FIGURE 4.
Effects of MCT-1 on undifferentiated or differentiated HL-60 cells. A, β-hexosaminidase release upon stimulation with various concentrations of fMLF (left) or MCT-1 (right) from the neutrophilic/granulocytic differentiated HL-60 cells following treatment with 500 μm dbcAMP for 24 (open triangles), 48 (closed triangles), or 72 h (open squares). The effects of the peptides on the undifferentiated cells were also measured (filled circles). B, [Ca2+]i increase in undifferentiated (filled bars) and differentiated (treated with 500 μm dbcAMP for 72 h; open bars) HL-60 cells after stimulation with vehicle, fMLF, or MCT-1. The effect of ATP was also determined as the control known to be unaffected by differentiation. All data are expressed as mean ± S.E. of six independent experiments.