外周P物质受体介导伤害性刺激所致脊髓背角c-fos基因的表达

PERIPHERAL SUBSTANCE P RECEPTOR MEDIATING c-fos GENE EXPRESSION IN THE SPINAL DORSAL HORN INDUCED BY PERIPHERAL NOXIOUS STIMULATION

用免疫组化染色方法，观察了P物质受体在外周对伤害性刺激信息的介导作用。于福尔马林注入双侧后肢足底前10min，将不同浓度（10-4，10-5和10－6mol／L）的SP受体特异性拮抗剂L668，169注入一侧足底，另一侧注入生理盐水。结果：10-4mol／L的L668，169明显抑制了该侧脊髓背角浅层（Ⅰ、Ⅱ层）c-fos基因的表达，而对深层影响不大；注入浓度为10－5mol／L和10－6mol／L的L668，169对背角深、浅层的作用均不明显。另外，将SP受体激动剂Sar－SP（10-4mol／L）或福尔马林分别注入不同动物的一侧后肢足底，另一侧注射等量的生理盐水，均可引起激动剂或福尔马林注入侧脊髓背角深、浅层的FOS阳性神经元数量的增多。上述结果提示，SP在外周具有致痛作用，该作用至少部分是通过SP与SP受体结合而参与介导伤害性信息向脊髓传递。

Employing imrnunohistochendcal staining for FOS protein, which is the eXpression product of c-fos proto-oncogene, the role of substance P receptor (SPR) in noxious information transgression at peripheral terminals of the dorsal root ganglion cells was investigated by means of a selective SPR antagonist In68, 169 and agonist Sar-SP.Unilateral injection of to68, 169 (10-4 mo;/L) into the plantal of hindpaw 10 min before injection of 4% formalin, the number of FOS-like immunoreactive (LI) neurons in the superficial ldrinae of dosal horn was significantly decreased, but the changes were not obvious in the deeper laminae. Smaller doses of L668, 169 (10-5, 10-6 mol/L) were almost ineffective on FOS-LI neurons in both the superficial and the deeper laminae.However, Sar-SP (10-4 mol/L) or formalin did result in the expression of c-fos gene in the superficial laminae of the dosal horn. These results indicated that SP might contribute to the transgression of nociceptive information and induce noxious sensation, at least in part by activating SPR in peripheral terminals of the dorsal root ganglion cells.