茶色素对吗啡成瘾小鼠脑内去甲肾上腺素、多巴胺、5-羟色胺和β-内啡肽的影响

目的:探索茶色素对吗啡依赖小鼠脑内去甲肾上腺素(NE)、多巴胺(DA)、5-羟色胺(5-HT)和β-内啡肽(β-EP)的影响。方法:建立吗啡依赖模型,采用催促戒断治疗实验测定小鼠跳跃反应次数。运用高效液相法测定下丘脑,脑干和大脑皮质内NE、DA、5-HT含量,采用放射免疫法测定大脑皮质内β-EP含量。结果:茶色素12.5,25,50,100 mg.kg-1组均显著降低吗啡依赖小鼠的跳跃次数。降低吗啡依赖小鼠下丘脑中NE和DA的含量。降低吗啡依赖小鼠大脑皮质内β-EP含量。但对下丘脑,脑干和大脑皮质内的5-HT含量没有明显影响。结论:茶色素能降低吗啡依赖小鼠的跳跃次数,其机制可能与茶色素降低吗啡依赖小鼠下丘脑中NE和DA及大脑皮质β-EP含量相关。     

2,3-吲哚醌对大鼠脑内单胺类神经递质含量与释放的影响

目的研究2,3-吲哚醌对大鼠脑内单胺类神经递质含量与释放的影响。方法给予Wistar大鼠2,3-吲哚醌(50,200 mg.kg-1,ip),2h后测定其纹状体Ach,DA含量;在脑片灌流液中加入2,3-吲哚醌(50,200μmol.L-1),测定其对纹状体及皮质脑片DA,5-HT,NE释放的影响。结果大鼠腹腔给予2,3-吲哚醌,其纹状体Ach和DA的浓度均有增加(P<0.05和P<0.01);脑片灌流液中加入2,3-吲哚醌促进皮质和纹状体内DA释放(P<0.01)。结论2,3-吲哚醌具有调节脑内DA和Ach两种神经递质功能平衡的作用。     

坤宁安对围绝经期综合征大鼠下丘脑β-内啡肽及神经递质的影响

目的探讨坤宁安对β-内啡肽及神经递质的影响,揭示其防治围绝经期综合征的作用机制。方法建立自然围绝经期综合征动物模型,放射免疫法、荧光分光光度法和比色法检测各实验组大鼠下丘脑组织β-内啡肽(β-EP)、5-羟色胺(5-HT)、去甲肾上腺素(NE)和外周血超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、丙二醛(MDA)的变化,光学及电子显微镜观察各组大鼠下丘脑组织结构变化。结果坤宁安浓缩丸能提高围绝经期综合征大鼠下丘脑β-EP、NE含量,降低5-HT水平和5-HT/NE比值,提高围绝经期大鼠血浆中SOD、GSH-PX的活性,降低血清中MDA的含量。各组超微结构变化与以上结果相一致。结论坤宁安浓缩丸通过调节神经—内分泌紊乱状态,改善自由基代谢,维持机体内环境相对稳定。     

芬氟拉明合用电针对大鼠脑内中央灰质单胺类释放的影响

目的:研究5-羟色胺释放剂芬氟拉明加强针刺镇痛前后大鼠脑内中央灰质(PAG)腹侧部单胺类递质的变化。方法:运用微透析及高效液相电化学检测方法。结果:电针后Nor的释放减少,而5-HT,5-HIAA和DA,HVA在AG部位含量升高(P<0.05,vs NS组)。当芬氟拉明合用电针时,5-HT,5-HIAA含量进一步升高,但Nor,DA及其代谢产物却无明显变化(P<0.05 vs NS EA组)。结论:电针能促进DA和5-HT释放但抑制Nor释放。芬氟拉明合用电针能进一步加强5-HT的释放。芬氟拉明加强针刺镇痛可能与进一步激活5-羟色胺系统有关。     

HPLC-ECD法测定大鼠脑组织中单胺类神经递质的含量

目的:建立测定大鼠脑组织中的单胺类神经递质含量的方法。方法:采用高效液相色谱-电化学法,以2,5-二羟基苯甲酸为内标,测定大鼠大脑皮层、小脑、海马组织、下丘脑、嗅球中以去甲肾上腺素(NE)和5-羟色胺(5-HT)为代表的单胺类神经递质的含量。色谱柱为DIKMAC18,流动相为缓冲盐溶液(醋酸钠、庚烷磺酸钠、乙二胺四乙酸二钠和柠檬酸)-甲醇(梯度洗脱),流速为1.0 ml/min,工作电压为+0.7 V。结果:NE、5-HT的检测质量浓度线性范围分别为0.084⁴.2μg/ml(r=0.999 9)和0.0054.2μg/ml(r=0.999 9)和0.005⁰.25μg/ml(r=0.999 1),平均加样回收率分别为98.85%(RSD=2.89%,n=3)和101.5%(RSD=2.41%,n=3),日内(n=5)和日间(n=3)RSD均不大于3%;NE在小脑中的含量最低[(0.343±0.14)mg/g],在下丘脑中含量最高[(3.062±1.51)mg/g];5-HT在小脑中的含量最低[(0.059±0.04)mg/g],在大脑皮层中含量最高[(0.383±0.21)mg/g]。结论:本方法灵敏、简便、快速,可用于大鼠脑组织中NE、5-HT含量的测定。     

黄连生物碱促小鼠睡眠实验研究

目的研究5种黄连生物碱(小檗碱、黄连碱、巴马汀、表小檗碱、药根碱)对小鼠睡眠的影响,初步探讨其作用机制。方法通过小鼠自主活动实验和阈上剂量、阈下剂量戊巴比妥钠诱导小鼠睡眠实验,观察药物对小鼠入睡行为的影响。同时建立PCPA小鼠失眠模型,利用高效液相-荧光检测器,检测其下丘脑中神经递质NE、DA和5-HT的含量。结果与对照组相比,在行为学实验中ig 75 mg·kg-1·d-1的小檗碱和黄连碱能明显抑制小鼠的自主活动能力,且增加阈下剂量戊巴比妥钠小鼠入睡百分率。与模型组相比,小檗碱和黄连碱的NE和5-HT含量明显增加(P<0.01),DA含量无影响(P>0.05)。结论小檗碱和黄连碱可能通过增加PCPA失眠模型小鼠下丘脑中5-HT和NE含量,来发挥一定的镇静、催眠的作用,且小檗碱作用强于黄连碱。其余各生物碱对小鼠睡眠无影响。     

抗抑郁候选化合物GL-21对大鼠脑皮质中神经递质含量影响的研究

目的:研究抗抑郁候选化合物GL-21对大鼠脑皮质中神经递质去甲肾上腺素(NE)及5-羟色胺(5-HT)含量的影响。方法:采用微透析法取样和高效液相色谱法测定大鼠脑皮质中NE及5-HT的含量。结果:分别给大鼠GL-21 2,4和8 mg/kg后,可大幅增加大鼠脑皮质中神经递质NE及5-HT的含量(P<0.05 or P<0.01),且呈一定的剂量关系。结论:抗抑郁候选化合物GL-21可增加大脑皮质单胺类递质NE及5-HT含量。     

钩藤碱对大鼠脑内去甲肾上腺素、5-羟吲哚乙酸的影响

目的 测定钩藤碱对大鼠脑内去甲肾上腺素(norepinephrine，NE)、5-羟吲哚乙酸(5-hydmxyindolea ceticadd，5-HIAA)影响，进一步探讨钩藤碱的镇静作用机制。方法 利用脑微透析方法收集药前及药后纹状体、海马及大脑皮质的细胞外液(透析液)。经反相高效液相电化学法(HPLC-ECD)检测其NE、5-HIAA的变化。结果 Rhy增高正常鼠脑纹状体及海马细胞外液中5-HIAA的含量，降低海马和皮层中NE的含量。结论 钩藤碱的镇静作用，可能与其改变脑内单胺类递质及其代谢产物的含量有关。     

高效液相色谱-电化学法测定大鼠纹状体细胞外液中单胺类神经递质含量

目的:建立应用常规高效液相色谱-电化学法(HPLC-ECD)测定大鼠脑微透析液中单胺类神经递质及其代谢产物。方法:将探针插入大鼠右侧纹状体,在清醒自由活动状态下,用Ringer氏液以1.5μL.min-1的速度灌流,每20 min收集l管透析液,将其注入HPLC-ECD仪,考察本方法的专属性、线性范围、精密度和准确度等,并对其中所含的NE、DA、DOPAC、HIAA、HVA和5-HT进行含量测定。结果:各递质在0.025～0.5 ng.μL-1范围内线性关系良好,方法加样回收完全,日间日内测定均RSD<3.8%。结论:本实验选用了高效液相色谱与电化学检测器连用的方法测定神经递质的含量,该方法简单准确、灵敏、特异性好。     

β-内啡肽对谷氨酸神经毒性作用的影响

采用形态学观察、β-内啡肽(β-End)放射免疫测定及单细胞内游离钙浓度——[Ca²⁺]i检测等方法,观察了β-End对谷氨酸单钠(MSG)诱发神经元损伤的影响,分析了可能的作用机制。结果表明,β-End可以明显加重MSG诱发的下丘脑弓状核神经元的损伤;β-End和MSG诱发的[Ca²⁺]i增高可被维拉帕米部分逆转。另外,吗啡可以进一步加剧MSG诱导的各脑区β-End含量的变化。提示β-End可以明显地加剧MSG的神经毒性作用,其机制与MSG能诱发脑内β-End的含量的增多及β-End可进一步破坏MSG引起的胞内钙稳态失衡有关。     

Effect of chlordecone (Kepone) on the rat brain concentration of 3-methoxy-4-hydroxyphenylglycol: evidence for a possible involvement of the norepinephrine system in chlordecone-induced tremor

3-Methoxy-4-hydroxyphenylglycol (MHPG) is the major metabolite of norepinephrine (NE) in the rat brain. A single injection of tremorigenic doses of chlordecone to adult male Fischer-344 rats resulted in significant increases in MHPG concentrations in hypothalamus, brain stem, cerebellum, and caudate nucleus. The increase in MHPG was accompanied by a decrease in NE in the hypothalamus, suggesting that chlordecone treatment caused an increase in the turnover of NE in the brain. There was a dose- and time-related correlation between the increases in the concentrations of MHPG in hypothalamus, brain stem, and cerebellum and tremor in rats. The increase in MHPG in hypothalamus and brain stem occurred as early as 1 hr postdosing; this preceded the earliest measurable sign of tremor and initial hypothermia. Whether the alterations in the brain NE system are involved in the expression of the tremor and the initial hypothermia induced by chlordecone or whether they are merely associated with these changes is not clear.     

Corticotropin-releasing factor administration elicits a stress-like activation of cerebral catecholaminergic systems

The cerebral content of the biogenic amines, dopamine (DA), norepinephrine (NE), and serotonin (5-HT) and their catabolites 30 min after CRF or saline injections was determined using HPLC with electrochemical detection. Injection of CRF (1.0 micrograms) into the lateral ventricles (ICV) of mice produced a behavioral activation in which their motor movements appeared as bursts of activity followed by periods of immobility. CRF administration (ICV or SC) did not alter the concentrations of DA, NE, tryptophan, 5-HT, or 5-hydroxyindoleacetic acid (5-HIAA) in any brain region measured. ICV CRF increased the concentrations of dihydroxyphenylacetic acid (DOPAC), the major catabolite of DA, and of 3-methoxy,4-hydroxyphenylethyleneglycol (MHPG), the major catabolite of NE, in several brain regions. DOPAC:DA ratios were consistently increased in prefrontal cortex, septum, hypothalamus, and brain stem relative to animals injected with saline. MHPG:NE ratios were also increased in the prefrontal cortex and hypothalamus, with a marginal effect (p = 0.06) in brain stem. SC CRF significantly increased DOPAC:DA in prefrontal cortex, and MHPG:NE in prefrontal cortex, hypothalamus and brain stem. Pretreatment with naloxone did not prevent any of the neurochemical responses to ICV CRF, but naloxone alone increased DOPAC:DA in medial profrontal cortex, and decreased MHPG:NE in nucleus accumbens in CRF-injected mice. These results suggest that administration of CRF either centrally or peripherally induces an activation of both dopaminergic and noradrenergic systems in several regions of mouse brain.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reduced metabolism and turnover rates of rat brain dopamine, norepinephrine and serotonin by chronic desipramine and zimelidine treatments

As part of of an ongoing effort to compare changes in whole body turnover of catecholamines and serotonin in man with those induced by antidepressants in the rat brain, we have evaluated the chronic effects of desipramine (DMI) and zimelidine (ZMI) on brain catecholamines and serotonin in the rat. The amines and metabolites measured include norepinephrine (NE), dopamine (DA) and their metabolites, 3-methoxy-4-hydroxyphenylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA). Three brain areas were analysed; the hypothalamus, caudate nucleus and frontal cortex. Chronic DMI and ZMI reduced hypothalamic MHPG and caudate nucleus DA metabolites, in particular HVA. Both drugs reduced NE and DA turnover rates (estimated after alpha-methyl-p-tyrosine injection) and the rate of MHPG formation in the hypothalamus (estimated after pargyline treatment). They did not change NE turnover rate, but reduced DA turnover rate and rate of HVA formation in the caudate nucleus. Chronic DMI but not ZMI reduced DOPAC rate of formation in the caudate nucleus. Apparently changes in DA turnover and metabolism produced by these antidepressants are better related to changes in HVA than DOPAC concentrations. Similar to their influence on hypothalamic and caudate nucleus catecholamines, both chronic DMI and ZMI produced changes in serotonin concentration in the caudate nucleus and frontal cortex serotonin that suggest a reduction in its turnover rate and metabolism. The reduction in NE turnover in hypothalamus is consistent with the effects of chronic DMI and ZMI on whole body NE turnover observed in man.(ABSTRACT TRUNCATED AT 250 WORDS)     

褪黑素镇痛的相关机制

目的　探讨褪黑素 (MT)镇痛作用与内源性阿片肽、去甲肾上腺素能神经系统及钙通道的关系。方法　大鼠和小鼠痛阈的测定采用热板法 ;β 内啡肽 (β EP)的测定采用放免法 (RIA)。结果　松果腺切除后d 8大鼠痛阈的昼夜节律性消失 ,icvMT 0 2 5mg·kg-1可出现明显的镇痛作用 ;ipMT(10 0mg·kg-1) 1h后下丘脑、垂体 β EP含量均明显降低 ;ip利血平 (3mg·kg-1)可使MT镇痛作用消失 ,而sc酚妥拉明 (10mg·kg-1)可减弱MT的镇痛作用 ;CaCl2 (2 30mg·kg-1)与MT(40mg·kg-1)合用时 ,可使MT的镇痛作用减弱 ,EGTA (180mg·kg-1)及维拉帕米 (15mg·kg-1)则可使之加强。结论　MT的镇痛作用可能与内源性阿片肽、去甲肾上腺素能神经系统及Ca2 + 通道等有关     

Methyl bromide alters catecholamine and metabolite concentrations in rat brain

The effects of inhalation exposure of rats methyl bromide (MB) on dopamine (DA), homovanillic acid (HVA), norepinephrine (NE), 3-methoxy-4-hydroxyphenylglycol (MHPG), serotonin (5HT), and 5-hydroxyindoleacetic acid (5HIAA) concentrations of various brain regions (striatum, hypothalamus, frontal cortex, midbrain, and medulla oblongata) were investigated. Rats received a single 8 hr exposure to MB, and amines and metabolites were separated by a reverse-phase HPLC, and were quantified via native fluorescence. An exposure to 100 ppm MB decreased tissue levels of DA and NE in all brain areas at 0 or 2 hr following exposure. HVA and MHPG contents were significantly increased in almost all brain regions. In a second study, rats were exposed to four concentrations of MB ranging from 31-250 ppm, and monoamine and metabolite levels in brain regions measured immediately after the exposure. Again, there were dose-dependent decreases of DA and NE, and increases in HVA and MHPG. Less clear changes in 5 HT and 5HIAA contents were observed. These data suggest that alterations of catecholamine metabolism may be a factor in MB-induced neurotoxicity.     

下丘脑弓状核参与左旋四氢巴马汀的镇痛作用(英文)

目的:研究弓状核在左旋四氢巴马汀(l-THP)镇痛效应中的作用,以阐明l-THP的镇痛作用机制。方法:应用辣根过氧化物酶(HRP)逆行追踪术追踪纹状体或伏膈核与PAG之间的纤维联系,HRP逆行追踪结合免疫组化观察投射神经元的性质,神经核团损毁和PAG核内注射药物观察对l-THP镇痛作用的影响。结果:纹状体或伏膈核通过弓状核或缰核间接与PAG联系,弓状核投射至PAG的神经元大部分是β内啡肽神经元。损毁弓状核后,l-THP的镇痛作用消失,而损毁缰核对l-THP的镇痛作用无明显影响。PAG核内注射纳洛酮能剂量依赖性翻转l-THP的镇痛作用。结论:弓状核的β内啡肽神经元在l-THP镇痛作用中起重要作用。     

Neurochemical evidence that supraspinally administered gabapentin activates the descending noradrenergic system after peripheral nerve injury

We have previously demonstrated that gabapentin supraspinally activates the descending noradrenergic system to produce analgesic effects after peripheral nerve injury. To further establish the neurochemical basis for its supraspinally mediated analgesic action, concentrations of spinal noradrenaline, 4-hydroxy-3-methoxyphenylglycol (MHPG), serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) and dopamine were measured using high-performance liquid chromatography in a murine neuropathic pain model that was prepared by partial ligation of the sciatic nerve (the Seltzer model). Intracerebroventricularly (i.c.v.) administered gabapentin (100 and 300 microg) increased the spinal MHPG concentration and the MHPG/noradrenaline ratio and alleviated mechanical hypersensitivity, whereas the concentrations of noradrenaline, 5-HT, 5-HIAA and dopamine were unchanged. By contrast, i.c.v. gabapentin neither affected the spinal MHPG concentration and MHPG/noradrenaline ratio nor exhibited analgesic effects in animals subjected to a sham operation. In addition, spinal monoamine levels in ligated animals were not changed after intrathecal administration of gabapentin which however generated analgesic effects. Thus, the supraspinally mediated analgesic effects of gabapentin are correlated with an increase in spinal noradrenaline turnover.