title: Characteristics of the effect of phorbol ester on rat mast cells: interaction with anti-IgE.
abstract: The phorbol ester 12-0-tetradecanoyl-13-acetate (TPA) induced a dose-dependent release of histamine from rat peritoneal mast cells at concentrations from 3 to 100 ng/ml. The release is biphasic: an early phase being complete in 15 min and being followed by a second phase extending for more than 50 min. Concentrations of TPA greater than 100 ng/ml produced decreasing releases of histamine. Synergistic interaction in the induction of histamine secretion was observed between TPA and A23187 and between TPA and anti-IgE. Such synergism with anti-IgE was only manifest at low concentrations of TPA and with incubations of the cells with TPA for 5 mins or less. At higher concentrations of TPA and longer incubations, TPA inhibited the response of rat peritoneal mast cells to anti-IgE stimulation. Synergism between A23187 and TPA was observed only at low levels of histamine release induced by calcium plus A23187: at higher levels of release TPA was inhibitory.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D006636:Histamine Release / Q000187:drug effects; D007073:Immunoglobulin E / Q000276:immunology*; D066298:In Vitro Techniques; D008297:Male; D008407:Mast Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D010704:Phorbols / Q000494:pharmacology*; D011493:Protein Kinase C / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D010704:Phorbols; D007073:Immunoglobulin E; D000001:Calcimycin; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium