The Inhibition of Anaphylactic Shock by the Intravenous Injection of Neoarsphenamine. ∗

Abstract

We have been particularly interested in the prevention or modification of anaphylactic shock by intravenous injection of colloidal substances into the sensitized animal before reinjection of the antigen, in connection with our studies on the rôle of the reticulo-endo-thelial system to various immunity phenomena. 1 Extensive studies on the effect of a large number of various colloids (India ink, trypan blue, collargol, casein, etc.), when introduced by the intravenous route into sensitized guinea pigs shortly before reinjection of the antigen, have in our hands, contrary to the findings of other investigators, led uniformly to negative or doubtful results. We have been able, however, to amplify the interesting contributions of Freud 2 and Walbum 3 in a similar field by observing that tuberculous guinea pigs frequently survived a fatal dose of tuberculin when this was preceded (a few hours) by an intravenous dose of India ink. More significant results, of which the following is a brief report, have recently been obtained with the intravenous administration of neoarsphenamine in sensitized guinea pigs shortly before reinjection of the specific antigen.

In one experiment 20 guinea pigs, weighing from 250 to 350 gm., were sensitized by the subcutaneous injection of 0.01 cc. of normal horse serum. The minimum dose of antigen, capable of producing after intravenous injection death from acute anaphylactic shock within 3 to 5 minutes, was determined in 4 animals, 3 weeks later, and found to be 0.3 cc. The remaining 16 animals, in groups of 4, were given at the same time, 1 cc. of a 1:50 dilution of neoarsphenamine intravenously, preceding the intravenous reinjection with 0.3 cc. of normal horse serum at intervals of 5 minutes, 15 minutes, 30 minutes and one hour.