Naftopidil dihydrochloride (KT-611 2HCl) is a selective 5-HT1A and α1-adrenergic receptor antagonist with IC50 of 0.1 μM and 0.2 μM, respectively.

5-HT1A:0.1 μM, α1-adrenoceptor:0.2 μM

Naftopidil diHCl不仅具有5-HT1A激动剂性质，还是α1-肾上腺素受体拮抗剂。[1] Naftopidil对雄激素敏感和不敏感的人类前列腺癌细胞系具有生长抑制作用，其对雄激素敏感的LNCaP细胞和雄激素不敏感的PC-3细胞的IC50分别为22.2 μM和33.2 μM。Naftopidil通过使细胞周期停滞在G1期来抑制细胞生长。在Naftopidil处理的LNCaP细胞中，p27kip1和p21cip1的表达显著增加。在PC-3细胞中，Naftopidil诱导p21cip1的表达，但不是p27kip1。[2] Naftopidil对胶原诱导的Ca2+动员产生浓度依赖性抑制，用40 μM Naftopidil可以达到最大抑制率(22.9%)。Naftopidil对肾上腺素诱导的[Ca2+]i上升有剂量依赖性抑制作用。[3] Naftopidil在缓解夜尿方面明显优于他索辛。[4] Naftopidil在PCa细胞和PrSC中都诱导G(1)期细胞周期阻滞。在经Naftopidil处理的PrSC中，总白细胞介素-6蛋白显著减少，并伴随细胞增殖抑制增加。[5]

向裸鼠口服给予Naftopidil可抑制PC-3肿瘤生长，与对照组的车用处理相比有显著差异。Naftopidil通过抑制传入神经活动，提高膀胱容量并促进松弛性排尿。[2] Naftopidil（0.1 μg–30 μg）能暂时消除等容膀胱节律性收缩，通过鞘内注射Naftopidil（3 μg–30 μg），膀胱收缩幅度减小。[6] 在麻醉犬模型中，Naftopidil选择性抑制苯肾上腺素引起的前列腺压力增加，与平均血压相比有显著差异。[7]

Cell cycle analysis is performed by flow cytometry. Cells are treated with either 20 μM Naftopidil (LNCaP), 40 μM Naftopidil (PC-3) or vehicle (0.1% DMSO) for 24 hours, then trypsinized and washed once with phosphate-buffer saline (PBS), fixed in 70% ethanol and stored at 4 °C for subsequent cell cycle analysis. Fixed cells are washed with PBS and incubated with PBS containing 20 μg/mL RNaseA and 0.3% NP-40 for 30 minutes at 37 °C, then stained with 50 μg/mL propidium iodide (PI) for 30 minutes at 4 癈 in the dark. The DNA content of 1 ?106 stained cells is analyzed on a FACS Caliburflow cytometer. The fractions of cells in the G0/G1, S and G2/M phases are calculated using Cell Quest software.(Only for Reference)