Characterization of aeroallergen-induced dyspnea in unrestrained guinea pigs by bias-flow-ventilated whole body plethysmography.

Aeroallergen-induced dyspnea in guinea pigs was associated with an increase in amplitude in the box pressure fluctuations (212%) and pseudo-flow signal (604%) and an 80% decline (from 0.19 to 0.04 s) in relaxation time (the time it takes the box pressure signal to drop from its peak to 1/3 of its peak value). All of these lung dysfunction changes were highly significant (P < 0.001). Pyrilamine (1 mg/kg, p.o., -2 h) inhibited dyspnea (delta P and delta F) by 50-53%. This technique allows quantitative analysis of allergic dyspnea in conscious, unrestrained guinea pigs.