tailieunhanh - Effect of α-Keto acids against H2O2-and NaN3 induced mutagenesis in different strains of salmonella typhimurium

The protective effects of α-keto acids on the mutagenicity of H2O2 and NaN3 was investigated in Salmonella typhimurium TA 98, TA 100, TA 102. H2O2 (340 µg/plate) was mutagenic to the strains TA 98 and TA 102 while NaN3 ( µg/plate) was mutagenic only to TA100. | Turk J Biol 29 (2005) 161-166 © TÜB‹TAK Effect of α-Keto Acids Against H2O2- and NaN3-Induced Mutagenesis in Different Strains of Salmonella Typhimurium Emine ÖKSÜZO⁄LU Department of Molecular Biology, Faculty of Science, Hacettepe University, Ankara - TURKEY Received: Abstract: The protective effects of α-keto acids on the mutagenicity of H2O2 and NaN3 was investigated in Salmonella typhimurium TA 98, TA 100, TA 102. H2O2 (340 µg/plate) was mutagenic to the strains TA 98 and TA 102 while NaN3 ( µg/plate) was mutagenic only to TA100. The extents of protective effect of pyruvate (220-440 µg/plate) and α-keto glutarate (335-600 µg/plate) against H2O2 were observed to be 37%- 65% in TA 98 and TA 102. α-keto acids were ineffective against NaN3 induced mutagenicity in TA 100. H2O2 (340 µg/plate), in the presence of NaN3 ( µg/plate) and α-keto acids (330-500 µg/plate), was found to be nonmutagenic to the strain TA102. This cross-adaptive response might have been due to the intactness of the DNA repair system in TA 102. The above combination of H2O2, NaN3 and α-keto acids were found to be cytotoxic in TA 98 and TA 100, possibly because these strains carry uvr B mutation causing defect in their DNA repair system. Key Words: α-keto acids, H2O2, NaN3, Ames test system, mutagenicity, antimutagenicity Salmonella Typhimurium’un Farkl› Sufllar›nda H2O2 ve NaN3 ile ‹ndüklenmifl Mutasyonlara Karfl› α-Keto Asitlerin Etkisi Özet: Salmonella typhimurium TA98, TA100 ve TA102 sufllar›nda α-keto asitlerin, H2O2 ve NaN3’nin mutajenitelerine karfl› koruyucu etkileri araflt›r›ld›. H2O2 (340 µg/plak), hem TA98 hem de TA102 suflunda mutajenik iken, NaN3 ( µg/plak) sadece TA100 suflunda mutajeniktir. Pürüvat (220-440 µg/plak) ve α-ketoglutarat’›n (335-600 µg/plak) H2O2’ye karfl› koruyucu etkileri, %37- %65 olarak bulundu. α-keto asitlerin, TA100 suflunda NaN3 taraf›ndan indüklenen mutajenesise karfl› koruyucu etkilerinin olmad›¤› saptand›. TA102 suflunda, NaN3 ( .