Transport of dopamine and levodopa and their interaction in COS-7 cells heterologously expressing monoamine neurotransmitter transporters and in monoaminergic cell lines PC12 and SK-N-SH

Hashimoto W.

Kitayama S.

Kumagai K.

Morioka N.

Morita Katsuya

Dohi Toshihiro

Life Sciences

The present study investigated the effects of levodopa, a precursor of dopamine (DA) therapeutically used for the treatment of Parkinson's disease, on DA transport in the two different systems, COS-7 cells heterologously expressing rat monoamine transporter cDNA and in monoaminergic cell lines PC12 and SK-N-SH. Levodopa enhanced uptake of [3H]DA and [3H]norepinephrine (NE) but not [3H]serotonin in the transfected COS-7 cells in a concentration-dependent manner. On the other hand, in PC12 and SK-N-SH cells where NET is functionally expressed, levodopa enhanced [3H]DA and [3H]NE uptake at low concentrations and inhibited the uptake at higher concentrations. The effects of levodopa on catecholamine transporters in the opposite direction suggest a different mechanism at the intra- and extracellular sites in a levodopa transport-dependent and independent manner.

Dopamine

Levodopa

Monoamine Transporter

Norepinephrine

Serotonin

Cocaine

Parkinson's disease

Medical sciences [ 490 ]

eng

Elsevier Inc.

Copyright (c) 2004 Elsevier Inc.

[ISSN] 0024-3205

[DOI] 10.1016/j.lfs.2004.08.029

[PMID] 15680169

[DOI] http://dx.doi.org/10.1016/j.lfs.2004.08.029 isVersionOf