CENTRAL STIMULANT ACTIONS OF α‐ALKYL SUBSTITUTED TRYPTAMINES IN MICE

Abstract

Much interest has been centred on the part played by 5-hydroxytryptamine in the actions of the central nervous system since it was shown that changes in the amount of this amine in the brain accompany the effects of many drugs. The central actions of 5-hydroxy- tryptamine cannot easily be studied by observing the effects due to its injection, since it does not readily penetrate to the brain from the circulation (Udenfriend, Bogdanski & Weissbach, 1957a). Effects may, however, be produced indirectly by administering the natural precursor of 5-hydroxytryptamine, 5-hydroxytryptophan, particularly when enzymic destruction of the 5-hydroxytryptamine formed in situ has been prevented by administration of monoamine oxidase inhibitors (Bogdanski, Weissbach & Udenfriend, 1958). Vane (1959) suggested that interesting central effects might be produced by tryptamine derivatives lacking the hydroxyl group which prevents 5-hydroxytryptamine from penetrating membranes, and also protected from the action of monoamine oxidase by suitable substitution. Among the substances suggested, he included a-methyltryptamine.