Correlation between the airway branching patterns and the heterogeneous distribution of the lesions in bleomycin-injured mouse lung: A 3-D morphometric study

The possible roles of airway branching patterns on the pathogenesis of lung diseases, especially on the heterogeneous distribution of the lesions, wer e examined through three-dimensional (3-D) morphometric analysis of a mouse lung injury, induced by bleomycin. On serial sections of a mouse lung dama ged by subcutaneous injection of bleomycin, we performed a computer-assiste d reconstruction of the lung for visualizing the relation of airways with t he distribution of the lesions, and defined the features of bronchial route s to each lesion by four parameters: LTB; the distance from the hilum, Ng; generation numbers, RD(min); irregularity of airway branching, and theta (T B) the grade of airway recurrence. Among these four parameters, only theta (TB) was found to correlate with the severity of lesions (p < 0.05 by an AN OVA test), which was proved by a posthoc test (p < 0.0001). These results s howing the acini supplied by recurrent branches are more prone to be damage d than those by non-recurrent branches suggest that branching patterns may underlie the heterogeneous distribution of lesions in diffuse interstitial lung diseases.