Studies on the relationship of the release of serotonin and histamine, by chemical means, to anaphylaxis in the rabbit

Anaphylaxis in the rabbit is accompanied by a drop in the whole-blood serotonin and histamine, a release of these amines into the plasma, and a rise in their concentration in the lung. When antigen is added to the blood from a sensitized rabbit, serotonin and histamine are released. If EDTA is used as an anticoagulant, however, the release is prevented. In this study a variety of materials were tested, both in vitro with rabbit whole blood and in vivo by intravenous injection, to determine whether or not any of them could duplicate the findings which occur during anaphylaxis. Of all the substances employed, glycogen reproduced exactly the changes in platelets, serotonin, and histamine seen after the intravenous injection of antigen-antibody complex into normal rabbits or during anaphylactic reaction in this species.