Silva Carvalho L, Silva Carvalho J, Moniz de Bettencourt J M
C R Seances Soc Biol Fil. 1981;175(6):913-5.
Acetylcholine was injected into the common carotid artery of 15 mongrel dogs. In the animals with tied internal carotid artery, hyperpnoea, bradycardia and hypotension was observed, and in the animals with free internal carotid artery the hyperphoea was followed by apnoea. The administration of phentolamine provokes a temporary decrease or abolition of the reflexes produced by acetylcholine. This action of the alpha-blocker is due to a local effect because when phentolamine is injected intravenously it does not happen and the reflexes produced by acetylcholine with starting place at the carotid sinus of the opposite side are not affected.
将乙酰胆碱注入15只杂种狗的颈总动脉。在结扎颈内动脉的动物中，观察到呼吸急促、心动过缓和低血压，而在颈内动脉未结扎的动物中，呼吸急促后出现呼吸暂停。给予酚妥拉明会引起乙酰胆碱产生的反射暂时减弱或消失。α受体阻滞剂的这种作用是由于局部效应，因为静脉注射酚妥拉明时不会出现这种情况，且起源于对侧颈动脉窦的乙酰胆碱产生的反射不受影响。
