Effects of arsenite on D-serine released from astrocytes and its related mechanism

Objective To investigate the intellectual impairment induced by arsenite through studying the effects of arsenite on D-serine released from astrocytes and its related mechanism.Methods The primary cultured astrocytes were divided into four groups randomly,in which astrocytes were exposed to 0,2.5,5 or 10 μmol/L arsenite for 24 hours.The level of D-serine was measured with high performance liquid chromatography(HPLC);the protein expression of serine racemase(SR)was measured with western blot;the intracellular free Ca²⁺ concentration(Ca²⁺_i)in astrocytes was measured with fluorescence dual wavelength spectrophotometer.Results Compared with those in control group,the levels of D-serine released from astrocytes(21.580±1.313,21.936±1.539 and 23.401±1.648 μmol/L)and the protein expression of SR(1.327±0.122,1.397±0.105,and 1.403±0.104)increased significantly in groups treated with arsenite;and Ca²⁺_i(0.26±0.01 μmol/L)in the group treated with 10 μmol/L arsenite increased significantly.Conclusion Arsenite could increase the level of D-serine released from astrocytes and its mechanism could be related with the increasing protein expression of SR and the elevated Ca²⁺_i in astroytes induced by arsenite.