DNA DAMAGE INDUCED IN MAMMALIAN CELLS BY ACTIVE OXYGEN SPECIES

The active oxygen species generated by ionizing radiation, hyperoxia, paraquat and hydrogen perox-ide induced unscheduled DNA synthesis and DNA synthesis rate inhibition in human fetal lung fibroblast(IMR-90) and transformed cell line derived from Syrian hamster embryo fibroblast (BP6T). The D-glu-cose and sucrose, which were unable to generate active oxygen species, could induce neither unscheduledDNA synthesis nor DNA synthesis rate inhibition. The indicator of DNA synthesis rate inhibition for ac-tive oxygen species was more sensitive than that of unscheduled DNA synthesis. All the enhancing chem-icals on active oxygen species aggravated DNA damage, while all the inhibiting chemicals alleviatedDNA damage. Results showed that active oxygen species do damge DNA. The active oxygen speciesmechanism for carcinogenesis, mutation and aging is applicable.