SR12813 (GW 485801) is a pregnane X receptor (PXR) agonist.

HMG-CoA reductase:850 nM

SR12813是一种对人类和兔子的PXR活化作用非常强大且有效的化合物，其EC50值分别约为200 nM和700 nM。相比之下，SR12813对大鼠和小鼠的PXR的活化作用非常弱[1]。SR-12813能抑制携带氚的水合成胆固醇，IC50为1.2 μM，但对脂肪酸的合成无影响。SR-12813还能降低细胞内3-羟基-3-甲基戊二酰辅酶A（HMG-CoA）还原酶的活性，IC50为0.85 μM。对HMG-CoA还原酶活性的抑制作用迅速，半衰期为10分钟[2]。

双磷酸酯SR12813能在包括大鼠、犬和灵长类动物在内的多种物种中降低胆固醇水平[1]。

Briefly, compounds are added to the cells in Me2SO (final concentration, 0.1%). After the experiment cells are lysed by the addition of 0.1 mL of 0.25% Brij 96, 0.1 M sucrose, 0.1 M KF, 50 mM KCl, 40 mM potassium dihydrophosphate, 30 mM EDTA, 5 mM dithiothreitol, pH 7.4 at room temperature. In some experiments KF is omitted to measure 'total' HMG-CoA reductase activity. HMG-CoA reductase activity in the cell lysate is further determined.

Hep G2 cells are incubated for 21 h with either 1 μM lovastatin or 3 μM SR-12813 in 5% LPDS medium. mRNA is isolated and analyzed by Northern blotting.(Only for Reference)