title: Counteracting effect of eosin and related dyestuffs on the production of respiration-deficient mutants in yeast by 4-nitroquinoline 1-oxide.
abstract: Production of respiration-deficient (rho-) mutants under growing conditions in a strain of Saccharomyces chevalieri by 4-nitroquinoline 1-oxide (4NQO), a potent carcinogen, reached 100%. The mutation frequency was considerably reduced when eosin Y was applied in various combinations with 4NQO. The counteracting effect was slight when eosin Y was applied concurrently with 4NQO, but was very strong and persistent when eosin Y was impregnated into the yeast cells before their exposure to 4NQO. Eosin B, erythrosin B and uranin also showed more or less counteracting effects agains 4NQO in producing the rho- mutants. Possible mechanisms for the counteracting effects of these dyestuffs against 4NQO are discusses in relation to antimutagenesis and chemotherapeutic interference.
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology*; D004396:Coloring Agents / Q000494:pharmacology*; D005787:Gene Frequency; D009153:Mutagens; D009154:Mutation; D009600:Nitroquinolines / Q000494:pharmacology*; D012440:Saccharomyces / Q000187:drug effects*
chemical_list: D004396:Coloring Agents; D009153:Mutagens; D009600:Nitroquinolines; D015112:4-Nitroquinoline-1-oxide