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Updated: Sep 23, 2026
Measuring Local Anaphylaxis in Mice
Published on: October 14, 2014
Involvement of platelet-activating factor in death following anaphylactic shock in boosted and in unboosted mice
C Z Amorim1, R S Cordeiro, B B Vargaftig
1Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Departamento de Fisiologia e Farmacodinâmica, Rio de Janeiro, Brazil.
Abstract:
The interference of the platelet-activating factor (PAF) receptor antagonist compound, WEB 2170, on death caused by antigen in boosted or unboosted immunized mice was investigated. Death was triggered by the i.v. injection of ovalbumin into animals actively sensitized 14 or 21 days before and that received (boosted) or did not receive (unboosted), a second immunization 14 days later. No significant difference in the response to PAF (50 micrograms/kg) or to ovalbumin (500 micrograms/kg) was noted in boosted or unboosted mice in terms of mortality. WEB 2170 was equieffective to prevent death by PAF in non-sensitized or sensitized boosted or unboosted mice. The i.p. treatment with WEB 2170 (8-16 mg/kg) 1 h before the antigenic challenge prevented death due to antigen in unboosted or in boosted mice. Our results suggest that PAF is involved in the anaphylactic shock in unboosted and boosted mice. In addition, different from the anaphylactic reaction developed in the mouse paw, the participation of PAF in the anaphylactic shock caused by antigen is not dependent on the delivery of a booster injection.
Insights
Platelet-activating factor (PAF) plays a role in anaphylactic shock in mice. The PAF receptor antagonist WEB 2170 effectively prevented antigen-induced death, regardless of booster immunization status.
Area of Science:
- Immunology
- Pharmacology
Background:
- Anaphylactic shock is a severe allergic reaction.
- Platelet-activating factor (PAF) is implicated in allergic responses.
- The role of PAF in antigen-induced anaphylaxis, with or without booster immunization, requires clarification.
Purpose of the Study:
- To investigate the involvement of PAF in antigen-induced anaphylactic shock in mice.
- To evaluate the efficacy of the PAF receptor antagonist WEB 2170 in preventing anaphylactic death.
Main Methods:
- Mice were immunized and challenged with ovalbumin to induce anaphylaxis.
- Some mice received a booster immunization.
- The PAF receptor antagonist WEB 2170 was administered before antigen challenge.
Main Results:
- WEB 2170 was equally effective in preventing death induced by PAF or antigen in both boosted and unboosted mice.
- Antigen-induced death was prevented by WEB 2170 treatment in both boosted and unboosted sensitized mice.
- Mortality rates did not significantly differ between boosted and unboosted mice in response to PAF or ovalbumin.
Conclusions:
- PAF is involved in anaphylactic shock in both boosted and unboosted mice.
- The role of PAF in antigen-induced anaphylactic shock is independent of booster immunization.
- WEB 2170 demonstrates efficacy in mitigating anaphylaxis, suggesting PAF as a therapeutic target.
