目的 探讨δ受体在瑞芬太尼诱发大鼠脊髓背角神经元NMDA受体微小兴奋性突触后膜电流(mEPSCs)中的作用.方法 取出生14～ 18 d的雄性Wistar大鼠,体重50～60 g,取腰段脊髓(L1～S1),制备脊髓切片,取脊髓切片24张,采用随机数字表法,将其随机分为4组(n=6):对照组(C组)置入人工脑脊液中培养；甘氨酸组(G组)置入含甘氨酸(终浓度0.24 μmol/L)的人工脑脊液中孵育；瑞芬太尼组(R组)制备脊髓切片,置入含瑞芬太尼(终浓度为4 nmol/L)的人工脑脊液中孵育；瑞芬太尼+δ受体拮抗剂纳曲吲哚组(RN组)制备脊髓切片,置入含瑞芬太尼和纳曲吲哚(终浓度分别为4nmol/L和1nmol/L)的人工脑脊液中孵育.各组孵育60 min后应用全细胞膜片钳技术记录脊髓背角神经元NMDA受体mEPSCs的幅值和频率.结果 与C组比较,R组mEPSCs的幅值和频率升高(P＜0.01),G组和RN组差异无统计学意义(P＞0.05)；与R组比较,RN组mEPSCs的幅值和频率降低(P＜0.01).结论 脊髓背角神经元δ受体激活后可增强NMDA受体功能,该作用可能参与了瑞芬太尼诱发的痛觉过敏.%Objective To investigate the role of δ-opioid receptor in remifentanil-induced N-methyl-D-aspartate (NMDA) receptor miniature excitatory postsynaptic currents (mEPSCs) in rat spinal dorsal horn neurons.Methods Male 14-18 d old Wistar rats weighing 50-60 g were used in this study.The animals were anesthetized with intraperitoneal choral hydrate 400 mg/kg and sacrificed.Their lumbar segments of spinal cord (L1-S1 ) were immediately removed and sliced.Twenty-four slices were randomly divided into 4 groups ( n =6 each): control group (group C) ; glycine group (group G) ; remifentanil group (group R) and remifentanil + naltrindole(a δ receptor antagon) (group RN).Slices were cultured in artificial cerebrospinal fluid (ACSF) (group C) or incubated in ACSF containing glycine 0.24 μmol/L (group G) or remifentanil 4 nmol/L (group R) or remifentanil 4 nmol/L+ naltrindole 1 nmol/L (group RN) for 60 min.Whole cell patch clamp technique was used to measure NMDA receptor mEPSCs.Results The amplitude and frequency of mEPSCs were significantly higher in group R than in groups C and RN ( P ＜ 0.01).There were no significant differences in amplitude and frequency of mEPSCs among gorups C,G and RN ( P ＞ 0.05).Conclusion Activation of δ-receptor can enhance NMDA receptor function in spinal dorsal horn neurons in rats which may be the mechanism of remifentanil-induced hyperalgesia.
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