Osborne P, Campbell G
Naunyn Schmiedebergs Arch Pharmacol. 1986 Oct;334(2):210-7. doi: 10.1007/BF00505824.
A study was made of the innervation of the longitudinal muscle of the toad ileum with particular emphasis on the splanchnic innervation by non-adrenergic, non-cholinergic (NANC) nerves. Nerve fibres containing substance P-like immunoreactivity (SP-LI) were observed in the gut wall and in the ileal wall after degenerative section of the splanchnic nerves. Incubation overnight in a high concentration of capsaicin (3 X 10(-4) M) caused degeneration of SP-LI fibres. No evidence was obtained for enteric neurons containing SP-LI. Substance P caused a contraction of the longitudinal muscle similar to that produced by nerve stimulation. The response to nerve stimulation was decreased by about 60% by treatment with alpha-chymotrypsin. Capsaicin normally evoked a contraction of the longitudinal muscle, but did not do so after degenerative section of the splanchnic nerves. Prolonged treatments with high concentrations of capsaicin (5 X 10(-5) M) abolished the excitatory response to nerve stimulation. The results suggest that substance P is the transmitter mediating the NANC contraction. The fibres releasing the transmitter are possibly antidromically activated, sensory afferents. Both transmural stimulation and capsaicin caused a NANC inhibition of longitudinal muscle. Stimulation of perivascular nerves after splanchnic nerve section caused a NANC excitation, as did transmural stimulation even after nerve section or capsaicin treatment.
对蟾蜍回肠纵行肌的神经支配进行了研究，特别着重于非肾上腺素能、非胆碱能（NANC）神经的内脏神经支配。在内脏神经变性切断后，在肠壁和回肠壁中观察到含有P物质样免疫反应性（SP-LI）的神经纤维。在高浓度辣椒素（3×10⁻⁴M）中孵育过夜导致SP-LI纤维变性。未获得含有SP-LI的肠神经元的证据。P物质引起纵行肌收缩，类似于神经刺激所产生的收缩。用α-糜蛋白酶处理后，对神经刺激的反应降低了约60%。辣椒素通常引起纵行肌收缩，但在内脏神经变性切断后则不会。用高浓度辣椒素（5×10⁻⁵M）长时间处理消除了对神经刺激的兴奋性反应。结果表明P物质是介导NANC收缩的递质。释放递质的纤维可能是逆向激活的感觉传入纤维。透壁刺激和辣椒素均引起纵行肌的NANC抑制。内脏神经切断后刺激血管周围神经引起NANC兴奋，即使在神经切断或辣椒素处理后透壁刺激也会引起NANC兴奋。
