延胡索及其有效成分抗吗啡成瘾多巴胺系统作用机制研究和效果比较

为了观察延胡索和左旋延胡索乙素(L-tetrahydropalmatine,L-THP)对吗啡条件性位置偏爱(conditioned place preference,CPP)大鼠学习记忆相关脑区海马(Hip)和纹状体(Str)内多巴胺递质含量,多巴胺转运体(dopamine transporter,DAT)和多巴胺D2受体(D2R)表达的影响。对各组大鼠颈背部皮下注射生理盐水或吗啡后(吗啡起始剂量为10 mg·kg-1,逐日递增,至第10天为100 mg·kg-1),末次训练48 h进行CPP测试确认模型建立成功,立即处死生理盐水对照组和模型组大鼠,分别取海马、纹状体脑组织。延胡索高、中、低剂量组大鼠则分别给予延胡索2,1,0.5 g·kg-1水提液(内含L-THP的量分别为0.274,0.137,0.069 mg),L-THP高、中、低剂量组分别给予L-THP 3.76,1.88,0.94 mg·kg-1灌胃治疗,生理盐水治疗组灌胃生理盐水,持续治疗6 d,再次CPP测试后处死,同前取材。采用高效液相色谱法检测多巴胺递质含量;Western blot技术检测DAT和D2R的表达。结果显示,与生理盐水治疗组比较,延胡索和L-THP高、中剂量组大鼠在白箱停留的时间显著减少(P0.01),同时海马和纹状体脑区内多巴胺递质含量明显降低(P0.01或P0.05),DAT表达上调(P0.01),D2R表达上调(P0.01)。学习记忆相关脑区海马和纹状体是延胡索和L-THP治疗精神依赖的又一神经解剖学作用位点,其机制与下调其升高的DA递质含量以及上调DAT和D2R的表达有关;对吗啡CPP效应消退的药效作用,以及对学习记忆相关脑区海马、纹状体中DA递质含量、DAT和D2R的影响,含1倍量L-THP单体的延胡索中药相当于单独应用约14倍L-THP单体的效果。

Effect of Corydalis Rhizoma and L-tetrahydropalmatine on dopamine system of hippocampus and striatum in morphine-induced conditioned place preference rats

To investigate the effects of Corydalis Rhizoma and L-tetrahydropalma-tine (L-THP) on the levels of dopamine neurotransmitter (DA), dopamine transporter (DAT) and the second dopamine receptor (D2R) in learning and memory-related brain areas, hippocampus and striatum, the DA, DAT and D2R were detected in conditioned place preference (CPP) rats suffered from morphine. And comparation the degree of similarity and consistency of the pharmacological effects was also studied. The rats were trained in black compartments and white ones (drug-paired compartment) with the increasing doses of morphine for 10 days (hypodermically injected from 10 mg·kg^-1 to 100 mg·kg^-1). Models of CPP were validated in those psychological dependence rats after 48 h training. The dopamine contents were detected as soon as the materials of hippocampus and striatum are harvested from rats of NS control group and model group. The DAT and D2R levels are measured by Western blot. The high, medium and low dose group of Corydalis Rhizoma are given Corydalis Rhizoma 2, 1, 0.5 g·kg^-1 water extraction liquid respectively (which contains L-THP were 0.274, 0.137 and 0.137 mg respectively), and the high, medium and low dose group of L-THP were given L-THP 3.76, 1.88, 0.94 mg·kg^-1 lavage treatment respectively, NS treatment group were lavaged normal saline for 6 days and they were killed after test of CPP, again tested DA levels and expression of DAT and D2R similar to the front of materials. The reduction effects of CPP were observed in the groups of both Corydalis Rhizoma (2, 1 g·kg^-1) and L-THP (3.76, 1.88 mg·kg^-1) subjected to medicine for 6 days (P<0.01). Compared with the NS treatment group and the model group, the higher values including in the contents of neurotransmitter dopamine were detected of hippocampus and striatum (P<0.01, P<0.05), the DAT and D2R protein expression of Corydalis Rhizoma (2, 1 g·kg^-1) and L-THP (3.76, 1.88 mg·kg^-1) increased in hippocampus and striatum (P<0.01). Learning and memory-related brain regions hippocampus and striatum was another neuroanatomical sites of action in the treatment of mental dependence of fumarate and L-THP, its mechanism was related to lowering its elevated DA neurotransmitter levels, and increasing the expression of DAT and D2R. Corydalis Rhizoma could be play 14-times roles in effect of L-THP. The similar effects were observed on the neurotransmitter dopamine, DAT and D2R in learning and memory-related brain areas, hippocampus and striatum of the morphine-dependent rats.