摘要
目的：探讨鸟苷酸环化酶（ｓＧＣ）抑制剂甲基蓝（ＭＢ）对阿片耐受和依赖的阻断作用。方法：体外培养ｉＮＯＳ稳定表达的神经细胞做为模型，竞争性蛋白结合法、放免法和３ＨＡｒｇ转化３ＨＣｉｔ法检测胞内ｃＡＭＰ，ｃＧＭＰ水平和ＮＯＳ活性，激光共聚焦扫描技术测定胞内Ｃａ２＋浓度。观察ＭＢ对δ阿片激动剂ＤＰＤＰＥ和吗啡预处理细胞４８ｈ及纳洛酮戒断，对胞内ｃＧＭＰ，ｃＡＭＰ含量、［Ｃａ２＋］ｉ和ＮＯＳ活性的影响。结果：ＭＢ可明显抑制阿片激动剂长时程所致ｃＧＭＰ含量增加（Ｐ＜００１），对ｃＡＭＰ含量、［Ｃａ２＋］ｉ和ＮＯＳ活性的变化无影响。结论：ＭＢ通过抑制ｓＧＣ活性，使ＮＯｃＧＭＰ通路下调，减缓阿片耐受和依赖的发生。
AIM: To explore the mechanism of blockade of opiate tolerance and dependence by methylene blue (MB), a soluble guanylyl cyclase (sGC) inhibitor. METHODS: An inducible nitric oxide synthase (iNOS) gene expressing nerve cell line was used as an in vitro model system. Competitive protein binding assay and radioimmunoassay were used to examine the intracellular cAMP and cGMP content. iNOS catalytic activity was assayed by measuring the calcium independent conversion of 3H arginine to 3H citrulline. Intracellular free Ca 2+ concentration was monitored with confocal laser scanning microscopy. Cells were exposed to δ opioid agonists DPDPE ( D Pen 2, D Pen 5 enkephalin) or morphine alone, and MB (10 -6 mol·L -1 ) combined with various opioid agonist for 48 hours. Cell withdrawal response was then precipitated by the addition of naloxone for 15 minutes. RESULTS: MB was found to significantly inhibit the elevation of cGMP level which resulted from long term treatment with opioid agonists and not affect the changes of forskolin stimulated cAMP accumulation, NOS activity and [Ca 2+ ]i. CONCLUSION: Methylene blue attenuates the development of opioid tolerance and withdrawal effects mainly through inhibition of sGC activity and subsequent down regulation of NO cGMP pathway.
出处
《药学学报》
CAS
CSCD
北大核心
1999年第8期576-581,共6页
Acta Pharmaceutica Sinica
基金
国家自然科学基金
关键词
药理依赖
阿片类
阻断作用
甲基蓝
methylene blue
opiate dependence
cyclic AMP
intercellular free calcium
nitric oxide synthase
cyclic GMP
