title: Involvement of platelet-activating factor (PAF) in glutamate neurotoxicity in rat neuronal cultures.
abstract: To clarify the role of platelet-activating factor (PAF) in glutamate neurotoxicity, in vitro experiments using primary neuronal cultures were performed. The anti-PAF immunoglobulin-G (aPAF-IgG) and the three PAF receptor antagonists (BN52021, CV6209, and E5880) were tested for their neuroprotective activity in primary neuronal cultures isolated from embryonic rat cerebral cortex. The cultured neurons were exposed to glutamate (1 mM) for 60 min. Twenty-four hours after this exposure, aPAF-IgG demonstrated evidence of protective effects against neuronal damage in a dose-dependent manner. Protective effects also were observed in cultures treated with the three PAF antagonists (P < 0.05 at 1 microg/ml aPAF-IgG, P < 0.01 at 100 microM BN52021, P < 0.05 at 10 nM CV6209 and P < 0.01 at 10 nM E5880). The Fura-2 assay was used to estimate whether low dosages of exogenous PAF affect cultured neurons. The cultured neurons were loaded with Fura-2/AM. After preincubation for 120 min, the Fura-2-loaded neurons were exposed to various concentrations of PAF for 60 min. By measuring the fluorescent intensity of the medium as representing the amount of Fura-2 released from damaged neurons, we detected an increased release of Fura-2, even at low doses of PAF (P < 0.01 at 10 nM PAF). We further studied PAF production by neurons in response to glutamate. The level of PAF measured in the medium exposed to glutamate was significantly higher than the level in the medium unexposed to glutamate (P < 0.05). Our results suggest an important role of PAF in glutamate neurotoxicity.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nogami
authors.forename: Y
authors.initials: Y
authors.lastname: Hirashima
authors.forename: S
authors.initials: S
authors.lastname: Endo
authors.forename: A
authors.initials: A
authors.lastname: Takaku
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D004224:Diterpenes; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian; D005343:Fibrinolytic Agents / Q000494:pharmacology; D005456:Fluorescent Dyes; D016257:Fura-2 / Q000031:analogs & derivatives; D046934:Ginkgolides; D018698:Glutamic Acid / Q000633:toxicity*; D007074:Immunoglobulin G; D007783:Lactones / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D009498:Neurotoxins; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000502:physiology*; D011726:Pyridinium Compounds / Q000494:pharmacology; D051381:Rats
chemical_list: D004224:Diterpenes; D005343:Fibrinolytic Agents; D005456:Fluorescent Dyes; D046934:Ginkgolides; D007074:Immunoglobulin G; D007783:Lactones; D009498:Neurotoxins; D010972:Platelet Activating Factor; D011726:Pyridinium Compounds; C053321:CV 6209; C049925:fura-2-am; D018698:Glutamic Acid; C045856:ginkgolide B; D016257:Fura-2