Functional imaging quantifies the extent to which β-ENaC-Tg mice express patchy lung disease.
(a) 4DPIV followed by ATL (coloured by expiratory time constant) show that lung disease in β-ENaC-Tg mice is heterogeneous. Histological sections of the lung are obtained at different locations (white lines) and are shown in (b,c). (b) AB/PAS stained histological sections from the same WT littermate as 3a (M02) shows no mucus plugging (black arrows). (c) AB/PAS stained histological sections from the same β-ENaC-Tg mouse as 3a (M11) shows clear airways (black arrows) as well as mucus obstructed airways (green arrow) within the same lobe, indicating non-homogenous disease. (d) Regional lung ventilation in β-ENaC-Tg mouse (M22) shows low ventilation in the right upper lobe of the lung (left panel, dashed box). (Middle panel) The corresponding histological section showing mucus blockage in the bronchial tree that feeds the right upper lobe of the lung. (Right panel) Airway tree coloured by expiratory time constant, the same analysis applied to data in a, shows the right upper region of the lung exhibits an increased resistance. This is validated by the mucus blockage evident in histology shown in the middle panel. Green arrow shows location of a mucus obstruction. Scale bars, 100 μm.