Evidence that substance P does not mediate slow synaptic excitation within the myenteric plexus
Evidence that substance P does not mediate slow synaptic excitation within the myenteric plexus
复制标题
有证据表明 P 物质不会介导肌间神经丛内的缓慢突触兴奋
作者：
P. Grafe;C. Mayer;J. Wood
在豚鼠小肠中，对所谓的AH1或II2型肌肠神经元的突触前纤维进行电刺激可引起缓慢的兴奋性突触后电位（e.p.s.p），其特征是与膜阻力增加和兴奋性增强相关的持久去极化3。有两种物质被认为可能是慢速e.p.s.p.的神经递质。Katayama和North报告说，将P物质应用于myenteric神经元模仿慢速e.p.s.p.4， J.D.W.和C.J.M.提出了几条证据，证明血清素是递质物质5,6。我们现在报道甲基塞吉特，一种既能消除慢速e.p.s.p又能消除外源性血清素5,6作用的药物，不影响P物质对豚鼠myenteric神经元的作用。结果表明，P物质不可能是介导慢速e.p.s.p的神经递质。
ELECTRICAL stimulation of presynaptic fibres to the so-called AH1 or type II2 myenteric neurones in guinea pig small intestine evokes a slow excitatory postsynaptic potential (e.p.s.p.) characterised by long-lasting depolarisation associated with increased membrane resistance and augmented excitability3. Two substances have been implicated as possible neurotrans-mitters for the slow e.p.s.p. Katayama and North reported that application of substance P to myenteric neurones mimicked the slow e.p.s.p.4, and J.D.W. and C.J.M. presented several lines of evidence for serotonin as the transmitter substance5,6. We now report that methysergide, a drug which abolishes both the slow e.p.s.p. and the action of exogenous serotonin5,6, does not affect the action of substance P on guinea pig myenteric neurones. The results suggest that substance P is unlikely to be the neuro-transmitter which mediates the slow e.p.s.p.