title: [Characterization of pacemaking currents in cultured interstitial cells of Cajal from mice small intestine].
abstract: OBJECTIVE
  Gastrointestinal motility is initiated by the periodic generation of slow waves. Interstitial cells of Cajal (ICC) are pacemaker cells that generate slow waves and drive spontaneous mechanical contractions of the gastrointestinal smooth muscle. Slow waves generate the periodic activation of spontaneous inward currents (pacemaker currents). The aim of this study was to investigate the characterization of pacemaker currents of ICC.
  
  
  METHODS
  The ICC in mice small intestine were cultured with stem cell factor for 2 days, and then we recorded pacemaker currents and slow waves using a whole-cell patch clamp technique.
  
  
  RESULTS
  Under voltage clamp at -80 mV of holding potential, ICC generated pacemaker currents. Tetrodotoxin and nifedipine did not affect on the pacemaker currents. In addition, tetraethylammonium, 4-aminopyridine and glibenclamide did not affect on the pacemaker currents. The reduction of external Na+ concentrations inhibited pacemaker currents. Moreover, these currents were completely abolished in the external Ca2+-free condition. Gadolinium and flufenamic acid, inhibitors of non-selective cationic currents, inhibited pacemaker currents. Thapsigargin and cyclopiazoic acid, inhibitors of Ca2+-ATPase in endoplasmic reticulum, abolished pacemaker currents. Carbachol depolarized membrane potential and increased inward currents.
  
  
  CONCLUSIONS
  These results suggest that pacemaker currents are mediated by the activation of non-selective cation channel and become a target of neurotransmitters in regulation of intestinal motility.
authors.affiliation: Department of Internal Medicine, Chosun University College of Medicine, Dong-gu, GwangJu, Korea.
authors.forename: Sung Jong
authors.initials: SJ
authors.lastname: Chang
authors.forename: Eun Tak
authors.initials: ET
authors.lastname: Cho
authors.forename: Gwang Sik
authors.initials: GS
authors.lastname: Heo
authors.forename: Chan Guk
authors.initials: CG
authors.lastname: Park
authors.forename: Man Woo
authors.initials: MW
authors.lastname: Kim
authors.forename: In Youb
authors.initials: IY
authors.lastname: Chang
authors.forename: Moo Kyoung
authors.initials: MK
authors.lastname: Shin
authors.forename: Kyung Hun
authors.initials: KH
authors.lastname: Cha
authors.forename: Cheol Ho
authors.initials: CH
authors.lastname: Yeum
authors.forename: Jae Yeoul
authors.initials: JY
authors.lastname: Jun
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004594:Electrophysiology; D005769:Gastrointestinal Motility / Q000502:physiology*; D007421:Intestine, Small / Q000166:cytology*; D007473:Ion Channels / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D009130:Muscle, Smooth / Q000166:cytology / Q000502:physiology; D018408:Patch-Clamp Techniques
chemical_list: D007473:Ion Channels