Shoham S, Weinstock M
Br J Pharmacol. 1974 Dec;52(4):597-603. doi: 10.1111/j.1476-5381.1974.tb09729.x.
1 Morphine caused a dose-dependent reduction in both the height of contraction and acetylcholine release from coaxially stimulated strips of guinea-pig ileum.2 Exposure of the tissue to morphine for 90 min produced acute tolerance to the effect of subsequent doses of morphine on contraction height.3 There was no change in the ability of morphine to suppress acetylcholine release.4 The responses of morphine-tolerant ileum to exogenous acetylcholine were enhanced 3 to 10-fold.5 If the ileum did not show tolerance to morphine it did not become more sensitive to acetylcholine.6 The results presented suggest that tolerance to morphine could result from a form of disuse supersensitivity.
吗啡使豚鼠回肠同轴刺激条的收缩高度和乙酰胆碱释放呈剂量依赖性降低。
将组织暴露于吗啡90分钟可产生对后续剂量吗啡对收缩高度影响的急性耐受性。
吗啡抑制乙酰胆碱释放的能力没有变化。
对吗啡耐受的回肠对外源性乙酰胆碱的反应增强了3至10倍。
如果回肠对吗啡未表现出耐受性,它对外源性乙酰胆碱就不会变得更敏感。
所呈现的结果表明,对吗啡的耐受性可能源于一种废用性超敏反应。