Abalo R, Pascual D, Goicoechea C, Martín M I
Departmento Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, 28040, Madrid, Spain.
Neurosci Lett. 2000 Sep 22;291(3):131-4. doi: 10.1016/s0304-3940(00)01355-0.
The aim of the present study was to analyse the correlation between functional and electrophysiological effects of the opioids in guinea pig ileum. Preparations of guinea pig ileum myenteric plexus-longitudinal muscle strips were used to compare the effect of two opioids, morphine (a mu-agonist) and U-50,488H (a kappa-agonist) on the electrically-induced contractile response and the excitatory postsynaptic potentials exhibited by the myenteric neurones when the internodal strands are electrically stimulated. Both opioids dose-dependently inhibited the contractile responses and the fast excitatory postsynaptic potentials (fEPSPs) in S neurones but did not modify the amplitude of the slow postsynaptic potentials. Pertussis toxin pretreatment was able to antagonise the effects of both morphine and U-50,448H. From our results it can be suggested that the effect of the opioids on guinea pig ileum involves the inhibition of neuronal fEPSPs.
本研究的目的是分析阿片类药物对豚鼠回肠的功能和电生理效应之间的相关性。使用豚鼠回肠肌间神经丛-纵行肌条制备物，比较两种阿片类药物，吗啡（一种μ激动剂）和U-50,488H（一种κ激动剂）对电刺激节间束时肌间神经元表现出的电诱导收缩反应和兴奋性突触后电位的影响。两种阿片类药物均剂量依赖性地抑制S神经元的收缩反应和快速兴奋性突触后电位（fEPSP），但不改变慢突触后电位的幅度。百日咳毒素预处理能够拮抗吗啡和U-50,448H的作用。从我们的结果可以推测，阿片类药物对豚鼠回肠的作用涉及对神经元fEPSP的抑制。
