Osborne P B, Campbell G, Evans B K
Department of Zoology, University of Melbourne, Australia.
Cell Tissue Res. 1989 Mar;255(3):663-7. doi: 10.1007/BF00218806.
A study was made of substance P-like-immunoreactive nerves within the small intestine of platypus, an Australian prototherian mammal. Both immunoreactive nerve cell bodies and fibers were present. No immunoreactive fibers were found in mesenteric nerves or on intramural blood vessels, suggesting that extrinsic sensory neurons containing substance P do not innervate platypus ileum. This was further supported by the result of in vitro experiments. Although applied substance P (10(-9) M-3 x 10(-8) M) caused contraction of the longitudinal muscle, neither mesenteric nerve stimulation nor application of capsaicin caused contractions.
对澳大利亚单孔目哺乳动物鸭嘴兽小肠内的P物质样免疫反应性神经进行了研究。免疫反应性神经细胞体和纤维均有存在。在肠系膜神经或壁内血管上未发现免疫反应性纤维，这表明含P物质的外在感觉神经元并不支配鸭嘴兽回肠。体外实验结果进一步支持了这一点。尽管施加的P物质（10^(-9)M - 3×10^(-8)M）可引起纵行肌收缩，但肠系膜神经刺激或辣椒素的应用均未引起收缩。
