Cultured human mast cells derived from umbilical cord blood cells in the presence of stem cell factor and interleukin-6 cannot be a model of human skin mast cells: fluorescence microscopic analysis of intracellular calcium ion mobilization

To know whether cultured human mast cells raised from umbilical cord blood cells in the presence of stem cell factor (SCF) and interleukin-6 (IL-6) can be a model of human skin mast cells, the cells were stimulated, and intracellular calcium ion ([Ca2+](i)) mobilization was analyzed by fluorescence microscopic techniques in parallel with a measurement of histamine released from the cells. When IgE-sensitized mast cells were activated by anti-IgE, [Ca2+](i) elevation began at the periphery and subsequently proceeded toward the center of the cells. The increase in [Ca2+](i) in calcium ionophore A23187-stimulated mast cells began at the center and spread to the periphery of the cells. Significant histamine release was observed by each stimulation. However, either compound 48/80 or substance P. failed to increase [Ca2+](i) with no appreciable histamine release. This study shows that there is heterogeneity of [Ca2+](i) mobilization in the activated human mast cells, and that cultured human mast cells derived from umbilical cord blood cells in the presence of SCF and IL-6 can not be a model of human skin mast cells. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.