Das S, Matwyshyn G A, Bhargava H N
Neuropeptides. 1984 Dec;5(1-3):45-8. doi: 10.1016/0143-4179(84)90023-4.
Chronic morphine treatment (subcutaneous pellet implantation of four morphine pellets) caused significant tolerance to morphine analgesia as observed at zero and 6 hrs. after pellet removal. However, such treatment failed to elicit any changes in striatal muscarinic receptors using (3H)-QNB binding studies. At 24 hours after pellet removal there was significant development of physical dependence but the affinity (Kd) as well as density (Bmax) of striatal muscarinic receptors remained unaffected. Although naloxone caused marked precipitation of abrupt withdrawal in morphine tolerant rats, it also failed to produce any changes in striatal muscarinic receptors. Results indicate that any cholinergic involvement in opiate tolerance and physical dependence does not involve an effect on muscarinic receptors.
慢性吗啡处理（皮下植入四粒吗啡微丸）导致对吗啡镇痛产生显著耐受性，这在取出微丸后0小时和6小时时可以观察到。然而，使用（3H）-QNB结合研究发现，这种处理未能引起纹状体毒蕈碱受体的任何变化。取出微丸24小时后出现了明显的身体依赖性，但纹状体毒蕈碱受体的亲和力（Kd）以及密度（Bmax）仍未受影响。尽管纳洛酮在吗啡耐受大鼠中引起明显的戒断症状突然发作，但它也未能使纹状体毒蕈碱受体产生任何变化。结果表明，任何胆碱能参与阿片类药物耐受性和身体依赖性的过程均不涉及对毒蕈碱受体的影响。
