Nardin Patrícia, Tortorelli Lucas, Quincozes-Santos André, de Almeida Lúcia Maria V, Leite Marina C, Thomazi Ana Paula, Gottfried Carmem, Wofchuk Susana T, Donato Rosario, Gonçalves Carlos-Alberto
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, Porto Alegre, RS, Brazil.
Neurochem Res. 2009 Sep;34(9):1603-11. doi: 10.1007/s11064-009-9949-0. Epub 2009 Mar 15.
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(+)).
海马切片已被广泛用于研究电生理和代谢神经元参数，以及星形胶质细胞活性参数，包括蛋白质磷酸化和谷氨酸摄取。S100B是一种星形胶质细胞衍生的蛋白质，在发育和兴奋性毒性损伤期间，它在细胞外发挥神经营养活性。在此，我们对暴露于细胞外培养基中不同浓度K(+)和Ca(2+)的急性海马切片中的S100B分泌进行了表征。缺乏Ca(2+)和/或低钾(0.2 mM KCl)导致S100B分泌增加，这可能是由于Ca(2+)内部储存的动员。相反，高钾(30 mM KCl)或钙通道阻滞剂导致S100B分泌减少。这项研究表明，将急性海马切片暴露于低钾和高钾环境中，可作为一种通过S100B分泌来评估星形胶质细胞活性的检测方法：低钾对其有正向调节作用（可能涉及Ca(2+)内部储存的动员），高钾对其有负向调节作用（可能继发于K(+)内流）。
