title: Elvax as a slow-release delivery agent for a platelet-activating factor receptor agonist and antagonist.
abstract: The ability of the slow-release polymer, Elvax, to deliver a large number of different molecules to distinct brain regions has been well-documented. However, there are currently no reports of Elvax-mediated delivery of ether phospholipids, whose lipid structure renders them difficult to solubilize and detect under experimental conditions. In order to potentially examine the role of platelet-activating factor (PAF) receptors in the brain in vivo, we tested the ability of Elvax to release the ether phospholipid. PAF receptor agonist, methyl-carbamyl platelet-activating factor (mc-PAF), and the ginkolide, PAF receptor antagonist, BN 52021. Mc-PAF and BN 52021 containing Elvax sections (200 microns) prepared in methylene chloride were assayed for release characteristics with a rabbit platelet aggregation bioassay. We measured a slow, sustained release of mc-PAF and BN 52021 from Elvax in vitro over a 5 day period. Similar in vivo mc-PAF and BN 52021 release kinetics were determined. Therefore, we believe that this novel method of slow-release delivery of PAF receptor agonists and antagonists as measured with platelet aggregation is viable and offers a simple, sensitive and inexpensive method for potential in vivo studies of the roles of PAF and its receptors in neural systems.
authors.affiliation: Cain Foundation Laboratories, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Bix
authors.forename: G D
authors.initials: GD
authors.lastname: Clark
mesh_terms: D000818:Animals; D003692:Delayed-Action Preparations; D004224:Diterpenes; D004305:Dose-Response Relationship, Drug; D046934:Ginkgolides; D007783:Lactones / Q000008:administration & dosage*; D010972:Platelet Activating Factor; D010974:Platelet Aggregation / Q000187:drug effects; D010980:Platelet Membrane Glycoproteins / Q000819:agonists / Q000037:antagonists & inhibitors / Q000187:drug effects*; D011145:Polyvinyls / Q000494:pharmacology*; D011817:Rabbits; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled
chemical_list: D003692:Delayed-Action Preparations; D004224:Diterpenes; D046934:Ginkgolides; D007783:Lactones; D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D011145:Polyvinyls; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; C016438:ethylenevinylacetate copolymer; C045856:ginkgolide B