Bodnar R J, Simone D A, Kordower J H, Kirchgessner A L, Nilaver G
Pharmacol Biochem Behav. 1983 Jan;18(1):65-71. doi: 10.1016/0091-3057(83)90253-8.
Capsaicin modulates animal pain perception, increasing chemosensitive and pressure thresholds following systemic administration, increasing thermal thresholds following intrathecal administration, and decreasing electric shock thresholds following intracerebroventicular (ICV) administration. Since morphine analgesia is decreased in a dose-dependent manner following ICV capsaicin, the present study examined whether ICV injections of capsaicin (0, 25, 50, 100 micrograms) would alter other analgesic responses as well. Experiment 1 demonstrated that the analgesic response to a 450 mg/kg dose of 2-deoxy-D-glucose was significantly reduced by the 25 and 50, but not the 100 micrograms capsaicin dose. Further, while analgesia induced by cold-water swims (CWS) in a 2 degrees C bath was significantly attenuated by the 25 micrograms capsaicin dose, the entire dose range eliminated analgesia induced by CWS in a 15 degrees C bath. Experiment 2 indicated that the capsaicin-induced alterations in CWS analgesia were not attributable to parallel changes in CWS hypothermia. Experiment 3 demonstrated that capsaicin failed to alter both the non-opioid analgesic response induced by 20 inescapable foot shocks (FS) and the opioid analgesic response induced by 80 FS. These data are discussed in terms of the similarities to and/or dissimilarities from capsaicin-induced effects upon morphine analgesia.
辣椒素可调节动物的疼痛感知，全身给药后可提高化学敏感性和压力阈值，鞘内给药后可提高热阈值，而脑室内（ICV）给药后可降低电击阈值。由于ICV注射辣椒素后吗啡镇痛作用呈剂量依赖性降低，因此本研究探讨了ICV注射辣椒素（0、25、50、100微克）是否也会改变其他镇痛反应。实验1表明，25微克和50微克辣椒素剂量可显著降低对450毫克/千克剂量的2-脱氧-D-葡萄糖的镇痛反应，但100微克辣椒素剂量则无此作用。此外，虽然25微克辣椒素剂量可显著减弱在2摄氏度水浴中冷水游泳（CWS）诱导的镇痛作用，但整个剂量范围均消除了在15摄氏度水浴中CWS诱导的镇痛作用。实验2表明，辣椒素引起的CWS镇痛改变并非归因于CWS体温过低的平行变化。实验3表明，辣椒素未能改变由20次不可逃避的足部电击（FS）诱导的非阿片类镇痛反应以及由80次FS诱导的阿片类镇痛反应。将根据辣椒素对吗啡镇痛作用的相似性和/或差异来讨论这些数据。
