Abstract
The distribution of histamine N-methyltransferase (HMT, EC 2. 1. 1. 8) activity was studied in various tissues of the guinea-pig and rat. The properties of HMT in rat kidney were shown to differ from those of HMT in the brain and kidney of guinea-pig and the brain of rat. Quinacrine, a potent HMT inhibitor, inhibited the activity of HMT by 50% at concentrations of about 10-5 M in rat kidney and about 10-7 M in other tissues.
