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Ion channels, phosphorylation and mammalian sperm apacitation 被引量:20
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作者 Pablo E Visconti Dario Krapf +2 位作者 Jose Luis de la Vega-Beltran Juan Jose Acevedo Alberto Darszon 《Asian Journal of Andrology》 SCIE CAS CSCD 2011年第3期395-405,511,共12页
Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive t... Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies. 展开更多
关键词 CAPACITATion ion channels LIPIDS PHOSPHORYLATion SPERM
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Diabetes-induced changes in cardiac voltage-gated ion channels 被引量:7
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作者 Nihal Ozturk Serkan Uslu Semir Ozdemir 《World Journal of Diabetes》 SCIE 2021年第1期1-18,共18页
Diabetes mellitus affects the heart through various mechanisms such as microvascular defects,metabolic abnormalities,autonomic dysfunction and incompatible immune response.Furthermore,it can also cause functional and ... Diabetes mellitus affects the heart through various mechanisms such as microvascular defects,metabolic abnormalities,autonomic dysfunction and incompatible immune response.Furthermore,it can also cause functional and structural changes in the myocardium by a disease known as diabetic cardiomyopathy(DCM)in the absence of coronary artery disease.As DCM progresses it causes electrical remodeling of the heart,left ventricular dysfunction and heart failure.Electrophysiological changes in the diabetic heart contribute significantly to the incidence of arrhythmias and sudden cardiac death in diabetes mellitus patients.In recent studies,significant changes in repolarizing K+currents,Na+currents and L-type Ca^(2+)currents along with impaired Ca^(2+ )homeostasis and defective contractile function have been identified in the diabetic heart.In addition,insulin levels and other trophic factors change significantly to maintain the ionic channel expression in diabetic patients.There are many diagnostic tools and management options for DCM,but it is difficult to detect its development and to effectively prevent its progress.In this review,diabetes-associated alterations in voltage-sensitive cardiac ion channels are comprehensively assessed to understand their potential role in the pathophysiology and pathogenesis of DCM. 展开更多
关键词 DIABETES Action potential Cardiac ion channels L-type Ca^(2+)channels Potassium channels Sodium channels
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Identification and Function of Acid-sensing Ion Channels in RAW 264.7 Macrophage Cells 被引量:2
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作者 Lan NI Peng FANG +4 位作者 Zhuang-li HU Hai-yun ZHOU Jian-guo CHEN Fang WANG You JIN 《Current Medical Science》 SCIE CAS 2018年第3期436-442,共7页
Activation of acid-sensing ion channels (ASICs) plays an important role in neuroinflammation. Macrophage recruitment to the sites of inflammation is an essential step in host defense. ASIC1 and ASIC3 have been repor... Activation of acid-sensing ion channels (ASICs) plays an important role in neuroinflammation. Macrophage recruitment to the sites of inflammation is an essential step in host defense. ASIC1 and ASIC3 have been reported to mediate the endocytosis and maturation of bone marrow derived macrophages. However, the expression and inflammation-related functions of ASICs in RAW 264.7 cells, another common macrophage, are still elusive. In the present study, we first demonstrated the presence of ASIC 1, ASIC2a and ASIC3 in RAW 264.7 macrophage cell line by using reverse transcriptase polymerase chain reaction (RT-PCR), Western blotting and immunofluorescence experiments. The non-specific ASICs inhibitor amiloride and specific homomeric ASICla blocker PcTxl reduced the production of iNOS and COX-2 by LPS-induced activating RAW 264.7 cells. Furthermore, not only amiloride but also PcTxl inhibited the migration and LPS-induced apoptosis of RAW 264.7 cells. Taken together, our findings suggest that ASICs promote the inflammatory response and apoptosis of RAW 264.7 cells, and ASICs may serve as a potential novel target for immunological disease therapy. 展开更多
关键词 acid-sensing ion channels (ASICs) RAW 264.7 cells INFLAMMATion apoptosis MIGRATion
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Role of ions and ion channels in capacitation and acrosome reaction of spermatozoa
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作者 Sharad B Purohit Malini Laloraya G.Pradeep Kumar 《Asian Journal of Andrology》 SCIE CAS CSCD 1999年第3期95-107,共13页
Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of bindi... Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of binding and fusionwith the oocyte. During capacitation various biochemical and biophysical changes occur in the spermatozoa and thespermatozoal membranes. Ions and ion channels also play important roles in governing the process of capacitation bychanging the fluxes of different ions which in turn controls various characteristics of capacitated spermatozoa. Alongwith the mobilization of ions the generation of free radicals and efflux of cholesterol also plays an important role in thecapacitation state of the spermatozoa. The generation of free radical and efflux of cholesterol change the mechano-dynamic properties of the membrane by oxidation of the polyunsaturated lipids and by generating the cholesterol freepatches. The process of capacitation renders the spermatozoa responsive to the inducers of the acrosome reaction. Theglycoprotein zona pellucida 3 (ZP3) of the egg coat zona pellucida is the potent physiological stimulator of the acro-some reaction; progesterone, a major compoent of the follicular fluid, is also an induce of the acrosome reaction.The inducers of the acrosome reaction cause the activation of the various ion-channels leading to high influxes of calci-um, sodium and bicarbonate. The efflux of cholesterol during the process of capacitation alters the permeablity of themembrane to the ions and generate areas which are prone to fusion and vesculation process during the acrosome reac-tion. Ths review focuses mainly on effects of the ion and ion-channels, free radicals, and membrane fluidity changesduring the process of capacitation and acrosome reaction. (Asian J Androl 1999 Sep; 1: 95-107) 展开更多
关键词 SPERMATOZOA CAPACITATion acrosome reaction ion channels free radicals membrane fluidity
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Does closure of acid-sensing ion channels reduce ischemia/reperfusion injury in the rat brain?
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作者 Jie Wang Yinghui Xu +5 位作者 Zhigang Lian Jian Zhang Tingzhun Zhu Mengkao Li Yi Wei Bin Dong 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第13期1169-1179,共11页
Acidosis is a common characteristic of brain damage. Because studies have shown that permeable Ca2+-acid-sensing ion channels can mediate the toxic effects of calcium ions, they have become new targets against pain a... Acidosis is a common characteristic of brain damage. Because studies have shown that permeable Ca2+-acid-sensing ion channels can mediate the toxic effects of calcium ions, they have become new targets against pain and various intracranial diseases. However, the mechanism associated with expression of these channels remains unclear. This study sought to observe the expression characteristics of permeable Ca2+-acid-sensing ion channels during different reperfusion inflows in rats after cerebral ischemia. The rat models were randomly divided into three groups: adaptive ischemia/reperfusion group, one-time ischemia/reperfusion group, and severe cerebral ischemic injury group. Western blot assays and immunofluorescence staining results exhibited that when compared with the one-time ischemia/reperfusion group, acid-sensing ion channel 3 and Bcl-x/I expression decreased in the adaptive ischemia/reperfusion group. Calmodulin expression was lowest in the adaptive ischemia/reperfusion group. Following adaptive reperfusion, common carotid artery flow was close to normal, and the pH value improved. Results verified that adaptive reperfusion following cerebral ischemia can suppress acid-sensing ion channel 3 expression, significantly reduce Ca2+ influx, inhibit calcium overload, and diminish Ca2+ toxicity. The effects of adaptive ischemia/reperfusion on suppressing cell apoptosis and relieving brain damage were better than that of one-time ischemia/reperfusion. 展开更多
关键词 neural regeneration brain injury acid-sensing ion channel 3 cerebral ischemia REPERFUSion apoptosis CALMODULIN calcium overload nerve cells grants-supported paper NEUROREGENERATion
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Ion Channels as Antivirus Targets
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作者 Xin LIANG Zhi-yuan LI 《Virologica Sinica》 SCIE CAS CSCD 2010年第4期267-280,共14页
Ion channels are membrane proteins that are found in a number of viruses and which are of crucial physiological importance in the viral life cycle. They have one common feature in that their action mode involves a cha... Ion channels are membrane proteins that are found in a number of viruses and which are of crucial physiological importance in the viral life cycle. They have one common feature in that their action mode involves a change of electrochemical or proton gradient across the bilayer lipid membrane which modulates viral or cellular activity. We will discuss a group of viral channel proteins that belong to the viroproin family, and which participate in a number of viral functions including promoting the release of viral particles from cells. Blocking these channel-forming proteins may be "lethal", which can be a suitable and potential therapeutic strategy. In this review we discuss seven ion channels of viruses which can lead serious infections in human beings: M2 of influenza A, NB and BM2 of influenza B, CM2 of influenza C, Vpu of HIV-1, p7 of HCV and 2B of picomaviruses. 展开更多
关键词 Viral ion channel Antiviral therapy Viruses AMANTADINE
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Mechanistic Insights into Structural Stability of the Selectivity Filters in Typical Cation Channels
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作者 Zhoubin Tang Hu Qiu Wanlin Guo 《Journal of Materials Science and Chemical Engineering》 CAS 2022年第7期17-32,共16页
The reliable functioning of ion channels should be closely related to their structural stability. The selectivity filter in the KcsA potassium channel possesses four stable ion binding sites that can coordinate nearly... The reliable functioning of ion channels should be closely related to their structural stability. The selectivity filter in the KcsA potassium channel possesses four stable ion binding sites that can coordinate nearly fully dehydrated ions, whereas only two of such binding sites exist in the non-selective NaK channel, and none of them is found in the NavAb sodium channel. Here we show that the stability of the selectivity filters in these tetrameric cation channels is inversely correlated with the number of stable binding sites by extensive molecular dynamics simulations. While the presence of coordinated ions is crucial for the selectivity filters of the KcsA and NaK channels to stabilize the conformations in their crystal structures, the selectivity filter of the NavAb channel shows higher stability, independent of the presence of ions. We further show that the distinct repulsive electrostatic interactions between negatively charged oxygen atoms in the selectivity filter which form the stable binding sites are responsible for the different stability of these cation channels. The hydrogen bonding networks between residues in the selectivity filter and its adjacent pore helix also play an important role in maintaining stability. Together, these results provide important mechanistic insights into the structural stability of the selectivity filters in typical cation channels. 展开更多
关键词 ion Channel Structural Stability Molecular Dynamics Electrostatic Potential Hydrogen Bonds
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Cooperative activation of sodium channels for downgrading the energy efficiency in neuronal information processing
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作者 严浩然 颜家琦 +1 位作者 俞连春 邵玉峰 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期758-763,共6页
The Hodgkin–Huxley model assumes independent ion channel activation,although mutual interactions are common in biological systems.This raises the problem why neurons would favor independent over cooperative channel a... The Hodgkin–Huxley model assumes independent ion channel activation,although mutual interactions are common in biological systems.This raises the problem why neurons would favor independent over cooperative channel activation.In this study,we evaluate how cooperative activation of sodium channels affects the neuron’s information processing and energy consumption.Simulations of the stochastic Hodgkin–Huxley model with cooperative activation of sodium channels show that,while cooperative activation enhances neuronal information processing capacity,it greatly increases the neuron’s energy consumption.As a result,cooperative activation of sodium channel degrades the energy efficiency for neuronal information processing.This discovery improves our understanding of the design principles for neural systems,and may provide insights into future designs of the neuromorphic computing devices as well as systematic understanding of pathological mechanisms for neural diseases. 展开更多
关键词 energy efficiency ion channel noise action potential generation neuronal dynamics
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Na^(+)/K^(+)-ATPase:ion pump,signal transducer,or cytoprotective protein,and novel biological functions 被引量:2
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作者 Songqiang Huang Wanting Dong +1 位作者 Xiaoqian Lin Jinsong Bian 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第12期2684-2697,共14页
Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^... Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^(+)/K^(+)-ATPase participates in Ca^(2+)-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane.Na^(+)/K^(+)-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells.Therefo re,it is not surprising that Na^(+)/K^(+)-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases.However,published studies have so far only elucidated the important roles of Na^(+)/K^(+)-ATPase dysfunction in disease development,and we are lacking detailed mechanisms to clarify how Na^(+)/K^(+)-ATPase affects cell function.Our recent studies revealed that membrane loss of Na^(+)/K^(+)-ATPase is a key mechanism in many neurological disorders,particularly stroke and Parkinson's disease.Stabilization of plasma membrane Na^(+)/K^(+)-ATPase with an antibody is a novel strategy to treat these diseases.For this reason,Na^(+)/K^(+)-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein,participating in signal transduction such as neuronal autophagy and apoptosis,and glial cell migration.Thus,the present review attempts to summarize the novel biological functions of Na^(+)/K^(+)-ATPase and Na^(+)/K^(+)-ATPase-related pathogenesis.The potential for novel strategies to treat Na^(+)/K^(+)-ATPase-related brain diseases will also be discussed. 展开更多
关键词 ANTIBODY biological functions cellular communication electrochemical gradient ion balance ion channels Na^(+)/K^(+)-ATPase neurological diseases neurotransmitter release signal transduction
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Do tensile and shear forces exerted on cells influence mechanotransduction through stored energy considerations?
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作者 FREDERICK H.SILVER TANMAY DESHMUKH 《BIOCELL》 SCIE 2024年第4期525-540,共16页
All tissues in the body are subjected externally to gravity and internally by collagenfibril and cellular retractive forces that create stress and energy equilibrium required for homeostasis.Mechanotransduction involve... All tissues in the body are subjected externally to gravity and internally by collagenfibril and cellular retractive forces that create stress and energy equilibrium required for homeostasis.Mechanotransduction involves mechanical work(force through a distance)and energy storage as kinetic and potential energy.This leads to changes in cell mitosis or apoptosis and the synthesis or loss of tissue components.It involves the application of energy directly to cells through integrin-mediated processes,cell-cell connections,stretching of the cell cytoplasm,and activation of the cell nucleus via yes-associated protein(YAP)and transcriptional coactivator with PDZ-motif(TAZ).These processes involve numerous complexes,intermediate molecules,and multiple pathways.Several pathways have been identified from research studies on vertebrate cell culture and from studies in invertebrates.These pathways involve mechanosensors and other molecules that activate the pathways.This review discusses the mitogen-activated protein kinase(MAPK)family,Hippo,Hedgehog,and Wingless-related integration site(WNT)/βcatenin signaling pathways.The mediators covered includeβcatenin,ion channels,growth factors,hormone receptors,members of the Ras superfamily,and components of the linker of nucleoskeleton and cytoskeleton(LINC)complex.However,the interrelationship among the different pathways remains to be clarified.Integrin-mediated mechanotransduction involves direct tensile loading and energy applied to the cell membrane via collagenfibril stretching.This energy is transferred between cells by stretching the cell-cell connections involving cadherins and the WNT/βcatenin pathway.These alterations induce changes in intracellular events in the cytoskeleton and nuclear skeleton caused by the release of YAP and TAZ.These coactivators then penetrate through the nuclear pores and influence nuclear cell function.Alteration in the balance of forces and energy applied to cells and tissues is hypothesized to shift the cell-extracellular matrix mechanical equilibrium by modifying mechanotransduction.The shift in equilibrium can lead to either tissue synthesis,genetic modifications,or promotefibrotic diseases,including epithelial cell-derived cancers,depending on the local metabolic conditions. 展开更多
关键词 MAPK family HIPPO HEDGEHOG WNT pathway βcatenin ion channels Growth factor receptors Hormone receptors Ras superfamily LINC complex COLLAGEN CADHERINS
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Self-assembled Supramolecular Artificial Transmembrane Ion Channels:Recent Progress and Application
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作者 LUO Yichen ZHU Canhong +2 位作者 ZHANG Tianlong YAN Tengfei LIU Junqiu 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2023年第1期3-12,共10页
Natural protein channels have evolved with fantastic spatial structures,which play pivotal physiological functions in all living systems.Learning from nature,chemical scientists have developed a myriad of artificial t... Natural protein channels have evolved with fantastic spatial structures,which play pivotal physiological functions in all living systems.Learning from nature,chemical scientists have developed a myriad of artificial transmembrane ion channels by using various chemical strategies,among which the non-covalent supramolecular ion channels exhibit remarkable advantages over other forms(e.g.,single-molecule ion channel),which exhibited facile preparation methods,easier structural modification and functionalization.In this review,we have systematically summarized the recent progress of supramolecular self-assembled artificial transmembrane ion channels,which were classified by different self-assembly mechanisms,such as hydrogen bonds,π-πinteractions,etc.Detailed preparation process and self-assembly strategies of the supramolecular ion channels have been described.Moreover,potential biomedical applications of the supramolecular ion channels have also been carefully discussed in this review.Finally,future opportunities and challenges facing this field were also elaborately discussed.It is anticipated that this review could provide a panoramic sketch and future directions towards the construction of novel artificial ion channels with novel functions and biomedical applications. 展开更多
关键词 SELF-ASSEMBLY SUPRAMOLECULAR Artificial ion channel Biomedical application
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Dynamics of Poisson-Nernst-Planck Systems and Ionic Flows Through Ion Channels:A Review
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作者 Weishi Liu 《Communications in Mathematical Research》 CSCD 2023年第3期342-385,共44页
Poisson-Nernst-Planck systems are basic models for electrodiffusion process,particularly,for ionic flows through ion channels embedded in cell membranes.In this article,we present a brief review on a geometric singula... Poisson-Nernst-Planck systems are basic models for electrodiffusion process,particularly,for ionic flows through ion channels embedded in cell membranes.In this article,we present a brief review on a geometric singular perturbation framework for analyzing the steady-state of a quasi-one-dimensional Poisson-Nernst-Planck model.The framework is based on the general geometric singular perturbed theory from nonlinear dynamical system theory and,most crucially,on the reveal of two specific structures of Poisson-Nernst-Planck systems.As a result of the geometric framework,one obtains a governing system-an algebraic system of equations that involves all physical quantities such as protein structures of membrane channels as well as boundary conditions,and hence,provides a complete platform for studying the interplay between protein structure and boundary conditions and effects on ionic flow properties.As an illustration,we will present concrete applications of the theory to several topics of biologically significant based on collaboration works with many excellent researchers. 展开更多
关键词 ion channel ionic flow Poisson-Nernst-Planck models
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Exercise-induced adaptation of neurons in the vertebrate locomotor system
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作者 Yue Dai Yi Cheng +2 位作者 Renkai Ge Ke Chen Liming Yang 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第2期160-171,共12页
Vertebrate neurons are highly dynamic cells that undergo several alterations in their functioning and physiologies in adaptation to various external stimuli.In particular,how these neurons respond to physical exercise... Vertebrate neurons are highly dynamic cells that undergo several alterations in their functioning and physiologies in adaptation to various external stimuli.In particular,how these neurons respond to physical exercise has long been an area of active research.Studies of the vertebrate locomotor system’s adaptability suggest multiple mechanisms are involved in the regulation of neuronal activity and properties during exercise.In this brief review,we highlight recent results and insights from the field with a focus on the following mechanisms:(a)alterations in neuronal excitability during acute exercise;(b)alterations in neuronal excitability after chronic exercise;(c)exercise-induced changes in neuronal membrane properties via modulation of ion channel activity;(d)exercise-enhanced dendritic plasticity;and(e)exercise-induced alterations in neuronal gene expression and protein synthesis.Our hope is to update the community with a cellular and molecular understanding of the recent mechanisms underlying the adaptability of the vertebrate locomotor system in response to both acute and chronic physical exercise. 展开更多
关键词 Dendritic plasticity EXCITABILITY Exercise ion channel modulation Neuron adaptation
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Effects of Chinese herbs on multiple ion channels in isolated ventricular myocytes 被引量:30
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作者 LI Ning MA Ke-juan +3 位作者 WU Xiang-feng SUN Qi ZHANG Yi-hui PU Jie-lin 《Chinese Medical Journal》 SCIE CAS CSCD 2007年第12期1068-1074,共7页
Background Shensong Yangxin (SSYX) is one of the compound recipe of Chinese materia medica. This study was conducted to investigate the effects of SSYX on sodium current (/Na), L-type calcium current (/Ca.L), tr... Background Shensong Yangxin (SSYX) is one of the compound recipe of Chinese materia medica. This study was conducted to investigate the effects of SSYX on sodium current (/Na), L-type calcium current (/Ca.L), transient outward potassium current (/to), delayed rectifier current (/K), and inward rectifier potassium currents (/K1) in isolated ventricular myocytes. Methods Whole cell patch-clamp technique was used to study ion channel currents in enzymatically isolated guinea pig or rat ventricular myocytes. Results SSYX decreased peak Na by (44.84±7.65)% from 27.21±5.35 to 14.88±2..75 pA/pF (n=-5, P〈0.05). The medicine significantly inhibited the /Ca,L. At concentrations of 0.25, 0.50, and 1.00 g/100 ml, the peak/Ca,L was reduced by (19.22±1.10)%, (44.82±6.50)% and (50.69±5.64)%, respectively (n=5, all P〈0.05). SSYX lifted the I-V curve of both /Na and /Ca,L without changing the threshold, peak and reversal potentials. At the concentration of 0.5%, the drug blocked the transient component of /to by 50.60% at membrane voltage of 60 mV and negatively shifted the inactive curve and delayed the recovery from channel inactivation. The tail current density of /K was decreased by (30.77±1.11)% (n=5, P〈0.05) at membrane voltage of 50 mV after exposure to the medicine and the time-dependent activity of /K was also inhibited. Similar to the effect on /K, the SSYX inhibited /K1 by 33.10% at the test potential of -100 mV with little effect on reversal potential and the rectification property. Conclusions The experiments revealed that SSYX could block multiple ion channels such as /Na /Ca,L, /k, /to and /K1, which may change the action potential duration and contribute to some of its antiarrhythmic effects. 展开更多
关键词 ion channels patch clamp antiarrhythmic drugs Shensong Yangxin capsule
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Differences of promethazine and terfenadine on ion channels in guinea pig ventricular myocytes 被引量:6
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作者 LI Xue-wen NIU Shuan-cheng +4 位作者 ZHANG Xuan-ping Lü Ji-yuan BAI Feng ZHANG Ling WU Bo-wei 《Chinese Medical Journal》 SCIE CAS CSCD 2006年第11期944-947,共4页
Promethazine, a first generation antihistamine,has an antiarrhythmic effect on ischemia-reperfusion inducing arrhythmias^1 and experimental arrhythmias.^2 However, terfenadine as a second generation of antihistamine, ... Promethazine, a first generation antihistamine,has an antiarrhythmic effect on ischemia-reperfusion inducing arrhythmias^1 and experimental arrhythmias.^2 However, terfenadine as a second generation of antihistamine, has been reported to elicit hypotension, bradycardia, prolongation of the QTc interval and torsades de pointes (TdP) like ventricular arrhythmia.^3 This may be due to the blockage on rectifier postassium current (Ik) of terfenadine, resulting in the prolongation of the action potential duration (APD) and dispersion of the repolarization duration, which might provoke a specific form of polymorphic ventricular tachydysrhythmia, i.e. TdP.^4 In clinical practice,however, the class Ⅲ antiarrhythmic agents, which target on the lk and prolong the action potential duration and QTc interval, rarely lead to arrhythmias.Other actions must be considered to underlie the arrhythmogenic tendency of terfenadine besides its inhibition on Ik. Though both promethazine and terfenadine block the H1 receptor, there must be a different pharmacology profile between the two compounds on ion channels of cardiac myocytes.Whole-cell patch clamp technique was used to investigate the effects of these two antagonists of the H1 receptor on the main ion currents in cardiac electrical activities. 展开更多
关键词 PROMETHAZINE TERFENADINE ion channels ventricular myocytes H1 receptor
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Ion Channels in Plant Bioenergetic Organelles, Chloroplasts and Mitochondria: From Molecular Identification to Function 被引量:5
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作者 Luca Carraretto Enrico Teardo +3 位作者 Vanessa Checchetto Giovanni Finazzi Nobuyuki Uozumi Ildiko Szabo 《Molecular Plant》 SCIE CAS CSCD 2016年第3期371-395,共25页
Recent technical advances in electrophysiological measurements, organelle-targeted fluorescence imaging, and organelle proteomics have pushed the research of ion transport a step forward in the case of the plant bioen... Recent technical advances in electrophysiological measurements, organelle-targeted fluorescence imaging, and organelle proteomics have pushed the research of ion transport a step forward in the case of the plant bioenergetic organelles, chloroplasts and mitochondria, leading to the molecular identification and functional characterization of several ion transport systems in recent years. Here we focus on channels that mediate relatively high-rate ion and water flux and summarize the current knowledge in this field, focusing on targeting mechanisms, proteomics, electrophysiology, and physiological function. In addition, since chloroplasts evolved from a cyanobacterial ancestor, we give an overview of the information available about cyanobacterial ion channels and discuss the evolutionary origin of chloroplast channels. The recent molecular identification of some of these ion channels allowed their physiological functions to be studied using genetically modified Arabidopsis plants and cyanobacteria. The view is emerging that alteration of chloroplast and mitochondrial ion homeostasis leads to organelle dysfunction, which in turn significantly affects the energy metabolism of the whole organism. Clear-cut identification of genes encoding for chan- nels in these organelles, however, remains a major challenge in this rapidly developing field. Multiple stra- tegies including bioinformatics, cell biology, electrophysiology, use of organelle-targeted ion-sensitive probes, genetics, and identification of signals eliciting specific ion fluxes across organelle membranes should provide a better understanding of the physiological role of organellar channels and their contribution to signaling pathways in plants in the future. 展开更多
关键词 ion channels CHLOROPLASTS MITOCHONDRIA CYANOBACTERIA ENDOSYMBIOSIS plant physiology
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The effects of paeoniflorin monomer of a Chinese herb on cardiac ion channels 被引量:5
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作者 WANG Rong-rong LI Ning ZHANG Yin-hui RAN Yu-qin PU Jie-lin 《Chinese Medical Journal》 SCIE CAS CSCD 2011年第19期3105-3111,共7页
Background Because of the potential proarrhythmic effect of current antiarrhythmic drugs, it is still desirable to find safer antiarrhythmic drugs worldwide. Paeoniflorin is one of the Chinese herb monomers that have ... Background Because of the potential proarrhythmic effect of current antiarrhythmic drugs, it is still desirable to find safer antiarrhythmic drugs worldwide. Paeoniflorin is one of the Chinese herb monomers that have different effects on many ion channels. The present study aimed to determine the effects of paeoniflorin on cardiac ion channels.Methods Whole-cell patch-clamp technique was used to record ion channel currents. L-type calcium current (/Ca-L),inward rectifier potassium current (/K1), and transient outward potassium current (/to1) were studied in rat ventricular myocytes and sodium current (/Na), slow delayed rectifier current (/Ks), and HERG current (/Kr) were investigated in transfected human embryonic kidney 293 cells.Results One hundred μmol/L paeoniflorin reduced the peak /ca-L by 40.29% at the test potential of ±10 mV (from (-9.78±0.52) pA/pF to (-5.84±0.89) pA/pF, n=5, P=0.028). The steady-state activation curve was shifted to more positive potential in the presence of the drug. The half activation potentials were (-11.22±0.27) mV vs. (-5.95±0.84) mV (n=5,P=0.007), respectively. However, the steady-state inactivation and the time course of recovery from inactivation were not changed. One hundred μmol/L paeoniflorin completely inhibited the peak /Na and the effect was reversible. Moreover,paeoniflorin inhibited the /K1 by 30.13% at the test potential of -100 mV (from (-25.26±8.21) pA/pF to (-17.65±6.52)pA/pF, n=6, F=0.015) without effects on the reversal potential and the rectification property. By contrast, 100 μmol/L paeoniflorin had no effects on/to1, /Ks or /Kr channels.Conclusions The study demonstrated that paeoniflorin blocked /Ca-L, /Na, and /Kf without affecting /to1, /Ks, or /Kr. The multi-channel block effect may account for its antiarrhythmic effects with less proarrhythmic potential. 展开更多
关键词 ion channels Chinese herbs antiarrhythmic drugs PAEONIFLORIN
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Differential Effect of Calcium-Activated Potassium and Chloride Channels on Rat Basilar Artery Vasomotion 被引量:3
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作者 李丽 王蕊 +5 位作者 马克涛 李新芝 张传林 刘卫东 赵磊 司军强 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2014年第4期482-490,共9页
Spontaneous, rhythmical contractions, or vasomotion, can be recorded from cerebral vessels under both normal physiological and pathophysiological conditions. We investigated the cellular mechanisms underlying vasomoti... Spontaneous, rhythmical contractions, or vasomotion, can be recorded from cerebral vessels under both normal physiological and pathophysiological conditions. We investigated the cellular mechanisms underlying vasomotion in the cerebral basilar artery (BA) of Wistar rats. Pressure myograph video microscopy was used to study the changes in cerebral artery vessel diameter. The main results of this study were as follows: (1) The diameters of BA and middle cerebral artery (MCA) were 314.5±15.7 μm (n=15) and 233.3±10.1 μm (n=12) at 10 mmHg working pressure (P〈0.05), respectively. Pressure-induced vasomotion occurred in BA (22/28, 78.6%), but not in MCA (4/31, 12.9%) from 0 to 70 mmHg working pressure. As is typical for vasomotion, the contractile phase of the response was more rapid than the relaxation phase; (2) The frequency of vasomotion response and the diameter were gradually increased in BA from 0 to 70 mmHg working pressure. The amplitude of the rhythmic con- tractions was relatively constant once stable conditions were achieved. The frequency of contractions was variable and the highest value was 16.7±4.7 (n=13) per 10 min at 60 mmHg working pressure; (3) The pressure-induced vasomotion of the isolated BA was attenuated by nifedipine, NFA, 181]-GA, TEA or in Ca2+-free medium. Nifedipine, NFA, 18^-GA or Ca2+-free medium not only dampened vasomotion, but also kept BA in relaxation state. In contrasts, TEA kept BA in contraction state. These results sug- gest that the pressure-induced vasomotion of the isolated BA results from an interaction between Ca2+-activated C1- channels (CaCCs) currents and Kca currents. We hypothesize that vasomotion of BA depends on the depolarizing of the vascular smooth muscle cells (VSMCs) to activate CaCCs. Depolarization in turn activates voltage-dependent Ca2+ channels, synchronizing contractions of adjacent cells through influx of extracellular calcium and the flow of calcium through gap junctions. Subsequent calcium-induced calcium release from ryanodine-sensitive stores activates Kca channels and hyperpo- larizes VSMCs, which provides a negative feedback loop for regenerating the contractile cycle. 展开更多
关键词 pressure myograph VASOMOTion basilar artery calcium-activated ion channels vascular smooth muscle cell gap junction
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Synchronous constructing ion channels and confined space of Co_(3)O_(4) anode for high-performance lithium-ion batteries 被引量:2
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作者 Yan Zhou Chao Wang +5 位作者 Feiran Chen Tingjuan Wang Yaoyao Ni Hongxia Sun Nan Yu Baoyou Geng 《Nano Research》 SCIE EI CSCD 2022年第7期6192-6199,共8页
The yolk–shell structure has a unique advantage in lithium-ion batteries applications due to its ability to effectively buffer the volume expansion of the lithiation/delithiation process.However,its development is li... The yolk–shell structure has a unique advantage in lithium-ion batteries applications due to its ability to effectively buffer the volume expansion of the lithiation/delithiation process.However,its development is limited by the low contact point between the core and shell.Herein,we propose a general strategy of simultaneous construction of sufficient reserved space and multicontinuous active channels by pyrolysis of two carbon substrates.A double-shell structure consisting of Co_(3)O_(4) anchored to hollow carbon sphere and external self-supporting zeolitic imidazolate framework(ZIF)layer was constructed by spray pyrolysis and additional carbon coating in-situ growth.In the process of high-temperature calcination,the carbon and nitrogen layers between the shells separate,creating additional space,while the Co_(3)O_(4) particles between the shells remain are still in close contact to form continuous and fast electron conduction channels,which can realize better charge transfer.Due to the synergy of these design principles,the material has ultra-high initial discharge capacities of 2,183.1 mAh·g^(−1) at 0.2 A·g^(−1) with capacity of 1,121.36 mAh·g^(−1) after 250 cycles,the long-term capacities retention rate is about 92.4%after 700 cycles at 1 A·g^(−1).This unique channel-type double-shell structure fights a way out to prepare novel electrode materials with high performance. 展开更多
关键词 double-shell structure ion channels confined space lithium-ion batteries Co_(3)O_(4)
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The macroscopic quantum state of ion channels:A carrier of neural information 被引量:1
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作者 Bo Song Lei Jiang 《Science China Materials》 SCIE EI CAS CSCD 2021年第10期2572-2579,共8页
Neuroscience has been extensively developed for more than seventy years;however,there still remains lack of breakthrough understanding in the neural information field.A quantum coherent state of ion channels is recent... Neuroscience has been extensively developed for more than seventy years;however,there still remains lack of breakthrough understanding in the neural information field.A quantum coherent state of ion channels is recently proposed in neural system as an information carrier,but its physical expression is still not fixed.Here,employing a simple K^(+)channel as a typical instance,we theoretically build a conceptual model for the quantum state of a neural ion channel and demonstrate the macroscopic coherence state of multiple ion channels.The underlying mechanism is revealed to the mid-infrared photons released by ion oscillation in one ion channel together with their resonant and coherent coupling with the oscillations in other channels.An additional environment field(e.g.,brain wave)may regulate the coherence,potentially relating to the human consciousness.Clearly,there exist the channels of other ions in a neural system,which also potentially form a macroscopic coherence state of themselves,with the mechanism identical to that of K^(+)channels.An environment field can be expected to further regulate the quantum states of various ionic channels,leading to a total macroscopic coherence state of these channels,which is like the conductor in a symphony to achieve the harmony in music.These findings are expected to provide a promising viewpoint for neuroscience,as well as to improve treatments of the diseases and health problems related to neural system. 展开更多
关键词 macroscopic coherence state biological ion channels neural information
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