Species differences in the N-acetylation by liver cytosol of mutagenic heterocyclic aromatic amines in protein pyrolysates

Publisher Website
Google Scholar
Abstract
The N-acetylation of 3-amino-1-methyl-5H-pyrido(4,3-b)-indole (Trp-P-2) and other heterocyctic aromatic amine pro-mutagens isolated originally from protein pyrolysates was investigated using liver cytosols from various animal species and acetyl-CoA as an acetyl donor. Marked species differences in the enzymatic N-acetylation activity of these heterocydk amines were observed. The N-acetylation activity also varied among the substrates used. The N-acetylation of these heterocydk amines by hepatic cytosols from all animal species used was much less than that of the non-heterocydic aromatic amine carcinogen, 2-aminofluorene (2-AF): the N-acetylation of Trp-P-2 was more than one hundred times less than that of 2-AF. These results suggested that the metabolic activation pathway of these mutagenic heterocydk amines is different from that of 2−AF. The hamster but not rat cytosol showed the ability to utilize N-hydroxy−2-acetyl-aminofluorene and 2-acetylaminofluorene as acetyl donor in the N-acetylation of Trp-P-2.