title: Neomycin is a potent agent for arachidonic acid release in human platelets.
abstract: Neomycin (10 microM - 1 mM) was found to induce considerable release of [3H]arachidonic acid from phosphatidylinositol, phosphatidylcholine and phosphatidylethanolamine in saponin-permeabilized human platelets prelabeled with [3H]arachidonic acid. The magnitude of arachidonate liberation was almost equal to that induced by A23187 (400 nM) or even greater than that caused by thrombin (1 U/ml). Moreover, neomycin enhanced arachidonic acid release induced by thrombin. Since no significant formation of diacylglycerol and phosphatidic acid via phospholipase C was observed, the arachidonate liberation was considered to be mainly catalyzed by phospholipase A2 action. Addition of neomycin (100 microM) to 45Ca2+-preloaded platelets elicited 45Ca2+ mobilization from intracellular stores. These results indicate evidence that neomycin evokes Ca2+ mobilization from internal stores, which leads to activation of phospholipase A2 to release arachidonic acid in human platelets.
mesh_terms: D015772:4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000097:blood; D002463:Cell Membrane Permeability / Q000187:drug effects; D006801:Humans; D009355:Neomycin / Q000494:pharmacology*; D010741:Phospholipases A / Q000097:blood; D054467:Phospholipases A2; D011720:Pyrazoles / Q000494:pharmacology; D012503:Saponins / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism; D013917:Thrombin / Q000494:pharmacology
chemical_list: D001095:Arachidonic Acids; D011720:Pyrazoles; D012503:Saponins; D016718:Arachidonic Acid; D012701:Serotonin; D000001:Calcimycin; D015772:4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; D010741:Phospholipases A; D054467:Phospholipases A2; D013917:Thrombin; D009355:Neomycin; D002118:Calcium