Allografted lungs in matched dogs with induced pulmonary hypertension.

Induction of chronic pulmonary hypertension in dogs treated by lung allotrans-plantation was performed in this study. Eight adult dogs, 3 mongrels and 5 purebred sibling foxhounds matched by mixed leukocyte culture, comprised group I and were subjected to recurrent macroembolization and compared to another group (II) of 8 unmatched normotensive animals who received allografts and immunosuppressive therapy. Findings in early biopsy specimens in the group I animals revealed endothelial edema. A mononuclear vasculitis, more marked around the veins, and a mononuclear chronic inflammatory infiltrate in the bronchial wall were additional findings in the early biopsy specimens. In the group I late biopsy specimens, electron-dense and electron-lucent endothelial cells and multilamination of the basement membrane were characteristic features. Fibrosis of the bronchial wall structures was noted during this time period, as was alveolar wall fibrosis. These pathologic endothelial lesions, the basement membrane multi-lamination and the alveolar wall fibrosis are similar to the lesions reported in the chronically rejected renal allograft.