title: S100B secretion in acute brain slices: modulation by extracellular levels of Ca(2+) and K (+).
abstract: Hippocampal slices have been widely used to investigate electrophysiological and metabolic neuronal parameters, as well as parameters of astroglial activity including protein phosphorylation and glutamate uptake. S100B is an astroglial-derived protein, which extracellularly plays a neurotrophic activity during development and excitotoxic insult. Herein, we characterized S100B secretion in acute hippocampal slices exposed to different concentrations of K(+) and Ca(2+) in the extracellular medium. Absence of Ca(2+) and/or low K(+) (0.2 mM KCl) caused an increase in S100B secretion, possibly by mobilization of internal stores of Ca(2+). In contrast, high K(+) (30 mM KCl) or calcium channel blockers caused a decrease in S100B secretion. This study suggests that exposure of acute hippocampal slices to low- and high-K(+) could be used as an assay to evaluate astrocyte activity by S100B secretion: positively regulated by low K(+) (possibly involving mobilization of internal stores of Ca(2+)) and negatively regulated by high-K(+) (likely secondary to influx of K(+)).
authors.affiliation: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, Porto Alegre, RS, Brazil.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Nardin
authors.forename: Lucas
authors.initials: L
authors.lastname: Tortorelli
authors.forename: André
authors.initials: A
authors.lastname: Quincozes-Santos
authors.forename: Lúcia Maria V
authors.initials: LM
authors.lastname: de Almeida
authors.forename: Marina C
authors.initials: MC
authors.lastname: Leite
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Thomazi
authors.forename: Carmem
authors.initials: C
authors.lastname: Gottfried
authors.forename: Susana T
authors.initials: ST
authors.lastname: Wofchuk
authors.forename: Rosario
authors.initials: R
authors.lastname: Donato
authors.forename: Carlos-Alberto
authors.initials: CA
authors.lastname: Gonçalves
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D005110:Extracellular Space / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009414:Nerve Growth Factors / Q000378:metabolism*; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011188:Potassium / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism*; D014700:Verapamil / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579158:S100b protein, rat; D018698:Glutamic Acid; D014700:Verapamil; D010751:Phosphopyruvate Hydratase; D005978:Glutathione; D011188:Potassium; D002118:Calcium