Dose–Response Curve: Temporal Dynamics of Respiratory Mechanics in Mice

A very usual practice in literature associated to respiratory mechanics is the challenge of the system, in order to evidence potential differences. Therefore, dose-response curves allow the assessment of respiratory mechanics. Despite the fact that the study of the dose-response curve using peak responses is important and desirable, an evaluation of the temporal dynamics of each dose in a dose-response curve could bring new perspectives about respiratory mechanics. Therefore, the present study aims to understand the kinetics of Newtonian resistance (Rn) of the respiratory system due to transient bronchoconstriction induced by administration of methacholine (MCh) in different concentration. Nine-week female Balb/c mice were studied, nine of the control group and ten of the lung inflammation group (OVA). The doses of MCh were 30, 100 and 300 μg/kg. The constants modelling the single exponential function were compared among of groups and doses. As a result, the increasing values of fitting constants are in direct relation to increasing values of MCh infusion. Additionally, the decay of the curve did follow the increase of the peak value for OVA group. However, it was possible to realize statistically that the temporal dynamics response of bronchoconstriction differs from control to OVA groups only at MCh dose of 100 μg/kg.