Phorbol esters and chemotactic factor induce distinct changes in cytoplasmic Ca2+ and pH in granulocytic like HL60 cells.
Differentiation of HL60 cells into neutrophil-like cells after exposure to dimethylsulfoxide is accompanied by an increase in intracellular pH (pHi) which results from an increased activity of the Na+/H+ antiporter at physiological pHi value, but not at acidic pHi values. The functional responses of differentiated HL60 cells to the chemotactic peptide, N-formylmethionylleucylphenylalanine (fMLP), and to phorbol myristate acetate (PMA) were studied. In differentiated cells fMLP produced a large increase in cytosolic Ca2+ levels and a small biphasic change in pHi, whereas PMA produced cellular acidification, which was potentiated by ethylisopropylamiloride and no change in [Ca2+]i. In undifferentiated HL60 cells, PMA produced the opposite effect on pHi, i.e., a cellular alkalinization. The extent of the acidification produced by PMA in differentiated HL60 cells correlated with the production of reactive oxygen species.
Ladoux
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A
Inserm U 204, Hôpital Saint Louis, Paris, France.
Krawice
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I
Damais
C
C
Frelin
C
C
D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D006098:Granulocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism*
D009240:N-Formylmethionine Leucyl-Phenylalanine; D000584:Amiloride; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; C039614:ethylisopropylamiloride; D004121:Dimethyl Sulfoxide