Stimulatory effect of potassium ions on MNU- and MNNG-induced mutagenesis in Salmonella typhimurium TA1535 and TA100.
The liquid suspension modification of the standard Salmonella mutagenicity assay employing Ames tester strains of Salmonella typhimurium TA1535 and T100 was used to study the influence of potassium, sodium and calcium on the mutagenic activity of MNU and MNNG. The toxic and mutagenic activities of MNU and MNNG were better expressed when potassium-containing solution was used as a solvent. Short-term pretreatment of bacteria cells with potassium-containing solutions increased the mutagenic efficiency of both chemicals. Potassium-induced increased sensibility of S. typhimurium TA1535 to MNU was completely reversible after 20 min incubation of bacteria in a nutrient broth at 37 degrees C. The mutagenic activity of MNU was reduced after a short-term pretreatment of S. typhimurium TA1535 with a 0.9% solution of CaCl2, while NaCl did not change the mutagenic response of bacteria to MNU.
D008769:Methylnitronitrosoguanidine; D008770:Methylnitrosourea; D009152:Mutagenicity Tests; D011188:Potassium / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects*; D012964:Sodium / Q000494:pharmacology
D008769:Methylnitronitrosoguanidine; D008770:Methylnitrosourea; D012964:Sodium; D011188:Potassium