Clarke R W, Harris J, Ford T W, Taylor J S
Department of Physiology and Environmental Science, University of Nottingham, School of Agriculture, Loughborough, Leicestershire.
Exp Physiol. 1991 Nov;76(6):987-90. doi: 10.1113/expphysiol.1991.sp003563.
Reflexes were evoked in the gastrocnemius medialis (GM) muscle nerve by selective electrical stimulation of the non-myelinated C fibres of the ipsilateral sural nerve of decerebrated, spinalized rabbits. The opioid antagonist (-)-quadazocine (555 micrograms/kg i.v.) enhanced responses to sural C fibre stimulation to an average of 236% of pre-drug levels. In addition, C fibre-evoked reflexes were depressed for 7-9 min after repetitive activation of the high threshold axons of the common peroneal nerve, and this effect was reversed after quadazocine. Thus, GM responses to stimulation of non-myelinated sural afferent fibres are suppressed by endogenous opioid peptides, but the degree of inhibition does not appear to be as profound as that previously reported for reflexes evoked by myelinated fibres.
通过对去大脑、脊髓横断的兔同侧腓肠神经的无髓鞘C纤维进行选择性电刺激，在内侧腓肠肌（GM）神经中诱发反射。阿片类拮抗剂（-）-夸达佐辛（555微克/千克静脉注射）使对腓肠C纤维刺激的反应增强至药物前水平的平均236%。此外，在反复激活腓总神经的高阈值轴突后，C纤维诱发的反射被抑制7 - 9分钟，而这种效应在夸达佐辛作用后被逆转。因此，GM对无髓鞘腓肠传入纤维刺激的反应受到内源性阿片肽的抑制，但抑制程度似乎不如先前报道的有髓鞘纤维诱发反射的抑制程度那么深。
