SN 6 (SN6) is a selective Na+/Ca2+ exchanger (NCX) inhibitor (IC50s of NCX1: 2.9 μM , NCX2: 16 μM ,NCX3: 8.6 μM)

NCX3:8.6 μM, NCX1:2.9μM , NCX2:16μM

SN-6 [2-[4-(4-nitrobenzyloxy)benzyl]噻唑啉-4-羧酸乙酯]，是一种新合成的、选择性的Na(+)/Ca(2+)交换(NCX)抑制剂。SN-6 (0.3-30 microM) 优先抑制细胞内Na(+)-依赖的(45)Ca(2+)吸收（即逆向模式）。在NCX1上（IC(50) = 2.9 microM），SN-6对(45)Ca(2+)吸收的抑制作用是对NCX2或NCX3的3到5倍。在较低剂量下（IC(50) = 0.63 microM），SN-6强效保护NCX1过表达的肾小管细胞免受缺氧/再氧化引起的细胞损伤，这表明该化合物主要在缺氧/缺血条件下发挥作用。SN-6的这些特性，可能源自其与XIP区域的相互作用，有利于将其开发为新型抗缺血药物。

Confluent transfectants in 24-well dishes were loaded with Na+ by incubation at 37°C for 40 min in 0.5 ml of balanced salt solution (BSS) (10 mM HEPES/Tris, pH 7.4, 146 mM NaCl, 4 mM KCl, 2 mM MgCl2, 0.1 mM CaCl2, 10 mM glucose, and 0.1% bovine serum albumin) containing 1 mM ouabain and 10 mM monensin. 45Ca2+ uptake was then initiated by switching the medium to Na+ -free BSS (replacing NaCl with equimolar choline chloride) or to normal BSS, both of which contained 0.1 mM 45CaCl2 (370 kBq/ml) and 1 mM ouabain. After a 30-s incubation, 45Ca2+ uptake was terminated by washing cells four times with an ice-cold solution containing 10 mM HEPES/Tris, pH 7.4, 120 mM choline chloride,and 10 mM LaCl3. Cells were then solubilized with 0.1 N NaOH, and aliquots were taken for determination of radioactivity and protein. When present, SN-6 and KB-R7943 were included in the medium 15 min before the start of 45Ca2+ uptake