Chahl L A
Neuropharmacology Laboratory, Faculty of Medicine, University of Newcastle, N.S.W., Australia.
Eur J Pharmacol. 1989 Oct 10;169(2-3):241-7. doi: 10.1016/0014-2999(89)90021-6.
Ruthenium red has recently been found to inhibit the effects of capsaicin on peripheral terminals of sensory neurones. Thus the effects of ruthenium red on the responses of the guinea-pig isolated ileum to capsaicin, acetylcholine (ACh), substance P (SP) and nicotine were investigated. Ruthenium red, 5 mumol/l, abolished responses to capsaicin 1.5 mumol/l and nicotine 2 mumol/l, and shifted the concentration-response lines to ACh and SP to the right. Pretreatment of ileum preparations with ruthenium red, 12.5 mumol/l for 2 min, prevented desensitization of ileum responses to capsaicin tested 30 min later. Tetrodotoxin, 1 mumol/l, abolished the response to capsaicin on control preparations and those pretreated with atropine, 5 mumol/l, ruthenium red, 12.5 mumol/l or spantide, 10 mumol/l. It is proposed that capsaicin acts via a specific receptor coupled to a receptor-operated membrane calcium channel, and that ruthenium red binds irreversibly to the calcium channel part of the complex but reversibly to some other site which prevents the action or binding of capsaicin at its specific receptor.
最近发现钌红可抑制辣椒素对感觉神经元外周终末的作用。因此，研究了钌红对豚鼠离体回肠对辣椒素、乙酰胆碱（ACh）、P物质（SP）和尼古丁反应的影响。5 μmol/L的钌红可消除对1.5 μmol/L辣椒素和2 μmol/L尼古丁的反应，并使对ACh和SP的浓度-反应曲线右移。用12.5 μmol/L钌红预处理回肠制剂2分钟，可防止30分钟后测试的回肠对辣椒素反应的脱敏。1 μmol/L的河豚毒素可消除对照制剂以及用5 μmol/L阿托品、12.5 μmol/L钌红或10 μmol/L spantide预处理的制剂对辣椒素的反应。有人提出，辣椒素通过与受体操纵的膜钙通道偶联的特异性受体起作用，并且钌红不可逆地结合到复合物的钙通道部分，但可逆地结合到其他一些位点，这些位点可阻止辣椒素在其特异性受体处的作用或结合。
