Rees H, Sluka K A, Urban L, Walpole C J, Willis W D
Marine Biomedical Institute, University of Texas Medical Branch, Galveston 77555-1069, USA.
Exp Brain Res. 1998 Aug;121(3):355-8. doi: 10.1007/s002210050468.
Substance P, acting through neurokinin I receptors, is involved in the processing of nociceptive information in the spinal cord. Sensitization of spinothalamic tract neurons occurs to low-intensity stimuli following capsaicin injection. The current study tested the effects of the novel neurokinin I receptor antagonist, SDZ NKT 343, on the sensitization of spinothalamic tract cells by capsaicin in monkeys. Spinothalamic tract cells from the lumbar enlargement with receptive fields in the hindpaw were isolated and recorded before and after intradermal injection of capsaicin. The background activity and responses to brushing, pressing and pinching the skin were assessed. Thirty minutes after capsaicin injection there was an increase in background activity and responses to brush and pressure applied to the receptive field. Infusion of SDZ NKT 343 (for 30-45 min) significantly reversed the increased response to brushing without affecting the increased background activity or the increased response to pressure. Thus, blockade of neurokinin 1 receptors reduces the sensitized responses to innocuous mechanical stimuli but not to noxious mechanical stimuli.
P物质通过神经激肽1受体发挥作用，参与脊髓中伤害性信息的处理。辣椒素注射后，脊髓丘脑束神经元对低强度刺激产生敏化。本研究测试了新型神经激肽1受体拮抗剂SDZ NKT 343对辣椒素引起的猴子脊髓丘脑束细胞敏化的影响。分离并记录来自腰膨大、后爪有感受野的脊髓丘脑束细胞，在皮内注射辣椒素前后进行评估。评估背景活动以及对皮肤轻刷、按压和捏压的反应。辣椒素注射30分钟后，背景活动以及对感受野轻刷和按压的反应增加。输注SDZ NKT 343（持续30 - 45分钟）显著逆转了对轻刷增加的反应，而不影响增加的背景活动或对按压增加的反应。因此，阻断神经激肽1受体可减少对无害机械刺激的敏化反应，但不影响对有害机械刺激的反应。
