Matheny J L, Carrier G O, Ahlquist R P
J Pharm Sci. 1977 Jan;66(1):93-5. doi: 10.1002/jps.2600660123.
The roles of neuronal and extraneuronal uptake mechanisms in the response of iris dilator muscles of rabbit to levarterenol (norepinephrine) and phenylephrine were investigated. Chemical denervation with 6-hydroxydopamine was used to eliminate neuronal uptake. Exposure to corticosterone prior to and during exposure to levarterenol or phenylephrine was used to assess the importance of extraneuronal uptake. Dose-response curves and ED50 values for levarterenol or phenylephrine in control and 6-hydroxydopamine-denervated tissues, both in the presence and absence of corticosterone, are shown. Curves illustrating the decay of tension on washout of levarterenol or phenylephrine from treated tissues were analyzed. 6-Hydroxydopamine denervation affected the response to levarterenol more than that to phenylephrine. Washout of both agonists was slower after 6-hydroxydopamine pretreatment, and washout of phenylephrine was more rapid when corticosterone was present. These data indicate that extraneuronal uptake in iris dilator muscles was more important in determining the response to phenylephrine than to levarterenol and that neuronal uptake was more important in determining tissue responsiveness to levarterenol than to phenylephrine.
研究了神经元摄取机制和非神经元摄取机制在兔虹膜开大肌对去甲肾上腺素（去甲肾上腺素）和苯肾上腺素反应中的作用。使用6-羟基多巴胺进行化学去神经支配以消除神经元摄取。在暴露于去甲肾上腺素或苯肾上腺素之前和期间暴露于皮质酮，以评估非神经元摄取的重要性。显示了在存在和不存在皮质酮的情况下，对照组织和6-羟基多巴胺去神经支配组织中去甲肾上腺素或苯肾上腺素的剂量-反应曲线和ED50值。分析了说明从处理过的组织中洗脱出肾上腺素或苯肾上腺素后张力衰减的曲线。6-羟基多巴胺去神经支配对去甲肾上腺素反应的影响比对苯肾上腺素的影响更大。6-羟基多巴胺预处理后，两种激动剂的洗脱都较慢，并且当存在皮质酮时，苯肾上腺素的洗脱更快。这些数据表明，虹膜开大肌中的非神经元摄取在决定对苯肾上腺素的反应中比去甲肾上腺素更重要，并且神经元摄取在决定组织对去甲肾上腺素的反应性方面比苯肾上腺素更重要。
