Voltage-sensitive chloride channels of large conductance in the membrane of pig aortic endothelial cells

Pflugers Arch. 1992 Jun;421(2-3):209-17. doi: 10.1007/BF00374829.


Single, large-conductance chloride-selective channels were studied in the membrane of pig aortic endothelial cells. These channels were usually inactive in cell-attached recordings and activated spontaneously upon formation of inside-out patches or amphotericin B-perforated vesicles. Channel activity was voltage dependent, with a maximum open probability within the range of -20 mV to + 20 mV. Addition of 1 mM Zn2+ to either the cytoplasmic or extracellular side blocked channel activity reversibly. Extracellular 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS) blocked the channels; the concentration necessary for half-maximum blockade was 100 mumol/l. The frequency of observing channels in cell-attached patches increased from less than 5% to 27% when cells were treated for several minutes with 1 mumol/l bradykinin and to 80% in the presence of the calcium ionophore A23187 (1 mumol/l). Both agents increase the cytoplasmic Ca2+ concentration, thereby stimulating nitric oxide (NO) synthesis and cGMP formation in endothelial cells. Sodium nitroprusside (100 mumol/l), which spontaneously releases NO, did not increase Cl- channel activity in intact cells. Polymyxin B (100 mumol/l), an inhibitor of protein kinase C, clearly enhanced Cl- channel activity in intact cells, resulting in the observation of Cl- channels in 70% of cell-attached patches. Our results demonstrate the existence of a large-conductance (LC-type) Cl- channel in vascular endothelium which is subject to a complex cellular regulation, possibly involving inhibition via phosphorylation by protein kinase C, and activation by a Ca2(+)-dependent process which is different from the NO/cGMP pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amphotericin B / pharmacology
  • Animals
  • Calcium / metabolism
  • Chlorides / metabolism*
  • Cytoplasm / drug effects
  • Cytoplasm / metabolism
  • Electrophysiology
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / metabolism*
  • In Vitro Techniques
  • Ion Channels / metabolism*
  • Membrane Potentials / physiology
  • Membranes / metabolism
  • Protein Kinase C / metabolism
  • Swine
  • Zinc / pharmacology


  • Chlorides
  • Ion Channels
  • Amphotericin B
  • Protein Kinase C
  • Zinc
  • Calcium