Evaluation of Airway Responses by Measurement of the Respiratory Resistance in Rats under Nonanesthetized Conditions

抄録

In this study, the airway responses of sensitized rats after antigen exposure were evaluated under nonanesthetized conditions. Prior to measuring the respiratory resistance and evaluating the airway responses, the effect of anesthetics on the increase in respiratory resistance induced by acetylcholine, the responsiveness of tracheal strips derived from sensitized rats towards antigen (DNBS-As), the time required for the nebulization of DNBS-As and changes in the antigenicity of the antigen during nebulization were examined. In addition, based on the results obtained, the conditions for measuring the respiratory resistance of rats were decided as follows: some anesthetics inhibited an increase in the respiratory resistance of rats, and therefore the respiratory resistance of rats should be measured under nonanesthetized conditions. The nebulization time for DNBS-As was set at 5 min, and the concentration of DNBS-As set at 1 mg/ml. Next, in order to evaluate airway responses, the respiratory resistance of sensitized rats under nonanesthetized conditions was measured with an Animal Asto TMC-2000 under the above conditions. The appearance rate for early phase responses 16-30 days after sensitization was higher than that 8-15 days after sensitization. On the other hand, the appearance rate for late phase responses 8-15 days after sensitization was higher than that 16-30 days after sensitization. Based on these results, it can be suggested that the late phase response appears more easily when the level of IgE antibody in the circulating blood is high.