title: [Ion channel mechanism of regulatory volume decrease in human epithelial cells].
abstract: OBJECTIVE
  To observe the regulatory volume decrease (RVD) process of human intestine cells and investigate its ion channel mechanism.
  
  
  METHODS
  Cultured human intestine cells were exposed to hypotonic solution and the cell volume was measured using Coulter Counter System. RT-PCR was explored to detect the mRNA expression of Ca(2+) -activated K+ channel.
  
  
  RESULTS
  Human intestine cells showed a RVD process and this process could be blocked by Cl- channel blocker NPPB and K+ channel blocker TEA. Further results demonstrated the subtype of K+ channel involved in RVD was an intermediate-conductance, Ca(2+) -activated K+ channel (IK) because of its high sensitivity to clotrimazole. RT-PCR results also showed the expression of IK in this cell line.
  
  
  CONCLUSIONS
  The RVD process of intestine cell was dependent on the parallel activation of Cl- channel and K+ channel. The subtype of K+ channel in volved in the RVD process was IK channel.
authors.affiliation: Department of Physiology, Capital Medical University, Beijing 100069, China.
authors.forename: Lu Ping
authors.initials: LP
authors.lastname: Shi
authors.forename: Yi Min
authors.initials: YM
authors.lastname: Zang
authors.forename: Xiao Li
authors.initials: XL
authors.lastname: Hou
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
mesh_terms: D002460:Cell Line; D048429:Cell Size / Q000187:drug effects*; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology*; D006801:Humans; D007038:Hypotonic Solutions; D007421:Intestine, Small / Q000166:cytology*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000378:metabolism*; D024681:Potassium Channels, Calcium-Activated / Q000378:metabolism
chemical_list: D018118:Chloride Channels; D007038:Hypotonic Solutions; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated