title: [G-protein potentiates the activation of TNF-alpha on calcium-activated potassium channel in ECV304].
abstract: OBJECTIVE
  Observe the effect of tumor necrosis factor-alpha (TNF-alpha) on calcium-activated potassium channel in ECV304 and the possible involvement of G-protein mediation in the action of TNF-alpha.
  
  
  METHODS
  Using the cell-attached configuration of patch clamp technique.
  
  
  RESULTS
  (1) the activity of high-conductance calcium-activated potassium channel (BKca) was recorded. Its conductance is (202.54 +/- 16.62) pS; (2) the activity of BKca was potentiated by 200 U/ml TNF-alpha; (3) G-protein would intensify this TNF-alpha activation.
  
  
  CONCLUSIONS
  TNF-alpha acted on vascular endothelial cell ECV304 could rapidly activate the activity of BKca. Opening of BKca resulted in membrane hyper-polarization which could increase electro-chemical gradient for the resting Ca2+ influx and open leakage calcium channel, thus resting cytoplasmic free Ca2+ concentration could be elevated. G-protein may exert an important regulation in this process.
authors.affiliation: Department of Physiology, Institute of Basic Medical Sciences, CAMS, PUMC, Beijing 100005, China.
authors.forename: L
authors.initials: L
authors.lastname: Lin
authors.forename: Y
authors.initials: Y
authors.lastname: Zheng
authors.forename: J
authors.initials: J
authors.lastname: Qu
authors.forename: G
authors.initials: G
authors.lastname: Bao
mesh_terms: D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D019204:GTP-Binding Proteins / Q000502:physiology*; D006801:Humans; D011188:Potassium / Q000378:metabolism; D024681:Potassium Channels, Calcium-Activated / Q000187:drug effects* / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D024681:Potassium Channels, Calcium-Activated; D014409:Tumor Necrosis Factor-alpha; D019204:GTP-Binding Proteins; D011188:Potassium; D002118:Calcium