The Specific Inhibition of in vitro Anaphylaxis and Histamine Release by Dialyzable Material from Ragweed Pollen

Abstract
Passive sensitization of isolated normal guinea-pig heart muscle with 2 different preparations of rabbit antiragweed serum failed to show a correlation between precipitating antibody and ability to sensitize. The dialyzable, small molecular weight fraction obtained from aqueous extracts of ragweed pollen inhibited the anaphylactic reaction when challenge was made with a nondialyzable fraction.