EFFECT OF DIETARY TRANS FATTY ACIDS ON MUTAGENESIS OF KNOWN CARCINOGENS (ISOMERS, AMES ASSAY, HYDROGENATED).

摘要

The effects of feeding rats a fat which contained approximately 46.6% trans fatty acids (trans fat) on the mutagenic potential of 2-aminofluorene (AF), benzo(a)pyrene (BP), dimethylbenz(a)anthracene (DMBA), and azoxymethane (AOM) were evaluated in the Ames assay. The corresponding control fat (cis fat) had a similar fatty acid composition, consisting only of cis isomers. Since both the cis and trans fats contained approximately 40% saturated fatty acids a comparison was made between these two types of fat and corn oil. All three fats were incorporated into a high fat, 20%, and moderate fat, 5%, diet and fed to male Sprague-Dawley rats for three weeks.;Only with DMBA did type of fat affect the positive and negative outcomes of the assays. DMBA gave a positive response only in the assays using livers from rats fed corn oil diets, with no differences between the 5% and 20% level of corn oil. No positive responses were found with DMBA in the assays with liver homogenates from rats fed trans fat or cis fat. This suggests that DMBA required a moderate to high level of polyunsaturated corn oil to produce a positive mutagenic response.;The effects of the level and type of fat on mutagenicity varied with the specific mutagen under investigation. The 20% level of fat whether cis, trans, or corn oil resulted in greater mutagenic activity with BP and AF when compared to the 5% level. At the 5% fat level the results for BP and AF were in conflict. The 5% trans fat resulted in the highest mutagenic response for AF, while the 5% corn oil resulted in the highest mutagenic response for BP. The trans fat produced a higher mutagenic potential at the 5% level with AF than the 5% cis fat, but at the 20% level no difference was found between the cis and trans fats. These findings indicate that not only does the quantity and type of fat alter the mutagenic response found in the Ames/Salmonella microsome assay, but also the effect of the fat in the assay varies with the mutagen tested.