The comparative pulmonary toxicity induced by bleomycin and talisomycin (former 
trivial name: tallysomycin A) was evaluated by measuring lung hydroxyproline 
content. Based on published subacute toxicity data, in which talisomycin was 
found to be four times as toxic as bleomycin, the following doses of each drug 
were given sc to BDF1 male mice twice weekly for 4 weeks: 2.5, 5, and 10 mg/kg 
of bleomycin and 0.625, 1.25, 2.5, and 3.75 mg/kg of talisomycin. Equivalent 
dose-related effects in body weight were produced by bleomycin and talisomycin 
at a respective dose ratio of 4:1. Similarly, equivalent dose-dependent 
increases in lung hydroxyproline content, an index of collagen, were produced by 
bleomycin and talisomycin. Neither drug caused deaths at the doses used.