Yoshimura M, Yonehara N, Ito T, Kawai Y, Tamura T
Central Research Laboratories, Maruishi Pharmaceutical Co., Ltd., Osaka, Japan.
Jpn J Pharmacol. 2000 Feb;82(2):116-21. doi: 10.1254/jjp.82.116.
The effects of capsaicin cream on neurogenic inflammation and thermal nociceptive threshold were investigated in rats. Firstly, for topical application of capsaicin cream to hind paw, we shaped boots from dental cement to prevent the animals from licking off the drug. Capsaicin cream (1%) led to significant increases in the amounts of Evans blue and substance P (SP) released into the perfusate, and the former response was significantly suppressed by pretreatment with RP67580, an NK1-receptor antagonist, but not by treatment with an NK2-receptor antagonist. Subsequent electrical stimulation of the sciatic nerve resulted in a significant reduction in Evans blue and SP extravasation 24 h after topical application of capsaicin cream. On the other hand, when capsaicin cream was repeatedly applied to both hind paws once a day, withdrawal latency for noxious heat stimulation decreased after 24 h, and this thermal hyperalgesia was reversed 3 days later. These results suggest that capsaicin cream initially affects neurogenic inflammation mechanisms and then blocks the pain transmission mechanism.
研究了辣椒素乳膏对大鼠神经源性炎症和热痛觉阈值的影响。首先，为了将辣椒素乳膏局部应用于后爪，我们用牙科水泥制作了靴子，以防止动物舔掉药物。辣椒素乳膏（1%）导致灌注液中伊文思蓝和P物质（SP）释放量显著增加，前一种反应被NK1受体拮抗剂RP67580预处理显著抑制，但未被NK2受体拮抗剂处理所抑制。随后，在局部应用辣椒素乳膏24小时后，对坐骨神经进行电刺激导致伊文思蓝和SP外渗显著减少。另一方面，当每天一次将辣椒素乳膏反复应用于双后爪时，有害热刺激的撤药潜伏期在24小时后缩短，这种热痛觉过敏在3天后逆转。这些结果表明，辣椒素乳膏最初影响神经源性炎症机制，然后阻断疼痛传递机制。
