title: Antagonist of phorbol ester receptor-mediated chemotaxis in mouse peritoneal macrophages.
abstract: Biologically active phorbol ester derivatives displace [3H]phorbol-12, 13-dibutyrate from thioglycollate-elicited mouse peritoneal macrophages in a time-, temperature-, and concentration-dependent manner. Scatchard analysis revealed an apparent Kd of 54.1 nM and 8.0 X 10(5) sites/cell, indicating that these macrophages possess saturable, high-affinity phorbol ester-binding sites. These derivatives also act as chemoattractants for the macrophage at equivalent concentrations. A notable exception to this pattern is phorbol-12,13-diacetate. Phorbol-12,13-diacetate inhibits specific binding of [3H]phorbol-12,13-dibutyrate (concentration required for a 50% inhibition of the maximum specific binding of [3H]phorbol-12,13-dibutyrate, 2.6 microM) and chemotaxis to phorbol-12-myristate, 13-acetate (concentration required for a 50% inhibition of the maximum chemotactic response, 0.39 microM) while exhibiting no activity as a chemoattractant at concentrations up to 10(-5) M. The data indicate that phorbol-12,13-diacetate may be an antagonist for receptor-mediated chemotaxis to phorbol-12-myristate, 13-acetate in the macrophage.
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology; D001667:Binding, Competitive; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D002633:Chemotaxis / Q000187:drug effects*; D005260:Female; D008264:Macrophages / Q000187:drug effects*; D051379:Mice; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000378:metabolism; D011493:Protein Kinase C; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011955:Receptors, Drug; D013755:Tetradecanoylphorbol Acetate / Q000378:metabolism; D013997:Time Factors
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D010703:Phorbol Esters; D011956:Receptors, Cell Surface; D011955:Receptors, Drug; C083141:phorbol ester binding protein; C027776:phorbol ester receptor; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate