Involvement of platelet-activating factor in death following anaphylactic shock in boosted and in unboosted mice.
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.
Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Departamento de Fisiologia e Farmacodinâmica, Rio de Janeiro, Brazil.
C Z
CZ
Amorim
R S
RS
Cordeiro
B B
BB
Vargaftig
D000707:Anaphylaxis / Q000188:drug therapy*; D000818:Animals; D001381:Azepines / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D007117:Immunization, Secondary; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D051379:Mice; D010047:Ovalbumin / Q000633:toxicity; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors* / Q000633:toxicity; D014230:Triazoles / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D014611:Vaccination
D001381:Azepines; D007074:Immunoglobulin G; D010972:Platelet Activating Factor; D014230:Triazoles; D007073:Immunoglobulin E; D010047:Ovalbumin; C063964:bepafant