title: Ascorbic acid does not modulate potassium currents in cultured human lymphocytes.
abstract: BACKGROUND
  Ascorbic acid (AA) is known to modulate lymphocyte function, but the mechanism of action is not clearly understood. As voltage-gated potassium currents play an important role in lymphocyte function, the effect of AA on voltage-gated potassium currents was studied.
  
  
  METHODS
  Peripheral blood mononuclear cells were cultured in the presence of increasing concentrations of AA (0, 0.125, 0.25, 0.5, and 1 mM). Potassium currents in resting lymphocytes were studied by whole cell patch clamp technique using a depolarizing protocol. Lymphocyte function was assessed by measuring interleukin-2 (IL-2) secretion after mitogenic stimulation by ELISA.
  
  
  RESULTS
  The mean current density of potassium currents recorded from cells cultured for 48 h in the presence of 0.125 mM AA was not significantly different from that of cells cultured in the absence of AA. There was about 50% inhibition of IL-2 secretion in cell cultures with 0.125 mM AA when compared to controls without AA. At higher concentrations of AA, the IL-2 secretion decreased further.
  
  
  CONCLUSIONS
  The results of the study indicate that the inhibition of lymphocyte function by AA in vitro may not be due to inhibition of potassium currents in the concentration tested.
authors.forename: Saravanakumar
authors.initials: S
authors.lastname: Snekalatha
authors.forename: Praghalathan
authors.initials: P
authors.lastname: Kanthakumar
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology*; D002478:Cells, Cultured; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism*
chemical_list: D015221:Potassium Channels; D001205:Ascorbic Acid; D011188:Potassium
keywords: culture; interleukin-2; patch clamp; potassium channels