1. Sinomenine and Irgapyrin, the two antirheumatics
known to be capable of releasing histamine, caused a marked
gastric secretion in the unanesthetized dog. 2. The facial edema and itching associated with histamine release by sinomenine was almost completely eliminated by NeoAntergan,
but the gastric secretion was not suppressed, or rather increased - an observation also reported by Paton and
Schachter with Compound 48/80. This indicates that the histamine release cannot be markedly prevented by antihistamine agents in this animal. 3. The gastric secretion induced by Irgapyrin was not suppressed
by Neo-Antergan but Irgapyrin originally never caused
other symptoms associated with histamine release. This is probably due to the antihistamine action inherent in this compound itself. 4. No such histamine-releasing activity, as determined by gastric secretion, could be observed in aminopyrine or butazolidine sodium, the components of Irgapyrin. 5. Sinomenine, differing from Irgapyrin and Compound 48/80, was ineffective by intramuscular injection.</p