title: Enhancement of DNA chain breakage by bleomycin A2 in the presence of microsomes and reduced nicotinamide adenine dinucleotide phosphate.
abstract: Chain breakage in DNA induced by bleomycin A2 (BLM) was enhanced more than 150-fold by the reduced nicotinamide adenine dinucleotide phosphate-dependent electron transport system of rat liver microsomes. However, the enhancement effect on DNA was partially reduced by the preincubation of BLM with the microsomal systems. BLM-Cu2+ was found to stimulate considerably microsomal reduced nicotinamide adenine dinucleotide phosphate-dependent oxygen consumption and malondialdehyde formation, whereas BLM inhibited both of the effects. These findings suggest that the pharmacological action of BLM is strongly affected by a membrane system, such as microsomes, that produces free radicals.
mesh_terms: D000818:Animals; D001761:Bleomycin / Q000031:analogs & derivatives / Q000494:pharmacology*; D002614:Chelating Agents; D003300:Copper / Q000494:pharmacology; D004247:DNA / Q000378:metabolism*; D004579:Electron Transport / Q000187:drug effects; D005609:Free Radicals; D066298:In Vitro Techniques; D008315:Malondialdehyde / Q000378:metabolism; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D009249:NADP / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats
chemical_list: D002614:Chelating Agents; D005609:Free Radicals; D001761:Bleomycin; D008315:Malondialdehyde; D009249:NADP; D003300:Copper; D004247:DNA