Evidence for Neuronal Localization of Histamine‐N‐Methyltransferase in Rat Brain

Abstract
Histamine may be a neurotransmitter in rat brain. Histamine in neurons of the CNS is easily released and rapidly turned over. The cellular localization of histamine-N-methyltransferase, the proposed histamine-inactivating enzyme, was investigated by measuring its activity in rat striatum after applying neurochemical or electrolytic lesions. A major neuronal localization of the enzyme evidently exists in this area.