Moises H C, Smith C B
Brain Res. 1987 Jan 1;400(1):110-26. doi: 10.1016/0006-8993(87)90658-5.
Radioligand binding experiments were carried out in conjunction with electrophysiological recordings in vivo in the parietal cortex in rats to assess changes in postsynaptic beta-adrenergic receptor function that result after chronic administration of morphine and during morphine withdrawal. Chronic treatment of rats with morphine for 14 days resulted in a 38% increase in the density of beta-adrenergic receptors in the parietal cortex, as measured by the binding of the specific antagonist [3H]dihydroalprenolol (DHA). In comparison, following withdrawal in the chronic morphine-treated animals, the number of specific [3H]DHA binding sites in this same cortical region was decreased 25%, when compared to saline-treated controls. These alterations in cortical beta-adrenergic receptor density were not accompanied by a significant change in the dissociation constant (Kd) for [3H]DHA or in the inhibitory constants (Ki) for the specific agonists norepinephrine and isoproterenol. Microiontophoretic testing revealed that the changes in beta-adrenergic receptor density found in parietal cortex after chronic morphine treatment and during morphine withdrawal were accompanied by a selective increase and decrease, respectively, in the sensitivity of cerebrocortical neurons in the same region to beta-adrenergic stimulation. These results suggest that changes in central adrenergic function might be related to the formation and/or expression of dependence on morphine.
在大鼠顶叶皮质进行体内电生理记录的同时，进行放射性配体结合实验，以评估慢性给予吗啡后及吗啡戒断期间突触后β - 肾上腺素能受体功能的变化。用吗啡对大鼠进行14天的慢性治疗后，通过特异性拮抗剂[³H]二氢阿普洛尔（DHA）的结合测定，顶叶皮质中β - 肾上腺素能受体的密度增加了38%。相比之下，在慢性吗啡治疗的动物戒断后，与生理盐水处理的对照组相比，同一皮质区域中特异性[³H]DHA结合位点的数量减少了25%。皮质β - 肾上腺素能受体密度的这些改变并未伴随着[³H]DHA的解离常数（Kd）或特异性激动剂去甲肾上腺素和异丙肾上腺素的抑制常数（Ki）的显著变化。微离子电泳测试显示，慢性吗啡治疗后及吗啡戒断期间在顶叶皮质发现的β - 肾上腺素能受体密度的变化，分别伴随着同一区域脑皮质神经元对β - 肾上腺素能刺激的敏感性选择性增加和降低。这些结果表明，中枢肾上腺素能功能的变化可能与对吗啡的依赖性形成和/或表达有关。
