Quantitative Aspects of the Inhibition of Anaphylactic Shock in Guinea Pigs

Abstract

Summary and Conclusions

The L. D.₁₀₀dose of a solution of hen egg white by intracardial injection was determined for a group of actively sensitized guinea pigs. It was found that 5 to 10 mg of pyribenzamine or benadryl injected intraperitoneally between 10 and 30 minutes before giving the shocking dose protected the animals against approximately 8 L. D.₁₀₀ doses of the antigen while injection of 10 or more L. D.₁₀₀ doses resulted in rapid death with symptoms indistinguishable from the control animals. If 6 or less L. D.₁₀₀ doses were given, no symptoms were noted in the protected group.

These results seem to indicate that the socalled anti-histaminic drugs do exert a protective influence, quantitative in nature, against anaphylaxis in the actively sensitized guinea pig. This fact might well be expected since a similar quantitative protection is obtained with these drugs against histamine shock. 1 , 2 , 3 The modifying action of these drugs again seems in accord with the theory that histamine plays a major role in anaphylaxis. It is of interest that approximately the same degree of protection was offered, in these experiments, by both the compounds used.