Dynamic monitoring of single-terminal norepinephrine transporter rate in the rodent cardiovascular system: a novel fluorescence imaging method

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)
178 Downloads (Pure)


Here, we validate the use of a novel fluorescent norepinephrine transporter (NET) substrate for dynamic measurements of transporter function in rodent cardiovascular tissue; this technique avoids the use of radiotracers and provides single-terminal resolution.

Rodent (Wistar rats and C57BL/6 mice) hearts and mesenteric arteries (MA) were isolated, loaded with NET substrate Neurotransmitter Transporter Uptake Assay (NTUA) ex vivo and imaged with confocal microscopy.

NTUA labelled noradrenergic nerve terminals in all four chambers of the heart and on the surface of MA. In all tissues, a temperature-dependent, stable linear increase in intra-terminal fluorescence upon NTUA exposure was observed; this was abolished by NET inhibitor desipramine (1 μM) and reversed by indirectly-acting sympathomimetic amine tyramine (10 μM). NET reuptake rates were similar across the mouse cardiac chambers. In both species, cardiac NET activity was significantly greater than in MA (by 62 ± 29% (mouse) and 21 ± 16% (rat)). We also show that mouse NET reuptake rate was twice as fast as that in the rat (for example, in the heart, by 94 ± 30%). Finally, NET reuptake rate in the mouse heart was attenuated with muscarinic agonist carbachol (10 μM) thus demonstrating the potential for parasympathetic regulation of norepinephrine clearance.

Our data provide the first demonstration of monitoring intra-terminal NET function in rodent cardiovascular tissue. This straightforward method allows dynamic measurements of transporter rate in response to varying physiological conditions and drug treatments; this offers the potential to study new mechanisms of sympathetic dysfunction associated with cardiovascular disease.
Original languageEnglish
Article number102611
Number of pages12
JournalAutonomic Neuroscience
Early online date26 Dec 2019
Publication statusPublished - Jan 2020

Bibliographical note

Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.


  • Norepinephrine transporter kinetics
  • fluorescence imaging
  • sympathetic
  • rodent
  • cardiovascular system
  • Cardiovascular system
  • Fluorescence imaging
  • Rodent
  • Sympathetic

ASJC Scopus subject areas

  • Endocrine and Autonomic Systems
  • Clinical Neurology
  • Cellular and Molecular Neuroscience


Dive into the research topics of 'Dynamic monitoring of single-terminal norepinephrine transporter rate in the rodent cardiovascular system: a novel fluorescence imaging method'. Together they form a unique fingerprint.

Cite this