Aspartate uptake, effect of inhibition of Na,K-ATPase α2 and of α2+ α1.

<p><b>A.</b> GFAP immunostaining of primary astrocytes with multiple thin processes. Astrocytes were derived from E17 rat striatum and cultured for 9–12 days in medium enriched with neuronal conditioned medium (NCM) during the last 24 h. <b>B.</b> Immunoblotting of Na,K-ATPase α1 and α2, GLAST and GLT-1 in whole brain lysate and in primary astrocyte culture treated with NCM (Astrocytes +NCM) or without NCM (Astrocytes -NCM). The expression of the glutamate transporter GLAST in primary astrocyte culture increased by 46% after application of NCM for 24 h (One-way ANOVA, N = 3 experiments, P<0.01). The expression of GLT-1, Na,K-ATPase α1 and α2 did not change. <b>C.</b> Increase in astrocyte [Na⁺]_i (Δ[Na⁺]_i) following treatment with ouabain 1 µM or 2000 µM for 15 min (One-way ANOVA, N = 38 cells, P<0.001). <b>D.</b> Decrease in D-Asp uptake following treatment with ouabain 1 µM or ouabain 2000 µM for 15 min (One-way ANOVA, N = 9 experiments, P<0.001).