Fig 1.
Diagram of the custom-built whole-body plethysmograph.
The apparatus included a cylindrical chamber made of transparent Plexiglas. Room air was continuously pumped (4 L/min) into the chamber. A plastic Y-connector was connected to chamber's outlet. One of the exit ports was linked to one input of a differential pressure transducer, and the other input being exposed to the room air. Another port Y-connector was connected to a one input of CO2 sensor. The other input of the CO2 sensor was opened to the room air. The respiratory signals were acquired at the sampling rate of 1 kHz.
Fig 2.
Respiratory pattern in a representative guinea pig.
(a), Representative fragments of the respiration signal display the inter-breath interval (IBI) and respiratory volume (RV), as well as deep inspiration. Original IBI (b) and RV (c) time series during 20 min of respiration in a representative guinea pig.
Fig 3.
Effect of Rho-kinase inhibition on hyperresponsiveness.
(a), Experimental protocols; (b), airway hyperresponsiveness in response to methacholine. Data are presented as percent of baseline and expressed as mean ± SEM (n = 6). * p<0.05 and ** p<0.01 compared to saline group; # p<0.05 compared to OVA+Y-27632 group; analyzed by repeated measure two-way ANOVA, with the Bonferroni post-test.
Fig 4.
Effect of Rho-kinase inhibition on airway remodeling and inflammation.
(a), immunohistofluorescence staining to illustrate expression of α-SMA (Scale bar 100 μm); (b), Masson trichrome staining to identify subepithelial collagen deposition (Scale bar 50 μm); (c), hematoxylin and eosin (H&E) staining to detect peribronchial inflammatory cell infiltration (Scale bar 50 μm). (d), periodic acid-Schiff (PAS) staining to assess epithelial goblet cells (Scale bar 20 μm).
Fig 5.
Effect of Rho-kinase inhibition on bronchoalveolar lavage (BAL) inflammatory cells.
Total inflammatory cell (a) and eosinophils (b). *** p<0.001 compared to saline. Data were analyzed by a one-way ANOVA, with the Bonferroni post-test.
Fig 6.
mRNA expression of TNF-α (a) and IL-13 (b) in the lung of experimental groups.
* p<0.05 and ** p<0.01 compared to Saline group. Data were analyzed by a Kruskal–Wallis test with a Dunn’s post-test.
Fig 7.
Effect of Rho-kinase inhibition on complexity of respiratory dynamics.
* p<0.05, ** p<0.01, and *** p<0.001 compared to saline group. Data were analyzed by one-way ANOVA with the Bonferroni post-test. CV, coefficient of variation; DFA, Detrended fluctuation analysis; SampEn, sample entropy; IBI, inter-breath interval; RV, respiratory volume.
Fig 8.
Effect of Rho-kinase inhibition on synchronization between IBI and RV.
* p<0.01 compared to saline group. Data was analyzed by one-way ANOVA with the Bonferroni post-test. IBI, inter-breath interval; RV, respiratory volume; Cross-SampEn, cross-sample entropy.