Moochhala S M, Sawynok J
Br J Pharmacol. 1984 Jun;82(2):381-8. doi: 10.1111/j.1476-5381.1984.tb10773.x.
The hyperalgesic effect of intrathecally administered substance P (SP), physalaemin, eledoisin and eledoisin-related peptide (ERP) was investigated in the rat tail flick test. Hyperalgesia produced by SP (2.5-15 micrograms, 1.9-11 nmol) was maximal 10-20 min after injection, lasted 30 min and was dose-related. The effect was mimicked by all of the peptides examined. The rank order of potency was physalaemin greater than SP greater than eledoisin greater than ERP. Desensitization to the hyperalgesic effect of SP was produced by three repeated intrathecal injections. Rats desensitized to SP no longer responded to physalaemin or ERP, indicating cross-desensitization. Phentolamine continued to produce hyperalgesia following such desensitization. The demonstration of a hyperalgesic effect for SP provides further support for a role for SP in nociceptive transmission. The receptor mediating this effect appears to be a SP-P subtype. Cross-desensitization between peptides suggests an action on the same receptor.
通过大鼠甩尾试验研究了鞘内注射P物质（SP）、雨蛙肽、伊索肽和伊索肽相关肽（ERP）的痛觉过敏效应。SP（2.5 - 15微克，1.9 - 11纳摩尔）产生的痛觉过敏在注射后10 - 20分钟达到最大，持续30分钟，且与剂量相关。所有检测的肽都能模拟这种效应。效力顺序为雨蛙肽＞SP＞伊索肽＞ERP。通过三次重复鞘内注射可使大鼠对SP的痛觉过敏效应产生脱敏。对SP脱敏的大鼠对雨蛙肽或ERP不再有反应，表明存在交叉脱敏。在这种脱敏后，酚妥拉明仍继续产生痛觉过敏。SP痛觉过敏效应的证明为SP在伤害性感受传递中的作用提供了进一步支持。介导这种效应的受体似乎是SP-P亚型。肽之间的交叉脱敏表明它们作用于同一受体。
