this concentration, it has no influence on the bioassay system and does not prevent effective antibody-antigen interaction. Hetrazan does not produce an irreversible inhibition and must be present at the time of antibody-antigen interaction to effectively prevent the formation and release of SRS-A_rat. Suppression of the 4-hour PCA reaction in the rat with Hetrazan plus mepyramine maleate and methysergide suggests that SRS-A_rat may be a permeability factor involved in this reaction.