Ouabain resistant

Sirianni SR, Huang CC. 1980. Comparison of induction of sister chromatid exchange, 8-azaguanine- and ouabain-resistant mutants by cyclophosphamide, ifosfamide and l-(pyridyl-3)-3,3-dimethyltriazene in Chinese hamster cells cultured in diffusion chambers in mice. Carcinogenesis 1 353-355. 

Matthews EJ, DelBalzo T, Rundell JO. 1985. Assays for morphological transformation and mutation to ouabain resistance of Balb/c-3T3 cells in culture. In Ashby J, de Serres FJ, et al., eds. 

DNA single-strand breaks were not induced by di(2-ethylhexyl) phthalate in primary cultures of rat or Syrian hamster hepatocytes or in Chinese hamster ovary (CHO) cells. Unscheduled DNA s5uithesis was not induced in rat or mouse primary hepatocytes exposed to di(2-ethylhexyl) phthalate. Only one of six studies reported induction of gene mutations at the Tk locus in mouse l5unphoma L5178Y cells exposed to di(2-ethylhexyl) phthalate in the absence of an exogenous metabolic activation system. Ouabain-resistant mutants were not induced in mouse lymphoma or BALB/c-3T3 cells. 

Marayama, H., Tanaka, T. Williams, GM. (1990) Effects of the peroxisome proliferator di(2-ethylhexyl)phthalate on enzymes in rat liver and on carcinogen-induced liver altered foci in comparison to the promoter phenobarbital Toxicol. Pathol., 18, 257-267 Matsushima, T, Muramatsu, M. Haresaku, M. (1985) Mutation tests on Salmonella typhimurium by the preincubation method. Prog. Mutat. Res., 5, 181-186 Matthews, E.J., DelBalzo, T. Rundell, J.O. (1985) Assays for morphological transformation and mutation to ouabain resistance of Balb/c-3T3 cells in culture. Prog. Mutat. Res., 5, 639-650... 

Gene mutation, Hprt locus, ouabain resistance, Chinese hamster ovary cells in vitro... 

Kuroki, T. Munakata, K. (1985) Assays for the induction of mutations to ouabain resistance in V79 Chinese hamster cells in culture with cell- or microsome-mediated metabolic activation. Prog. Mutat. Res., 5, 543-545... 

Amacher, D.E. Dunn, E.M. (1985) Mutagenesis at the ouabain-resistance locus of 3.7.2C L5178Y cells by chromosomal mutagens. Environ. Mutag.. 7, 523—533... 

In addition to genotoxicify studies with chlorophenols themselves, the corresponding activity of some of their metabolites has also been examined. The major metabolite of pentachlorophenol in mice and rats, tetrachloro-7 ora-hydroquinone, induced mutations in the hprt locus (but not the ouabain-resistance locus) of V79 Chinese hamster cells (Jansson Jansson, 1991), covalent damage (including 8-hydroxyguanine) in naked DNA in the presence of Cu(Il) (Naito et al., 1994), DNA strand breaks and accumulation of p53 in NIH 3T3 cells in vitro and transfonnation of mouse embryo fibroblasts in a two-stage model (Wang et al., 1997). The same metabolite, as well as tetrachloro-1,4-benzoquinone and tetrachloro-l,2-benzoquinone, caused DNA strand breaks in V79 Chinese hamster cells (Dahlhaus et al., 1996). 

The Na-K ATPase, in the plasma membrane of mammalian cells, is inhibited when ouabain binds to the a subunit that is phosphorylated during catalysis.21 372 Unlike HGPRT" and TK"/", the ouabain-resistant phenotype (assigned to chromosome 3 in the mouse)218 is dominant, stable, and characterized by a reduced uptake of 86Rb and 1 2K in the presence of ouabain and by reduced binding of ouabain to the plasma membrane.21 Ouabain resistance can be induced... 

Lehmann, and C.M. Coleila. A comparison of the 8-azaguanine and ouabain-resistance systems for the selection of induced mutant Chinese hamster cells. Mutat. Res. 33 261-278, 1975. 

Till. Ouabain-resistant mutants of mouse and hamster cells in culture. Cell 1 9-21, 1974. 

Hsu, I.C., C.C. Harris, M. Yamaguchi, B.F. Trump, and P.W. Schafer. Induction of ouabain-resistant mutation and sister chromatid exchanges in Chinese hamster cells with chemical carcinogens mediated by human pulmonary macrophages. J. Clin. Invest. 64 1245-1252, 1979. 

Kozak, C.A., R.E.K. Fournier, L.A. Leinwald, and F.H. Ruddle. Assignment of the gene governing cellular ouabain resistance to Mus musculus chromosome 3 using human/mouse microcell hybrids. Biochem. Genetics 17 23-34, 1979. 

Robbins, A.R., and R.M. Baker. (Na, K)ATPase activity in membrane preparations of ouabain-resistant HeLa cells. Biochemistry 16 5163-5168, 1977. 

Landolph JR and Heidelberger C (1979) Chemical carcinogens produce mutations to ouabain resistance in transformable C3H/10T1/2 Cl 8 mouse fibroblasts. Proceedings of the National Academy of Sciences of the United States of America 76 930-934. 

Ahmed FE, Lewis NJ, Hart RW. 1977b. Pesticide induced ouabain resistant mutants in Chinese hamster V-79 cells. Chem Biol Interact 19 369-374. 

Aflatoxin Bg is a potent mutagen toward 5. typhimurium in the presence of rat liver homogenate. Liver cells or fibroblasts derived from rats have also been used as feeder layers for Chinese hamster V79 cells. Mutation to ouabain-resistant cells was found to occur only in the presence of liver cells. Fibroblast cells were incapable of metabolizing AfBj (286). Studies on the mutagenic activity of related aflatoxins have not employed the sophisticated biochemical systems which have recently been studied. The use, for example, of duck liver homogenate in the metabolic activation of AfBg may result in enhanced mutagenic potential compared to use of rat liver. Incorporation of the advances in the biochemical studies on aflatoxin metabolism to in vitro assay systems can be expected in the near future. 

DNA single-strand break frequency was measured by alkaline elution [16] and sister chromatid exchanges (SCEs) were assayed by the method described by Wolff [32]. Hypoxanthine-guanine phosphoribosyl transferase (HPRT 6-thioguanine) and Na/K ATPase (ouabain) resistant mutants of CHO were determined by the methods described by Cleaver [7]. Repair replication after MMS treatment was measured in isopycnic gradients [8]. 

Cleaver JE (1977) Induction of thioguanine- and ouabain-resistant mutants and single-strand breaks in the DNA of Chinese hamster ovary cells by H-thymidine. Genetics 87 129-138... 

Fig. 5. Effect of MBA on MNNG-induced mutation at the ouabain lod. After treatment and expression performed as described in Fig. 5, cells were reseeded for determination of ouabain-resistant colonies in medium containing 3 vnM ouabain. After 16 days the mutant colonies were fixed, stained, and counted. Mutants/10 viable cells for cells treated with MNNG ( ) and MNNG + MBA(O)...

Survival and Mutagenesis from Radiation in CHO Cells. 3AB (1 vaM) had no significant effect on cell survival or the yield of 6-thioguanine-resistant mutations after irradiation with X-rays (Tables 1 and 2). Ouabain mutations were not investigated because of the extremely low yield of ouabain-resistant mutants from X-rays [8]. 

Survival and Mutagenesis from MMS. 3AB (1 vaM) caused a large increase in the toxicity of MMS, which was expressed predominantly by elimination of the shoulder of the survival curve (Table 1). The extrapolation number was reduced from 18.0 to 1.0, but the Do was not changed significantly. The mutation frequencies to ouabain resistance... 

The gastric H,K ATPase is not inhibited by ouabain, and chimers of the Na,K and H,K ATPases are ouabain sensitive when the N terminal of the chimer is Na,K ATPase and the C terminal is H,K but ouabain resistant when the N-terminal half is the H,K ATPase. This shows that ouabain binds to the N-terminal half of the sodium pump but not to the N-terminal half of the acid pump. 

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