Synergistic action of protein kinase C and calcium for histamine release from rat peritoneal mast cells

When rat mast cells were stimulated by concanavalin A, phosphatidylinositol turnover was induced. Concurrently, several cytosol proteins were phosphorylated and histamine was released. 1-Oleoyl-2-acetyl-glycerol ( OAG ) and 12-O-tetradecanoylphorbol-13-acetate (TPA), known as direct activators of protein kinase C in intact cells, induced phosphorylation of the same spectrum of proteins. These proteins also served in vitro as preferable substrates for protein kinase C. The simultaneous addition of OAG or TPA and A23187 synergistically enhanced histamine release from mast cells. It is suggestive that protein kinase C activation and Ca2+ mobilization play essential roles for this cellular response.