title: Paraquat-resistant cell lines derived from Chinese hamster ovary cells.
abstract: Two paraquat-resistant clones, PR-1 and PR-2, were selected from CHO K1 cells pretreated with ethyl methanesulfonate. PR-1 and PR-2, routinely cultured in a normal medium without paraquat, were six fold more resistant to paraquat than the parental CHO K1 cells. There was no difference in the uptake of [3H]paraquat among PR-1, PR-2, and CHO K1 cells. Both PR-1 and PR-2 cells showed no cross resistance to free radical generating agents and no increase in total activity of superoxide dismutase. The activities of paraquat-dependent NADPH oxidase and glucose-6-phosphate dehydrogenase were significantly reduced in PR-1 and PR-2 cells, hence the rate of paraquat radical formation will be limited. In addition, an elevation of glutathione levels in PR-1 cells or an increase in glutathione S-transferase activity in PR-2 cells may also play a certain role in protective mechanisms against the toxicity of paraquat.
authors.affiliation: Institutes of Biomedical Sciences, Academia Sinica, Taiwan, R.O.C.
authors.forename: T C
authors.initials: TC
authors.lastname: Lee
authors.forename: F M
authors.initials: FM
authors.lastname: Lin
authors.forename: I C
authors.initials: IC
authors.lastname: Ho
authors.forename: T Y
authors.initials: TY
authors.lastname: Liu
authors.forename: T C
authors.initials: TC
authors.lastname: Wang
authors.forename: Y I
authors.initials: YI
authors.lastname: Chu
authors.forename: H Y
authors.initials: HY
authors.lastname: Chang
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D002999:Clone Cells; D006224:Cricetinae; D004351:Drug Resistance; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005609:Free Radicals; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D019255:NADPH Oxidases; D010269:Paraquat / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000494:pharmacology
chemical_list: D005609:Free Radicals; D013481:Superoxides; D005020:Ethyl Methanesulfonate; D006861:Hydrogen Peroxide; D005954:Glucosephosphate Dehydrogenase; D013482:Superoxide Dismutase; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D005982:Glutathione Transferase; D005978:Glutathione; D010269:Paraquat