Antihistaminic Substances in Histamine Poisoning and Anaphylaxis of Mice

The conditions under which mice can be sensitized and the manifestations of sensitization in mice closely simulate those of anaphylaxis in guinea pigs and other animals (Braun, 1 Schultz and Jordan, 2 Ritz, 3 Sarnowski, 4 . Bourden, 5 Weiser, Golub and Hamre 6 ). Active sensitizations can be produced with various protein substances, horse, sheep, cow, guinea pig serum, or egg white; passive sensitizations with immune rabbit serum, antihorse guinea pig serum, antihorse rabbit serum, antipneu-mococcus Type I rabbit serum, etc. The sensitizations are specific and their duration varies from several weeks to several months. Refractoriness occurs after recovery from shock and active desensitization is obtained by The usual desensitization methods. Specific precipitins are formed in mice actively sensitized against egg white with a titer varying from 1:100 to 1:400. From all these facts it has been concluded that the “protein shock” in mice is a true anaphylaxis; they fulfill indeed Doerr's 7 criteria of allergy. The mechanism which ultimately leads to the various anaphylactic manifestations in the different animal species is certainly not the same. The tissue which becomes the principal site of sensitization in guinea pigs is that of the lungs; in rabbits, that of the vascular system; in dogs, that of the liver; etc. The site of sensitization in mice is unknown. The similarity of the symptoms of anaphylactic shock in guinea pigs or dogs to those of histamine poisoning was first recognized by Dale and Laidlaw. 8 The significant increases of the histamine level in the blood during anaphylactic shock in guinea pigs and dogs are strong support for the “histamine theory” of anaphylaxis. It is today commonly accepted that at least in these animal species the antigen-antibody reaction leads to a liberation of histamine or a histamine-like substance, which is the ultimate cause of the anaphylactic shock.