Barbaccia M L, Reggiani A, Spano P F, Trabucchi M
Pharmacol Biochem Behav. 1980;13 Suppl 1:303-6. doi: 10.1016/s0091-3057(80)80046-3.
Different behavioral and biochemical data suggest that ethanol has different effects on central dopaminergic transmission in rat and mouse. We found that ethanol induces an increase of striatal dopamine turnover which does not persist after chronic drinking. Following chronic ethanol treatment, we observed the development of supersensitivity of the striatal dopamine (DA) recognition sites, in terms of an enhanced affinity. We investigated various experimental models to clarify the existence of an enkephalinergic modulation of ethanol effects on the dopaminergic system. We found that in the rat, a pretreatment with naloxone abolishes the striatal DA turnover increase observed after ethanol. DBA 2J mice, which differ from C57 BL/6J and Swiss Albino, by genetically lacking enkephalinergic modulation on dopaminergic activity in the striatum, do not show any change of DA metabolism after acute ethanol. In the rat retina, where we hypothesized a less operant regulation of dopaminergic activity by enkephalins, tolerance does not develop after chronic drinking to the increase in DA turnover as it did in striatum. Our results confirm the importance of the endogenous opioid system in the regulation of the ethanol induced neurochemical and behavioral effects.
不同的行为学和生物化学数据表明，乙醇对大鼠和小鼠的中枢多巴胺能传递有不同影响。我们发现，乙醇会导致纹状体多巴胺周转率增加，但长期饮酒后这种增加不会持续。经过长期乙醇处理后，我们观察到纹状体多巴胺（DA）识别位点出现超敏反应，表现为亲和力增强。我们研究了各种实验模型，以阐明脑啡肽能对乙醇作用于多巴胺能系统的调节作用是否存在。我们发现，在大鼠中，用纳洛酮预处理可消除乙醇后观察到的纹状体DA周转率增加。DBA 2J小鼠与C57 BL/6J和瑞士白化小鼠不同，其纹状体中多巴胺能活性缺乏脑啡肽能调节，急性乙醇处理后DA代谢无任何变化。在大鼠视网膜中，我们推测脑啡肽对多巴胺能活性的调节作用较小，长期饮酒后不会像在纹状体中那样对DA周转率的增加产生耐受性。我们的结果证实了内源性阿片系统在调节乙醇诱导的神经化学和行为效应中的重要性。
