Characteristics of cultured lung fibroblasts from bleomycin-treated rats. Comparisons with in vitro exposed normal fibroblasts.

Bleomycin is an antineoplastic agent that causes pulmonary fibrosis. This report describes fibroblasts cultured from lung tissue explants of in vivo bleomycin-exposed and control rats. Proliferation of cultured fibroblasts from bleomycin-exposed lungs was decreased compared with that from control cultures, both in rate of growth and maximal cell yield. The diminished proliferative capacity of these fibroblasts from exposed lungs persisted over 9 wk of serial subcultivation. Fibroblast cultures from exposed lungs typically had a greater proportion of large cells exhibiting extensive cytoskeletal structures than did control cultures. Comparisons of these fibroblasts with normal fibroblasts exposed in vitro to bleomycin showed similarities in size, morphologic features, and proliferation.