De Koninck Y, Salter M W, Henry J L
Department of Physiology, McGill University, Montréal, Québec, Canada.
Neurosci Lett. 1994 Jul 18;176(1):128-32. doi: 10.1016/0304-3940(94)90887-7.
To investigate the interaction at the spinal level of endogenously released substance P with the effects of endogenously released adenosine, extracellular single-unit activity was recorded from dorsal horn neurons in the anesthetized cat. Vibration to the skin inhibited on-going activity of nociceptive neurons; 20 mg/kg caffeine reversibly blocked this inhibition, indicating mediation via adenosine receptors. In half of the cases, this inhibition was potentiated by iontophoretic application of substance P. High-intensity electrical stimulation to a sensory nerve produced excitation which was blocked by an NK-1 (substance P) receptor antagonist, implicating an endogenous neurokinin. When electrical stimulation preceded the vibrational stimulus, the inhibitory effect of vibration was potentiated. Thus, we suggest that endogenous substance P may potentiate the inhibitory response to endogenous adenosine. The results have important implications for integration of inputs from different sensory modalities, especially as they relate to nociception and pain.
为了研究内源性释放的P物质在脊髓水平与内源性释放的腺苷的作用之间的相互作用，在麻醉猫的背角神经元中记录了细胞外单单位活动。皮肤振动抑制伤害性神经元的持续活动；20mg/kg咖啡因可逆转这种抑制作用，表明是通过腺苷受体介导的。在一半的实验中，这种抑制作用通过离子电渗法施加P物质而增强。对感觉神经的高强度电刺激产生兴奋，该兴奋被NK-1（P物质）受体拮抗剂阻断，提示存在内源性神经激肽。当电刺激先于振动刺激时，振动的抑制作用增强。因此，我们认为内源性P物质可能增强对内源性腺苷的抑制反应。这些结果对于整合来自不同感觉模式的输入具有重要意义，特别是与伤害感受和疼痛相关的输入。
