快速起效抗抑郁药物的研究进展

目前临床使用的抗抑郁药物存在起效延迟的不足,这不仅降低了病人的依从性,还增加了其自杀的危险性。因此,如何研制出高效低毒且快速起效的抗抑郁药物成为研发热点。研究表明,选择性5-HT1A、α2自身受体拮抗剂及5-HT2A受体拮抗剂可加快5-羟色胺重摄取抑制剂及去甲肾上腺素重摄取抑制剂等抗抑郁药物的起效速度。此外,5-HT/NE双重重摄取抑制剂及5-HT/NE/DA三重重摄取抑制剂起效时间也缩短。该文将重点围绕单胺系统对抗抑郁药物起效延迟的原因及快速起效抗抑郁药物的研究进展作一综述。     

单胺重摄取抑制剂的研究进展

单胺重摄取抑制剂在临床上被广泛应用于抑郁症的治疗.本文通过文献检索综述了2004～2010年间5-羟色胺重摄取抑制剂和去甲肾上腺素再摄取抑制剂的研究进展,发现具有5-HT、NA重摄取抑制(选择性抑制或双重抑制)活性的新结构及部分构效关系.     

单胺重摄取抑制剂的研究进展

单胺重摄取抑制剂在临床上被广泛应用于抑郁症的治疗。本文通过文献检索综述了2004～2010年间5-羟色胺重摄取抑制剂和去甲肾上腺素再摄取抑制剂的研究进展,发现具有5-HT、NA重摄取抑制(选择性抑制或双重抑制)活性的新结构及部分构效关系。     

人源去甲肾上腺素转运蛋白稳定表达细胞系的构建及其功能鉴定

目的构建人源去甲肾上腺素转运蛋白(h NET)稳定表达细胞系,并对细胞系h NET的结合和重摄取功能进行研究。方法采用脂质体转染法将h NET转染于母细胞-人胚肾(HEK)293细胞(HEK293-h NET);采用RT-PCR和Western蛋白质印迹法在基因和蛋白水平对HEK293-h NET细胞系进行鉴定和稳定性验证;采用放射性配基结合实验检测HEK293-h NET的结合和重摄取功能。并采用三环类抗抑郁药地昔帕明(DIM)和5-羟色胺/去甲肾上腺素双重重摄取抑制剂度洛西汀(DLX),在0~1×10-4mol·L-1浓度梯度范围绘制药物与h NET的结合与重摄取抑制曲线,进一步验证HEK293-h NET细胞系的结合和重摄取功能。结果 RT-PCR和Western蛋白质印迹实验结果表明,所建立的HEK293-h NET细胞系在15代内均稳定表达h NET;放射性配基结合实验表明,HEK293-h NET细胞具有内源性h NET的结合和重摄取功能。并且,DIM和DLX与HEK293-h NET细胞中h NET具有明显的特异性结合(Ki值分别为2.45和3.40 nmol·L-1),并可显著抑制h NET对去甲肾上腺素的重摄取作用(IC50分别为5.78和10.23 nmol·L-1)。结论成功建立的可稳定表达h NET的HEK293-h NET细胞系具有内源性h NET的结合和重摄取功能,可用于h NET靶标药物研究。     

生物胺系统抗抑郁药物依赖性评价研究进展

生物胺系统抗抑郁药物呈现出良好的经济效益和开发前景,近年来针对5-羟色胺(5-HT)/去甲肾上腺素(NE)/多巴胺(DA)三重靶点再摄取抑制作用的抗抑郁药物研发得到快速发展,但其可能伴随的副作用─滥用与成瘾,已成为世界公共卫生领域的严重问题.美国食品药品监督管理局(FDA)、欧洲药品管理局(EMA)和我国国家药品监督管...     

苯丙胺类似物的结构、药理及毒理

<正>苯丙胺(amphetamine,AMP)与多巴胺(dopamine,DA)、去甲肾上腺素(norepinephrine,NE)和5-羟色胺(serotonin,5-HT)等单胺类神经递质的化学结构相似(图1),是一种具有神经兴奋、致幻作用的化合物。AMP的基本药理毒理学机制包括:(1)抑制单胺氧化酶(monoamine oxidase,     

单胺重摄取抑制剂抗抑郁作用评价策略和体系

现有临床抗抑郁药物多以单胺为靶标设计,单胺重摄取抑制剂仍是抗抑郁新药研发的热点方向。新药研发周期长,投资高,风险大,如何快速准确完成药物筛选和临床前评价至关重要。该课题组采用体外高通量筛选和整体动物药效学验证相结合的评价模式,建立了单胺重摄取抑制剂评筛体系,该体系的建立将对单胺重摄取抑制剂的快速评价产生推动作用,也有助于挖掘新的研究思路。该文围绕抗抑郁药效学评价、作用靶标研究、单胺递质含量检测及神经元电活动研究对单胺重摄取抑制剂的评价策略和体系作一综述。     

对氨基水杨酸钠对氯化锰染毒大鼠脑单胺递质的影响

本文报道了对氨基水杨酸钠(PAS-Na)对氯化锰腹腔注射染毒大鼠脑单胺递质水平的影响。PAS-Na能使锰染毒所降低了的脑多巴胺(DA)水平逆转;锰使脑去甲肾上腺素(NE)含量增加,染毒后以PAS-Na治疗则使之进一步升高;锰染毒和染毒后治疗组的5-羟色胺(5-HT)及5-羟吲哚醋酸(5-HIAA)的变化与DA相似,但PAS-Na使5-HT、5-HIAA水平升高的幅度大都较NE和DA的要小,提示5-HT能神经元对PAS-Na治疗作用的敏感性低于儿茶酚胺(CA)能神经元。     

文拉法辛缓释胶囊与舍曲林治疗抑郁症的临床疗效和安全性对照研究

<正>文拉法辛及其活性代谢产物O-去甲基文拉法辛(ODV)是一种二环类苯乙胺族化合物,是5-羟色胺和去甲肾上腺素再摄取抑制剂(serotonin and noradrenaline reuptake inhibitor,SNRI)类抗抑郁药物,能选择性阻断5-羟色胺(5-HT)转运体和去甲肾上腺素(NE)转运体的再摄取作用,具有双重活性,能快速起效,起到抗抑郁作用。本研究比较文拉法辛与舍曲林对抑郁症的治疗效果及安全性,     

非单胺靶标抗抑郁药研究进展

目前临床上所使用的抗抑郁药绝大多数以5-羟色胺、去甲肾上腺素和多巴胺等单胺受体为靶标.这些单胺靶标抗抑郁药起效慢、疗效不佳、易复发,远不能满足临床需求.抑郁症的病理学研究表明,一些非单胺受体也参与其中并起重要作用,以非单胺受体为靶标的抗抑郁药已成为抗抑郁药研究的热点.非单胺靶标抗抑郁药在体内外实验中有良好的活性,有些已经进入临床研究,临床研究表明其中某些抗抑郁药起效较快.文中综述非单胺靶标抗抑郁药的研究进展.     

Pharmacology of monoamine neurotransmitter transporters

Following exocytotic release, the biogenic amine neurotransmitters, norepinephrine, dopamine, and serotonin are removed from the synaptic cleft by the respective transporter, NET, DAT, and SERT, located on the plasma membrane and then re-stored into synaptic vesicles by vesicular monoamine transporter, VMAT. The molecular cloning of these transporters revealed that NET, DAT, and SERT are members of a sodium-dependent neurotransmitter transporter gene family, while VMATs arise from proton-dependent transporter gene family. Structural features common to NET, DAT, and SERT reveal a putative 12 transmembrane-spanning domain structure with cytosolic N- and C-terminal regions. Recent evidence suggest the regulation of the functional expression of these transporters via phosphorylation, which include direct phosphorylation of transporter proteins and/or of associated proteins that may control transporter function/expression. In addition, the substrates and inhibitors for these transporters appear capable of regulating transporter cell surface expression, thereby suggesting both activity-dependent and pharmacological regulatory mechanisms for transporter expression. Analyses of the genes provide new insight into their relation to neuronal diseases since NET, DAT and SERT are the molecular targets for many antidepressants as well as drugs of abuse such as cocaine and amphetamine. The availability of cDNAs of these and vesicular transporters has permitted detailed pharmacological studies in heterologous expression systems, and thus would promise the development of novel drugs with diverse chemical structures.     

Methylone and monoamine transporters: correlation with toxicity

Methylone (2-methylamino-1-[3,4-methylenedioxyphenyl]propane-1-one) is a synthetic hallucinogenic amphetamine analog, like MDMA (3,4-methylenedioxy- methamphetamine), considered to act on monoaminergic systems. However, the psychopharmacological profile of its cytotoxicity as a consequence of monoaminergic deficits remains unclear. We examined here the effects of methylone on the transporters for dopamine (DAT), norepinephrine (NET), and serotonin (SERT), using a heterologous expression system in CHO cells, in association with its cytotoxicity. Methylone inhibited the activities of DAT, NET, and SERT, but not GABA transporter-1 (GAT1), in a concentration-dependent fashion with a rank order of NET > DAT > SERT. Methylone was less effective at inhibiting DAT and NET, but more effective against SERT, than was methamphetamine. Methylone alone was not toxic to cells except at high concentrations, but in combination with methamphetamine had a synergistic effect in CHO cells expressing the monoamine transporters but not in control CHO cells or cells expressing GAT1. The ability of methylone to inhibit monoamine transporter function, probably by acting as a transportable substrate, underlies the synergistic effect of methylone and methamphetamine.     

Selective inhibition of monoamine neurotransmitter transporters by synthetic local anesthetics

Synthetic local anesthetics (LAs) have been found to have cocaine-like characteristics with some psychotomimetic action, possibly through monoaminergic neurotransmission. To gain insight into the relation between LA action and monoamine transporters, we investigated the effect of synthetic LAs on neurotransmitter transporters, including monoamine transporters. We used cloned transporter cDNAs and examined transient functional expression in COS cells and stable expression in HeLa cells. Among the LAs tested, procaine and other ester-type LAs inhibited [3H]DA uptake and binding of [3H]2-beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane (CFT), a cocaine analogue, in COS cells expressing rat dopamine transporter (DAT). The inhibition was concentration-dependent. The inhibitory effect on [3H]DA uptake was reversible and not dependent on pH, as observed in HeLa cells stably expressing DAT. Procaine also inhibited uptake of norepinephrine (NE) and serotonin (5-HT) by the norepinephrine transporter (NET) or serotonin transporter (SERT) expressed in COS cells. On the other hand, procaine and other LAs had little or no effect on [3H]GABA and [3H]glutamate uptake in COS cells expressing mouse GABA or rat glutamate/aspartate transporter. IC50 values for [3H]DA uptake inhibition correlated well with those for [3H]CFT binding inhibition, but not with intrinsic anesthetic potency. Kinetic analysis of monoamine uptake inhibition by procaine in COS cells expressing rat DAT, NET or SERT revealed a competitive action similar to that of cocaine. These results demonstrate that certain LAs selectively inhibit monoamine transporters. This might contribute to the cocaine-like psychotomimetic action of certain LAs.     

Synthesis, monoamine transporter binding, properties, and functional monoamine uptake activity of 3beta-[4-methylphenyl and 4-chlorophenyl]-2 beta-[5-(substituted phenyl)thiazol-2-yl]tropanes

Synthetic methods were developed for the synthesis of the 3beta-(4-substituted phenyl)-2 beta-[5-(substituted phenyl)thiazol-2-yl]tropanes (4a-s). The compounds were evaluated for their monoamine transporter binding and monoamine uptake inhibition properties using both rat brain tissue and cloned transporter assays. In general, the compounds showed higher dopamine transporter (DAT) affinity relative to the serotonin and norepinephrine transporters (SERT and NET, respectively) and greater [3H]dopamine uptake inhibition potency relative to [3H]serotonin and [3H]norepinephrine uptake inhibition. Several compounds were DAT selective relative to the SERT and NET in the monoamine transporter binding assays. The most potent and selective analog in the functional monoamine uptake inhibition test was 3beta-(4-methylphenyl-2 beta-[5-(3-nitrophenyl)thiazol-2-yl]tropane (4p).     

5-Methoxy-N,N-diisopropyltryptamine (Foxy), a selective and high affinity inhibitor of serotonin transporter

5-Methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT) is a synthetic orally active hallucinogenic tryptamine derivative, known also as Foxy or Foxy methoxy. However, few studies have examined its effects in vitro. In the present study, we investigated the actions of 5-MeO-DIPT against monoamine neurotransmitter transporters, including the transporters for dopamine (DAT), norepinephrine (NET), and serotonin (SERT), using COS-7 cells heterologously expressing these transporters and rat brain synaptosomes. 5-MeO-DIPT specifically inhibited the uptake of [³H]serotonin (5-HT) by the SERT-expressing COS-7 cells and rat striatal synaptosomes in a high affinity manner at concentrations similar to those for cocaine. The effect was reversible and competitive. 5-MeO-DIPT failed to stimulate reverse transport of [³H]5-HT through SERT, while it prevented the releasing action of methamphetamine. 5-MeO-DIPT induced cell toxicity at high concentrations in COS-7 cells, and it was not influenced by the expression of SERT. These results demonstrated that 5-MeO-DIPT acts as a competitive SERT inhibitor and has an inability to cause reverse transport, underlying its serotonergic actions.     

Ex vivo assessment of binding site occupancy of monoamine reuptake inhibitors: methodology and biological significance

The goal of this study was to develop and validate ex vivo binding assays for serotonin (SERT), norepinephrine (NET) and dopamine (DAT) transporters, and to use these assays to evaluate the binding site occupancy of triple and double monoamine reuptake inhibitors in rat brains. This study demonstrated that while autoradiographic methods provided anatomic precision and regional resolution, the homogenate binding method for site occupancy assessment yielded comparable sensitivity with markedly improved throughput. For ex vivo binding assays, the reduction of temperature and time during the in vitro process (primarily incubation with a radioligand) markedly decreased the dissociation of test agents from binding sites in brain tissues. This reduction, in turn, minimized the potential for underestimation of site occupancy in vivo especially for test compounds with affinity >10nM. The ratios of measured occupancy ED(50) values (doses at which 50% occupancy occurs) among SERT, NET and DAT sites for duloxetine, venlafaxine, nomifensine, indatraline, DOV 21,947 and DOV 216,303 were consistent with the ratios of the in vitro affinities between these target binding sites. The biological relevance of the monoamine transporter occupancy for these compounds is discussed.     

Further structural exploration of trisubstituted asymmetric pyran derivatives (2S,4R,5R)-2-benzhydryl-5-benzylamino-tetrahydropyran-4-ol and their corresponding disubstituted (3S,6S) pyran derivatives: a proposed pharmacophore model for high-affinity interaction with the dopamine, serotonin, and norepinephrine transporters

In our previous report, we described a novel series of asymmetric pyran derivatives (2S,4R,5R)-2-benzhydryl-5-benzylamino-tetrahydropyran-4-ol and their enantiomers as blockers of monoamine transporters in the brain. In this report, we describe the further exploration of this series of molecules by incorporating functional groups in the molecular template, which should promote the formation of H bonds with the transporters. In addition, a new synthetic scheme for the asymmetric synthesis of disubstituted cis-(6-benzhydryl-tetrahydro-pyran-3-yl)-benzylamine analogues and their biological characterization is reported. All synthesized derivatives were tested for their affinities for the dopamine transporter (DAT), serotonin transporter (SERT), and norepinephrine transporter (NET) in the brain by measuring their potency in inhibiting the uptake of [(3)H]DA, [(3)H]5-HT, and [(3)H]NE, respectively. The compounds were also tested for their binding potency at the DAT by their ability to inhibit binding of [(3)H]WIN 35, 428. The results indicated that the presence of functional groups, such as -OH, -NH(2), and the bioisosteric 5-substituted indole moiety in both di and trisubstituted compounds, significantly increased their potencies for the SERT and NET, especially for the NET. Among the trisubstituted compounds, (-)-4b exhibited the highest potency for the NET and the SERT (K(i) of 2.13 and 15.3 nM, respectively) and was a serotonin norepinephrine reuptake inhibitor (SNRI). Compound (-)-4a exhibited the highest selectivity for the NET. Among the disubstituted compounds, a number of compounds, such as (-)-9a, (+)-9b, (-)-9b, and (+)-9d, exhibited significant low-nanomolar potencies for the SERT and the NET. Interestingly, compound (-)-9d exhibited appreciable potencies at all three transporters. On the basis of our present and past findings, we propose a qualitative model for the interaction of these compounds with monoamine transporters, which will be refined further in the future.     

Stimulant and reinforcing effects of cocaine in monoamine transporter knockout mice

A large body of evidence supports the hypothesis that the reinforcing effects of cocaine depend on its ability to block the dopamine transporter (DAT), thereby increasing dopamine extracellular concentration within the mesocorticolimbic system. However, the fact that cocaine similarly binds to the serotonin and norepinephrine transporters (SERT and NET, respectively), raises the possibility that modulation of mesocorticolimbic dopaminergic transmission might be achieved through alternate pathways. The successful disruption of the genes coding for the DAT, the SERT and the NET offered ideal tools to determine the extent of the participation of these transporters and respective monoaminergic systems in the reinforcing effects of cocaine. Studies of cocaine-induced motor activation and maintenance of intravenous (i.v.) self-administration in DAT- and in NET-knockout (KO) mice are reviewed here, and discussed in light of new observations obtained from double monoamine transporters KO mice (i.e., DAT-KO/SERT-KO, NET-KO/SERT-KO). The reinforcing potency of cocaine is maintained in the absence of the DAT but decreased in the absence of the NET; its motivational rewarding effect is observed in the absence of the SERT, but not when both DAT and SERT are lacking. Moreover, a dichotomy between cocaine motor activating and reinforcing effects is reported. Such dichotomy is suggestive of independent mechanisms underlying the psychomotor stimulant and reinforcing effects of cocaine. Overall, these studies provide evidence that cocaine dynamically acts at multiple sites through pathways that might be exchangeable under certain circumstances.     

Substituted methcathinones differ in transporter and receptor interactions

The use of synthetic methcathinones, components of “bath salts,” is a world-wide health concern. These compounds, structurally similar to methamphetamine (METH) and 3,4-methylendioxymethamphetamine (MDMA), cause tachycardia, hallucinations and psychosis. We hypothesized that these potentially neurotoxic and abused compounds display differences in their transporter and receptor interactions as compared to amphetamine counterparts. 3,4-Methylenedioxypyrovalerone and naphyrone had high affinity for radioligand binding sites on recombinant human dopamine (hDAT), serotonin (hSERT) and norepinephrine (hNET) transporters, potently inhibited [³H]neurotransmitter uptake, and, like cocaine, did not induce transporter-mediated release. Butylone was a lower affinity uptake inhibitor. In contrast, 4-fluoromethcathinone, mephedrone and methylone had higher inhibitory potency at uptake compared to binding and generally induced release of preloaded [³H]neurotransmitter from hDAT, hSERT and hNET (highest potency at hNET), and thus are transporter substrates, similar to METH and MDMA. At hNET, 4-fluoromethcathinone was a more efficacious releaser than METH. These substituted methcathinones had low uptake inhibitory potency and low efficacy at inducing release via human vesicular monoamine transporters (hVMAT2). These compounds were low potency (1) h5-HT_1A receptor partial agonists, (2) h5-HT_2A receptor antagonists, (3) weak h5-HT_2C receptor antagonists. This is the first report on aspects of substituted methcathinone efficacies at serotonin (5-HT) receptors and in superfusion release assays. Additionally, the drugs had no affinity for dopamine receptors, and high-nanomolar to mid-micromolar affinity for hSigma1 receptors. Thus, direct interactions with hVMAT2 and serotonin, dopamine, and hSigma1 receptors may not explain psychoactive effects. The primary mechanisms of action may be as inhibitors or substrates of DAT, SERT and NET.