摘要
目的探讨N-甲基-D-天门冬氨酸（NMDA）受体在大鼠中枢炎性痛形成中的作用。方法SD大鼠30只,体重220～250 g,随机分为3组（n=10）：对照组（C组）、脂多糖组（LPS组）和MK-801组。MK-801组于鞘内注射LPS前2 h,腹腔注射MK-801 0.3 mg/kg,LPS组和C组腹腔注射等容量生理盐水。LPS组和MK-801组鞘内注射LPS 0.1 mg,C组鞘内注射等量生理盐水。于鞘内注射LPS前即刻、鞘内注射LPS后1、3、6、12、24 h时,测定热伤害性刺激痛阈和机械性触痛痛阈。鞘内注射LPS后24 h取腰段脊髓,测定一氧化氮（NO）含量、一氧化氮合酶（NOS）和诱导型一氧化氮合酶（iNOS）活性。结果鞘内注射LPS后,与C组比较,LPS组热伤害性刺激痛阈降低、机械性触痛痛阈升高,MK-801组热伤害性刺激痛阈升高、机械性触痛痛阈降低（P〈0.05）;与LPS组比较,MK-801组热伤害性刺激痛阈升高、机械性触痛痛阈降低（P〈0.01）。鞘内注射LPS后,与C组比较,LPS组NO含量、NOS和iNOS活性均升高,MK-801组NO含量降低,NOS活性升高（P〈0.01）;与LPS组比较,MK-801组NO含量、NOS和iNOS活性均降低（P〈0.05）。结论NMDA受体的激活通过升高脊髓NO含量、NOS和iNOS活性,参与了鞘内注射LPS诱导的大鼠中枢炎性痛的形成。
Objective To investigate the role of NMDA receptor in inflammatory pain originating in central nervous system and the underlying mechanism. Methods Thirty SD rats of both sexes weighing 220-250 g were randomly divided into 3 groups （n = 10 each） ： group Ⅰ control; groupⅡ LPS and group Ⅲ MK-801 ＋ LPS. Inflammatory pain of central origin was induced by LPS 0.1 mg in 20 μl injected intrathecally at L4,5 interspace in groupⅡ and Ⅲ. In group Ⅲ MK-801 （a non-competitive NMDA receptor antagonist） 0.3 mg/kg was given intraperitoneally 2 h before intrathecal （IT） LPS. Paw withdrawal latency in hot plate test and to mechanical stimuli usingvon Frey filament were measured before （baseline） and at 1 h, 3 h, 6 h, 12 h and 24 h after IT LPS injection. The animals were killed at 24 h after IT LPS injection. The lumbar segment of the spinal cord was removed for determination of NO content and NOS and iNOS activities in the spinal cord. Results Intrathecal LPS significantly decreased pain threshold to noxious heat and mechanical stimuli and increased NO content and NOS and iNOS activities in the spinal cord in group LPS as compared to control group. IP MK-801 significantly counteracted the IT LPS-induced allodynia and hyperalgesia and increase in NO content and NOS and iNOS activities in the spinal cord. Conclusion Activation of NMDA receptor is involved in the inflammatory hyperalgesia induced by IT LPS by increasing NO content and activities of NOS and iNOS in the spinal cord in rats.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2007年第9期803-805,共3页
Chinese Journal of Anesthesiology
