Protease-activated receptor 2 activation inhibits N-type Ca2+ currents in rat peripheral sympathetic neurons

Young Hwan Kim, Duck Sun Ahn, Myeong Ok Kim, Ji Hyun Joeng, Seungsoo Chung

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


The protease-activated receptor (PAR)-2 is highly expressed in endothelial cells and vascular smooth muscle cells. It plays a crucial role in regulating blood pressure via the modulation of peripheral vascular tone. Although several mechanisms have been suggested to explain PAR-2- induced hypotension, the precise mechanism remains to be elucidated. To investigate this possibility, we investigated the effects of PAR-2 activation on N-type Ca2+ currents (ICa-N) in isolated neurons of the celiac ganglion (CG), which is involved in the sympathetic regulation of mesenteric artery vascular tone. PAR-2 agonists irreversibly diminished voltage- gated Ca2+ currents (ICa), measured using the patchclamp method, in rat CG neurons, whereas thrombin had little effect on ICa. This PAR-2-induced inhibition was almost completely prevented by ω-CgTx, a potent N-type Ca2+ channel blocker, suggesting the involvement of N-type Ca2+ channels in PAR-2-induced inhibition. In addition, PAR-2 agonists inhibited ICa-N in a voltage-independent manner in rat CG neurons. Moreover, PAR-2 agonists reduced action potential (AP) firing frequency as measured using the current- clamp method in rat CG neurons. This inhibition of AP firing induced by PAR-2 agonists was almost completely prevented by ω-CgTx, indicating that PAR-2 activation may regulate the membrane excitability of peripheral sympathetic neurons through modulation of N-type Ca2+ channels. In conclusion, the present findings demonstrate that the activation of PAR-2 suppresses peripheral sympathetic outflow by modulating N-type Ca2+ channel activity, which appears to be involved in PAR-2-induced hypotension, in peripheral sympathetic nerve terminals.

Original languageEnglish
Pages (from-to)804-811
Number of pages8
JournalMolecules and Cells
Issue number11
StatePublished - Nov 1 2014
Externally publishedYes


  • Celiac ganglion
  • Hypotension
  • N-type Ca channel
  • Peripheral sympathetic output
  • Protease-activated receptor 2


Dive into the research topics of 'Protease-activated receptor 2 activation inhibits N-type Ca2+ currents in rat peripheral sympathetic neurons'. Together they form a unique fingerprint.

Cite this