Passive air-pouch anaphylaxis in rats. I. Induction of anaphylaxis

Induction of an experimental passive anaphylaxis of the air-pouch type, passive air-pouch anaphylaxis, was carried out in an attempt to induce a reproducible anaphylaxis model suitable for quantitative studies. Rats were injected subcutaneously with 10 ml of air into the dorsal skin to make an air-pouch and with 2 ml of antiserum at an appropriate dilution for passive sensitization, and then 5 ml of air was removed. The challenge with 5 ml of antigen solution into the air-pouch 48 h later provoked mast cell degranulation and increased vascular permeability induced by released histamine. Treatment with monovalent hapten prior to the antigen challenge almost completely inhibited histamine release and plasma exudation to levels similar to those in the nonsensitized group. In this model, mast cell-dependent late-phase allergic reaction, such as leukocyte migration or the increase of plasma exudation following mast cell degeneration, was not observed.