Cellularity in bone marrow, peripheral blood, lung parenchma and bronchoalveolar lavage fluid before and after bleomycin after 10 weeks of bromodeoxyuridine pulse chase. Total cell number in bone marrow, blood, lung and airways after 10 weeks of chase following12-hourly pulsing for up to 6 days in the saline-treated control mice (Con) and bleomycin-treated (Bleomycin) (one i.t. dose of 0.075 U/ml). P values < 0.05 compared to the control were considered significant. Data were averaged from three independent experiments. FACsans and flow sorts were done in triplicate per sample. Samples were counted in duplicate tubes per sample for each data point (n = four to five per group). Mortality was less than 2%. In this experiment no significant change was found in total cellularity. Abbreviations: BM, bone marrow; PB, peripheral blood; BALf, bronchoalveolar lavage fluid; LP, lung parenchyma; BrdU, bromodeoxyuridine.