Intraperitoneal systemic anaphylaxis in the mouse. I. Age-dependence of fatal anaphylactic shock

Following the i.p. challenge of a shocking dose of BSA from 9 days up to 133 days after the s.c. injection of BSA in CFA, fatal anaphylaxis was induced regularly in female ICR mice that had been given the immunizing antigen when 8 weeks old. These immunized mice provided an antiserum to BSA that had the capacity to transfer fatal shock to normal recipient mice at a minimum Ab-N dose of 8 microgram when the i.p. route for challenge was employed. The optimal dose-range of antigen and antibody in order to elicit fatal shock following the i.p. challenge was much broader than that obtained by i.v. injection. Age is critical in producing fatal shock in mice; a 100% fatal anaphylaxis never occurred in groups of 6- and 7-week-old recipient mice although those at 8 weeks and older were sufficiently sensitized by the amounts of antibody given.