title: Inhibition of histamine secretion from rat peritoneal mast cells and rabbit leukocytes by p-bromophenacyl bromide, a phospholipase A2 inhibitor.
abstract: The present investigation was undertaken to explore the role of phospholipase A2 (PLA2) activation in histamine secretion from rabbit leukocytes and rat peritoneal mast cells (RPMC) by using p-bromophenacyl bromide (p-BPB), a potent inhibitor of PLA2. p-BPB exerted concentration dependent inhibition of allergic histamine release from RPMC and rabbit leukocytes as well as calcium ionophore A23187-stimulated histamine release from RPMC with IC50s of 36.2, 1.3 and 80.0 nM, respectively. pBPB exerted a bell-shaped (biphasic) concentration-effect (inhibition) curve on ragweed antigen-induced histamine secretion from rabbit leukocytes. The data obtained in this study suggest that PLA2 activation plays an essential role in histamine secretion from rabbit leukocytes and RPMC.
mesh_terms: D000098:Acetophenones / Q000494:pharmacology*; D000818:Animals; D006636:Histamine Release / Q000187:drug effects*; D066298:In Vitro Techniques; D007700:Kinetics; D007962:Leukocytes / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000502:physiology*; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D054467:Phospholipases A2; D011817:Rabbits; D051381:Rats
chemical_list: D000098:Acetophenones; D010741:Phospholipases A; D054467:Phospholipases A2; C006821:4-bromophenacyl bromide