Galanin suppresses calcium conductance and activates inwardly rectifying potassium channels in myenteric neurones from guinea-pig small intestine

J. Ren, H. Z. Hu, A. L.M. Starodub, J. D. Wood

Research output: Contribution to journalArticle

16 Scopus citations

Abstract

Whole-cell patch-clamp recording methods were used to investigate the ionic mechanisms underlying the hyperpolarizing action of galanin in enteric neurones. Galanin suppressed calcium current (ICa) and activated inwardly rectifying potassium current (IK,ir) in AH-type myenteric neurones of guinea-pig small intestine. Both suppression of ICa and activation of IK,ir were concentration-dependent, with an EC50 of 1.4 nmol L-1 and 55 nmol L-1, respectively. Pretreatment with pertussis toxin eliminated both actions of galanin, suggesting that both galanin-induced inhibition of ICa and galanin-induced activation of IK,ir involved activation of Gi/Go proteins. Both suppression of ICa and activation of IK,ir by galanin were mimicked by the N-terminal fragment of galanin, galanin-(1-16) suggesting that the first 16 amino acids of the peptide were sufficient for both actions. The galanin receptor antagonist galantide suppressed the galanin-induced activation of IK,ir with an EC50 of 16 nmol L-1. However, galantide alone suppressed ICa. The results suggest two mechanisms of action for galanin: one is opening of inwardly rectifying potassium channels and the second is blockade of voltage-activated calcium channels.

Original languageEnglish
Pages (from-to)247-254
Number of pages8
JournalNeurogastroenterology and Motility
Volume13
Issue number3
DOIs
StatePublished - Jun 21 2001
Externally publishedYes

Keywords

  • Enteric nervous system
  • Enteric neurones
  • Galanin
  • Intestine
  • Myenteric plexus

Fingerprint Dive into the research topics of 'Galanin suppresses calcium conductance and activates inwardly rectifying potassium channels in myenteric neurones from guinea-pig small intestine'. Together they form a unique fingerprint.

  • Cite this