NMDA和非NMDA受体参与介导猫脊髓内脏伤害性信息传递(英文)

Involvement of NMDA and non-NMDA receptors in transmission of spinal visceral nociception in cat

目的:研究NMDA(N-methyl-D-aspartic acid)和非NMDA受体在介导脊髓内脏痛传入中的作用,方法:气球膨胀(3-15 kPa,20 s)麻醉猫结-直肠诱发脊髓背角痛敏神经元发放,结果:1)扩张结-直肠引起神经元发放增加的为兴奋性型:17个SLA型(短潜伏期突然增加);11个SLS型(短潜伏期渐增);9个LL型(长潜伏期),15个神经元属于抑制性的Inh型,2)67.6％,78.4％和59.5％的膨胀肠诱发兴奋的神经元,分别被微电泳NMDA、使君子酸(QA)和海人藻酸(KA)激活;60％,86.7％和53.3％的Inh神经元也分别被3个酸激活.3)微电泳NMDA受体拮抗剂d,l-2-amino-5-phosphonovalemte(APV)和非NMDA受体拮抗剂6,7-dinitro-quinoxaline-2,3-dione(DNQX),分别使兴奋性反应减少35％±10％和65％±14％,DNQX明显强于APV(P<0.05).DNQX使3/7个Inh神经元抑制翻转30％-50％,而APV无效,结论:NMDA和非NMDA受体均参与介导脊髓内脏伤害性信息传递,而非NMDA受体的作用更强。 (责任编辑 李颖)

AIM: To study the role of N-methyl-D-aspartic acid (NMDA) and non-NMDA receptors in processing nociceptive visceral information in the spinal cord. METHODS: The firing of spinal dorsal horn neurons to colorectal distension (3-15 kPa, 20 s) by inflation with air of latex balloon was recorded in 25 anesthetized cats. RESULTS:1) According to the patterns of responses to colorectal distension, the neurons with increase and decrease in firing were classified as excitatory and inhibitory, respectively. The former consisted of 17 short-latency abrupt (SLA) neurons, 11 short-latency sustained (SLS) neurons, 9 long-latency (LL) neurons. The 15 inhibited (Inh) neurons were recorded. 2) Microelectrophoretic administration of NMDA, quisqualic acid (QA), and kainic acid (KA) activated 67.6%, 78.4%, and 59.5% of the colorectal distension-excited neurons tested. Also, 60 %, 86.7 %, and 53.3 % of Inh neurons were activated by these 3 amino acids. 3) Colorectal distension-induced excitatory responses were reduced by 35 %± 10 % and 65 %±14 % by a selective NMDA receptor antagonist d, l-2-amino-5-phosphonovalerate (APV) and a selective non-NMDA receptor antagonist6, 7-dinitro-quinoxaline-2, 3-dione (DNQX), respectively. Such DNQX-induced inhibition was significantly more potent than that by APV (P < 0.05). Colorectal distension-induced inhibitory responses were partially relieved by 30 % - 50 % in 3/7 Inh neurons by DNQX, but not APV. CONCLUSION: Both NMDA and non-NMDA receptors are involved in transmission and/or modulation of spinal visceral nociceptive information and non-NMDA receptors may play more important role than NMDA receptors.