Repeated Antigen Inhalation-Induced Reproducible Early and Late Asthma in Guinea Pigs
Takeshi Nabe, Naoki Shinoda, Masahiro Yamada, Tomohiko Sekioka, Yuji
Saeki, Hideki Yamamura and Shigekatsu Kohno
Department of Pharmacology, Kyoto Pharmaceutical University, 5 Nakauchi,
Misasagi, Yamashina, Kyoto 607, Japan
Abstract: To develop a model of chronic experimental asthma in guinea
pigs, the animal was forced to inhale the mist of a low dose of ovalbumin
(OA) adsorbed on fine Al(OH)3 for sensitization once every 4 weeks. The
animal was challenged by inhalation with the mist of OA on day 14 after
the respective sensitizations. Either the first or the second antigen challenge
markedly induced an early asthmatic response (EAR), whereas there was hardly
any late asthmatic response (LAR). At the 3rd challenge, LAR also emerged
with some severity. These dual responses were consistently observed until
the 10th challenge. On the other hand, repeated inhalation/challenge, once
every 2 weeks, with OA alone at the same dose tended to lead to the desensitization
of the EAR. In addition, LAR was hardly observed throughout the experiments.
In both groups, gamma1 and IgE levels in the serum were elevated by the
repetitive antigen inhalations, yet no obvious relationship between these
antibody levels and the intensity of either EAR or LAR was recognized. The
present results indicate that the asthmatic model with reproducible EAR
and LAR developed in this study appears to be very beneficial for the investigation
of bronchial asthma and for the assessment of anti-asthma drugs.
Keywords: Late asthmatic response, Early asthmatic response, Asthma,
Aluminum hydroxide, IgE