Anaphylactoid Reaction of the Mouse to Dextran.

The mouse has been found to exhibit signs of an anaphylac-toid reaction to partially hydrolyzed dex-trans of 41,000 and 80,000 average molecular weight. In the unanesthetized animal the reaction was characterized by minimal clinical symptoms and markedly increased capillary permeability detected by T-1824 blueing of the skin, but in animals under barbiturate anesthesia it resulted in cyanosis and death. The reaction was prevented by epinephrine, ether, and Phenergan, and was not evoked by administration of other plasma volume expanders.