Patch-clamp profile of ion channels in resting murine B lymphocytes.
Patch-clamp studies of single ion channel currents in freshly isolated murine B lymphocytes are characterized here according to their respective unitary conductances, ion selectivities, regulatory factors, distributions and kinetic behavior. The most prevalent ion channel in murine B lymphocytes is a large conductance (348 pS) nonselective anion channel. This report characterizes additional conductances including: two chloride channels (40 and 128 pS), a calcium-activated potassium channel (93 pS), and an outwardly rectifying potassium channel which displays two distinct conductances (18 and 30 pS). Like the anion channel, both chloride channels exhibit little activity in the cell-attached patch configuration. The kinetic behavior of all of these channels is complex, with variable periods of bursting and flickering activity interspersed between prolonged closed/open intervals (dwell times). It is likely that some of these channels play an important role in the signal transduction of B cell activation.
Department of Physiology, Dartmouth Medical School, Hanover, New Hampshire 03756.
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Noelle
D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology; D002478:Cells, Cultured; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism / Q000502:physiology; D004553:Electric Conductivity; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D015221:Potassium Channels / Q000502:physiology
D018118:Chloride Channels; D002712:Chlorides; D007473:Ion Channels; D008565:Membrane Proteins; D015221:Potassium Channels; D002118:Calcium