White D M, Zimmermann M
II Physiologisches Institut der Universität, Heidelberg, F.R.G.
Neurosci Lett. 1988 Sep 23;92(1):108-13. doi: 10.1016/0304-3940(88)90751-3.
It has previously been shown that electrical stimulation of a peripheral nerve induces a release of substance P (SP) from cutaneous nerve terminals. In this study, we investigate whether SP is released from nerve fibre endings in experimentally induced rat saphenous nerve neuromas. The neuromas were induced in pentobarbital anaesthetized rats by ligating and cutting the saphenous nerve 5 weeks prior to the release experiments. The 5-week-old neuromas were desheathed, placed in a perspex chamber, in situ, and superfused with Tyrode solution. The SP-like immunoreactivity (SPLI) content of the superfusate was measured by radioimmunoassay. Addition of 90 microM bradykinin to the superfusate resulted in a calcium-dependent release of SPLI. The other inflammatory mediators, histamine and serotonin, did not induce a release of SPLI. Furthermore, repetitive electrical stimulation of the saphenous nerve (50 V, 5 Hz, 0.5 ms) or superfusion of the neuroma with 50 microM veratridine or 40 mM K+ also failed to induce a release of the peptide. The release of SPLI, induced by bradykinin, from nerve fibre endings in the rat cutaneous nerve neuroma, appears to involve a neurochemical interaction that is independent of electrophysiological excitation.
先前的研究表明，对周围神经进行电刺激会诱导皮肤神经末梢释放P物质（SP）。在本研究中，我们调查了在实验诱导的大鼠隐神经神经瘤中，SP是否从神经纤维末梢释放。在释放实验前5周，通过结扎和切断戊巴比妥麻醉大鼠的隐神经来诱导神经瘤形成。将5周龄的神经瘤去鞘，原位放置在有机玻璃腔室中，并用台氏液灌流。通过放射免疫测定法测量灌流液中SP样免疫反应性（SPLI）的含量。向灌流液中添加90微摩尔缓激肽会导致SPLI的钙依赖性释放。其他炎症介质组胺和血清素不会诱导SPLI的释放。此外，对隐神经进行重复电刺激（50伏，5赫兹，0.5毫秒）或用50微摩尔藜芦碱或40毫摩尔钾对神经瘤进行灌流也未能诱导该肽的释放。缓激肽诱导的大鼠皮肤神经瘤神经纤维末梢SPLI的释放似乎涉及一种独立于电生理兴奋的神经化学相互作用。
