Studies on Experimental Asthma : I. In Vitro Passive Sensitization of Guinea-Pig Tracheal Rings with Homocytotropic Antibodies

Abstract

In vitro passive sensitization of guinea pig tracheal rings with homocytotropic antibodies was demonstrated. The passive tracheal anaphylaxis (PTA) reactions were expressed by values on four parameters. Each parameter was thermo-dependent. At 37℃, under low oxygen supply, the following were observed: Latent periods, which were lacking in curves induced by histamine paralleled reversedly with antigen doses at a given antiserum dilution. The contracting phases were within a narrow range (1′44″±0.22″) irrespective of concetrations of antiserum and antigen. Antigen doses had a trend to parallel with heights of contraction peak at a given antiserum dose and vice versa. Γ_1 antibody masked the activity of reaginic antibody. Contractions induced by antigen fell to the baseline aroud 15 minutes after the challenge while curves induced by histamine had T1/2 values (the period elapsing between the time of challenge and the point at which relaxation phase falls to half of the contraction peak) far over 15 minutes. Increased oxygen supply elongated T1/2 values remarlably through abolishing the later portion of the relaxation. The meaning of each parameter and the applicability of PTA reactions were shortly discussed.