Effects of Activation and Blockade of Serotonin 5-HT1A Receptors on the Immune Response in Rats Selected for Different Levels of Aggressiveness

The present study examines the effects of serotonin (5-HT) 1A receptor ligands on humoral im-mune response in two rat lines selected for over 75 generations for the enhancement or elimination of aggression. Activation of presynaptic 5-HT1A receptors with a low dose of the selective 5-HT1A receptor agonist 8-OH-DPAT (0.1 mg/kg) or the blockade of postsynaptic 5-HT1A receptors with the antagonist WAY-100635 (1.0 mg/kg) did not affect the numbers of IgM-antibody forming cells (IgM-AFC) in the spleen of highly aggressive rats, which were characterized by higher immune responsiveness compared to nonaggressive line. On the other hand, the same doses of 8-OH-DPAT and WAY-100635, as well as a higher dose of 8-OH-DPAT (1.0 mg/kg), which is known to activate postsynaptic 5-HT1A receptors, produce immunostimulation in nonaggressive rats. However, only the highest dose of 8-OH-DPAT (5.0 mg/kg) was able to cause immunosuppression in nonaggressive rats that was mainly dependent on stimulation of postsynaptic 5-HT1A receptors. In contrast to nonaggressive rats, the dose of 1.0 mg/kg 8-OH-DPAT was sufficient to produce a decrease in the numbers of IgM-AFC in highly aggressive rats. Thus, pharmacological activation of pre- and postsynaptic 5-HT1A receptors, as well as the blockade of postsynaptic 5-HT1A receptors, produced different effects on the immune response in two lines of rats selected for high level of aggression or its absence. These data may have implications for more efficient treatments of a number of mental disorders associated with abnormal aggression.

Prophylactic effects of asiaticoside-based standardized extract of Centella asiatica(L.) Urban leaves on experimental migraine: Involvement of 5HT1A/1B receptors

The present study aimed at evaluation of prophylactic efficacy and possible mechanisms of asiaticoside （AS） based standardized extract of Centella asiatica （L.） Urban leaves （INDCA） in animal models of migraine. The effects of oral and intranasal （i.n.） pretreatment of INDCA （acute and 7-days subacute） were evaluated against nitroglycerine （NTG, 10 mg·kg^-1, i.p.） and bradykinin （BK, 10 μg, intra-arterial） induced hyperalgesia in rats. Tail flick latencies （from 0 to 240 rain） post-NTG treatment and the number of vocalizations post-BK treatment were recorded as a measure of hyperalgesia. Separate groups of rats for negative （Normal） and positive （sumatriptan, 42 mg.kg ^-1, s.c.） controls were included. The interaction of 1NDCA with selective 5-HT1A, 5-HT1B, and 5-HTI D receptor antagonists （NAN-190, Isamoltane hemifumarate, and BRL-15572 respectively） against NTG-induced hyperalgesia was also evaluated. Acute and sub-acute pre-treatment of INDCA [10 and 30 mg.kg^-1 （oral） and 100 μg/rat （i.n.） showed significant anti-nociception activity, and reversal of the NTG-induced hypera｜gesia and brain 5-HT concentration decline. Oral pre-treatment with INDCA （30 mg·kg ^-1, 7 d） showed significant reduction in the number of vocalization. The anti-nociceptive effects of INDCA were blocked by 5-HTIA and 5-HT1B but not 5-HT1D receptor antagonists. In conclusion, 1NDCA demonstrated promising anti-nociceptive effects in animal models of migraine, probably through 5-HT1A/1B medicated action.

1-[2-(2-Methoxyphenylthio) benzyl]-4-arylpiperazines derivatives:Synthesis and evaluation for dual 5-HT_(1A)/SSRI activities

A series of 1-[2-（2-methoxyphenylthio） benzyl]-4-arylpiperazines derivatives was designed and synthesized based on 5-HT1A/ SSRI drugs design strategies. The synthesized compounds were evaluated for their dual 5-HT1A/5-HTT activities. 2007 Ai Jun Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

1-(N-(2-(2-Methoxyphenylthio)benzyl)-N-methylamino-3-aryloxypropan-2-ols:Synthesis and evaluation for dual 5-HT_(1A)/SSRI activities

A series of 1-（N-（2-（2-methoxyphenylthio）benzyl）-N-methylamino-3-aryloxypropan-2-ols derivatives were designed and synthesized based on 5-HT1A/SSRI drugs design strategies. The synthesized compounds were evaluated for their dual 5-HT1A/ 5-HTT activities. 2007 Ai Jun Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Molecular signaling of 5-HT_1Aand presence of serotonergic cells in the fetal cerebral cortex

Early appearance of the serotonergic system in the fetal brain and the various effects of serotonin (5-HT) on brain morphogenesis, have given support to a neurotrophic role of serotonin. This function of serotonin is accomplished through a system of serotonin nerve terminals in the target regions that involves various 5-HT receptors. In visual, auditory and somatosensory cortex an early and intense serotonergic innervation is particularly important. The neuronal somata of these terminals are normally located in the mesencephalon and they have not been observed in the maturing cerebral cortex, neither in the adult brain. By using immunolabeling techniques, fluorescence and confocal microscopy, we observe the presence of both, 5-HT terminals and 5-HT cells in mesencephalon (Me, E17) and in the neopallium (Np, E13-E16) cocultures. Cells immunopositive to 5-HT and to tryptophan-5-hydroxilase are also observed in the Np on day 12 of culture. These results concerning the unexpected presence of serotonergic cells in the fetal cerebral cortex are interesting and may be of importance in corticogenesis. As it happens with other elements of the serotonergic system, the presence of these phenotypically serotonergic cells in the early cerebral cortex may be transitory and probably supporting cortex maturation processes. The molecular signaling path of the 5-HT1A receptor has also been identified.

应用脑微透析技术研究白细胞介素-6对F344大鼠下丘脑前叶5-羟色胺释放的影响:合用白细胞介素-1_β具有协同效应(英文)

本文应用在体脑微透析技术研究了白细胞介素 1β(IL 1β)和白细胞介素 6 (IL 6 )在清醒活动的大鼠局部灌注下丘脑前叶 (AHY)对 5 羟色胺 (5 HT)释放的影响。IL 1β(1ng/rat)或IL 6 (5 0ng/rat)直接注入AHY可产生一个快速、短暂的细胞外液 5 HT水平的升高 ,分别从基础值 10 0 %上升到 16 1%和 145 % (p <0 0 1)。局部灌注IL 1受体拮抗剂IL 1ra(2 μg/rat)可以阻断IL 1β的效应 ,但不影响IL 6的作用。下丘脑局部灌注IL 6 (10ng/rat)和IL 1β(0 5ng/rat)可产生协同释放 5 HT的效应。我们的研究表明IL 6和IL 1β两者均可调节大鼠下丘脑前叶 5 HT的释放。

Uncarialins J-M from Uncaria rhynchophylla and Their Anti-depression Mechanism in Unpredictable Chronic Mild Stress-Induced Mice via Activating 5-HT_(1A) Receptor

Uncaria rhynchophylla has been widely used to treat central nervous system diseases for a long history.After investigation of U.rhynchophylla,eleven monoterpene indole alkaloids,including four new compounds uncarialins J-M(1-4)and seven known analogues(5-11),were isolated and identified.Their structural characterization was conducted using HRESIMS,1D and 2D NMR,electronic circular dichroism(ECD)spectra,and quantum chemical computations.Compounds 1,2,7,and 9-11 displayed significant ag-onistic effects towards 5-HT_(1A) receptor,and their EC_(50) values were 7.86,732,2.24,1.18,1.52,and 3.75μmol/L,respectively.Furthermore,in vivo experimental results fully revealed that hirsuteine(7)displayed a significant antidepression effect in unpredictable chronic mild stress(UCMS)-induced depression mice mainly via regulating 5-HT_(1A) signaling pathway.Molecular docking and site-directed amino acid mutation verified that amino acid residues Aspll6 and Asn386 were the binding sites of hirsuteine(7)with 5-HT_(1A) receptor.In addition,pre-treatment of mice with WAY 100635 also blocked the anti-depression effect of hirsuteine(7),which further demonstrated that 5-HT_(1A) receptor was a potential target of hirsuteine(7)to effectively treat depression.These findings indicated the therapeutic material basis of U.rhynchophylla and the anti-depression underlying mechanism of hirsuteine(7),and further provided the useful guidance for the development of hirsuteine(7)as a potential antidepressant candidate.

Synthesis of several MPP derivatives for ^(99m)Tc-labelling and evaluated as potential 5-HT_(1A) receptor imaging agents

The(2-methoxyphenyl) piperazine(MPP) was selected as the functional group and conjugated to dithiocarbamate through different spacers.A series of new MPP derivatives(MPPnDTC,n = 2-6) were synthesized and radiolabelled with 99mTc-nitrido core or 99mTc-tricarboxyl core as potential 5-HT1A receptor imaging agents.All the six 99mTc-labelled complexes were lipophilic and neutral.Biodistribution results showed that those radiotracers had moderate initial brain and hippocampus uptake.There have no significant relation was observed between the biological properties of these tracers with the length of its carbon chain.The radioactivity concentrations of hippocampus of 99mTcN-MPP2DTC,99mTcN-MPP3DTC,99mTcN-MPP4DTC,99mTcN-MPP5DTC,99mTcN-MPP6DTC and 99mTc(CO)3-MPP3DTC at 2 min post-injection time(p.i.) were 0.43,1.15,0.99,1.04,1.13 and 0.83 %ID/g,respectively.

Synthesis and biological evaluation of ^(99m)Tc-HEDTA/HYNIC-MPP4 complex for 5-HT_(1A) receptor imaging

5-HT_(1A)receptor is associated with a variety of pathophysiology of neuropsychiatric disorders.Accordingly,we have synthesized a new 5-HT_(1A) receptor ligand(HYNIC-MPP4)and labeled it with^(99m)Tc using N-(2-hydroxyethyl)ethylenediaminetriacetic acid(HEDTA)as coligand.^(99m)Tc-HEDTA/HYNIC-MPP4 was prepared under pH 6 at room temperature.Biodistribution of^(99m)Tc-HEDTA/HYNIC-MPP4 in normal mice showed that this complex had moderate brain uptake(0.60%ID·g^(-1)at 2 min p.i.)and good retention.The hippocampus had the highest radioactivity uptake at 2 min p.i.(1.84%ID·g^(-1)).The ratio of Hipp/CB was 3.1 at 2 min p.i.and increased to 4.4 at 60 min p.i.After blocking with 8-hydroxy-2-(dipropylamino)tetralin,the uptake of hippocampus was decreased significantly from 1.84%ID·g^(-1) to 0.53%ID·g^(-1) at 2 min p.i.,while the cerebellum had no significant decrease.This^(99m)Tc complex could be a potent agent for 5-HT_(1A) receptor imaging.

新靶点抗精神病药SEP-363856研究进展

精神分裂症是一种慢性高致残性精神障碍,其病因和病理机制复杂。既往抗精神病药主要通过作用于多巴胺2型受体发挥疗效,对阴性症状和认知损害症状的疗效欠佳且出现较多的不良反应,严重影响患者的治疗依从性和功能康复。因此,作用于新靶点的抗精神病药的研发显得尤为迫切。SEP-363856是基于表型筛选策略发现的一种不与多巴胺2型受体结合的独特抗精神病药,临床前研究数据表明,SEP-363856的疗效可能与激活痕量胺相关受体1和5-羟色胺1A受体有关,该药的发现有望为精神分裂症患者带来新的治疗选择。本文中简要介绍了SEP-363856的研发历程,包括临床前研究结果及最新的临床试验数据,便于读者了解这一新型抗精神病药。