Contraction of guinea pig trachea with antibodies to guinea pig IgE. An in vitro model for asthma. II. Reactivity of guinea pig tracheas to anti IgG1 and anti IgG2 in comparison with anti IgE.

Although relatively small quantities of antibody to guinea pig IgE were shown to contract isolated guinea pig trachea in vitro, relatively large quantities of anti IgG1 were required to elicit similar responses. Under similar conditions, anti IgG2 did not provoke contraction. Following intravenous injection of these antisera into normal guinea pigs, anaphylaxis or asthma could be only provoked by anti IgE.