Genetic deficiency of α1‐PI in mice influences lung responses to bleomycin

Abstract
It has recently been suggested that proteinase inhibitors modulate the fibrotic response in the lung. This study investigated the development of bleomycin-induced pulmonary changes in pallid mice, deficient in serum α1‐proteinase inhibitor, and with a lower elastase inhibitory capacity, and in congenic C57Bl/6J mice.Male pallid and C57Bl/6J mice received a single intratracheal instillation of either saline or bleomycin. The investigation was carried out by means of biochemical, morphological and morphometrical methods.In both strains, 21 and 72 h after bleomycin, the lungs showed foci of inflammatory cell infiltration associated with emphysema. Fibrosis developed with time after bleomycin. At 14 days fibrosis affected 23.46±9.48% (mean± sd) and 40.62±13.34% (p1‐proteinase inhibitor deficiency.