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Role of membrane potential in the regulation of lectin‐induced calcium uptake
Author(s) -
Gelfand Erwin W.,
Cheung Roy K.,
Grinstein Sergio
Publication year - 1984
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041210312
Subject(s) - extracellular , lectin , depolarization , biophysics , incubation , membrane potential , calcium , cytoplasm , chemistry , biochemistry , membrane , microbiology and biotechnology , biology , organic chemistry
Incubation of lymphocytes with mitogenic lectins triggers Ca 2+ uptake. This increase in free cytoplasmic Ca 2+ is postulated to be an important signal in the initiation of DNA synthesis. Transmembrane fluxes of monovalent ions and changes in membrane potential are also associated with lectin‐induced activation of lymphocytes. We have examined the relationship between extracellular monovalent ion substitution, the associated electrical potential changes (measured with cyanine dyes), phytohemagglutinin‐induced Ca 2+ uptake (measured with Quin‐2) and proliferation in human T cells. The results show that (1) the magnitude of the increase in free cytoplasmic Ca 2+ concentration is correlated with the extent of the lymphoproliferative response, (2) lectin‐induced Ca 2+ fluxes are sensitive to membrane potential, decreasing with depolarization, and are likely conductive, and (3) the presence of extracellular Na + during incubation with phytohemagglutinin is not essential to mitogenic triggering.