Increased Susceptibility of Mice to Anaphylactic Shock Following Cobalt-60 Gamma Radiation

Abstract

Gamma radiation exposure of 650 rep. markedly enhanced active anaphylactic shock in mice sensitized with alum-precipitated tetanus toxoid and challenged with fluid tetanus toxoid 7 days post-radiation. The enhancing effect of ionizing radiation upon the severity of the anaphylactic response is not of an immediate nature, but appears during a 2- to 7-day post-radiation period. Passive and reversed passive anaphylaxis was more severe in 7-day post-radiated mice sensitized with homologous antibody. Irradiated mice sensitized with anti-bovine albumin rabbit serum demonstrated increased sensitivity to passive anaphylaxis when challenged 1 day later with bovine albumin antigen. Seven-day post-radiated mice did not show increased sensitivity to intravenous injection of histamine. The antihistaminic agents, Thephorin, Benadryl, and Pyronil, afforded almost complete protection from fatal anaphylaxis in irradiated mice.