Hua X Y, Saria A, Gamse R, Theodorsson-Norheim E, Brodin E, Lundberg J M
Neuroscience. 1986 Sep;19(1):313-9. doi: 10.1016/0306-4522(86)90024-2.
The release of tachykinins from isolated slice preparations of the guinea-pig spinal cord and ureter was studied in vitro. Capsaicin (10 microM) caused release of substance P, neurokinin A and an eledoisin-like component from both the spinal cord and ureter. The release of tachykinins induced by capsaicin or potassium (60 mM) was calcium dependent. No detectable release of neurokinin B or neuropeptide K, an N-terminally extended form of neurokinin A, was induced by capsaicin. No detectable release of tachykinins could be demonstrated after exposure to agents which are known to activate C-fibre afferents, such as histamine, bradykinin, serotonin, prostaglandins E1, E2 or acetylcholine. Protein extravasation in the ureter, as determined by the Evans Blue extravasation technique was used as a functional correlate to the tachykinin release. Protein extravasation was induced in vivo by local intraluminal injections of capsaicin at several hundred-fold lower concentrations than those required to induce a detectable release of tachykinins in vitro. The difference may, however, partly depend on the experimental conditions and the detection limit of the tachykinin assay used. The protein extravasation response to capsaicin was absent after systemic capsaicin pretreatment, which causes a marked depletion of tachykinins in the ureter. In conclusion, capsaicin evokes release of several tachykinins from both central and peripheral endings of primary afferent neurons. The peptides released from sensory nerves in the periphery may induce effects such as protein extravasation and smooth muscle contraction.
在体外研究了豚鼠脊髓和输尿管分离切片制剂中速激肽的释放。辣椒素（10微摩尔）可引起脊髓和输尿管中P物质、神经激肽A和一种类eledoisin成分的释放。辣椒素或钾（60毫摩尔）诱导的速激肽释放是钙依赖性的。辣椒素未诱导出神经激肽B或神经激肽K（神经激肽A的N端延伸形式）的可检测释放。在暴露于已知可激活C纤维传入神经的物质（如组胺、缓激肽、血清素、前列腺素E1、E2或乙酰胆碱）后，未证明有速激肽的可检测释放。通过伊文思蓝外渗技术测定的输尿管中的蛋白质外渗被用作速激肽释放的功能相关指标。在体内，通过局部腔内注射比体外诱导速激肽可检测释放所需浓度低数百倍的辣椒素可诱导蛋白质外渗。然而，这种差异可能部分取决于实验条件和所使用的速激肽测定的检测限。全身辣椒素预处理后，对辣椒素的蛋白质外渗反应消失，这会导致输尿管中速激肽的显著耗竭。总之，辣椒素可引起初级传入神经元中枢和外周末梢释放多种速激肽。外周感觉神经释放的肽可能诱导蛋白质外渗和平滑肌收缩等效应。
