Stereoselective features of catecholamine disposition and their behavioral implications

Abstract

The post-synaptic receptor actions of norepinephrine but not of dopamine are strikingly stereospecific. A considerably lesser “stereoselectivity” characterizes the presynaptic uptake and release properties of norepinephrine neurons in the peripheral sympathetic nervous system and in the brain. Dopamine nerve terminals display still less stereoselectivity in their uptake mechanism, none being demonstrable at the β-carbon while a variable degree can be detected at the α-carbon. The differential stereoselectivity of dopamine and norepinephrine neurons has prompted the use of isomers of amphetamine in attempts to discern whether particular behaviors in animals, such as turning after unilateral nigrostriatal lesion, stereotyped behavior, locomotor activation and hypothalamic or midbrain self-stimulation, are predominantly dopamine or norepinephrine mediated. In man, amphetamine isomers have been evaluated for central stimulant effects, production of “amphetamine psychosis” and exascerbation of schizophrenic symptoms.