Effects of arsenite on gliotransmitter release from primary cultured astrocytes / 中华地方病学杂志

ABSTRACT

Objective To investigate the impairment mechanism of learning and memory function induced by arsenite exposure through studying the effects of sodium arsenite on gliotransmitter release from astrocytes.Methods Primary cultured astrocytes were isolated from neonatal (0-3 days) Wistar rats and determined by glial fibrillary acidic protein (GFAP) immunofluorescence staining.The primary cultured astrocytes were randomly divided into four groups,in which astrocytes were exposed to 0.0,2.5,5.0,or 10.0 μmol/L sodium arsenite,respectively,for 24 h.Intracellular free Ca2+ concentration ([Ca2+]i) in astrocytes was measured by fluorescence dual wavelength spectrophotometer;,concentrations of glutamate,D-serine,glycine and γ-aminobutyric acid were measured by high performance liquid chromatography (HPLC).Results More than 95％ cells were positive for GFAP immunofluorescence staining.The difference of [Ca2+]i among groups treated with sodium arsenite was statistically significant (F =20.030,P ＜ 0.05).[Ca2+]i increased significantly in group treated with 10.0 μmol/L sodium arsenite [(263.27 ± 14.80)nmol/L] compared with those in groups treated with 0.0,2.5,5.0 μmol/L sodium arsenite [(204.24 ± 27.21),(214.49 ± 21.85),(232.74 ± 23.14)nmol/L,all P ＜ 0.05].The differences of the levels of D-serine,glycine and γ-aminobutyric acidamong groups treated with sodium arsenite were significant (F =26.599,33.539,5.599,all P ＜ 0.05).The levels of D-serine [(21.580 ± 1.313),(21.936 ± 1.539),(23.401 ± 1.648)μmol/L],glycine [(26.353 ± 2.449),(29.711 ± 1.530),(29.234 ± 2.057)μmol/L] and γ-aminobutyric acid [(27.277 ± 3.421),(30.213 ± 2.098),(29.364 ± 2.588)μmol/L] released by astrocytes increased significantly in groups treated with 2.5,5.0,10.0 μmol/L sodium arsenite compared with those in groups treated with 0.0 μmol/L sodium arsenite [(16.017 ± 1.046),(16.763 ± 3.007),(22.736 ± 4.139)μmol/L,all P ＜ 0.05].Conclusion Arsenite could affect gliotransmitter release from astrocytes,and further impair learning and memory function.