In vivo direct monitoring of interstitial norepinephrine levels at the sinoatrial node

Shuji Shimizu, Tsuyoshi Akiyama, Toru Kawada, Toshiaki Shishido, Masaki Mizuno, Atsunori Kamiya, Toji Yamazaki, Shunji Sano, Masaru Sugimachi

Research output: Contribution to journalArticle

13 Scopus citations


We assessed in vivo interstitial norepinephrine (NE) levels at the sinoatrial node in rabbits, using microdialysis technique. A dialysis probe was implanted adjacent to the sinoatrial node of an anesthetized rabbit and dialysate was sampled during sympathetic nerve stimulation. Atrial dialysate NE concentration correlated well with heart rate. Desipramine significantly increased dialysate NE concentrations both before and during sympathetic nerve stimulation compared with the absence of desipramine. However, desipramine did not affect the relation between heart rate and dialysate NE concentration. These results suggest that atrial dialysate NE level reflects the relative change of NE concentration in the synaptic cleft. Microdialysis is a powerful tool to assess in vivo interstitial NE levels at the sinoatrial node.

Original languageEnglish (US)
Pages (from-to)115-118
Number of pages4
JournalAutonomic Neuroscience: Basic and Clinical
Issue number1-2
StatePublished - Jan 15 2010



  • Desipramine
  • Heart rate
  • Microdialysis
  • Norepinephrine
  • Sinoatrial node
  • Sympathetic nerve terminal activity

ASJC Scopus subject areas

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

Cite this

Shimizu, S., Akiyama, T., Kawada, T., Shishido, T., Mizuno, M., Kamiya, A., Yamazaki, T., Sano, S., & Sugimachi, M. (2010). In vivo direct monitoring of interstitial norepinephrine levels at the sinoatrial node. Autonomic Neuroscience: Basic and Clinical, 152(1-2), 115-118.