Chronic depolarization stimulates norepinephrine transporter expression via catecholamines.

Article Details

Citation

Habecker BA, Willison BD, Shi X, Woodward WR

Chronic depolarization stimulates norepinephrine transporter expression via catecholamines.

J Neurochem. 2006 May;97(4):1044-51. Epub 2006 Mar 29.

PubMed ID
16573647 [ View in PubMed
]
Abstract

Chronic depolarization increases norepinephrine (NE) uptake and expression of the norepinephrine transporter (NET) in sympathetic neurons, but the mechanisms are unknown. Depolarization of sympathetic neurons stimulates catecholamine synthesis, and several studies suggest that NET can be regulated by catecholamines. It is not clear if the depolarization-induced increase in NET is because of nerve activity per se, or is secondary to elevated catecholamines. To determine if induction of NET mRNA was a result of increased catecholamines, we used pharmacological manipulations to (i) inhibit tyrosine hydroxylase activity in neurons depolarized with 30 mm KCl, thereby preventing increased catecholamines, or (ii) stimulate tyrosine hydroxylase activity in the absence of depolarization. Inhibiting the depolarization-induced increase in catecholamines prevented the up-regulation of NET mRNA, but did not block the increase in tyrosine hydroxylase (TH) mRNA. Furthermore, stimulating catecholamine production in the absence of depolarization elevated NE uptake, NET protein, and NET mRNA in sympathetic neurons. Similarly, elevating endogenous catecholamines in SK-N-BE2M17 neuroblastoma cells increased NE uptake and NET expression. These data suggest that chronic depolarization of sympathetic neurons induces NET expression through increasing catecholamines, and that M17 neuroblastoma cells provide a model system in which to investigate catechol regulation of NET expression.

DrugBank Data that Cites this Article

Drug Transporters
DrugTransporterKindOrganismPharmacological ActionActions
DroxidopaSodium-dependent noradrenaline transporterProteinHumans
Unknown
Substrate
Details
NorepinephrineSodium-dependent noradrenaline transporterProteinHumans
Unknown
Substrate
Details