Ketanserin (Ketanserinum) is a quinazoline derivative and serotonin (5-hydroxytryptamine, 5HT) receptor subtype 2 (5-HTR2) antagonist with potential antihypertensive and antiplatelet activities. Following administration, ketanserin binds to and inhibits the signaling mediated by 5-HTR2, which inhibits serotonin-dependent vasoconstriction and platelet activation.

5-HT2C (rat):50 nM(Ki), 5-HT2A:2.5 nM(Ki), 5-HT2C (human):100 nM(Ki)

在乙酸诱导和热板的扭体测试中,Ketanserin使大鼠产生剂量依赖性抗伤害感受,ED50值分别为0.62 mg/kg和1.51 mg/kg,但对甩尾测试没有影响.

研究发现在外侧膝状体核中,Ketanserin可使α1 - 肾上腺素能受体介导的反应以及去甲肾上腺素引起的兴奋性反应程度降低,其是诱导而非减弱5-HT的抑制作用。在分离的大鼠尾动脉,颈动脉,犬基底,胃脾动脉和冠状动脉,犬隐静脉和胃脾静脉中,Ketanserin可剂量依赖性抑制5-羟色胺诱导的收缩反应。在大鼠心肌细胞中,Ketanserin使动作电位时程显著增加,复极可从50％达218％、90％达256％,且对其它动作电位参数无显著影响。Ketanserin抑制连接后α-肾上腺素能受体激活犬隐静脉和大鼠尾动脉的收缩。Ketanserin抑制灌注豚鼠胃血管对5-羟色胺的收缩反应,在某些实验中还可逆转该反应。Ketanserin以时间和浓度依赖性方式抑制Ito电荷区（EC50：8.3 μM）。Ketanserin还以剂量依赖性方式抑制Ito和持续电流（EC50：11.2 μM）,但不影响L型钙电流和内向整流钾电流。

Ketanserin is dissolved in DMSO to produce a stock solution of 100 mM. Ketanserin stock is diluted in experimental solutions to achieve the final concentrations[1]. The established HEK 293 cell line stably expressing hERG channels is cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% foetal bovine serum, 400 μg/mL G418. The HEK 293 cell line stably expressing recombinant human cardiac KCNQ1/KCNE1 channel current (IKs) is maintained in DMEM containing 10% foetal bovine serum and 100 μg/mL hygromycin. Cells used for electrophysiology are seeded on a glass coverslip. The mutant hERG channels are constructed, and are transiently expressed in HEK 293 cells using 10 μL of Lipofectamine 2000 with 4 μg of hERG mutant cDNA in pCDNA3 vector[1].