γ-氨基丁酸受体及相关药物研究进展

目的介绍-γ-氨基丁酸受体及相关药物研究进展。方法综合最新国内外文献报道,总结γ-氨基丁酸受体及相关药物的研究近况。结果-γ-氨基丁酸受体及相关药物的研究取得很大进展。结论这些药物的研究进展对治疗γ-氨基丁酸在大脑中的水平异常及γ-氨基丁酸受体功能障碍引起的多种疾病有重大意义。     

γ-氨基丁酸受体及相关药物研究进展

目的 介绍γ-氨基丁酸受体及相关药物研究进展.方法 综合最新国内外文献报道,总结γ-氨基丁酸受体及相关药物的研究近况.结果 γ-氨基丁酸受体及相关药物的研究取得很大进展.结论 这些药物的研究进展对治疗γ-氨基丁酸在大脑中的水平异常及γ-氨基丁酸受体功能障碍引起的多种疾病有重大意义.     

γ-氨基丁酸能中间神经元与自闭症谱系障碍的研究进展

越来越多的研究证据支持γ-氨基丁酸能中间神经元异常与自闭症谱系障碍（ASD）、癫痫以及精神分裂症等神经发育类疾病有关。近年来研究发现多种药物能靶向调控γ-氨基丁酸能中间神经元上的离子通道及受体,其中主要是钠离子通道和N-甲基-D-天冬氨酸（NMDA）受体等。钠离子通道的激活剂通过降低钠离子通道的失活来增强γ-氨基丁酸能中间神经元的动作电位;NMDA受体作为ASD的潜在治疗靶点,可以通过药物恢复γ-氨基丁酸能中间神经元的NMDA功能来治疗行为学缺陷。此外,γ-氨基丁酸能中间神经元上还有多种离子通道及受体均与ASD有关,未来会有更多药物应用于对γ-氨基丁酸能中间神经元的治疗中。本文回顾和讨论了γ-氨基丁酸能中间神经元在ASD发病过程中的作用和机制并据此进行干预的相关研究进展。     

经前期综合征肝气逆证模型大鼠海马γ-氨基丁酸A受体β2亚基mRNA表达

目的探讨大鼠海马γ-氨基丁酸A受体(GABAA受体)β2亚基mRNA表达的变化与经前期综合征肝气逆证的关系。方法采用半定量RT-PCR基因扩增技术对正常组、经前期综合征肝气逆证模型组和白香丹胶囊给药组大鼠海马中GABAA受体β2亚基的表达变化进行检测。结果与正常组大鼠相比,模型组大鼠海马GABAA受体β2亚基mRNA表达显著升高(P<0.05),调肝方药白香丹胶囊干预能改变该受体表达水平异常升高的状态。结论经前期综合征肝气逆证的发病机制与海马GABAA受体β2亚基有关。     

γ-氨基丁酸及其受体在大鼠纹状体边缘区的表达

目的观察γ-氨基丁酸(GABA)及其受体GABARB1mRNA在纹状体边缘区的表达,探讨GABA对边缘区学习记忆功能的调控。方法应用免疫细胞化学方法观察GABA及其合成酶谷氨酸脱羧酶(GAD)在纹状体边缘区的分布。用分子原位杂交方法观察GABA受体GABARB1mRNA在纹状体边缘区内的表达。结果在纹状体边缘区内可见密集的GABA及GAD免疫阳性纤维及少量胞体,在皮层、海马等处也可见阳性纤维及胞体。边缘区内可见许多GABARB1mRNA表达阳性的细胞,尾壳核内只有少量GABARB1mRNA阳性细胞分布,皮层、海马等处也呈GABARB1mRNA阳性表达。结论证实边缘区存在着GABA及其受体的表达,表明存在着抑制性氨基酸对边缘区的调控,推测GABA通过抑制突触前递质的释放及调控其他神经递质来影响边缘区的学习记忆功能。     

腺苷与精神分裂症

精神分裂症是一组起病缓慢、原因未明的精神障碍,以往有关其病因的神经生物学研究多集中在脑内多巴胺(DA)、γ-氨基丁酸(GABA)、谷氨酸(Glu)等受体功能异常方面.     

GABA能信号系统与神经发育障碍

γ-氨基丁酸(GABA)作为神经系统中重要的抑制性神经递质,通过GABA A型受体通道或G蛋白偶联B型受体参与多种中枢神经系统功能.本文将阐述GABA能信号系统的关键方面在神经发育障碍(neuro-developmental disorders,NDDs)病因中的作用,为推进NDDs精确治疗提供参考.     

血浆γ-氨基丁酸的放射受体分析测定

本文采用放射受体分析法测定24只正常大鼠的血浆γ-氨基丁酸,其浓度为805±79pmol/ml((?)±SE).方法学实验表明,变异系数为2%、血浆γ-氨基丁酸回收率为75.9%,测定基本不受标本溶血的影响.资料说明本法测定血浆γ-氨基丁酸浓度,是一种特异、敏感、较为简便的方法.     

GABAA受体在爪蟾卵母细胞的表达

目的 将鼠源γ-氨基丁酸A型（GABAA）受体表达于爪蟾卵母细胞膜上并行功能测定。方法 微量注射仪将纯化的大鼠脑mRNA注入准备好的爪蟾卵母细胞内并于19℃温浴48h以上使其表达；使用常规双电极电压钳记录卵母细胞表达的受体特性。结果 爪蟾卵母细胞注射大鼠脑mRNA 48h后有GABAA受体的表达，此受体具有天然GABAA受体的氯通道特性。结论 爪蟾卵母细胞具有表达外源GABAA受体的特性，是研究GABA受体生理和药理功能的一种重要工具。     

γ氨基丁酸-苯二氮受体在西番莲提取物抗大鼠惊厥中的作用(英文)

目的:探讨γ氨基丁酸-苯二氮(卓)受体在西番莲提取物抗大鼠惊厥中的作用.方法:给大鼠脑室内分别注射0.125、0.25、0.55和1.5 μg西番莲提取物,观察其对大鼠的抗惊厥作用.结果:西番莲提取物对用戊四氮引发最小阵发性痉挛和阵发性强直性抽搐的大鼠的保护作用存在剂量依赖关系.5 nmol/L氟马西尼可阻断西番莲提取物对最小阵发性痉挛和阵发性强直性抽搐的抗惊厥作用.结论:西番莲提取物可能通过影响大脑内γ氨基丁酸-苯二氮(卓)受体的地西泮异构体结合位点来实现抗惊厥的作用.     

兔脑 —氨基丁酸结合蛋白（受体）在非洲瓜蟾卵母细胞上的重建

Gurdon's Xenopus laevis oocyte translation system has been extensively employed to investigate the molecular biology of gamma-aminobutyric acid (GABA) receptors in the brains of embryonic chick, rat, etc. As GABA and its receptor may play a role in the pathogenesis of hepatic encephalopathy and a rabbit model of fulminant hepatitis has been established, we reconstituted the rabbit model of fulminant hepatitis has been established, we reconstituted the rabbit brain GABA binding protein (receptor) on Xenopus laevis oocytes to offer a base for further study of the pathological effects of GABA receptor at molecular level. In this report, total RNA was extracted from rabbit brain by guanidine hydrochloride method. The total RNA was then subjected to oligo-(dT)-cellulose affinity chromatography to isolate mRNA. All the RNA samples achieved a high purity with an average OD260/OD280 ratio of about 2.10. The clear bands of 18 S and 28S rRNA in electrophoresis implied that the RNA was not degraded and was therefore available for expression. After two days of incubation of the oocytes injected with mRNA, radioreceptor assay indicated that saturable and specifically displaceable GABA binding sites were implanted onto the oocyte membrane. This result led us to the conclusion that rabbit brain GABA binding protein (receptor) can be reconstituted by injecting exogenous mRNA inclusive of those encoding the receptor into Xenopus oocytes. However, the functional activity of the reconstituted receptor as a GABA gated chloride ion channel needs to be further characterized by patch clamping.     

γ—氨基丁酸及其受体在大鼠纹状体边缘区的表达

目的：观察γ－氨基丁酸（GABA）及其受体GABARB1 mRNA在纹状体边缘区的表达，探讨GABA对边缘区学习记忆功能的调控。方法：应用免疫细胞化学方法观察GABA及其合成酶谷氨酸脱羧酶（GAD）在纹状体边缘区的分布，用分子原位杂交方法观察GABA受体GABARB1 mRNA在纹状体边缘区内的表达。结果：在纹状体边缘区内可见密集的GABA及GAD免疫阳性纤维及少量胞体，在皮层，海马等处也可见阳性纤维及胞体，边缘区内可见许多GABAR1 mRNA表达阳性的细胞，尾壳核内只有少量GABARB1 mRNA阳性细胞分布，皮层，海马等处也呈GABARB1 mRNA阳性表达。结论：证实边缘区存在着GABA及其受体的表达，表明存在着抑制性氨基酸对边缘区的调控，推测GABA通过抑制突触前递质的释放及调控其他神经递质来影响边缘区的学习记忆功能。     

脑血管畸形血管自动调节功能异常的分子机制探讨

目的：探讨脑血管畸形（AVMs)血管自动调节功能异常的分子机制。方法：14例AVMs及周边脑组织行显微外科手术切除，标本提取总RNA，应用RT－PCR检测脑AVMs中ppET-1和ETA表达变化，并与8例正常脑血标本进行比较。结果：在脑血管畸形血管中，发现ppET-1mRNA和ETA mRNA表达较正常脑血管下降。结论：脑AVMs如ppET-1mRNA表达的下降可能会导致AVMs中ET－1的下降，而脑AVMs中ET－1下降很可能是畸形管自动调节功能异常的主要原因之一；ET1mRNA表达较正常血管下降，可能阻止外源性ET－1，并加强脑AVMs中ET－1的抑制作用，导致脑AVMs血管自动调节功能异常。     

RT—PCR分析探测人胚胎卵巢中的褪黑素受体

目的：研究入胚胎卵巢中是否存在褪黑素受体。方法：取人胚胎卵巢,用逆转录一多聚酶链反应方法鉴别褪黑素受体。结果：人胚胎卵巢总RNA以MT1及MT2两种受体引物进行的RT-PCR产物电泳呈现阳性条带,测序显示扩增产物与人类脑组织褪黑素受体cDNA相吻合,结论：人胚胎卵巢组织中存在有MT1、MT2两种褪黑素受体。证明卵巢是褪黑素作用的靶器官,褪黑素可能直接作用于卵巢,参与胚胎卵巢的发育或调节胚胎卵巢的功能。     

γ-氨基丁酸受体基因转染对癫痫大鼠海马缝隙连接蛋白43表达的影响

目的： 探讨下丘脑乳头体上核内转染γ-氨基丁酸(GABA)受体基因对海人藻酸(KA)致痫大鼠海马区缝隙连接蛋白43(CX43)表达的影响。 方法：将24只Wistar雄性大鼠分为4组：正常对照组（n=2）、手术对照组（n=2）、KA对照组（n=10）及GABA受体基因转染组（n=10），正常对照组未经任何处置，手术对照组在右侧杏仁核注射生理盐水1 μL，KA对照组在杏仁核注射KA 1 μL（1　μg），GABA受体基因转染组则在KA注射前48 h预先将GABA 受体mRNA 400 nL (40 ng)注射到下丘脑的乳头体上核。采用原位杂交法观察4组大鼠各个时程（3 h、6 h、24 h、3 d、7 d）海马区形态及CX43阳性细胞数变化。 结果：正常对照组和手术对照组大鼠海马神经元结构完整；KA对照组海马神经元肿胀变性，其程度随时间延长而加重；GABA受体基因转染组海马神经元变性坏死程度相对于KA对照组减轻。CX43表达阳性细胞数定量分析显示，正常及手术对照组CX43表达阳性细胞数较少，KA对照组随时间延长CX43阳性表达细胞数逐渐增多， GABA受体基因转染组大鼠CX43阳性表达细胞数在各个时程均比KA对照组减少。 结论: 下丘脑内转染GABA受体基因可以下调海马区CX43的表达。     

Detection of GABAA alpha 2 mRNA in rat cochlear spiral neuron with in situ hybridization]

OBJECTIVE: To investigate the expression of gamma-aminobutyric acid (GABA)A receptor alpha 2 subunit mRNA on rat cochlear spiral neurons and its' significance. METHODS: In the rat cochlear paraffin slides, the GABAA alpha 2 receptor in spiral ganglion neuron was detected with in situ hybridization. Digoxigenin-GABAA alpha 2 cDNA probe (549 base pair), anti-digoxigenin-AP(Fab fragments) and BM purple substrate(precipitating) were used. RESULTS: Positive signals(GABAA alpha 2 mRNA) were seen in all cochlear spiral neurons and their nerves. GABAA alpha 2 mRNA was not found in other structure such as bony spiral lamina. As a positive control, GABAA alpha 2 mRNA was seen in Purkinje cells, granule cells and their axons in rat's cerebellum. GABAA alpha 2 mRNA was not found in OMP cDNA probe (olfactory membrane estrogen receptor probe) negative control, non-probe negative control and non-anti-digoxingenin control in cochlear spiral neuron and cerebellum. CONCLUSION: GABAA alpha 2 receptor has been found in type I spiral neurons and their nerves. It strongly indicates that GABA as a nerve transmitter plays an important role in inhibiting the excessive stimulation transmission of the inner hair cells.     

Effects of free radicals and amyloid β protein on the currents of expressed rat receptors in Xenopus oocytes

Objective To investigate the effects of free radicals (FRs) and amyloid β protein 1-40 ( Aβ(1-40)) on the functions of expressed neurotransmitter receptors (NRs) i n Xenopus oocytes.Methods Total RNA and messenger RNA (mRNA) was prepared from 3-month-old Wistar rat br ain tissues with Promega kits and microinjected into maturated Xenopus oocyt es (stages Ⅴ-Ⅵ) with 50 nl (50 ng) for each oocyte. The microinjec ted oocy tes were incubated with modifiedBath’s solution at 19.0℃±1.0℃ for receptor expression and their currents were recorded with double electrode voltage clamp technique. Superoxide anion free radicals (SAFRs) were produced via a reaction system (HPXXO) with hypoxanthine (HPX, 0.05 mol/L) and xanthine oxidase (XO, 0.1 U/L). In order to observe the effects of Aβ and SAFRs on the e xpressed glutamate receptor, HPX/XO and Aβ(1-40) were added to incubation solution at 12 h, 24 h and 96 h before recording.Results The results showed that the oocytes expressed functional NRs originating from ra t brain tissues. These NRs included muscarinic acetylcholine (mACh), glutamate (Glu), dopamine (DA), serotonin (5-HT) and γ-aminobutyric acid (GABA). T he c urrent characteristics of expressed receptors were inward currents carried by ch loride ion with their equibrilium potentials close to -22 mV. The extent of ef fect on the current of expressed glutamate receptor from rat brain was different among different Aβ concentrations and incubation times. Aβ(1-40) at a c oncentration of 20 nmol/L had little effect on the currents of expressed rat br ain glutamate receptors up to 24 h of incubation period; but the currents of gl utamate receptor were significantly decreased (25% off, P&lt;0.01) in the trea tment of 60 nmol/L Aβ(1-40) over 24 h. Moreover, when 20 nmol/L Aβ (1-40) was co-incubated over 12 h with SAFRs produced by the reaction syste m of HPXXO, it was found that the currents of expressed rat bra in glutamate rec eptors had been changed markedly. When the oocytes were co-treated with 60 nm ol/L Aβ(1-40) and SAFRs over a period of 12 h, the currents of glutamate receptor significantly decreased (21% off, P&lt;0.05), and the decreased perce ntage reached 52% over 24 h co-treatment with 60 nmol/L Aβ(1-40) and SA FRs. In addition, vitamin E had a partial effect against this inhi bitory effect.Conclusion The results suggest that Aβ has a kind of inhibitory effect upon the current of the glutamate receptor, similar to the effects of free radicals. The effects c an be antagonized by vitamin E. These imply that Aβ may play a role via inhibi ting receptor function in the pathophysiology of Alzheimer’s disease.     

非洲爪蟾卵母细胞内源性及外源性ATP和GABA受体介导的膜反应比较

目的 :对非洲爪蟾卵母细胞表达的ATP和GABA激活电流进行比较。方法 :包括mRNA和cDNA的提取、卵母细胞的微量注射及双电极电压钳技术。结果 :①在表达P2X2 或P2X4 的卵母细胞上 ,外加ATP可分别诱导一被Zn2 + 增强的内向电流。②在表达鸡脑mRNA的卵母细胞上 ,可记录到GABA激活电流 ,且此电流可被bicucul line(一种GABAA 受体选择拮抗剂 )所阻断。③在表达了人视网膜 ρ1亚基cRNA的卵母细胞上 ,外加GABA可引起一不被bicuculline阻断的内向电流 ,后者可被I4AA(一种GABAC 受体特异性拮抗剂 )阻断。④在具有滤泡膜的卵母细胞上可记录到 3种形式的ATP激活电流和一外向的慢的GABA激活电流。⑤在除去滤泡膜的卵母细胞上均未记录到ATP和GABA激活电流。结论 :卵母细胞上存在内源性的嘌呤受体、GABAB 和GABAC 受体 ;且此内源性受体存在于滤泡膜上 ;P2X2 、P2X4 嘌呤受体及GABAA 和GABAC 受体均可在卵母细胞上表达 ,表达的受体所介导的激活电流与内源性受体介导的激活电流有明显区别     

凝血酶对U937细胞uPAR mRNA表达的影响

目的 研究凝血酶通过凝血酶受体（ＴＲ）对细胞ｕＰＡＲ ｍＲＮＡ表达的影响。方法 在凝血酶、灭活凝血酶、和抗ＴＲ小肽多抗等作用下,以ＲＴ－ＰＣＲ法测定培养Ｕ９３７细胞ｕＰＡＲ ｍＲＮＡ的表达量。结果 凝血酶增强ｕＰＡＲ ｍＲＮＡ表达呈现凝血酶剂艇时间的依赖性。其作用机制与凝血酶和细胞膜上ＴＲ间的结合、以及凝血酶的蛋白水解活性有关。高浓度凝血酶或中等浓度凝血酶在延长作用时间长,对Ｕ９３７细胞ｕＰＡＲｍ