In this study, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) were used to determine the inhibition of arylamine N-acetyltransferase (NAT) activity and DNA adduct formation in human bladder tumour cell line T-24. The activity of NAT was measured by high-performance liquid chromatography, assaying for the amounts of N-acetyl-2-aminofluorene and N-acetyl-p-aminobenzoic acid and remaining 2-aminofluorene and p-aminobenzoic acid. Human bladder tumour cell line T-24 cytosols and intact cells were used for examining NAT activity and carcinogen-DNA adduct formation. The results demonstrated that NAT activity and 2-aminofluorene-DNA adduct formation in human bladder tumour cells were inhibited and decreased by BHA and BHT in a dose-dependent manner. The effects of BHA and BHT on the values of the apparent Km and Vmax also were determined in both systems examined. The results indicated that BHA and BHT decreased the apparent values of Km and Vmax from human bladder tumour cells in both cytosol and intact cells.
