Effect of bleomycin on lipid peroxides, glutathione peroxidase and collagenase in cultured lung fibroblasts.

Bleomycin-Cu(II) complex tended to increase the lipid peroxide level in cultured lung fibroblasts, though neither free bleomycin nor free cupric ion increased the level. Simultaneous addition of DL-alpha-tocopherol decreased the level significantly. Bleomycin-Cu(II) complex decreased glutathione peroxidase activity remarkably, though free bleomycin reduced the activity only slightly. Collagenase activity was not decreased but rather increased by both free bleomycin and bleomycin-Cu(II) complex. Accordingly, the accumulation of collagen induced by bleomycin could be explained not by a decrease in collagenase activity, but by the occurrence of cross-linking of collagen due to the increased lipid peroxides.