Erdö F, Polgár K, Máté I, Székely J I
Institute for Drug Research, Budapest, Hungary.
Acta Physiol Hung. 1990;76(3):219-27.
The aim of the present work was to obtain some data on the eventual role of nucleus accumbens in the antidopamine action of some opioids. Classical neuroleptics are known to inhibit the dopamine-elicited hypermotility when injecting them into the nucleus accumbens of rats pretreated with MAO inhibitors. In the present study the effects of some opioids have been examined in this model. The opioids examined were morphine, a mu-selective classical opiate, D-Ala2, Nle5-enkephalin sulphonic acid (ES), a delta selective opioid peptide and D-Met2, Pro5-enkephalinamide (EA), a non-selective opioid peptide. Haloperidol and chlorpromazine have been used for comparison. EA and morphine, especially the former, potently antagonized the dopamine-induced hyperactivity, similarly to haloperidol and chlorpromazine. ES exerted biphasic effect, the initial inhibition was followed by potentiation of the dopamine-elicited excitation. Thus the order of potency was: EA greater than haloperidol approximately equal to morphine greater than chlorpromazine greater than EA. The data indicate that the antidopamine action of opioids might be mediated, at least in part, by mu-receptors in the nucleus accumbens.
本研究的目的是获取一些关于伏隔核在某些阿片类药物抗多巴胺作用中最终作用的数据。已知经典抗精神病药物在注射到用单胺氧化酶抑制剂预处理的大鼠伏隔核中时，会抑制多巴胺引起的运动亢进。在本研究中，已在该模型中检测了一些阿片类药物的作用。所检测的阿片类药物有吗啡（一种μ选择性经典阿片）、D - Ala2，Nle5 - 脑啡肽磺酸（ES，一种δ选择性阿片肽）和D - Met2，Pro5 - 脑啡肽酰胺（EA，一种非选择性阿片肽）。已使用氟哌啶醇和氯丙嗪作比较。EA和吗啡，尤其是前者，与氟哌啶醇和氯丙嗪类似，能有效拮抗多巴胺诱导的多动。ES产生双相作用，最初的抑制之后是多巴胺诱导兴奋的增强。因此效力顺序为：EA＞氟哌啶醇≈吗啡＞氯丙嗪＞ES。数据表明阿片类药物的抗多巴胺作用可能至少部分是由伏隔核中的μ受体介导的。
