目的:速激肽对胃肠道的收缩作用是众所周知的,但是它们如何调制慢波,特别是在能够呕吐的物种中,仍然很大程度上未知。我们旨在阐明速激肽对Suncusmurinus分离的胃肠道组织的肌电和收缩活动的影响。
方法:P物质(SP)的影响,神经激肽(NK)A,NKB和选择性NK1(CP122,721,CP99,994),NK2(SR48,968,GR159,897)和NK3(SB218,795,SB222,200)受体拮抗剂对离体胃,十二指肠,研究了回肠和结肠段。使用等距力位移传感器记录机械收缩活动。使用微电极阵列记录电起搏器活动。
结果:与NKA相比,SP在胃组织中引起较大的收缩,在肠段中引起较小的收缩,在肠段振荡幅度增加的地方,但不是胃。CP122,721和GR159,897抑制了电场刺激引起的胃收缩,回肠和结肠.NKB和NK3对收缩活动影响较小。SP和NKA对结肠和回肠蠕动频率的抑制作用,分别,与电起搏器频率相关。SP,NKA和NKB抑制十二指肠和回肠的起搏器活动,但增加了胃和结肠。SP在结肠中引起剂量依赖性的矛盾的起搏器频率响应。
结论:这项研究揭示了速激肽对胃和结肠的机械和电特性的明显影响。近端肠,就速激肽对胃肠相关症状的蠕动和起搏器活动的影响而言,提供了神经肌肉相关性的独特方面。
OBJECTIVE: The contractile effects of tachykinins on the gastrointestinal tract are well-known, but how they modulate slow-waves, particularly in species capable of emesis, remains largely unknown. We aimed to elucidate the effects of tachykinins on myoelectric and contractile activity of isolated gastrointestinal tissues of the Suncus murinus.
METHODS: The effects of substance P (SP), neurokinin (NK)A, NKB and selective NK1 (CP122,721, CP99,994), NK2 (SR48,968, GR159,897) and NK3 (SB218,795, SB222,200) receptor antagonists on isolated stomach, duodenum, ileum and colon segments were studied. Mechanical contractile activity was recorded using isometric force displacement transducers. Electrical pacemaker activity was recorded using a microelectrode array.
RESULTS: Compared with NKA, SP induced larger contractions in stomach tissue and smaller contractions in intestinal segments, where oscillation magnitudes increased in intestinal segments, but not the stomach. CP122,721 and GR159,897 inhibited electrical field stimulation-induced contractions of the stomach, ileum and colon. NKB and NK3 had minor effects on contractile activity. The inhibitory potencies of SP and NKA on the peristaltic frequency of the colon and ileum, respectively, were correlated with those on electrical pacemaker frequency. SP, NKA and NKB inhibited pacemaker activity of the duodenum and ileum, but increased that of the stomach and colon. SP elicited a dose-dependent contradictive pacemaker frequency response in the colon.
CONCLUSIONS: This study revealed distinct effects of tachykinins on the mechanical and electrical properties of the stomach and colon vs. the proximal intestine, providing a unique aspect on neuromuscular correlation in terms of the effects of tachykinin on peristaltic and pacemaker activity in gastrointestinal-related symptoms.