Phenoxybenzamine hydrochloride (NCI-c01661) is the hydrochloride salt form of phenoxybenzamine, a synthetic, dibenzamine alpha-adrenergic antagonist with antihypertensive and vasodilatory properties. Phenoxybenzamine non-selectively and irreversibly blocks the postsynaptic alpha-adrenergic receptor in smooth muscle, thereby preventing vasoconstriction, relieving vasospasms, and decreasing peripheral resistance. Reflex tachycardia may occur and may be enhanced by blockade of alpha-2 receptors which enhances norepinephrine release. Phenoxybenzamine is reasonably anticipated to be a human carcinogen.

Phenoxybenzamine hydrochloride对[3H]yohimbine结合的阻断所导出的IC50（100 nM）明显低于其对Noradrenaline 引起的环磷酸腺苷（cyclic AMP）积累效应的逆转IC50（550 nM）[1]。Phenoxybenzamine hydrochloride（50 nM）与Phenoxybenzamine hydrochloridetolamine（1000 nM）联合使用比单独使用Phenoxybenzamine hydrochloride（50 nM）时更能增强Phenoxybenzamine hydrochlorideylephrine诱导的血管收缩，这一效果在完整内皮的主动脉中同样观察到。无论是dexmedetomidine（300或1000 nM）与Phenoxybenzamine hydrochloride（50 nM）的联合使用，还是Phenoxybenzamine hydrochloridetolamine（1000 nM）与Phenoxybenzamine hydrochloride（50 nM）的联合处理，相比单独使用Phenoxybenzamine hydrochloride（50 nM），都能增强Phenoxybenzamine hydrochlorideylephrine引发的收缩反应。此外，与dexmedetomidine（1000 nM）和Phenoxybenzamine hydrochloride的联合使用相比，Phenoxybenzamine hydrochloridetolamine与Phenoxybenzamine hydrochloride的联合使用在增强Phenoxybenzamine hydrochlorideylephrine引起的收缩方面更为显著。高浓度dexmedetomidine（1000 nM）与Phenoxybenzamine hydrochloride的联合使用，比低浓度dexmedetomidine（300 nM）与Phenoxybenzamine hydrochloride的联合使用，更能增强Phenoxybenzamine hydrochlorideylephrine诱发的收缩作用[2]。

Phenoxybenzamine hydrochloride（20 nM，皮下注射）有效抑制了小鼠中胶质瘤细胞的肿瘤生成，且Phenoxybenzamine hydrochloride-U87 mg移植瘤的细胞密度显著下降[3]。以Phenoxybenzamine hydrochloride（1 mg/kg，静脉注射）处理的大鼠在神经症状打分（NSS）和足失误评分方面显示出显著改善[4]。

Phenoxybenzamine hydrochloride is dissolved in DMSO. After cytometry, 1×3 cells are implanted in a 96-well plate in 100 μL DMEM supplemented with 10 % FBS. Ten microliter (10 % of the total volume) WST-1 (Water Soluble Tetrazolium) is added to cells and incubated at 37°C for 30 min before colorimetric assay with 450 nm excitation and 630 nm emission at 24 h intervals up to 96 h. The mean fluorescence value is counted, and the cell number is determined using the standard curve.