Cox M R, Padbury R T, Harvey J R, Baker R A, Toouli J, Saccone G T
Department of Surgery, Flinders University, Flinders Medical Centre, Adelaide, Australia.
Neurogastroenterol Motil. 1998 Apr;10(2):165-73. doi: 10.1046/j.1365-2982.1998.00090.x.
Substance P containing nerves are widely distributed throughout the gastrointestinal tract. The aims of this study were to determine the distribution of substance P containing nerves in the extrahepatic biliary tree of the Australian brush-tailed possum and to characterize the effect of exogenous substance P on the sphincter of Oddi (SO) motility and transphincteric flow in vivo. Immunohistochemical staining of fixed specimens (n = 8) found moderate numbers of substance P containing nerve cell bodies and fibres throughout the neural plexuses of the SO, in particular in the serosal and intraluminal nerve trunks of the SO and gallbladder. Synthetic porcine substance P (1-2000 ng kg-1), administered by close intra-arterial injection (i.a.; n = 7), produced a dose-dependent elevation in basal pressure [P < 0.01] and an associated dose-dependent reduction in trans-sphincteric flow [P < 0.0001]. Substance P had no significant dose-dependent effect on SO phasic contraction amplitude or frequency. Tetrodotoxin (9 micrograms kg-1, i.a.) did not inhibit the effect of substance P on SO motility and trans-sphincteric flow (n = 5). In conclusion, substance P containing nerves are found throughout the possum extrahepatic biliary tree. Exogenous substance P stimulates SO motility and reduces trans-sphincteric flow in vivo by acting directly on the sphincter smooth muscle.
含P物质的神经广泛分布于整个胃肠道。本研究的目的是确定澳大利亚刷尾负鼠肝外胆管树中含P物质的神经分布，并在体内表征外源性P物质对Oddi括约肌（SO）运动性和经括约肌流量的影响。对固定标本（n = 8）进行免疫组织化学染色发现，在SO的神经丛中，特别是在SO和胆囊的浆膜下和腔内神经干中，有中等数量的含P物质的神经细胞体和纤维。通过动脉内近距离注射（i.a.；n = 7）给予合成猪P物质（1 - 2000 ng kg-1），可使基础压力呈剂量依赖性升高[P < 0.01]，并使经括约肌流量呈相关的剂量依赖性降低[P < 0.0001]。P物质对SO的相性收缩幅度或频率无显著的剂量依赖性影响。河豚毒素（9微克 kg-1，i.a.）不抑制P物质对SO运动性和经括约肌流量的作用（n = 5）。总之，在负鼠肝外胆管树中均发现了含P物质的神经。外源性P物质通过直接作用于括约肌平滑肌来刺激SO的运动性并降低体内的经括约肌流量。
