title: Generation of photoemissive species by mitomycin C redox cycling in rat liver microsomes.
abstract: Generation of reactive oxygen species during redox cycling is thought to be involved in the chemotherapeutic action of quinone anticancer drugs. A clinically used agent which contains a quinone moiety is mitomycin C (Mit C). With isolated rat liver microsomes we detected photoemissive species during Mit C-induced redox cycling. After addition of reduced glutathione (GSH) a large increase in Mit C-induced chemiluminescence was observed. The increase of photoemission in deuterium oxide as well as greater than 90% of intensity at wavelengths greater than 610 nm suggest that singlet oxygen is a photoemissive species generated by this system. Glutathione disulfide (GSSG) accumulates during the reaction. We propose that superoxide anion radicals formed during redox cycling of Mit C react with GSH. Generation of glutathionyl radicals followed by oxygen addition then leads to the formation of photoemissive species and GSSG.
mesh_terms: D000818:Animals; D005978:Glutathione / Q000378:metabolism / Q000494:pharmacology; D008163:Luminescent Measurements; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D051381:Rats; D011919:Rats, Inbred Strains; D014812:Vitamin K / Q000494:pharmacology
chemical_list: D008937:Mitomycins; D014812:Vitamin K; D016685:Mitomycin; D005978:Glutathione; D010100:Oxygen