Budai D, Wilcox G L, Larson A A
Department of Veterinary Pathobiology, University of Minnesota College of Veterinary Medicine, St. Paul 55108.
Eur J Pharmacol. 1992 Jun 17;216(3):441-4. doi: 10.1016/0014-2999(92)90443-8.
The effects of an N-terminal fragment of substance P, substance P-(1-7) [SP-(1-7)], on the responses of dorsal horn nociceptive neurons to N-methyl-D-aspartate (NMDA) and (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) were tested by combined single-unit extracellular recordings/microiontophoresis. While SP-(1-7) had no effects when applied by itself, it was a potent and long-lasting modulator of both NMDA- and AMPA-mediated excitation of spinal dorsal horn nociceptive neurons. NMDA responses were transiently decreased (by an average of 36% of control at minimum) by SP-(1-7) followed by a more sustained increase (by 76% at maximum). In contrast, AMP responses were only increased by SP-(1-7) (by 81% at maximum). It is hypothesized that the actions of SP-(1-7) on excitatory amino acid (EAA) responses of dorsal horn nociceptive neurons reflect a novel mechanism by which SP and EAAs interact to modulate pain transmission.
通过联合单单位细胞外记录/微量离子电泳法，测试了P物质的N端片段P物质-(1-7)[SP-(1-7)]对背角伤害性神经元对N-甲基-D-天冬氨酸（NMDA）和（R,S）-α-氨基-3-羟基-5-甲基异恶唑-4-丙酸（AMPA）反应的影响。虽然单独应用SP-(1-7)时没有作用，但它是NMDA和AMPA介导的脊髓背角伤害性神经元兴奋的强效且持久的调节剂。SP-(1-7)可使NMDA反应短暂降低（最低时平均降低对照的36%），随后出现更持久的增加（最高增加76%）。相比之下，AMPA反应仅被SP-(1-7)增强（最高增加81%）。据推测，SP-(1-7)对背角伤害性神经元兴奋性氨基酸（EAA）反应的作用反映了一种SP与EAA相互作用以调节疼痛传递的新机制。
