DDT and Immunological Responses

Abstract

Serum antibody levels were measured in guinea pigs which had been injected with 10 to 20 mg/kg of DDT prior to add following immunization with diphtheria toxoid. Protection of animals from injected toxin, neutralization of toxin in vitro, and magnitude of γ-globulin fraction were the factors which indicated the antitoxin levels unaltered by DDT administration. The anaphylactic shock induced in the same animals by a challenge with diphtheria toxoid was markedly reduced in the DDT-treated animals. Reduced severity of the shock was also noted when DDT was injected for only three days prior to the induction of anaphylaxis: 63% of the control animals died, whereas only 22% of the DDT-treated animals died. As the antibody level was not affected, the results suggest a direct effect by DDT on the mechanism of anaphylaxis.