N-Acetyltransferase (Nat) 1 and 2 Expression in Nat2 Knockout Mice

Arylamine N-acetyltransferases (Nat) 1 and 2 catalyze the N-acetylation of aromatic amine and hydrazine drugs and carcin-ogens. After N-hydroxylation, they also catalyze the metabolic activation of N-hydroxy-arylamines via O-acetylation. Func-tional characterization of mouse Nat1 and Nat2 was investi-gated in an Nat2 knockout (KO) model and compared with the wild-type (WT) strain. Nat1- and Nat2-specific mRNA, deter-mined by quantitative real-time polymerase chain reaction, was detected in all tissues examined and did not differ significantly (p 0.05) between Nat2 KO and WT mice. Nat1 catalytic activity was present in all tissues examined and did not differ significantly (p 0.05) between the Nat2 KO and WT mice. In contrast, Nat2 catalytic activity was present in all tissues ex-amined from male WT mice but was below the limit of detectio