4-acetamido-4--isothiocyanatostilbene-2-2--disulfonic-acid and Leukemia--Myeloid--Acute

The changes in activation of Na+-H+ exchange on granulocytic differentiation of human leukemic promyelocytic HL60 cells have been studied by measuring changes in intracellular pH with the fluorescent pH indicator 2,7-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF). It was found that the Na+-H+ exchanger is activated by stimulation of protein kinase C in the dimethyl sulfoxide (DMSO)-differentiated (neutrophil-like) HL60 cell, but not in the undifferentiated (promyelocyte-like) cell. In contrast, osmotic shrinkage of the cells triggers the exchanger in the undifferentiated cells, but not in the DMSO-differentiated cells. The data suggest that activation of Na+-H+ exchange by osmotic shock does not occur exclusively through stimulation of kinase C.

Topics: 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; Carrier Proteins; Cell Differentiation; Cell Line; Dimethyl Sulfoxide; Fluoresceins; Granulocytes; Humans; Hydrogen-Ion Concentration; Leukemia, Myeloid, Acute; NADH, NADPH Oxidoreductases; NADPH Oxidases; Protein Kinase C; Sodium-Hydrogen Exchangers; Tetradecanoylphorbol Acetate