Angel F, Go V L, Szurszewski J H
J Physiol. 1984 Dec;357:93-108. doi: 10.1113/jphysiol.1984.sp015491.
The innervation of the muscularis mucosae of the canine large intestine was studied in vitro using superfusion and radioimmunological techniques. In the majority of preparations, electrical field stimulation (10 V, 200 microseconds, 10 Hz) elicited a biphasic neurogenic response which consisted of a contraction followed, after cessation of the stimulus, by relaxation. Electrical field stimulation released VIP-, substance P- and bombesin-like immunoreactivity. Release of these peptides and the biphasic response to nerve stimulation were blocked by tetrodotoxin and a 'calcium-free' solution. Several observations suggest that neuronally released substance P (or a closely related peptide) mediated the contraction by a direct action on the muscle. The contraction caused by substance P was tetrodotoxin insensitive. Desensitization to substance P abolished the excitatory response to nerve stimulation. The contraction elicited by nerve stimulation was blocked by substance P antiserum. Several observations suggest that bombesin or a closely related peptide caused contraction of the muscle by releasing substance P from intramural neurones. Bombesin caused an increase in substance P-like immunoreactivity in the superfusate which was blocked by tetrodotoxin, as was the contraction; substance P antibodies blocked the contractile response to bombesin. In addition, while the excitatory response to electrical nerve stimulation was blocked by substance P antiserum, there was still an increase in bombesin-like immunoreactivity in the superfusate. The data also suggest that VIP or a closely related peptide might have mediated the relaxation by a direct action on the muscle. The inhibitory response to nerve stimulation was mimicked by VIP and abolished by VIP antiserum.
利用灌流和放射免疫技术，在体外对犬大肠黏膜肌层的神经支配进行了研究。在大多数标本中，电场刺激（10V，200微秒，10Hz）引发双相神经源性反应，该反应包括一次收缩，刺激停止后接着是舒张。电场刺激释放血管活性肠肽（VIP）、P物质和蛙皮素样免疫反应性物质。这些肽的释放以及对神经刺激的双相反应被河豚毒素和“无钙”溶液阻断。多项观察结果表明，神经元释放的P物质（或一种密切相关的肽）通过直接作用于肌肉介导了收缩。P物质引起的收缩对河豚毒素不敏感。对P物质脱敏消除了对神经刺激的兴奋性反应。神经刺激引起的收缩被P物质抗血清阻断。多项观察结果表明，蛙皮素或一种密切相关的肽通过从壁内神经元释放P物质引起肌肉收缩。蛙皮素使灌流液中P物质样免疫反应性增加，这被河豚毒素阻断，收缩也被阻断；P物质抗体阻断了对蛙皮素的收缩反应。此外，虽然对电神经刺激的兴奋性反应被P物质抗血清阻断，但灌流液中蛙皮素样免疫反应性仍有增加。数据还表明，VIP或一种密切相关的肽可能通过直接作用于肌肉介导了舒张。对神经刺激的抑制性反应可被VIP模拟，并被VIP抗血清消除。
