title: Effects of Lizhong Tang on cultured mouse small intestine interstitial cells of Cajal.
abstract: OBJECTIVE
  To investigate the effects of Lizhong Tang, an herbal product used in traditional Chinese medicine, on mouse small intestine interstitial cells of Cajal (ICCs).
  
  
  METHODS
  Enzymatic digestions were used to dissociate ICCs from mouse small intestine tissues. The ICCs were morphologically distinct from other cell types in culture and were identified using phase contrast microscopy after verification with anti c-kit antibody. A whole-cell patch-clamp configuration was used to record potentials (current clamp) from cultured ICCs. All of the experiments were performed at 30-32 °C.
  
  
  RESULTS
  ICCs generated pacemaker potentials, and Lizhong Tang produced membrane depolarization in current-clamp mode. The application of flufenamic acid (a nonselective cation channel blocker) abolished the generation of pacemaker potentials by Lizhong Tang. Pretreatment with thapsigargin (a Ca²⁺-ATPase inhibitor in the endoplasmic reticulum) also abolished the generation of pacemaker potentials by Lizhong Tang. However, pacemaker potentials were completely abolished in the presence of an external Ca²⁺-free solution, and under this condition, Lizhong Tang induced membrane depolarizations. Furthermore, When GDP-β-S (1 mmol/L) was in the pipette solution, Lizhong Tang still induced membrane depolarizations. In addition, membrane depolarizations were not inhibited by chelerythrine or calphostin C, which are protein kinase C inhibitors, but were inhibited by U-73122, an active phospholipase C inhibitors.
  
  
  CONCLUSIONS
  These results suggest that Lizhong Tang might affect gastrointestinal motility by modulating pacemaker activity in interstitial cells of Cajal.
authors.affiliation: Department of Sasang Constitutional Medicine, College of Korean Medicine, Kyung-hee University, Seoul 130-701, South Korea.
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Hwang
authors.forename: Jung Nam
authors.initials: JN
authors.lastname: Kim
authors.forename: Ho Jun
authors.initials: HJ
authors.lastname: Song
authors.forename: Bora
authors.initials: B
authors.lastname: Lim
authors.forename: Young Kyu
authors.initials: YK
authors.lastname: Kwon
authors.forename: Byung Joo
authors.initials: BJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000187:drug effects*; D015415:Biomarkers / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects; D056885:Interstitial Cells of Cajal / Q000187:drug effects* / Q000378:metabolism; D007421:Intestine, Small / Q000187:drug effects* / Q000378:metabolism; D007473:Ion Channels / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D049990:Membrane Transport Modulators / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D015415:Biomarkers; D004365:Drugs, Chinese Herbal; D004791:Enzyme Inhibitors; D007473:Ion Channels; D049990:Membrane Transport Modulators; C544920:nonselective cation channel protein, mouse; C582768:yijung-tang; D019009:Proto-Oncogene Proteins c-kit; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases
keywords: Gastrointestinal tract; Interstitial cells of Cajal; Lizhong Tang; Motility; Whole-cell patch clamp configuration