Magnuson D S, Sullivan A F, Simonnet G, Roques B P, Dickenson A H
Department of Pharmacology, University College, London.
Neuropeptides. 1990 Aug;16(4):213-8. doi: 10.1016/0143-4179(90)90065-7.
An in vivo preparation of the rat spinal cord was used to investigate the electrophysiological actions of two non-opioid peptides, cholecystokinin (CCK8) and FLFQPQRF-NH2 (FMRFamide-like peptide) applied intrathecally. These compounds were examined alone and as a pretreatment before DAGO, a mu opioid agonist, and DSTBULET, a delta opioid agonist, both which selectively reduce C-fibre evoked dorsal horn neurone activity elicited by transcutaneous electrical stimulation. Given alone, CCK8 (1 microgram) elicited a modest enhancement of C-fibre induced activity which returned to control levels after 20 min, while FLFQPQRF-NH2 (10 micrograms) had no significant effect on C-fibre evoked firing. As a pretreatment, however, both peptides selectively prevented the inhibition of C-fibre evoked activity normally resulting from intrathecal DAGO, while having no effect on that resulting from DSTBULET. Further, CCK8 enhanced the facilitation of C-fibre evoked firing normally observed with low doses of DAGO. These data indicate that the anti-opioid roles suggested for CCK8 and FLFQPQRF-NH2 may be specific for neural elements utilizing the mu opioid receptor.
采用大鼠脊髓的体内制备方法，研究鞘内注射两种非阿片肽——胆囊收缩素（CCK8）和FLFQPQRF-NH2（FMRF酰胺样肽）的电生理作用。单独检测这些化合物，并在给予μ阿片受体激动剂DAGO和δ阿片受体激动剂DSTBULET之前进行预处理，这两种激动剂均能选择性降低经皮电刺激诱发的C纤维引起的背角神经元活动。单独给予时，CCK8（1微克）引起C纤维诱导活动适度增强，20分钟后恢复至对照水平，而FLFQPQRF-NH2（10微克）对C纤维诱发的放电无显著影响。然而，作为预处理，两种肽均能选择性地阻止鞘内注射DAGO通常引起的C纤维诱发活动的抑制，而对DSTBULET引起的抑制无影响。此外，CCK8增强了低剂量DAGO通常观察到的C纤维诱发放电的易化作用。这些数据表明，CCK8和FLFQPQRF-NH2所提示的抗阿片作用可能对利用μ阿片受体的神经元元件具有特异性。
