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Expression levels of K_(ATP)channel subunits and morphological changes in the mouse liver after exposure to radiation
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作者 Ming Zhou Tao-Sheng Li +3 位作者 Hiroshi Abe Hideo Akashi Ryoji Suzuki Yoshio Bando 《World Journal of Experimental Medicine》 2024年第2期103-113,共11页
BACKGROUND ATP sensitive K+(K_(ATP))channels are ubiquitously distributed in various of cells and tissues,including the liver.They play a role in the pathogenesis of myocardial and liver ischemia.AIM To evaluate the r... BACKGROUND ATP sensitive K+(K_(ATP))channels are ubiquitously distributed in various of cells and tissues,including the liver.They play a role in the pathogenesis of myocardial and liver ischemia.AIM To evaluate the radiation-induced changes in the expression of K_(ATP)channel subunits in the mouse liver to understand the potential role of K_(ATP)channels in radiation injury.METHODS Adult C57BL/6 mice were randomly exposed toγ-rays at 0 Gy(control,n=2),0.2 Gy(n=6),1 Gy(n=6),or 5 Gy(n=6).The livers were removed 3 and 24 h after radiation exposure.Hematoxylin and eosin staining was used for morphological observation;immunohistochemical staining was applied to determine the expression of K_(ATP)channel subunits in the liver tissue.RESULTS Compared with the control group,the livers exposed to 0.2 Gyγ-ray showed an initial increase in the expression of Kir6.1 at 3 h,followed by recovery at 24 h after exposure.Exposure to a high dose of 5.0 Gy resulted in decreased expression of Kir6.1 and increased expression of SUR2B at 24 h.However,the expression of Kir6.2,SUR1,or SUR2A had no remarkable changes at 3 and 24 h after exposure to any of these doses.CONCLUSION The expression levels of Kir6.1 and SUR2B in mouse liver changed differently in response to different radiation doses,suggesting a potential role for them in radiation-induced liver injury. 展开更多
关键词 Radiation exposure atp-sensitive k^(+)channel MOUSE LIVER
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Effects of Mitochondrial ATP-sensitive K^+ Channel on Protein Kinase C Pathway and Airway Smooth Muscle Cell Proliferation in Asthma 被引量:4
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作者 万璇 赵建平 谢俊刚 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2012年第4期480-484,共5页
The effects of ATP-sensitive mitochondrial K + channel(mitoK ATP) on mitochondrial membrane potential(Δψm),cell proliferation and protein kinase C alpha(PKCα) expression in airway smooth muscle cells(ASMCs) were in... The effects of ATP-sensitive mitochondrial K + channel(mitoK ATP) on mitochondrial membrane potential(Δψm),cell proliferation and protein kinase C alpha(PKCα) expression in airway smooth muscle cells(ASMCs) were investigated.Thirty-six Sprague-Dawley(SD) rats were immunized with saline(controls) or ovalbumin(OVA) with alum(asthma models).ASMCs were cultured from the lung of control and asthma rats.ASMCs were treated with diazoxide(the potent activator of mitoK ATP) or 5-hydroxydencanote(5-HD,the inhibitor of mitoK ATP).Rhodamine-123(R-123) was used to detect Δψm.The expression of PKCα protein was examined by using Western blotting,while PKCα mRNA expression was detected by using real-time PCR.The proliferation of ASMCs was measured by MTT assay and cell cycle analysis.In diazoxide-treated normal ASMCs,the R-123 fluorescence intensity,protein and mRNA levels of PKCα,MTT A values and percentage of cells in S phase were markedly increased as compared with untreated controls.The ratio of G 0 /G 1 cells was decreased(P<0.05) in diazoxide-treated ASMCs from normal rats.However,there were no significant differences between the ASMCs from healthy rats treated with 5-HD and the normal control group.In untreated and diazoxide-treated ASMCs of asthmatic rats,the R-123 fluorescence intensity,protein and mRNA levels of PKCα,MTT A values and the percentage of cells in S phase were increased in comparison to the normal control group.Furthermore,in comparison to ASMCs from asthmatic rats,these values were considerably increased in asthmatic group treated with diazoxide(P<0.05).After exposure to 5-HD for 24 h,these values were decreased as compared with asthma control group(P<0.05).In ASMCs of asthma,the signal transduction pathway of PKCα may be involved in cell proliferation,which is induced by the opening of mitoK ATP and the depolarization of Δψm. 展开更多
关键词 ASTHMA airway smooth muscle cells atp-sensitive k + channel protein kinase C
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Localization of ATP-sensitive K^+ channel subunits in rat liver
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作者 Ming Zhou Kiwamu Yoshikawa +5 位作者 Hideo Akashi Mitsutaka Miura Ryoji Suzuki Tao-Sheng Li Hiroshi Abe Yoshio Bando 《World Journal of Experimental Medicine》 2019年第2期14-31,共18页
BACKGROUND ATP-sensitive K^+(KATP)channels were originally found in cardiac myocytes by Noma in 1983.KATP channels were formed by potassium ion-passing poreforming subunits(Kir6.1,Kir6.2)and regulatory subunits SUR1,S... BACKGROUND ATP-sensitive K^+(KATP)channels were originally found in cardiac myocytes by Noma in 1983.KATP channels were formed by potassium ion-passing poreforming subunits(Kir6.1,Kir6.2)and regulatory subunits SUR1,SU2A and SUR2B.A number of cells and tissues have been revealed to contain these channels including hepatocytes,but detailed localization of these subunits in different types of liver cells was still uncertain.AIM To investigate the expression of KATP channel subunits in rat liver and their localization in different cells of the liver.METHODS Rabbit anti-rat SUR1 peptide antibody was raised and purified by antigen immunoaffinity column chromatography.Four of Sprague-Dawley rats were used for liver protein extraction for immunoblot analysis,seven of them were used for immunohistochemistry both for the ABC method and immunofluorescence staining.Four of Wistar rats were used for the isolation of hepatic stellate cells(HSCs)and Kupffer cells for both primary culture and immunocytochemistry.RESULTS Immunoblot analysis showed that the five kinds of KATP channel subunits,i.e.Kir6.1,Kir6.2,SUR1,SUR2A,and SUR2B,were detected in liver.Immunohistochemical staining showed that Kir6.1 and Kir6.2 were weakly to moderately expressed in parenchymal cells and sinusoidal lining cells,while SUR1,SUR2A,and SUR2B were mainly localized to sinusoidal lining cells,such as HSCs,Kupffer cells,and sinusoidal endothelial cells.Immunoreactivity for SUR2A and SUR2B was expressed in the hepatocyte membrane.Double immunofluorescence staining further showed that the pore-forming subunits Kir6.1 and/or Kir6.2 colocalized with GFAP in rat liver sections and primary cultured HSCs.These KATP channel subunits also colocalized with CD68 in liver sections and primary cultured Kupffer cells.The SUR subunits colocalized with GFAP in liver sections and colocalized with CD68 both in liver sections and primary cultured Kupffer cells.In addition,five KATP channel subunits colocalized with SE-1 in sinusoidal endothelial cells.CONCLUSION Observations from the present study indicated that KATP channel subunits expressed in rat liver and the diversity of KATP channel subunit composition might form different types of KATP channels.This is applicable to hepatocytes,HSCs,various types of Kupffer cells and sinusoidal endothelial cells. 展开更多
关键词 atp-sensitive k^+channel LIVER Hepatic stellate cells kupffer cells Sinusoidal endothelial cells Rat
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普通烟草外向整流Shaker K^(+)通道NtSKOR1的组织表达分析
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作者 农童嘉 徐方正 +8 位作者 袁佳苹 向海英 王学瑛 袁光 OLUWASEYI Setonji Hunpatin 崔萌萌 宁扬 王倩 戴培刚 《中国烟草科学》 CSCD 北大核心 2024年第2期90-98,共9页
外向整流Shaker K^(+)通道SKOR(Stelar K^(+)outward rectifier)是一类定位于植物根部中柱细胞质膜的外向整流Shaker K^(+)通道。为探究普通烟草NtSKOR1的启动子活性和不同时期组织表达情况,克隆该基因上游2439 bp的启动子序列,创制启... 外向整流Shaker K^(+)通道SKOR(Stelar K^(+)outward rectifier)是一类定位于植物根部中柱细胞质膜的外向整流Shaker K^(+)通道。为探究普通烟草NtSKOR1的启动子活性和不同时期组织表达情况,克隆该基因上游2439 bp的启动子序列,创制启动子驱动β-葡萄糖苷酸酶基因(GUS)的烟草材料并进行组织化学染色,通过RT-qPCR验证该基因的表达。结果表明NtSKOR1启动子含有光响应、逆境胁迫和激素等相关的顺式作用元件;转ProNtSKOR1::GUS烟草的组织化学染色试验表明:萌发期至子叶展平期未检测到GUS活性;小十字期,在真叶叶脉和茎尖分生组织开始检测到GUS活性;生根期,除茎和叶脉的维管组织外,在根部维管组织也开始检测到明显GUS活性,且活性随烟株生长而逐渐增强;盛花期,主要在烟草的根、茎和叶脉维管组织检测到活性,且上部叶叶脉中的GUS活性高于下部叶叶脉。RT-qPCR与GUS活性检测结果基本一致。综上可知,NtSKOR1主要在烟草小十字期及后续发育阶段的根、茎、叶的维管组织中表达,烟草进入盛花期后,该基因在光合作用较强的上部叶中的表达高于下部叶,推测该基因可能参与烟草K^(+)转运和同化产物协同运输。 展开更多
关键词 NtSkOR1 Shaker k^(+)通道 GUS活性 烟草 基因表达
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Ion channels in neurodevelopment:lessons from the Integrin-KCNB1 channel complex
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作者 Alessandro Bortolami Federico Sesti 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第11期2365-2369,共5页
Ion channels modulate cellular excitability by regulating ionic fluxes across biological membranes.Pathogenic mutations in ion channel genes give rise to epileptic disorders that are among the most frequent neurologic... Ion channels modulate cellular excitability by regulating ionic fluxes across biological membranes.Pathogenic mutations in ion channel genes give rise to epileptic disorders that are among the most frequent neurological diseases affecting millions of individuals worldwide.Epilepsies are trigge red by an imbalance between excitatory and inhibitory conductances.However,pathogenic mutations in the same allele can give rise to loss-of-function and/or gain-of-function va riants,all able to trigger epilepsy.Furthermore,certain alleles are associated with brain malformations even in the absence of a clear electrical phenotype.This body of evidence argues that the underlying epileptogenic mechanisms of ion channels are more diverse than originally thought.Studies focusing on ion channels in prenatal cortical development have shed light on this apparent paradox.The picture that emerges is that ion channels play crucial roles in landmark neurodevelopmental processes,including neuronal migration,neurite outgrowth,and synapse formation.Thus,pathogenic channel mutants can not only cause epileptic disorders by alte ring excitability,but further,by inducing morphological and synaptic abnormalities that are initiated during neocortex formation and may persist into the adult brain. 展开更多
关键词 developmental and epileptic encephalopathies epilepsy k+channel kCNB1 kv2.1 NEURODEVELOPMENT potassium channel
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Effect of G_(αq/11) Protein and ATP-sensitive Potassium Channels on Ischemic Preconditioning in Rat Hearts
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作者 马守国 付润芳 +2 位作者 冯国清 王振基 翁世艾 《South China Journal of Cardiology》 CAS 2007年第1期33-37,共5页
Objectives To investigate the effect of Gαq/11 signaling pathway and ATP-sensitive potassium channel ( KATP channel ) on ischemic preconditioning (IPC) protection in rat hearts. Methods Two series of experiments were... Objectives To investigate the effect of Gαq/11 signaling pathway and ATP-sensitive potassium channel ( KATP channel ) on ischemic preconditioning (IPC) protection in rat hearts. Methods Two series of experiments were performed in Wistar rat hearts. In the first series of experiment, ischemic preconditioning was induced by left anterior descending occlusion (three, 5 min episodes separated by 5 min of reperfusion), ischemia-reperfusion injury was induced by 30 min coronary artery occlusion followed by 90 min reperfusion. Hemodynamics, infarct size and scores of ventricular arrhythmias were measured. The expression of Gαq/11 protein in the heart was measured by Western blot analysis in the second series. Results Ischemic preconditioning rats showed decreased infarct size and scores of ventricular arrhythmia vs non-IP control rats. The effect of IPC was significantly attenuated by glibenclamide (1 mg/kg, ip), a nonselective KATP channel inhibitor. IPC caused a significant increase in the expression of Gαq/11 protein. Conclusions Activations of Gαq/11 signal pathway and KATP channel played significant roles in the classical cardioprotection of ischemic precon-ditioning rat heart and might be an important mechanism of signal transduction pathway during the ischemic preconditioning. 展开更多
关键词 Gαq/11 protein atp-sensitive potassium channel Ischemic preconditioning Signal transduction Ischemia-reperfusion
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无线信道建模中二分K均值聚类多径分簇算法
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作者 聂益芳 MBUGUA Allan Wainaina +2 位作者 李余 姚行艳 蔡雪松 《电波科学学报》 CSCD 北大核心 2023年第2期284-291,共8页
为了对无线信道中的多径分量进行合理分簇,提出了一种毫米波信道二分K均值聚类多径分簇方法,解决了传统的K均值聚类分簇方法只能实现局部最优分簇的问题.采用马氏距离(Mahalanobis distance,MD)衡量多径分量距离(multi-path component d... 为了对无线信道中的多径分量进行合理分簇,提出了一种毫米波信道二分K均值聚类多径分簇方法,解决了传统的K均值聚类分簇方法只能实现局部最优分簇的问题.采用马氏距离(Mahalanobis distance,MD)衡量多径分量距离(multi-path component distance,MCD),以簇分裂和迭代计算的方式对多径进行分簇.采用毫米波室内信道实验测试数据,验证了所提算法的有效性和可行性.结果表明,所提算法比传统K均值聚类分簇方法获得的分簇结果更合理,能将信道中多径参数相似度较高的多径有效且唯一地分配到同一簇. 展开更多
关键词 二分k均值 马氏距离(MD) 多径分簇 毫米波信道建模
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磁耦合谐振式无线电能传输磁场对海马齿状回区神经元K^(+)通道的影响
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作者 赵军 张冰茜 +1 位作者 赵毅航 王晓轩 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2023年第8期1982-1994,共13页
目的磁耦合谐振式无线电能传输(magnetically-coupled resonant wireless power transfer,MCR-WPT)具有传输距离较大、传输效率高、穿透性好等优点,为人们生活带来便利的同时其引起的生物电磁效应安全问题备受人们关注。本文通过研究MCR... 目的磁耦合谐振式无线电能传输(magnetically-coupled resonant wireless power transfer,MCR-WPT)具有传输距离较大、传输效率高、穿透性好等优点,为人们生活带来便利的同时其引起的生物电磁效应安全问题备受人们关注。本文通过研究MCR-WPT电磁环境对小鼠海马齿状回(DG)区神经元K^(+)通道特性的影响,为无线电能传输(WPT)技术的发展及其合理开发应用提供实验依据。方法每天对小鼠不间断辐射5 h,持续30 d,对比分析对照组和磁场暴露5 d、15 d、30 d组小鼠的学习记忆能力、海马DG区神经元的瞬时外向K^(+)通道电流(IA)和延迟整流K^(+)通道电流(IK)的变化。结果磁场暴露组瞬时外向K^(+)通道的激活过程受到抑制、延迟整流K^(+)通道的激活特性向去极化方向移动,减少K^(+)的外流,增强了神经兴奋性,但磁场暴露组小鼠行为上无显著性变化。结论长期处于MCR-WPT电磁环境会改变K^(+)通道的电流-电压(I-V)特性和动力学特性,抑制IA和IK,改变神经元动作电位的发放频率,但这些变化并没有引起小鼠学习记忆能力的下降以及认知功能障碍。 展开更多
关键词 k^(+)通道 电流-电压(I-V)特性 无线电能传输 齿状回区
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Inhibitory Effects of Blockage of Intermediate Conductance Ca^(2+) -Activated K^+ Channels on Proliferation of Hepatocellular Carcinoma Cells 被引量:5
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作者 杨筱嵬 刘谨文 +3 位作者 张汝超 殷 茜 沈文状 易继林 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2013年第1期86-89,共4页
The roles of intermediate conductance Ca2+-activated K+ channel (IKCal) in the pathogene- sis of hepatocellular carcinoma (HCC) were investigated. Immunohistochemistry and Western blotting were used to detect th... The roles of intermediate conductance Ca2+-activated K+ channel (IKCal) in the pathogene- sis of hepatocellular carcinoma (HCC) were investigated. Immunohistochemistry and Western blotting were used to detect the expression of IKCal protein in 50 HCC and 20 para-carcinoma tissue samples. Real-time PCR was used to detect the transcription level of IKCal mRNA in 13 HCC and 11 para-carcinoma tissue samples. The MTT assay was used to measure the function of IKCal in human HCC cell line HepG2 in vitro. TRAM-34, a specific blocker of IKCal, was used to intervene with the function of IKCal. As compared with para-carcinoma tissue, an over-expression of IKCal protein was detected in HCC tissue samples (P〈0.05). The mRNA expression level of IKCal in HCC tissues was 2.17 times higher than that in para-carcinoma tissues. The proliferation of HepG2 cells was suppressed by TRAM-34 (0.5, 1.0, 2.0 and 4.0 pxnol/L) in vitro (P〈0.05). Our results suggested that IKCal may play a role in the proliferation of human HCC, and IKCal blockers may represent a potential therapeutic strategy for HCC. 展开更多
关键词 intermediate conductance Ca2+-activated k channel hepatocellular carcinoma TRAM-34 PROLIFERATION
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Beneficial effects of adenosine triphosphate-sensitive K^+ channel opener on liver ischemia/reperfusion injury 被引量:2
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作者 Mateus Antunes Nogueira Ana Maria Mendona Coelho +4 位作者 Sandra Nassa Sampietre Rosely Antunes Patzina Fabiano Pinheiro da Silva Luiz Augusto Carneiro D'Albuquerque Marcel Cerqueira Cesar Machado 《World Journal of Gastroenterology》 SCIE CAS 2014年第41期15319-15326,共8页
AIM:To investigate the effect of diazoxide administration on liver ischemia/reperfusion injury.METHODS:Wistar male rats underwent partial liver ischemia performed by clamping the pedicle from the medium and left anter... AIM:To investigate the effect of diazoxide administration on liver ischemia/reperfusion injury.METHODS:Wistar male rats underwent partial liver ischemia performed by clamping the pedicle from the medium and left anterior lateral segments for 1 h under mechanical ventilation.They were divided into 3 groups:Control Group,rats submitted to liver manipulation,Saline Group,rats received saline,and Diazoxide Group,rats received intravenous injection diazoxide(3.5 mg/kg) 15 min before liver reperfusion.4 h and 24 h after reperfusion,blood was collected for determination of aspartate transaminase(AST),alanine transaminase(ALT),tumor necrosis factor(TNF-α),interleukin-6(IL-6),interleukin-10(IL-10),nitrite/nitrate,creatinine and tumor growth factor-β1(TGF-β1).Liver tissues were assembled for mitochondrial oxidation and phosphorylation,malondialdehyde(MDA) content,and histologic analysis.Pulmonary vascular permeability and myeloperoxidase(MPO) were also determined.RESULTS:Four hours after reperfusion the diazoxide group presented with significant reduction of AST(2009 ± 257 U/L vs 3523 ± 424 U/L,P = 0.005); ALT(1794 ± 295 U/L vs 3316 ± 413 U/L,P = 0.005); TNF-α(17 ± 9 pg/mL vs 152 ± 43 pg/mL,P = 0.013; IL-6(62 ± 18 pg/mL vs 281 ± 92 pg/mL); IL-10(40 ± 9 pg/mL vs 78 ± 10 pg/mL P = 0.03),and nitrite/nitrate(3.8 ± 0.9 μmol/L vs 10.2 ± 2.4 μmol/L,P = 0.025) when compared to the saline group.A significant reduction in liver mitochondrial dysfunction was observed in the diazoxide group compared to the saline group(P < 0.05).No differences in liver MDA content,serum creatinine,pulmonary vascular permeability and MPO activity were observed between groups.Twenty four hours after reperfusion the diazoxide group showed a reduction of AST(495 ± 78 U/L vs 978 ± 192 U/L,P = 0.032); ALT(335 ± 59 U/L vs 742 ± 182 U/L,P = 0.048),and TGF-β1(11 ± 1 ng/mL vs 17 ± 0.5 ng/mL,P = 0.004) serum levels when compared to the saline group.The control group did not present alterations when compared to the diazoxide and saline groups.CONCLUSION:Diazoxide maintains liver mitochondrial function,increases liver tolerance to ischemia/reperfusion injury,and reduces the systemic inflammatory response.These effects require further evaluation for using in a clinical setting. 展开更多
关键词 Liver ISCHEMIA/REPERFUSION DIAZOXIDE k+ channel OP
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Nitric oxide activation of a potassium channel (BK_(Ca)) in feline lower esophageal sphincter 被引量:2
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作者 Marie-Claude L'Heureux Ahmad Muinuddin +1 位作者 Herbert Y Gaisano Nicholas E Diamant 《World Journal of Gastroenterology》 SCIE CAS CSCD 2010年第46期5852-5860,共9页
AIM:To assess the effect of nitric oxide (NO) on the large conductance potassium channel (BKCa) in isolated circular (CM) and sling (SM) muscle cells and muscle strips from the cat lower esophageal sphincter (LES) to ... AIM:To assess the effect of nitric oxide (NO) on the large conductance potassium channel (BKCa) in isolated circular (CM) and sling (SM) muscle cells and muscle strips from the cat lower esophageal sphincter (LES) to determine its regulation of resting tone and relaxation.METHODS:Freshly enzymatically-digested and isolated circular smooth muscle cells were prepared from each LES region.To study outward K + currents,the perforated patch clamp technique was employed.To assess LES resting tone and relaxation,muscle strips were mounted in perfused organ baths.RESULTS:(1) Electrophysiological recordings from isolated cells:(a) CM was more depolarized than SM (-39.7 ± 0.8mV vs-48.1 ± 1.6 mV,P < 0.001),and maximal outward current was similar (27.1 ± 1.5 pA/pF vs 25.7 ± 2.0 pA/pF,P > 0.05);(b) The NO donor sodium nitroprusside (SNP) increased outward currents only in CM (25.9 ± 1.9 to 46.7 ± 4.2 pA/pF,P < 0.001) but not SM (23.2 ± 3.1 to 27.0 ± 3.4 pA/pF,P > 0.05);(c) SNP added in the presence of the BK Ca antagonist iberiotoxin (IbTX) produced no increase in the outward current in CM (17.0 ± 2.8 vs 13.7 ± 2.2,P > 0.05);and (d) L-NNA caused a small insignificant inhibition of outward K + currents in both muscles;and (2) Muscle strip studies:(a) Blockade of the nerves with tetrodotoxin (TTX),or BK Ca with IbTX had no significant effect on resting tone of either muscle;and (b) SNP reduced tone in both muscles,and was unaffected by the presence of TTX or IbTX.CONCLUSION:Exogenous NO activates BK Ca only in CM of the cat.However,as opposed to other species,exogenous NO-induced relaxation is predominantly by a non-BK Ca mechanism,and endogenous NO has minimal effect on resting tone. 展开更多
关键词 Circular smooth muscle FELINE k+ channel Lower esophageal SPHINCTER NITRIC oxide SLING TONE
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Potassium channel α-subunit AtKC1 negatively regulates AKTl-mediated K^+ uptake in Arabidopsis roots under Iow-K^+ stress 被引量:23
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作者 Yi Wang Liu He +2 位作者 Hao-Dong Li Jiang Xu Wei-Hua Wu 《Cell Research》 SCIE CAS CSCD 2010年第7期826-837,共12页
关键词 钾离子通道 根系吸收 拟南芥 介导 压力 亚基 负调控 介电
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K^+channels inhibited by hydrogen peroxide mediate abscisic acid signaling in Vicia guard cells 被引量:26
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作者 ZhanX MiaoYC 《Cell Research》 SCIE CAS CSCD 2001年第3期195-202,共8页
A number of studies show that environmental stress conditions increase abscisic acid (ABA) and hydrogen peroxide (H2O2) levels in plant cells. Despite this central role of ABA in altering stomatal aperture by regulati... A number of studies show that environmental stress conditions increase abscisic acid (ABA) and hydrogen peroxide (H2O2) levels in plant cells. Despite this central role of ABA in altering stomatal aperture by regulating guard cell ion transport, little is known concerning the relationship between ABA and H2O2 in signal transduction leading to stomatal movement. Epidermal strip bioassay illustrated that ABA- inhibited stomatal opening and ABA-induced stomatal closure were abolished partly by externally added catalase (CAT) or diphenylene iodonium (DPl), which are a H2O2 scavenger and a NADPH oxidase inhibitor respectively. In contrast, internally added CAT or DPI nearly completely or partly reversed ABA-induced closure in half-stoma. Consistent with these results, whole-cell patch-clamp analysis showed that intracellular application of CAT or DPI partly abolished ABA-inhibited inward K+ current across the plasma membrane of guard cells. H2O2 mimicked ABA to inhibit inward K+ current, an effect which was reversed by the addition of ascorbic acid (Vc) in patch clamping micropipettes. These results suggested that H2O2 mediated ABA-induced stomatal movement by targeting inward K+ channels at plasma membrane. 展开更多
关键词 H2O2 脱落酸 k^+通道 保卫细胞
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Adenosine triphosphate-sensitive potassium channel opener protects PC12 cells against hypoxia-induced apoptosis through PI3K/Akt and Bcl-2 signaling pathways 被引量:1
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作者 Hong Zhang Chunhong Jia Danyang Zhao Yang Lu Runling Wang Jia Li 《Neural Regeneration Research》 SCIE CAS CSCD 2010年第22期1706-1711,共6页
Although previous studies have shown the neuroprotective effects of the adenosine triphosphate (ATP)-sensitive potassium (KATP) channel opener against ischemic neuronal damage, little is known about the mechanisms... Although previous studies have shown the neuroprotective effects of the adenosine triphosphate (ATP)-sensitive potassium (KATP) channel opener against ischemic neuronal damage, little is known about the mechanisms involved. Phosphatidylinositol-3 kinase (PI3K)/v-akt murine thy-moma viral oncogene homolog (Akt) and Bcl-2 are thought to be important factors that mediate neuroprotection. The present study investigated the effects of KATP openers on hypoxia-induced PC12 cell apoptosis, as well as mRNA and protein expression of Akt and Bcl-2. Results demon-strated that pretreatment of PC12 cells with pinacidil, a KATP opener, resulted in decreased PC12 cell apoptosis following hypoxia, as detected by Annexin-V fluorescein isothiocyanate/ propidium iodide double staining flow cytometry. In addition, mRNA and protein expression of phosphorylated Akt (p-Akt) and Bcl-2 increased, as detected by immunofluorescence, Western blot analysis, and reverse-transcription polymerase chain reaction. The protective effect of this preconditioning was attenuated by glipizide, a selective KATP blocker. These results demonstrate for the first time that the protective mechanisms of KATP openers on PC12 cell apoptosis following hypoxia could result from activation of the PI3K/Akt signaling pathway, which further activates expression of the downstream Bcl-2 gene. 展开更多
关键词 atp-sensitive potassium channel PC12 cells HYPOXIA apoptosis PINACIDIL phosphatidylinositol-3 kinase/v-akt murine thymoma viral oncogene homolog BCL-2
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HERG K+ channels expression in gastric cancers and analysis of its regulation in tumor cell proliferation and apoptosis 被引量:1
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作者 Qing Lu Huiyu Li +1 位作者 Xiaoming Lu Guobin Wang 《Journal of Nanjing Medical University》 2009年第3期157-162,共6页
Objective: To investigate the expression of hergl gene in tumor tissues from gastric carcinomas and gastric carcinoma cell lines, and study the relationship between HERG K+ channel expressions and tumor cell prolife... Objective: To investigate the expression of hergl gene in tumor tissues from gastric carcinomas and gastric carcinoma cell lines, and study the relationship between HERG K+ channel expressions and tumor cell proliferation and apoptosis. Methods: RT-PCR and PCR assays were used to detect the expression of hergl gene in 64 gastric carcinomas and the gastric cancer cell line SGC-7901. Blocking the HERG K+ channels was used to evaluate their effects on tumor cell proliferation and apoptosis. Results:The statistically significant expression of hergl gene was detected in all the gastric cancers and SGC-7901 cells, but not in normal tissues. The HERG K+ channel blocker, E-4031, increased the cell population in G0/G1(P 〈 0.05) and the number of apoptotic tumor cells(P 〈 0.05). Conclusion: HERG K+ channels were expressed in all gastric carcinomas tested and these channels appear to modulate tumor cell proliferation and apoptosis. 展开更多
关键词 gastric carcinoma HERG k channel herg 1 gene PROLIFERATION APOPTOSIS
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Involvement of leak K^+ channels in neurological disorders 被引量:3
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作者 Hiroki Toyoda 《World Journal of Neurology》 2015年第1期52-56,共5页
TWIK-related acid-sensitive K+(TASK) channels give rise to leak K+ currents which influence the resting membrane potential and input resistance. The wide expression of TASK1 and TASK3 channels in the central nervous s... TWIK-related acid-sensitive K+(TASK) channels give rise to leak K+ currents which influence the resting membrane potential and input resistance. The wide expression of TASK1 and TASK3 channels in the central nervous system suggests that these channels are critically involved in neurological disorders. It has become apparent in the past decade that TASK channels play critical roles for the development of various neurological disorders. In this review, I describe evidence for their roles in ischemia, epilepsy, learning/memory/cognition and apoptosis. 展开更多
关键词 LEAk k^+channel TWIk-related acidsensitive k^+channel NEUROLOGICAL disorder
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基于CSI和K-means-SVR的多指纹库室内定位方法 被引量:2
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作者 王逸 裴生雷 王煜 《计算机应用》 CSCD 北大核心 2023年第5期1636-1640,共5页
传统的Wi-Fi室内定位方法需要与所有指纹数据库中的指纹数据进行匹配后才能定位,导致人群聚集区域定位效率不高,体验较差。提出一种基于信道状态信息(CSI)、K均值(K-means)聚类算法与支持向量回归(SVR)算法相结合的多指纹库室内定位方... 传统的Wi-Fi室内定位方法需要与所有指纹数据库中的指纹数据进行匹配后才能定位,导致人群聚集区域定位效率不高,体验较差。提出一种基于信道状态信息(CSI)、K均值(K-means)聚类算法与支持向量回归(SVR)算法相结合的多指纹库室内定位方法。该方法首先根据CSI的簇分布特点,利用K-means算法对所有定位点内的CSI数据聚类后得到多个簇的CSI数据;然后,基于多个簇分别建立多个指纹库,并将CSI数据分别存入多个指纹库,进而在每个指纹库中分别训练SVR模型用于Wi-Fi定位。相较于传统的支持向量机(SVM)定位方法,所提方法在离线阶段需要的训练样本更少,定位效率更高;在线阶段,该方法既降低了匹配的复杂度,也提高了定位的精度。由于使用了多指纹库,Wi-Fi定位系统可以根据人流量实时调整资源分配策略,提高服务器运行效率和定位服务体验。 展开更多
关键词 位置服务 室内定位 k均值聚类算法 支持向量回归 多指纹库 信道状态信息
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Neuroprotective effects of a mitochondrial K^+-ATP channel opener (diazoxide) are mediated by Bcl-2 expression upregulation 被引量:2
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作者 Majid Katebi Mansooreh Soleimani Mehdi Mehdizadeh 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第12期956-960,共5页
Mitochondrial K+-ATP (mito-KATP) channels play an important role in cellular function and survival following ischemic stress. The present results revealed that intervention with diazoxide, a mito-KATP channel opene... Mitochondrial K+-ATP (mito-KATP) channels play an important role in cellular function and survival following ischemic stress. The present results revealed that intervention with diazoxide, a mito-KATP channel opener, led to an increase in Bcl-2 expression in the cerebral cortex of rats subjected to cerebral ischemia reperfusion injury. In addition, the intervention also led to clear improvements in neuronal mitochondrial morphology and consciousness post-injury. Glibenclamide a mito-KATP channel blocker, exhibited the converse effects. Both diazoxide and glibenclamide exerted dose-dependent effects (in particular, at 18 mg/kg diazoxide and 25 mg/kg glibenclamide). These findings suggest that diazoxide exerts a neuroprotective effect on cerebral ischemia reperfusion injury by opening mito-KATP channels and upregulating Bcl-2 expression. 展开更多
关键词 k-ATP channel BCL-2 cerebral ischemia reperfusion injury DIAZOXIDE
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K X-ray fluorescent source for energy-channel calibration of the spectrometer 被引量:1
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作者 TAN Da-Gang, QIN Yue-Ting (Department of Physics, Shen yang Normal University, Shenyang 110084 ) Techniques 《Nuclear Science and Techniques》 SCIE CAS CSCD 2001年第4期289-294,共6页
A new K X-ray fluorescent source for calibrating the X or γ-ray multichannel analyzer spectrometer is introduced. A detailed description of the K fluorescent source device is given. The calibration method used and ex... A new K X-ray fluorescent source for calibrating the X or γ-ray multichannel analyzer spectrometer is introduced. A detailed description of the K fluorescent source device is given. The calibration method used and experimental results obtained are presented. The purity and efficiency of K fluorescence photons from this device are discussed. This new fluorescent source may be used as a substitute for radioactive nuclides for the energy-channel calibration of some MCA spectrometers. 展开更多
关键词 放射性物理学 kX射线荧光源 能谱准直分光仪
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K-ATP channel openers facilitate glutamate uptake by GluTs in rat primary cultured Astrocytes 被引量:7
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作者 Sun, X. L. Zeng, X. N. +3 位作者 Zhou, F. Dai, C. P. Ding, J. H. Hu, G. Nanjing Med Univ,Dept Anat Histol & Pharmacol,Neuropharmacol Lab,Nanjing 210029,Jiangsu,Peoples R China. 《南京医科大学学报(自然科学版)》 CAS CSCD 北大核心 2008年第6期757-757,共1页
Increasing evidence, including from our laboratory, has revealed that opening of ATP sensitive potassium channels(K-ATP channels) plays the neuronal protective roles both in vivo and in vitro. Thus K-ATP channel opene... Increasing evidence, including from our laboratory, has revealed that opening of ATP sensitive potassium channels(K-ATP channels) plays the neuronal protective roles both in vivo and in vitro. Thus K-ATP channel openers(KCOs) have been proposed as potential neuroprotectants. Our previous studies demonstrated that K-ATP channels could regulate glutamate uptake activity in PC12 cells as well as in synaptosomes of rats. Since glutamate transporters(GluTs) of astrocytes play crucial roles in glutamate uptake and KATP channels are also expressed in astrocytes, the present study showed whether and how KATP channels regulated the function of GluTs in primary cultured astrocytes. The results showed that nonselective KCO pinacidil, selective mitochondrial KCO diazoxide, novel, and blood-brain barrier permeable KCO iptakalim could enhance glutamate uptake, except for the sarcolemmal KCO P1075. Moreover pinacidil, diazoxide, and iptakalim reversed the inhibition of glutamate uptake induced by 1-methyl-4-phenylpyridinium(MPP+). These potentiated effects were completely abolished by mitochondrial K-ATP blocker 5-hydroxydecanoate. Furthermore, either diazoxide or iptakalim could inhibit MPP+-induced elevation of reactive oxygen species (ROS) and phosphorylation of protein kinases C(PKC). These findings are the first to demonstrate that activation of K-ATP channel, especially mitochondrial K-ATP channel, improves the function of GluTs in astrocytes due to reducing ROS production and downregulating PKC phosphorylation. Therefore, the present study not only reveals a novel pharmacological profile of KCOs as regulators of GluTs, but also provides a new strategy for neuroprotection. 展开更多
关键词 星形胶质细胞 谷氨酸酯 医学实验
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