title: Effect of ebselen and organochalcogenides on excitotoxicity induced by glutamate in isolated chick retina.
abstract: In this study, we evaluated the effects of three simple organochalcogenides (diphenyl diselenide, diphenyl ditelluride and diphenyl telluride) and ebselen on the glutamate-driven 45Ca2+ influx into chick embryonic retinal cells, as well as their effects on the excitotoxic injury in retina cells. None of the compounds tested interfered with basal 45Ca2+ uptake. Diphenyl diselenide and diphenyl ditelluride had no effects on glutamate-driven 45Ca2+ influx. Diphenyl telluride (100-400 microM) decreased and ebselen (100-400 microM) completely blocked the glutamate-driven 45Ca2+ influx (P < 0.01) into chick retinal explants. The assessment of neural injury was made spectrophotometrically by quantification of cellularly reduced MTT (3(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide) 24 h after the beginning of glutamate exposure (8 h). Ebselen had no effects on retinal MTT reduction when co-incubated with glutamate for 8 h. However, when ebselen (100 and 400 microM) was co-incubated for 8 h with glutamate and remained in the incubation media until MTT evaluation (24 h after the beginning of incubation), it protected retinal cells against the decrease in MTT reduction induced by glutamate. These data indicate that besides its capacity of interacting with Ca2+ channels, other mechanisms are involved in the neuroprotection afforded by ebselen in this work, possibly its antioxidant properties.
authors.affiliation: Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brasil.
authors.forename: Fernanda Bossemeyer
authors.initials: FB
authors.lastname: Centurião
authors.forename: Cristiane Lenz Dalla
authors.initials: CL
authors.lastname: Corte
authors.forename: Márcio Weber
authors.initials: MW
authors.lastname: Paixão
authors.forename: Antônio Luís
authors.initials: AL
authors.lastname: Braga
authors.forename: Gilson
authors.initials: G
authors.lastname: Zeni
authors.forename: Tatiana
authors.initials: T
authors.lastname: Emanuelli
authors.forename: João Batista Teixeira
authors.initials: JB
authors.lastname: Rocha
mesh_terms: D000818:Animals; D001393:Azoles / Q000494:pharmacology*; D001555:Benzene Derivatives / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D018011:Chalcogens / Q000494:pharmacology*; D002642:Chick Embryo; D004305:Dose-Response Relationship, Drug; D018698:Glutamic Acid; D054833:Isoindoles; D009410:Nerve Degeneration / Q000139:chemically induced / Q000517:prevention & control; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009498:Neurotoxins; D009942:Organometallic Compounds / Q000494:pharmacology*; D016566:Organoselenium Compounds / Q000494:pharmacology*; D012160:Retina / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D013691:Tellurium / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism
chemical_list: D001393:Azoles; D001555:Benzene Derivatives; D015220:Calcium Channels; D018011:Chalcogens; D054833:Isoindoles; D018696:Neuroprotective Agents; D009498:Neurotoxins; D009942:Organometallic Compounds; D016566:Organoselenium Compounds; D013778:Tetrazolium Salts; D013844:Thiazoles; C503220:diphenyl telluride; C434247:diphenylditelluride; C061132:diphenyldiselenide; D018698:Glutamic Acid; C042986:ebselen; C022616:thiazolyl blue; D013691:Tellurium; D002118:Calcium