SEA0400 is a selective inhibitor of the Na+/Ca2+ exchanger.

NCX:5 -33 nM.

SEA0400在培养的神经元、星形胶质细胞和小胶质细胞中，抑制Na+-依赖的45Ca2+摄取。SEA0400的IC50值分别为：神经元33 nM、星形胶质细胞5.0 nM和小胶质细胞8.3 nM[1]。此外，SEA0400还能够阻止硝普钠（SNP）在外细胞Ca2+依赖性条件下，增加ERK和p38 MAPK的磷酸化，以及活性氧种（ROS）的产生[2]。

SEA0400 (3 mg/kg + 3 mg/kg/h，持续2小时，静脉注射) 在麻醉大鼠中能够减少大脑皮层和纹状体的梗死体积，而不影响平均区域性皮质血流量[1]。此外，SEA0400还能够保护MPTP处理的C57BL/6J小鼠免受多巴胺能神经毒性的伤害，这一效应通过测定中脑和纹状体中的多巴胺水平、黑质和纹状体内酪氨酸羟化酶的免疫反应性、纹状体多巴胺释放及运动缺陷来确定[3]。

Na+-Ca2+ exchange activity is determined by assaying Na+-dependent 45Ca2+ uptake as reported previously. Briefly, the cells are preincubated in Hanks' balanced saline solution (HBSS) for 20 min, and the medium is switched to HBSS containing 45Ca2+?and incubated for 5 min. To increase intracellular Na+?concentration, 1 mM ouabain plus 20 μM monensin (for astrocytes and microglia) and 10 μM monensin (for neurons) are used. Monensin is added simultaneously with the isotope. Ouabain is added 5 min before monensin in astrocytes and microglia. SEA0400 and KB-R7943 are added 5 min before monensin and present during 45Ca2+?uptake reaction.

SEA0400 is dissolved in DMSO (final concentration 0.1%). Cells, plated in 96-well plastic tissue culture plates, are incubated at 37°C for 30 min in normal or Ca2+-free HBSS containing 10 μM H2DCF-DA and 0.25 μg/mL Cremophor EL, and then rinsed twice with normal HBSS to remove excess dye. The cells are reperfused in normal HBSS for 1 h, and the conversion of H2DCF-DA to its fluorescent product dichlorofluorescein by ROS, presumably Water2 and hydroxyl radical, is determined with excitation at 485 nm and emission at 535 nm using a Wallac Multilabel counter. ROS production is expressed as a percentage of control cells. The linearity and sensitivity of ROS assay are confirmed using Water2 prior to the experiment. SEA0400 at the indicated concentrations is added 10 min before Ca2+?reperfusion and present until assay.