FORMATION OF ?-GLUTAMYLHISTAMINE FROM HISTAMINE IN RAT BRAIN

– γ-Glutamyl amides of histamine, serotonin and dopamine were formed from these amines by the transfer of the γ-glutamyl moiety from γ-glutamyl peptides in the presence of γ-glutamyl transpeptidase. [I4C]Histamine was injected intraventricular into rats, and the formation of γ-glutamyl-[14C] histamine in the brain was confirmed by purification and identification with the authentic compound. The radioactivity was highest 30 min after the injection. The possible significance of γ-glutamyl amides in nerve transmission is discussed.