左旋硝基精氨酸甲酯和地佐环平和硝苯地平对吗啡致NG108-15细胞内钙浓度变化的影响

目的　探讨一氧化氮合酶抑制剂左旋硝基精氨酸甲酯 (L NAME)、N 甲基 D 天冬氨酸 (NMDA)受体拮抗剂地佐环平 (MK 80 1)和钙通道阻滞剂硝苯地平对吗啡作用的影响是否与细胞 Ca2 + ]i 有关。方法　体外培养NG10 8 15细胞 ,用荧光指示剂Fura2 AM负载 ,荧光分光光度计动态测定细胞 Ca2 + ]i。结果　吗啡、MK 80 110 μmol·L- 1、硝苯地平 1,2和3μmol·L- 1急性处理能降低由NMDA刺激 (模拟兴奋性刺激 )所致的细胞 Ca2 + ]i 升高。MK 80 110μmol·L- 1和硝苯地平 3μmol·L- 1与吗啡合用均能完全对抗NMDA的作用。吗啡处理细胞 4 8h后 ,再用纳洛酮处理 ,细胞 Ca2 + ]i 可增加约 39% ,L NAME ,MK 80 1和硝苯地平与吗啡合用均能降低纳洛酮引起的细胞 Ca2 + ]i 的升高。结论　MK 80 1,L NAME和硝苯地平对吗啡调节的作用均与胞内Ca2 + 浓度的变化密切相关

Effects of Nω-nitro-L-arginine methyl ester, MK-801, nifedipine on the intracellular calcium concentration alternated by morphine in NG108-15 cells

AIM To explore if the influence of N^ω-nitro-L-arginine methyl ester (L-NAME, nric oxide synthase inhibitor), dizocilpine 〔MK-801, N-methyl-D- aspartate(NMDA) receptor antagonist〕 and nifedipine (calcium channel blocker) on the action of morphine is mediated by variation of intracellular calcium concentration (［Ca²⁺］_i). METHODS The ［Ca²⁺］_i of NG108-15 cells cultured in vitro was measured dynamically with fluorospectrophotometer after treated with fluorescent probe Fura2-AM. RESULTS The increases in ［Ca²⁺］_i induced by NMDA treatment (simulating the excitatory stimulation) were inhibited by morphine or MK-801 10 μmol•L^-1 or nifedipine 3 μmol•L^-1 acute treatment, and inhibited completely by MK-801 10 μmol•L^-1 or nifedipine 3 μmol•L^-1 cotreated with morphine. After having been treated with morphine for 48 h, the cells were then treated with naloxone, the ［Ca²⁺］_i overshooting by 39% approximately. These overshoots induced by naloxone could be blocked by L-NAME, MK-801 or nifedipine cotreated with morphine. CONCLUSION The modulation with morphine effects by L-NAME, MK-801 and nifedipine was related to the variation of ［Ca²⁺］_i.