Sacerdote P, Mantegazza P, Panerai A E
Brain Res. 1985 Dec 16;359(1-2):34-8. doi: 10.1016/0006-8993(85)91409-x.
Three antagonists at the mu opiate receptor site: naloxone, naltrexone and diprenorphine, and one agonist-antagonist compound nalorphine, at doses usually not analgesic elicited analgesia in rats when administered after non-naloxone-reversible shock-induced analgesia had disappeared. The chi receptor antagonist, MR 2266, and the delta antagonist, ICI 154129, were all ineffective. This effect was no longer present when non-naloxone-reversible shock-induced analgesia was inhibited by the administration of the chi receptor antagonist, MR 2266. These results suggest that the mu opiate receptor may change its conformation under particular conditions such as continuous inescapable shock.
三种μ阿片受体位点拮抗剂：纳洛酮、纳曲酮和二丙诺啡，以及一种激动剂 - 拮抗剂化合物烯丙吗啡，在非纳洛酮可逆性休克诱导的镇痛作用消失后给药时，通常无镇痛作用的剂量在大鼠中引发了镇痛作用。κ受体拮抗剂MR 2266和δ拮抗剂ICI 154129均无效。当通过给予κ受体拮抗剂MR 2266抑制非纳洛酮可逆性休克诱导的镇痛作用时，这种效应不再出现。这些结果表明，μ阿片受体可能在特定条件下（如持续不可逃避的休克）改变其构象。
