Morphological alterations in rat peritoneal mast cells by stem cell factor.

Stem cell factor (SCF) stimulates mast cell adhesion and, because SCF is produced normally in tissues, it may be a major factor responsible for the adhesion of mast cells to connective tissue matrix. We found that the morphology of rat peritoneal mast cells (RPMC) altered after the addition of recombinant murine SCF (rmSCF) in vitro. The ability of rmSCF to enhance morphological alteration was dose dependent and completely abolished by anti-c-kit ACK2 monoclonal antibody. Exposure of RPMC to transforming growth factor-beta 1, wortmannin, genistein, herbimycin A, staurosporine, indomethacin and cytochalasin D before the addition of rmSCF antagonized rmSCF-induced morphological alteration. However, nordihydroguiaretic acid had no effect. Many RPMC appeared to respond also to nerve growth factor (NGF) but the total number of cells with altered morphology was much greater when the culture was stimulated by rmSCF than by NGF. We suggest that morphological alterations of mast cells by rmSCF is an important step for the participation in adhesion to tissue under resident physiological conditions.