title: Cyclic AMP-modulated potassium channels in murine B cells and their precursors.
abstract: A voltage-dependent potassium current (the delayed rectifier) has been found in murine B cells and their precursors with the whole-cell patch-clamp technique. The type of channel involved in the generation of this current appears to be present throughout all stages of pre-B-cell differentiation, since it is detected in pre-B cell lines infected with Abelson murine leukemia virus; these cell lines represent various phases of B-cell development. Thus, the presence of this channel is not obviously correlated with B-cell differentiation. Although blocked by Co2+, the channel, or channels, does not appear to be activated by Ca2+ entry. It is, however, inactivated by high intracellular Ca2+ concentrations. In addition, elevation of intracellular adenosine 3', 5'-monophosphate induces at all potentials a rapid decrease in the peak potassium conductance and increased rates of activation and inactivation. Therefore, potassium channels can be physiologically modulated by second messengers in lymphocytes.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism* / Q000502:physiology; D002118:Calcium / Q000494:pharmacology; D002454:Cell Differentiation; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D007121:Immunocompetence; D007473:Ion Channels / Q000187:drug effects* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D011188:Potassium / Q000378:metabolism*
chemical_list: D007473:Ion Channels; D008070:Lipopolysaccharides; D005576:Colforsin; D006160:Guanosine Triphosphate; D000242:Cyclic AMP; D011188:Potassium; D002118:Calcium