Detection of ligand-activated conductive Ca2+ channels in human B lymphocytes.
It has been assumed that uptake of extracellular Ca2+ occurs through ligand-activated Ca2+ channels in anti-IgM stimulated human B cells. If so, then uptake should be associated with a depolarizing inward current. Instead, a hyperpolarization due to Ca2+-sensitive K+ conductance is observed. To demonstrate conductive Ca2+ channels in human B lymphocytes, we loaded the cells with 1,2-bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetate (BAPTA), an intracellular Ca2+ chelating agent. This increased the magnitude of the Ca2+ current and delayed the Ca2+-dependent K+ conductance. In BAPTA-loaded B cells suspended in Ca2+-free medium and activated with anti-IgM, reintroduction of Ca2+ resulted in a depolarization that was inhibited by high (microM) concentrations of verapamil and was observed when Ca2+ was replaced by Ba2+ but not Mg2+. These data demonstrate the opening of selective, Ca2+ conductive channels in human B cells following cross-linking of surface immunoglobulins.[1]References
- Detection of ligand-activated conductive Ca2+ channels in human B lymphocytes. MacDougall, S.L., Grinstein, S., Gelfand, E.W. Cell (1988) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg