Bläsig J, Gramsch C, Laschka E, Herz A
Arzneimittelforschung. 1976;26(6):1104-6.
The role of dopamine (DA) in precipitated withdrawal jumping was studied in morphine dependent rats. Pretreatment with various dopaminergic agonists induced a dose-dependent increase in naloxone induced jumping. Pimocide totally blocked the facilitatory effect of piribedil while naloxone induced jumping was not dose-dependently decreased. Biochemical measurements revealed that during precipitated withdrawal the level of DA was elevated and the accumulation of 3,4-dihydroxy-phenylacetic acid (DOPAC) and homovanillic acid (HVA) after probenecid as well as the level of 3-methoxytyramine in the striatum was reduced. Unilateral inactivation of the caudate by local injection of KCl induced contralateral circling during withdrawal. Additional systemic haloperidol pretreatment did not change the direction of circling while additional apomorphine pretreatment changed the direction to ipsilateral and increased the circling rate highly. These latter as well as the biochemical findings strongly suggest an inhibition of striatal DA-mechanisms during withdrawal. The apparent contradiction of these findings to the above finding showing a facilitatroy role of DA-agonists on jumping is discussed.
在吗啡依赖大鼠中研究了多巴胺（DA）在诱发戒断性跳跃中的作用。用各种多巴胺能激动剂预处理可导致纳洛酮诱发的跳跃呈剂量依赖性增加。匹莫齐特完全阻断了piribedil的促进作用，而纳洛酮诱发的跳跃并未呈剂量依赖性降低。生化测量显示，在诱发戒断期间，DA水平升高，丙磺舒处理后纹状体内3,4-二羟基苯乙酸（DOPAC）和高香草酸（HVA）的积累以及3-甲氧基酪胺水平降低。通过局部注射氯化钾使尾状核单侧失活会在戒断期间诱发对侧转圈。额外的全身性氟哌啶醇预处理并未改变转圈方向，而额外的阿扑吗啡预处理则使转圈方向变为同侧，并显著提高了转圈速率。这些结果以及生化发现强烈表明在戒断期间纹状体DA机制受到抑制。讨论了这些发现与上述显示DA激动剂对跳跃有促进作用的发现之间明显的矛盾。
