Pulmonary function testing. A. Airway resistance in WT vs. gp91phox-/-. Symbols used are white triangle WA (Wildtype alum), black circles WO (WT OVA), white cross in black box NOX (alum gp91phox-/-) and black box NOXO (OVA treated gp91phox-/-). Airway resistance obtained by invasive plethysmography show increased values in both gp91phox-/- and gp91phoxMM12 double knockout mice compared to wildtype post-OVA. Symbols used are open square WA, closed square WO, open triangle DKOA (alum double knockout), closed triangle DKOO (OVA treated DKO. On d 22, 24 h after the last intra-tracheal allergen (OVA) challenge invasive pulmonary mechanics were measured using a commercial plethysmography system (Model PLY4111 plethysmograph, MAX II amplifier and pressure transducer system, and Biosystem XA software, Buxco Electronics, Inc.) mice receiving aerosolized solutions of methacholine (0, 3.125, 6.25, 12.5, 25, 50, and 100 mg/ml in normal saline) via an AER 1021 nebulizer aerosol system (Buxco Electronics, Inc., Wilmington, NC) with 2.5-4 micron aerosol particle size generated by NEB0126 nebulizer head (Nektar Therapeutics, San Carlos, CA), and RL as calculated from measures of pressure and flow and expressed as cmH2O/ml/s was determined. Figures show Airway resistance (RL) values ± SEM of data obtained from 3 independent experiments (n = 5/group). C. Non-invasive plethysmography (expressed as Penh) was also assessed on d 22 in independent experiments with gp91phox-/- only and this co-related with the airway resistance values obtained by invasive plethysmography. Symbols used are black diamond WA, open triangle NOX, small black square WO, open large square NOXO: For non-invasive plethysmography, mice were challenged with increasing doses of aerosolized methacholine (0, 5, and 20, 40, and 100 mg/ml in normal saline) generated by an ultrasonic nebulizer (DeVilbiss Health Care, Inc., Somerset, PA) for 2 min. and the degree of bronchoconstriction was expressed as enhanced pause (Penh), a calculated dimensionless value that correlates with measurement of airway resistance, impedance, and intrapleural pressure. Penh is primarily independent of FRC, tidal volume, and respiratory rate since the ratio of measurements is obtained during the same breath and has a strong correlation with both airway resistance (Raw) measured directly in anesthetized, tracheotomized, and mechanically ventilated mice. *denotes p value < 0.01 compared to post-OVA wildtype values.
Banerjee and Henderson Clinical and Molecular Allergy 2012 10:2 doi:10.1186/1476-7961-10-2