title: Stimulation of human platelet aggregation by phospholipase-A and a saline "extract" of a polyurethane.
abstract: A saline extract of polyurethane (SPU) induces enzymatic conversion of arachidonic acid (either exogenous or released through the action of exogenous phospholipase-A) by activating a hitherto undiscovered labile enzyme, synthetase-alpha which is not blocked by aspirin. Addition of SPU, plus arachidonic acid or SPU plus phospholipase-A to platelet-rich plasma (PRP) triggers a biphasic platelet aggregation. Incubation of SPU with PRP results in activation and exhaustion of synthetase-alpha; this renders platelets refractory to the various aggregating agents.
mesh_terms: D001241:Aspirin / Q000494:pharmacology; D006801:Humans; D010740:Phospholipases / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects*; D011140:Polyurethanes / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis; D013268:Stimulation, Chemical
chemical_list: D011140:Polyurethanes; D011451:Prostaglandin-Endoperoxide Synthases; D010740:Phospholipases; D001241:Aspirin