title: Ebselen protects Ca2+ influx blockage but does not protect glutamate uptake inhibition caused by Hg2+.
abstract: The goal of this study was to investigate the isolated and combined effect of ebselen and Hg2+ on calcium influx and on glutamatergic system. We examined the in vitro effects of 2 phenyl-1,2-benzisoselenazol-3(2H)-ona), (Ebselen) on 45Ca2+ influx in synaptosomes of rat at rest and during depolarization and glutamate uptake into synaptosomes. Entry of 45Ca was measured during exposure to mercury in non-depolarizing and depolarizing solutions. Ebselen abolished the inhibition of 45Ca2+ influx on non-depolarizing conditions; however, ebselen did no modify inhibition uptake of 45Ca2+ caused by Hg2+ in high K+ depolarizing medium. Ebselen did not modify glutamate uptake inhibition caused by Hg2+ in synaptosomes. These results indicate that ebselen has an in vitro protective effect against Hg2+ induced inhibition of Ca2+ influx into synaptosomes, depending on the depolarizing conditions of the assay. The effects of Hg2+ on glutamate uptake were not modified by ebselen, suggesting that its protection is dependent on the target protein considered.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, Brazil. beatriz@smail.ufsm.br
authors.forename: M B
authors.initials: MB
authors.lastname: Moretto
authors.forename: J
authors.initials: J
authors.lastname: Franco
authors.forename: T
authors.initials: T
authors.lastname: Posser
authors.forename: C W
authors.initials: CW
authors.lastname: Nogueira
authors.forename: G
authors.initials: G
authors.lastname: Zeni
authors.forename: J B T
authors.initials: JB
authors.lastname: Rocha
mesh_terms: D000818:Animals; D001393:Azoles / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects* / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism*; D054833:Isoindoles; D008297:Male; D008628:Mercury / Q000494:pharmacology*; D016566:Organoselenium Compounds / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism
chemical_list: D001393:Azoles; D054833:Isoindoles; D016566:Organoselenium Compounds; D018698:Glutamic Acid; C042986:ebselen; D008628:Mercury