Function of monoamine neurotransmitter transporters

by Sasa M.
Department of Pharmacology,
Hiroshima University School of Medicine.
Nippon Rinsho 2001 Aug;59(8):1457-64

ABSTRACT

Monoamine transporters include plasma membrane and vesicular monoamine transporters(VMAT). The former selectively and Na+/Cl(-)-dependently transport dopamine, noradrenaline and serotonin into the cytoplasma, and the latter non-selectively carries monoamine into the vesicle. These transporters are composed of amino acid groups containing 12 folds more transmembrane components. Cytoplasmic transporters are a target site of certain drugs. Antiepileptic drugs such as SSRIs and tricyclic antidepressants bind with the serotonin transporter(SERT), noradrenaline transporter(NET) and/or dopamine transporters(DAT) to inhibit transport of monoamines into the cytoplasma, thereby increasing monoamine levels within the synaptic cleft. However, amphetamine, known to induce drug dependence, is transported by DAT and inhibits VMAT to induce reverse-transport of monoamines into the synaptic area, thereby producing psychiatric and behavioral alterations. Thus, monoamine transporters are target sites of drugs, and functional changes in the transporters may be involved in the pathogenesis of affective diseases, schizophrenia and/or personality disorders including neurogenerative diseases such as Parkinson’s disease.