Moya-Huff F A, Maher T J
J Pharm Pharmacol. 1987 Feb;39(2):108-12. doi: 10.1111/j.2042-7158.1987.tb06954.x.
The ability of (+/-)-norephedrine (phenylpropanolamine) and its component isomers, (+)-and (-)-norephedrine, to activate adrenergic receptor subtypes in the cardiovascular system of the urethane/chloralose-anaesthetized pithed rat has been investigated. At all adrenoceptor subtypes, (-)-norephedrine was the most potent agonist followed by (+/-)- then (+)-norephedrine. The greatest activity was observed at the alpha 1-receptor, with little activity observed at either beta 1 or beta 2-adrenoceptors. Reserpinization shifted the (-)-norephedrine dose-response curve slightly to the right, indicating that only a minor portion of its activity is due to the release of stored endogenous catecholamines. These results suggest that most of the cardiovascular activity of the compounds is through the direct activation of alpha 1-adrenoceptors.
研究了（±）-去甲麻黄碱（苯丙醇胺）及其异构体（+）-和（-）-去甲麻黄碱在乌拉坦/氯醛糖麻醉的脊髓切断大鼠心血管系统中激活肾上腺素能受体亚型的能力。在所有肾上腺素能受体亚型中，（-）-去甲麻黄碱是最有效的激动剂，其次是（±）-去甲麻黄碱，然后是（+）-去甲麻黄碱。在α1受体上观察到最大活性，在β1或β2肾上腺素能受体上几乎没有活性。利血平化使（-）-去甲麻黄碱的剂量反应曲线略向右移，表明其活性只有一小部分是由于储存的内源性儿茶酚胺的释放。这些结果表明，这些化合物的大部分心血管活性是通过直接激活α1肾上腺素能受体实现的。
