Expression of N-acetyl transferase in a human monocytic cell-line, U937

1. N-acetyl transferase (NAT) catalyses the acetylation of arylamine and hydrazine drugs and other xenobiotics. The activity of one isozyme (polymorphic NAT) varies amongst individuals but the other (monomorphic NAT) does not. 2. The human monocytic cell-line U937 transcribes the gene for monomorphic N-acetyl transferase. 3. Although the gene for polymorphic N-acetyl transferase is present in these cells, its expression is not detected. 4. It is concluded that U937 cells are a useful model for studying the metabolism of arylamines and hydrazines by human monomorphic N-acetyl transferase.