Arylamine N-acetyltransferase activities in cell lines of mouse, rat, hamster and man differing in their sensitivity to 1,6-dinitropyrene

Abstract

This study was aimed at monitoring N-acetyltransferase activities of continuous cell lines, which differ in their sensitivity to the toxic effects of nitroaromatic compounds. Transferase activities were measured toward the acetyl acceptors sulfamethazine and p-aminobenzoic acid in partially purified preparation of cytosols. Cell lines such as hamster V79, BHK, rat hepatoma H4IIEC3G- or fibroblast 208F, which are sensitive to 1,6-dinitropyrene (1,6-DNP), possess high transferase activities ranging from 120–270 nmol/min × mg protein. In contrast, human lung cells NCI-H322, mouse and rat hepatoma cells BW1J and H5, respectively, which are resistant to 1,6-DNP contain no or low transferase activity of less than 15 nmol/min × mg. There was no apparent correlation between 1,6-DNP sensitivity and acetyltransferase levels in a few cell lines, e.g. rat hepatoma HTC, 2sFou and 5L, which express intermediate transferase activities ranging from 25–50 nmol/min × mg protein. The results suggest that acetylation is an essential step in activating 1,6-DNP to toxic products in mammalian cells.