Heimans R L
Arch Int Pharmacodyn Ther. 1975 May;215(1):13-9.
The sensitivity of the isolated, electrically stimulated guinea-pig ileum to acetylcholine aan physostigmein was found not to be reduced during 'dependence' or 'withdrawal' responses to morphine. There was no evidence that exaggerated release of acetylcholine occurred following withdrawal of high concentrations of morphine from 'dependent' longitudinal muscle strips incubated with 14C-choline. These data cast doubt on the hypothesis put forward by Paton in 1963to explain the development of 'tolerance' and 'dependence' to morphine in the ileum. The potency of morphine in producing responses of the ileum was reduced in the presence of raised concentrations of calcium, indicating that the effect of morphine may be mediated via a calcium-sensitive step.
实验发现，对吗啡产生“依赖”或“戒断”反应期间，分离出的经电刺激的豚鼠回肠对乙酰胆碱和毒扁豆碱的敏感性并未降低。没有证据表明，在用14C-胆碱孵育的“依赖”纵向肌条中，高浓度吗啡撤药后会出现乙酰胆碱的过度释放。这些数据对帕顿于1963年提出的用以解释回肠对吗啡产生“耐受性”和“依赖性”的假说提出了质疑。在钙浓度升高的情况下，吗啡引起回肠反应的效力降低，这表明吗啡的作用可能是通过一个钙敏感步骤介导的。
