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《生理学报》2019,(6)
脊髓α运动神经元直接支配骨骼肌活动,是躯体运动和行为控制的最后公路(final common path)。因此,运动神经元兴奋性调控对于运动行为的执行至关重要。事实上,脊髓运动神经元接受多种神经调质的传入,尤其是单胺能神经调质。然而,组胺和下丘脑组胺能神经系统对脊髓运动神经元的调控作用及其下游离子机制至今仍不清楚。本研究采用大鼠脊髓脑片细胞内记录方法,发现组胺H1和H2受体的激活均能增强脊髓α运动神经元的重复放电行为和兴奋性。钾通道的关闭和钠-钙交换体的激活共同参与了H1受体激活介导的脊髓运动神经元的兴奋,而超极化激活的环核苷酸门控(hyperpolarizationactivated cyclic nucleotide-gated, HCN)通道的开放则负责H2受体激活介导的兴奋性效应。以上结果提示,通过切换与组胺受体相耦联的离子通道和交换体的功能状态,组胺可以有效地偏置脊髓α运动神经元的兴奋性,而下丘脑组胺能神经传入很可能以这种方式直接调控最终的运动输出并主动调节脊髓运动反射和运动执行。 相似文献
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蛋白激酶C研究的最新进展 总被引:9,自引:1,他引:8
作为能使蛋白激酶C(PKC)活化的第二信使甘油二酯(DAG)不仅可由磷脂酰肌醇(PtdIns)水解产生,大量实验表明还可从磷脂酰胆碱(PC)水解而来,其中磷脂酶C(PLC)及磷脂酶D(PLD)参与了这一过程,磷脂酶A2(PLA2)的作用产物脂肪酸(FA)也能激活PKC.PKC至少有10种亚型,依据其活化方式可分三大类:典型PKC,新PKC和非典型PKC.PKC参与了基因表达的调控. 相似文献
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LXRs在脂质代谢中的作用 总被引:8,自引:1,他引:7
LXRs ,为liverX activatedreceptors的简称 ,是核受体超家族的成员 ,包括两种同源亚型LXRα(NR1H3)和LXRβ(NR1H2 )。LXRs被内源性配体氧化甾醇或人工合成配体激活后 ,先与RXRα(retinoidXreceptorα ,亦称NR2B1)形成异二聚体 ,再与其靶基因的LXR调控元件结合 ,通过转录调节调控胆固醇的代谢、储存、吸收和转运 ,从而维持甾醇和脂肪酸代谢平衡。此外 ,LXRs也参与糖代谢调节 ,活化的LXRs可通过抑制肝脏糖异生而改变II型糖尿病动物的血糖水平。因此 ,LXRs有望成为治疗动脉粥样硬化和II型糖尿病的新靶点 相似文献
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黑素皮质素受体-2(melanoeortin2-receptor,MC2R)属于A类七个跨膜α螺旋G蛋白受体,具有通过CA/cAMP/PKA信号转导途径调节类固醇激素分泌的昼夜节律和应激引起变化的功能。MC2R基因表达障碍可导致一种常染色体隐性遗传疾病,即家族性糖皮质激素缺陷(FGD)。黑素皮质素受体-2(melanocortin2-receptor,MC2R)基因在特定组织中是否表达,表达丰度的高低是由多种调控因子相互作用决定的。本文就参与其表达调控的类固醇转录因子-1(steroidogenic factor-1,SF-1)、过氧化物增值物激活受体γ(PPARγ)、视黄酸X受体α(RXRα)、活化激活蛋白1(activatorproteinl,AP-1)DAX-1(dosage-sensitive sexreversal adrenal hypoplasia gene on the X chromosome,gene-1)和E-盒结合蛋白等因子做一综述。 相似文献
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将磷脂酰胆碱专一性磷脂酶D2基因及其功能缺陷点突变基因 (K75 8R)从真核表达载体pCGN中克隆至带有绿色荧光标记蛋白的穿梭质粒pAdTrack CMV中 ;再与腺病毒骨架载体一起在大肠杆菌BJ5183中进行同源重组 ,成功构建磷脂酶D2重组腺病毒。该病毒颗粒感染人胚肾 2 93细胞 ,高效表达磷脂酶D2及其功能缺陷蛋白。这种表达对M3乙酰胆碱受体介导的细胞内磷脂酶D激活无影响。但磷脂酶D2功能缺陷蛋白对蛋白激酶C介导的胞内磷脂酶D激活有显著抑制作用 ;相反 ,磷脂酶D2蛋白有显著增强作用。结果表明 相似文献
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雌激素受体(estrogen receptorα,ERα)是依赖配体活化转录因子的核受体家族成员之一,参与靶细胞的增殖和分化。ERα活化的经典途径是与雌激素结合后直接作用于靶基因上游的雌激素受体反应元件(ERE),从而诱导靶基因转录。雌激素受体的功能受许多因子调节,包括与之结合的配体、DNA上的顺式元件、募集的辅助调节因子及细胞环境等。在雌激素受体相关疾病中,除乳腺癌和子宫内膜癌外,近年研究表明心血管疾病、骨质疏松症、阿尔茨海默氏病等疾病也与雌激素受体密切相关。雌激素的生物效应与多种疾病的发生、转归和预后密切相关。本文将综述几类辅助调节因子对雌激素受体介导的基因转录的调控,雌激素受体相关疾病,及环境有害物质对ERα功能的影响。 相似文献
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In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980. 相似文献
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N. P. Vesselkin Yu. V. Natochin 《Journal of Evolutionary Biochemistry and Physiology》2010,46(6):592-603
Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms.
The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal
mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization
followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The
mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction
of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms
are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning
of physiological systems and organs of the living organism 相似文献
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