Effect of Recombinant Human c-kit Receptor Ligand on Mediator Release from Human Skin Mast Cells.

We studied the activity of recombinant human stem cell factor (rhSCF) on the release of mediators from human skin mast cells. High concentrations of rhSCF (1 ng/ml-1 μg/ml) induced a rapid and sustained rise in intracellular Ca2+ levels that was accompanied by release of histamine and prostaglandin D2 (PGD2). A brief incubation (10 min) with lower concentrations of rhSCF (0.1 pg/ml-1 ng/ml) enhanced anti-IgE-induced histamine release, but not the release of PGD2. Since some of the effects of rhSCF on mast cell mediator release in vitro occur at concentrations of cytokine similar to those found in the serum of normal subjects it is possible that SCF contributes to the modulation of mast cell function under physiological conditions.