5-HT_(1A)受体激动剂类抗抑郁药的研究与开发

综述5-HT1A-受体激动剂抗抑郁作用的机制及其新产品的研究与开发。5-HT1A受体激动剂通过激动突触后膜 的5-HT1A受体,负反馈抑制海马5-HT能神经元上的自主受体而发挥抗抑郁作用,克服了传统抗抑郁药的滞后效应。     

5-HT_(1A)受体拮抗剂WAY-100635的合成

2-氨基吡啶和2-氯乙酰氯经酰胺化、与N'-(邻甲氧基苯基)哌嗪缩合、氢化铝锂还原得4-(邻甲氧基苯基)-1-[2-[(2-吡啶基)氨基]乙基]哌嗪,再与环己甲酰氯缩合得到5-HT1A受体拮抗剂WAY-100635,总收率35%。     

5-HT_(2C)受体的螺旋结构与功能

5-羟色胺(5-HT)是动物中枢神经和外周神经系统中重要的递质〔1〕,在人的中枢神经系统中调节人体的许多活动;在非神经组织中,5-HT也同样起重要作用。迄今为止,在人类的中枢神经系统已经发现了14种5-HT受体亚型,即5-HT1A,5-HT1B,5-HT1D,52HT1E,5-HT1F,5-HT2A,5-HT2B,5-HT2C,5-HT3     

5-羟色胺（5-HT）1A受体配体的研究进展

5-羟色胺（5-HT）是重要的神经递质，5-HT受体（5-HTR）在认知、情感等众多神经活动中发挥着重要作用，是重要的药物靶标。5-HT1A受体（5-HT1AR）是众多5-HTR亚型中研究最为广泛和深入的一类受体，研究5-HT1A受体配体（5-HT1ARL）对于临床上治疗焦虑、抑郁、疼痛等疾病都具有重要的价值。该文主要从5-HT1ARL结构类型的角度综述5-HT1ARL的最新研究进展，并简要介绍定向多靶标配体的研究成果，展望5-HT1ARL药物的开发前景。     

5-HT_(2A)受体基因1438A/G多态性与海洛因依赖的关系

目的··:探讨5 -HT2A 受体基因多态性与海洛因依赖易感性的关系。方法··:用聚合酶链式反应 (PCR)技术结合限制性片段长度多态性 (RFLP)分析技术 ,检测了99名海洛因依赖者和80名正常对照者5 -HT2A 受体基因1438A/G多态性的基因型和等位基因频率。结果··:海洛因依赖者5 -HT2A 受体基因1438A/G多态性基因型A1/A2的频率较对照组高。结论··:5 -HT2A 受体基因1438A/G多态性可能与海洛因依赖的易感性有关     

吗啡对急性心肌缺血期大鼠丘脑束旁核神经元5-HT_(1A)受体mRNA表达的影响

目的:观察吗啡对急性心肌缺血期大鼠丘脑束旁核神经元5-HT1A受体mRNA表达的影响,探讨吗啡对急性心肌缺血伤害性刺激的作用及其机制。方法:将体重260g~280g的健康成年雄性SD大鼠18只,随机分为三组:对照组,即非冠状动脉扎闭组(C组),开胸后冠状动脉左前降支下穿线,不结扎;扎闭冠脉组(CAO组),扎闭冠脉6h;吗啡+CAO组(MCAO组),CAO前15min静脉注射吗啡1.25mg/kg,然后CAO6h。CAO6h处死动物,取含有大鼠丘脑束旁核的脑片行原位杂交。5-HT1A受体mRNA杂交结果检测采用IDA-2000数码显微图像分析系统进行半定量分析。结果:与C组比较,CAO组大鼠丘脑束旁核5-HT1A受体mRNA的表达增强(P<0.05),与CAO组比较,MCAO组5-HT1A受体mRNA表达降低(P<0.05)。结论:急性心肌缺血可诱发大鼠丘脑束旁核5-HT1A受体mRNA表达增强,5-HT1A受体参与急性心肌缺血伤害性刺激在丘脑束旁核的调制,吗啡可抑制急性心肌缺血诱发的大鼠丘脑束旁核5-HT1A受体mRNA的表达增强。     

海洛因依赖与5-HT_(2A)受体基因-1438A/G多态性的相关研究

目的 :探讨海洛因依赖和 5 -羟色胺 2A (5 -HT2A)受体基因 - 14 38A G多态性的关系。方法 :采用聚合酶链式反应 (polymerasechainreaction ,PCR)技术 ,检测 2 6 5例海洛因依赖者和 195例正常对照的 5 -HT2A 受体基因 -14 38A G多态性。结果 :海洛因依赖者和对照组之间 5 -HT2A受体基因 - 14 38A G多态性的基因型和等位基因频率的差异均无显著性 (χ2 值分别为 3.2 3,P >0 .0 5和 0 .0 0 1,P >0 .0 5 )。结论 :5 -HT2A 受体基因 - 14 38A G多态性和海洛因依赖的易感性无关     

5-HT重摄取抑制/5-HT1A受体拮抗双重作用抗抑郁药研究进展

5-HT重摄取抑制/5-HT1A受体拮抗双重作用抗抑郁药是在单胺递质学说的基础上研发的新一代抗抑郁药,此类药物研发的策略主要是通过分子拼合原理,在单一分子中引入2种药效团在体内共同发挥抗抑郁作用.文中对该类药物中几种典型的结构构效关系及生物活性评价结果进行综述,以期为抗抑郁药物的研发提供参考.新型化合物在有效性、安全耐受性及起效时间等方面表现出很多优势,但是目前还没有相关的临床报道数据.     

5-HT1A和5-HT2A/2C受体在粉防己碱增强戊巴比妥钠睡眠中的介导作用

前期研究表明粉防己碱增强戊巴比妥钠诱导的催眠作用与5-HT系统相关。本研究采用戊巴比妥钠（45 mg/kg,i.p.）诱导的小鼠翻正反射消失和恢复实验方法,对粉防己碱与不同5-HT受体在增强戊巴比妥钠诱导睡眠中的相互作用进行了探讨。结果表明粉防己碱分别与选择性5-HT1A受体拈抗剂p-MPPI（1 mg/kg,i.p.）,选择性5-HT2A/2C受体拮抗剂ketanserin（1.5 mg/kg,i.p.）合用可以显著增强戊巴比妥钠诱导的催眠作用。选择性5-HT1A受体激动剂8-OH-DPAT（0.1 mg/kg,s.c.）或5-HT2A/2C受体激动剂DOI（0.2mg/kg,i.p.）能够显著减少戊巴比妥钠诱导的小鼠睡眠时间,而粉防己碱（60 mg/kg,i.g.）可以显著拮抗这种睡眠抑制作用。此结果提示,粉防己碱增强戊巴比妥钠诱导的催眠作用可能与5-HT1A受体和5-HT2A/2C受体有关。     

5-羟色胺5-HT_(2C)受体激动剂抑制吗啡依赖小鼠纳洛酮诱导的戒断行为

目的观察5-羟色胺2C受体(5-HT2CR)激动剂WAY对吗啡依赖小鼠纳洛酮诱导戒断症状的防治作用,探讨5-HT2CR在吗啡成瘾导致的躯体依赖中的作用。方法采用Etho Vision动物行为分析系统观察5-HT2CR激动剂WAY对正常小鼠自发活动的影响;剂量递增法诱导小鼠吗啡依赖模型,观察WAY对吗啡依赖小鼠纳洛酮诱导戒断症状的影响。结果 WAY(0.5、0.75、1.0 mg·kg-1,i.p.)对小鼠自发活动没有明显影响。慢性吗啡诱导依赖小鼠运动距离、速度和跳跃等行为活动增加。WAY(0.5、0.75、1.0 mg·kg-1)和可乐定(0.2 mg·kg-1,i.p.)对吗啡依赖小鼠纳洛酮催促出现的打洞、跳跃、清理皮毛、站立、"湿狗"样抖动、摇头、清理脸部、抓挠戒断症状有明显的抑制作用(P<0.05)。结论药物激活5-HT2CR可明显的抑制吗啡依赖小鼠纳洛酮催促的戒断症状。5-HT2CR可能是潜在的治疗吗啡躯体依赖、渴求和复吸的靶点。     

Relevance of dorsal raphe nucleus firing in serotonin 5-HT2C receptor blockade-induced augmentation of SSRIs effects

Selective serotonin reuptake inhibitors are the most widely prescribed antidepressant drugs. However, they exhibit a slow onset of action, putatively due to the initial decrease in serotonin cell firing mediated via somato-dendritic autoreceptors. Interestingly, blockade of 5-HT_2C receptors significantly potentiates the effect of citalopram, a selective serotonin reuptake inhibitor, on serotonin efflux in the hippocampus and prefrontal cortex (Cremers, T.I.F.H., Giorgetti, M., Bosker, F.J., Hogg, S., Arnt, J., Mork, A., Honig, G., Bøgesø, K.P., Westerink, B.H.C., den Boer, J.A., Wikstrøm, H.V., Tecott, L.H., 2004. Inactivation of 5-HT_2C receptors potentiates consequences of serotonin reuptake blockade. Neuropsychopharmacology 29, 1782-1789; Cremers, T.I.F.H., Rea, K., Bosker, F.J., Wikström, H.V., Hogg, S., Mørk, A., Westerink, B.H.C., 2007. Augmentation of SSRI effects on serotonin by 5-HT_2C antagonists: mechanistic studies. Neuropsychopharmacology 32, 1550-1557.). Using in vivo electrophysiology, we show in the present study that the purported selective 5-HT_2C receptor antagonist, SB242,084, dose-dependently counteracts citalopram-induced inhibition of serotonin cell firing. Even though the effect of SB242,084 is significant at a dose found in vivo to also partially occupy 5-HT_2A receptors, indicating a possible contribution of a partial blockade of 5-HT_2A receptors together with 5-HT_2C receptors, we suggest that high occupancy at 5-HT_2C receptors is essential for the blockade of the inhibitory effect of citalopram on 5-HT cell firing. Using microdialysis, we also show that the potentiation by SB242,084 on serotonin efflux requires an action of citalopram outside the terminal, most likely at the somato-dendritic level (i.e., on serotonin cell firing). Further experiments using local 5-HT_2C receptor blockade indicate a role of 5-HT_2C receptors located in the prefrontal cortex. Modulation of short or long feedback loops originating in the prefrontal cortex by 5-HT_2C receptors could directly inhibit serotonin efflux, or alternatively, regulate serotonin cell firing in the dorsal raphe nucleus, thereby modulating serotonin efflux indirectly.     

Blockade of paeoniflorin on sodium current in mouse hippocampal CA_1 neurons

AIM: To study the blockade of paeoniflorin (Pae) on I_(Na) in the acutely isolated hippocampus neurons of mice. METHODS: The whole-cell patch clamp technique was used. RESULTS: Pae inhibited I_(Na) in frequency-dependent and concentration-dependent manners, with an IC_(50) of 271μmol/L. Pae 0.3 mmol/L shifted the activation potential of the maximal I_(Na) from -40 mV to -30 mV, shifted the steady-state activation and inactivation curves toward more positive and negative potentials by 10.8 mV, and 18.2 mV, respectively, and postponed the recovery of I_(Na) inactivation state from (4.2±0.7) ms to (9.8±1.2) ms. CONCLUSION: Pae inhibited I_(Na) in mouse hippocampus neurons.     

Subcellular localization of neuronal nitric oxide synthase in rat small intestine

The subcellular localization of neuronal nitric oxide synthase (NOS I, EC 1.14.13.39) was investigated in the longitudinal muscle/myenteric plexus (LM/MP) preparation of rat small intestine. The presence of NOS I, inducible nitric oxide synthase (NOS II), and endothelial nitric oxide synthase (NOS III) was assessed after homogenization and low-speed centrifugation in a postnuclear supernatant by immunological detection after PAGE and Western blotting. Only NOS I was clearly present, whereas NOS II and NOS III were below detection limits. After high-speed centrifugation of the postnuclear supernatant, soluble and particulate fractions were obtained, and the presence of NOS I in these fractions was investigated by measurement of NOS I immunoreactivity and enzyme activity. We found that 90 +/- 1% of NOS I immunoreactivity and 97 +/- 1% of NOS enzyme activity were confined to the soluble fraction of the tissue. Further immunological analysis demonstrated that washing the particulate fraction revealed detectable amounts of NOS I only after concentration of the washing supernatant. Most particulate NOS I remained in the pellet and therefore represents cell organelle-associated enzyme. No NOS I immunoreactivity could be detected as a soluble protein within organelles of the cell. Particulate NOS I could in part be solubilized by Triton X-100 treatment, and the detection of Triton X-100-soluble NOS I was dependent on the antibody used. In conclusion, our results indicate that NOS I in the LM/MP preparation of rat small intestine is mainly soluble and that the particulate NOS I is partly an intrinsic membrane protein and can partly be solubilized by detergent treatment.     

Dependence of serotonin release in the locus coeruleus on dorsal raphe neuronal activity

The serotonergic innervation of the locus coeruleus paetly derives from the dorsal raphe nucleus (DRN). Using the push-pull superfusion technique, we investigated whether and to what extent the release of serotonin and the extracellular concentration of its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the locus coeruleus are influenced by the neuronal activity of the DRN. In anaesthetized rats, a push-pull cannula was inserted into the locus coeruleus, which was continuously superfused with artificial cerebrospinal fluid (aCSF). Serotonin and 5-HIAA levels in the superfusate were determined by HPLC combined with electrochemical detection. Electrical stimulation (5 Hz, 300 μA, 1 ms) of the DRN for 5 min, or its chemical stimulation by microinjection of glutamate (3.5 nmol, 50 nl), led to an increased release of serotonin in the locus coeruleus and to a slight (2 mmHg) decrease in blood pressure. Superfusion of the locus coeruleus with tetrodotoxin (1 μM) abolished the increase in the release rate of serotonin evoked by electrical stimulation of the DRN, while the slight fall in blood pressure was not influenced. Thermic lesion (75 °C, 1 min) of the DRN elicited a pronounced decline in serotonin release rate within the locus coeruleus, the maximum decrease being 52%. The decrease in the release of serotonin was associated with a long-lasting rise in blood pressure. Microinjection of the serotonin neurotoxin 5,7-dihydroxytryptamine (5 μg, 250 nl) into the DRN led to an initial increase in the serotonin release rate that coincided with a short-lasting fall in blood pressure. Subsequently, the release of serotonin was permanently reduced and was associated with hypertension. Microinjection of the 5-HT_1A receptor agonist (±)-8-hydroxy-dipropylaminotetralin (8-OH-DPAT; 7.5 nmol, 50 nl) into the DRN led to a long-lasting reduction of the release rate of serotonin in the locus coeruleus. Microinjection of 8-OH-DPAT into the DRN also slightly lowered blood pressure (3 mmHg). Neither stimulations nor lesion of the DRN, nor microinjection of 8-OH-DPAT into this raphe nucleus, altered the extracellular concentration of 5-HIAA. Judging from the present biochemical results it appears that the serotonergic afferents to the locus coeruleus originate to more than 50% from cell bodies located in the DRN. The neuronal serotonin release in the locus coeruleus is modulated by 5-HT_1A receptors lying within the DRN. Changes in blood pressure and release of serotonin elicited by stimulating or lesioning the DRN point to the importance of serotonergic neurons extending between this raphe nucleus and the locus coeruleus in central cardiovascular control. Received: 5 November 1998 / Accepted: 21 February 1999     

Subcellular localization of a thromboxane A2/prostaglandin H2 receptor antagonist binding site in human platelets

The subcellular localization of a binding site for the competitive thromboxane A2/prostaglandin H2 (TXA2/PGH2) antagonist, 9,11-dimethylmethano-11,12-methano-16-(3-iodo-4- hydroxyphenyl)-13,14-dihydro-13-aza-15 alpha beta-omega-tetranor TXA2 ([125I]-PTA-OH), was determined. Subcellular fractions of platelets were prepared by glycerol lysis or nitrogen cavitation, and were characterized by the use of enzymatic markers specific for plasma membranes, endoplasmic reticulum (dense tubular system), mitochondria, granules, and cytosolic constituents. The Kd and density of binding sites in the subcellular fractions were determined by Scatchard analysis of equilibrium binding data. The Kd and Bmax for [125I]-PTA-OH determined in the lysates were 49 +/- 11 nM and 4.1 +/- 1.7 pmol/mg protein respectively (N = 6). The Kd values were not significantly different in any of the fractions assayed. The binding sites were coenriched (4.5 +/- 0.66 fold) with the enzymatic markers for plasma membranes (3.7 +/- 0.5 fold) and dense tubular system (2.4 +/- 0.4 fold). The binding sites were not coenriched with markers for cytoplasmic constituents, mitochondria, or granules. The ability of the TXA2/PGH2 mimetic U46619 to compete with [125I]-PTA-OH for the binding site was also determined for the various subcellular fractions. The IC50 for U46619 was 5.4 +/- 1.2 microM in the lysate, and was not significantly different in the subcellular fractions. These data suggest that the binding site is the TXA2/PGH2 receptor described previously. These data are consistent with the notion that the putative TXA2/PGH2 receptor is localized in the plasma membranes and/or the dense tubular system.     

Cocaine-induced 'active immobility' and its modulation by the serotonin1A receptor

'Active immobility' (AI) is an independent behaviour that can be characterized by behavioural immobility, an increased muscular rigidity and the sustaining of an unusual posture. In previous studies with cocaine we observed, concomitant with hyperlocomotion and increased rearing activity, an increase in AI in well-habituated animals, which may constitute another 'positive' acute effect of cocaine on behaviour. The contribution of the serotonergic (5-HT) system to AI is well established. However, little information exists about the contribution of particular 5-HT-receptor subtypes. In order to examine a possible role of the 5-HT1A receptor on this effect of cocaine, we systematically re-analysed four previous experiments in well-habituated animals and one in little-habituated animals, focusing on the acute behavioural effects of cocaine on AI. We found that, in well-habituated animals, cocaine at a medium dose (10 mg/kg, i.p.) induces AI behaviour, which, however, does not correlate with cocaine effects on locomotion, rearing or grooming behaviour. However, there was no effect of cocaine (1, 5 or 15 mg/kg, i.p.) on AI in little-habituated animals. The 5-HT1A-receptor antagonist, WAY 100635 [N-[2-(4-2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide trihydrochloride] (0.4 mg/kg, i.p.), potentiated cocaine-induced AI in well-habituated animals, while the 5-HT1A-receptor agonist, 8-OH-DPAT (0.2 mg/kg, i.p.), attenuated it. The local application of 8-OH-DPAT [8-hydroxy-2-(di-n-propylamino)tetralin] into the nucleus accumbens (0, 1, 10 micromol/l) or hippocampus (0, 0.1, 1, 10 micromol/l) modulated cocaine-induced AI in a complex way. These results showed that cocaine induces AI at a medium dose in well-habituated but not in little-habituated animals. The cocaine-induced AI in well-habituated animals can be potentiated by systemic 5-HT1A-receptor antagonism and attenuated by 5-HT1A-receptor agonism. Two experiments with local activation of postsynaptic 5-HT1A receptors revealed that both nucleus accumbens and hippocampal 5-HT1A-receptor populations are involved in the expression of cocaine-induced AI.     

Ipsapirone depresses neuronal activity in the dorsal raphe nucleus and the hippocampal formation

Ipsapirone, a putative, novel anxiolytic with a high affinity for 5-HT1A binding sites, suppressed neuronal activity in both the dorsal raphe nucleus and hippocampal formation of urethane-anesthetized rats. In the hippocampus, dentate granule cells matched the responsiveness of dorsal raphe serotonin neurons, the median effective dose for 50% inhibition being 125.0 micrograms/kg in both areas. In contrast, the responses of CA1 pyramidal cells were related directly to baseline firing rates. Slow-firing neurons, for example, were inhibited by 31.3 micrograms/kg and fast-firing cells were unresponsive even up to a dose of 500.0 micrograms/kg. These results indicate a potent effect of ipsapirone on neuronal activity in sites with a high density of 5-HT1A receptors.     

Effects of the serotonin 5-HT(7) receptor antagonist SB-269970 on the inhibition of dopamine neuronal firing induced by amphetamine

Using extracellular unitary recordings in anaesthetized rats, this study examined the implication of the serotonin 7 (5-HT₇) receptors in the inhibitory effect of amphetamine on ventral tegmental area and substantia nigra pars compacta dopamine neuronal activity. The acute administration of the selective 5-HT₇ receptor antagonist, SB-269970 (0.1, 0.5 and 1 mg/kg, i.p.), did not alter the firing activity of dopamine neurons. Interestingly, this antagonist prevented significantly the inhibition of dopamine neuronal firing activity induced by amphetamine (1 mg/kg, i.v.) in the ventral tegmental area, but not in the substantia nigra pars compacta. The present results suggest that 5-HT₇ receptors modulate the dopamine firing activity in the ventral tegmental area, thus affecting preferentially the mesocorticolimbic pathway.