Correlation between the Airway Branching Patterns and the Heterogeneous Distribution of the Lesions in Bleomycin-Injured Mouse Lung: A 3-D Morphometric Study

Correlation between the Airway Branching Patterns and the Heterogeneous Distribution of the Lesions in Bleomycin-InjuredMouse Lung: A 3-D Morphometric Study

KAZUYA ONUMA,^1,2 MASAHITO EBINA,¹ TOHRU TAKAHASHI^2,3 and TOSHIHIRO NUKIWA¹

¹Department of Respiratory Oncology and Molecular Medicine,
²Department of Pathology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, and
³Pathology Section, Ishinomaki Red Cross Hospital, Ishinomaki 986-8522

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

Keywords —— 3-D morphometry; bleomycin; irregular branching; recurrent branch

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Tohoku J. Exp. Med., 2001, 194, 147-156

Address for reprints: Masahito Ebina, M.D., Ph.D., Department of Respiratory Oncology and Molecular Medicine, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryomachi, Aoba-ku, Sendai 980-8575, Japan.

e-mail: ebinam@idac.tohoku.ac.jp