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Zinc is an important regulator of various biological processes such as protein synthesis, cell proliferation, migration and autophagy. The zinc transporter ZIP13 (SLC39A13) is a homodimeric metal transporter functioning in transport of zinc, iron, and calcium plasma in body. ZIP13 is involved in disease by regulating zinc homeostasis, such as the key role of ZIP13 in connective tissue development because it is involved in the BMP/TGF-β signaling pathway. ZIP13 promotes the metastasis of human ovarian cancer cells by activating the Src/FAK signaling pathway and ZIP13 inhibits the biogenesis and energy expenditure of beige adipocytes by regulating C/EBP-β expression. [ABSTRACT FROM AUTHOR]

Thedimension,structure and surface chemistry of nanochannels have great impact on the distribution structure and transport properties of the confined solutions. In this paper,a graphene prismatic nanochannel is proposed and investigated. This idealized channel is similar to the nanoporous structure of metal-organic framework material ( MOF), which has been widely studied recently,and has a completely different internal structure from the conventional carbon nanotubes. In this paper,the properties of KCl solution inside graphene prismatic nanochannel with different sizes are studied by molecular dynamics simulation,and then are compared with single-walled carbon nanotubes with the similar size. The results show that there are several high density areas inside the small channel ( ＜ 20 Å ),which is a tendency of crystallization. The results of this study will promote the structural design of MOF and the desire to achieve the nanochannel with high selectivity and high transport rate similar to biological ion channels. [ABSTRACT FROM AUTHOR]

[ Objective ] The NAC transcription factor family is a class of transcription factors that is widely studied in plants. It plays an important role in regulating plant growth and development and responding to abiotic stress. Maize is one of the three major food crops , which faces various adverse stresses in growth and development. Salt stress is one of the main environmental factors limiting crop growth and produc- tion. Therefore , it is of great significance to identify maize salt resistance genes and analyze their salt re- sistance mechanism for breeding stress-resistant maize varieties. [ Methods ] This study cloned the maize transcription factor ZmNAC59 and analyzed its conserved domain and phylogenetic relationship using bioinformatics methods. The expression pattern of the gene in leaves under NaCl and MeJA treatments was analyzed using the quantitative real-time PCR method. The stable transgenic system was used to het- erologously express the gene in Arabidopsis thaliana for phenotype observation. At the same time , virus- induced silencing technology was used to silence the gene in maize , followed by phenotype observation un- der salt stress and enzyme activity detection. [ Results ] The qRT-PCR results showed that ZmNAC59 was up-regulated by NaCl and MeJA treatments. After virus-induced silencing of ZmNAC59 , the silenced strains were more sensitive to salt stress and accumulated more ROS. After over expression of ZmNAC59 in A . thaliana , the over expression lines had higher survival rate , less accumulation of ROS , and lower Na + / K + ratios under salt stress , indicating that ZmNAC59 , as a positive regulator of salt stress , can im- prove plant salt resistance by regulating ion homeostasis. qRT-PCR results showed that Na + and K + transport related genes were significantly up-regulated in A . thaliana overexpression lines. After transient expression of ZmNAC59 in maize protoplasts , the expression of ZmSOS1 , ZmNHX1 , and ZmNHX7 were significantly up-regulated after salt treatment. The Dual-LUC experiment showed that ZmSOS1 was the target gene of ZmNAC59. [ Conclusion ] This study finds that ZmNAC59 activates ZmSOS1 promoter and regulates its expression to promote ion transport under salt stress , thereby improving plant salt resist- ance. This provides a basis for the screening of maize stress resistant genes and variety cultivation.

To investigate the effects of sulfate on the properties of cementitious materials, mortar specimens with water-cement ratio of 0. 5 and 0. 35 were designed and subjected to full immersion tests to study the effects of different sulfate concentrations on the water transport properties, mechanical properties and sulfate ion transport properties of cementitious materials at different depths. The results show that the water absorption of cementitious materials after sulfate attack increases with the age of attack. The flexural and compressive strength of cementitious materials shows a trend of increasing and then decreasing with the age of sulfate attack and the concentration of attack solution. The concentration of sulfate ions increases with the increase of sulfate concentration and the concentration of sulfate ions at the same depth. The sulfate attack of cementitious materials produce swelling products to fill the internal pores and increase the mechanical properties of the specimens. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ta-doped lithium-lanthanum-zirconium-oxygen (Li6.5La3Zr1.5Ta0.5O12, LLZTO) solid electrolytes with a high ionic conductivity at room temperature were prepared by the solid-phase reaction method, and the effects of irradiated electron beams on their structure and properties were investigated in detail. The results showed that no other heterogeneous phases were produced after irradiation with different doses (250 kGy and 500 kGy) of electron beams, and the lattice spacing became larger with an increase in the dose, which is conducive to the reduction of the diffusion energy barrier of ions in the lattice. First-principles calculations revealed that the Li+ diffusion energy barrier of the low-dose electron-beam irradiated sample was reduced by 0.07 eV compared with that of the unirradiated sample, suggesting that the defects created by irradiation can promote Li+ diffusion. An AC impedance test of the electrolytes before and after irradiation further confirmed that low-dose electron beam irradiation is beneficial for enhancing their ionic conductivity. Exploring the effect of electron beam irradiation on the structure and conductivity of LLZTO oxide solid state electrolytes holds significance in the study of solid state electrolytes.

Tooth development is a complex biomineralization process formed through the interaction between epithelial tissue and mesenchymal tissue. The Ca 2+ transport channel is the intrinsic regulatory mechanism of this process, which regulates the concentration of Ca 2+ inside and outside the cell in time and space, thereby affecting the biological functions of various cells and the growth of extracellular hydroxyapatite. This article reviews the researches on the effects of Ca 2+ transport in tooth biomineralization and corresponding cell development in recent years, with the aim of providing ideas and basis for the prevention of tooth developmental defects, assisting in early clinical diagnosis, and improving treatment methods.

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Solid oxide fuel cell (SOFC) is a kind of all solid-state power generation equipment with high energy conversion efficiency, friendly environment and flexible fuel, which provides a choice for the sustainable development of energy resources. Oxygen ions are conducted through oxygen vacancies in solid electrolyte. Increasing the concentration of oxygen vacancy is the key to improve the ionic conductivity, and electrolyte materials with high ionic conductivity promote the development of SOFC. In this paper, the ion transport mechanism of solid electrolyte and the structure, research progress, advantages and disadvantages of ZrO2 based electrolyte, CeO2 based electrolyte, Bi2O3 based electrolyte and LaGaO3 based electrolyte materials are reviewed. The development trend of electrolyte materials in the future is prospected. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective To explore the changes of ion transport function in rats with pattern of dampness retention due to spleen deficiency (DRSD) and the mechanism of coix seed (Yiyiren? Semen Coicis) on strengthening the spleen and draining dampness. Methods The animal model of DRSD was established by swimming-induced labor combined with specific feedstuff The model rats were randomly divided into 6 groups (n = 10). These rats except those in the model group were orally administered with coix decoction (6.25 g/kg)，coix oil (287.5 mg/kg)，coix polysaccharide (911.3 mg/kg)，coix protein (281.3 mg/kg)，and coix starch (1 798. 1 mg/kg) by intragastric gavage once daily. Another 10 normal rats were taken as the control group. After 14 days of intervention, the small intestine samples were collected and the gene expression of rat intestine was detected by using Agilent's whole genome expression microarray. After screening the differential genes expression (DEGs) of ion transport between model group and control group，principal component analysis (PC A) and cluster analysis were carried out for the differential genes of each group. The PC A loading and scores were also analyzed. Results There were 38 DEGs in ion transport between model rats and control rats. Bi-plot analysis of PC A on the DEGs showed that the model group was farthest from the control group，which was consistent with the clustering results of samples. After treatment with different components of coix seed，the result of each treatment group was between the model group and the control group. The analysis of DEGs showed the top 10 genes were Atoxl, Slc5a4，Slc40al, Slc5al，Slcl 1 a2, Cfir，Fxyd5, Cacnali，Kcnjl3 and Atp5d7 and most of them were in the same category in cluster analysis. Conclusion There are apparent changes of ion transport gene in intestinal epithelial cells of DRSD rats. Different components of coix seed， especially the oil and the protein components, have strong effects on ion transport function. Solute carrier (Sic) family is the main target of spleen-strengthening and dampness-draining effects. Besides, Atoxl and Cftr also play a significant role in these effects. [ABSTRACT FROM AUTHOR]

Based on the finite element method(FEM)， the discharge and ion transport processes of the sputter ion pumping units were studied. The plasma module， the magnetic field module， and the charged particle tracking module were coupled by COMSOL Multiphysics. The distribution law of electron density in the anode cylinder was obtained. The effects of parameters such as pressure， anode voltage and magnetic field strength on electron density were investigated. The trajectories of the ions at different pressures were tracked， and the impact energy and angle of the ions to the cathode plates were obtained. The obtained parameters were then applied to the theoretical pumping speed calculation and the results were compared with the experimental pumping speed. They have good consistency and verify the accuracy of the simulation model， which provides a suitable method for structural design and performance optimization of sputter ion pumps. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To investigate the effect of Erchen Decoction on iron homeostasis in mice with nonalcoholic fatty liver disease (NAFLD) and its mechanism for regulating iron transport in spleen cells., Methods: Thirty male C57BL/6J mice were given a high-fat diet for 12 weeks and randomized ( n =6) at the 7th week for gavage (3 times a week) of drinking water (NAFLD model group), Erchen Decoction at low, medium and high doses (7.5, 15, and 30g/kg, respectively), or polyene phosphatidyl choline (PPC; 9.12 mg/kg), with another 6 mice with low-fat and low-sugar feeding as the control group. The active components of Erchen Decoction were determined by HPLC-MS. Lipid accumulation in the liver was evaluated by HE staining and Nile red staining. Prussian blue staining was used to observe iron content in the spleen. The iron ion content in the liver tissue was detected using a detection kit. The expressions of ferroportin1 (Fpn1), transferrin receptor (TfR), Steap3, HO-1, Ter-119, CD163 and CD68 were detected using Western blotting, immunohistochemistry and immunofluorescence staining., Results: Medium- and high-dose Erchen Decoction partially reversed the increase of lipid accumulation in the liver of NAFLD mice and showed better lipid-lowering effect than PPC. The NAFLD mice showed significantly decreased iron ion content in the spleen with increased hepatic and serum iron contents ( P < 0.05), decreased TfR protein expression ( P < 0.05), and increased Fpn1 and Steap3 protein expressions ( P < 0.05), and these changes were significantly improved by the drug interventions. Erchen Decoction also improved the function of CD163 macrophages in the spleen of NAFLD mice by up-regulating the expression of HO-1 ( P < 0.05)., Conclusion: Erchen Decoction can alleviate high-fat diet-induced iron metabolism disorder by improving the iron ion transport ability of the spleen cells to delay the progression of NAFLD.

Nonselective cation channels(NSCCs) are a diverse group of ion channels located on the biomembranes. They are directly involved in a lot of physiological processes as uptake of nutrients, turgor maintenance, signal conduction, etc. NSCCs are permeable to many essential cations like Ca2+, K+, Mg2+ and toxic heavy metal cations as well. Understanding the interaction between heavy metal ions and NSCCs is of great importance in regulating the uptake of toxic heavy metal ions in plants when they are grown in contaminated environment. In this review, influence of ion types and concentrations on the gating mechanism of NSCCs were summarized. These advances would provide important references for developing new channel modulators and exploring the regulation mechanism of modulators on NSCCs. [ABSTRACT FROM AUTHOR]

Background: Segmentectomy has gradually become one of the standard surgical methods for small pulmonary nodules with early lung cancer on imaging. This study aimed to investigate the perioperative outcomes of patients who underwent uniport video-assisted thoracoscopic surgery (VATS) segmentectomy for identifying the intersegmental boundary line (IBL) by the near-infrared fluorescence imaging with intravenous indocyanine green (ICG) method or the modified inflation-deflation (MID) method and assess the feasibility and effectiveness of the ICG fluorescence (ICGF)-based method., Methods: We retrospectively analyzed the perioperative data in total 198 consecutive patients who underwent uniport VATS segmentectomy between February 2018 and August 2020. With the guidance of preoperative intelligent/interactive qualitative and quantitative analysis-three dimensional (IQQA-3D), the targeted segment structures could be precisely identified and dissected, and then the IBL was confirmed by ICGF-based method or MID method. Clinical effectiveness and postoperative complications of the two methods were evaluated., Results: An IBL was visible in 98% of patients by the ICGF-based group, even with the low-doses of ICG. The ICGF-based group was significantly associated with the shorter IBL clear presentation time [(23.59±4.47) s vs (1,026.80±318.34) s] (P<0.01) and operative time [(89.3±31.6) min vs (112.9±33.3) min] (P<0.01), compared to the MID group. The incidence of postoperative prolonged air leaks was higher in the MID group than in the ICGF-based group (8.0% vs 26.5%, P=0.025). There were no significant differences in bleeding volume, chest tube duration, postoperative hospital stays, surgical margin width and other postoperative complications (P>0.05)., Conclusions: The ICGF-based method could highly accurately identify the IBL and make anatomical segmentectomy easier and faster, and therefore has the potential to be a feasible and effective technique to facilitate the quality of uniport VATS segmentectomy.

The aim of the present study was to establish a cell model of volume-regulated anion channel subunit LRRC8A and investigate the physiological characteristics of LRRC8A. The eukaryotic expression vectors of LRRC8A and YFP-H148Q/I152L were constructed and transfected into Fischer rat thyroid (FRT) cells by Lipofectamine 2000. The FRT cell lines co-expressing LRRC8A and YFP-H148Q/I152L were obtained by antibiotic screening. The expression of LRRC8A and YFP-H148Q/I152L in FRT cells was detected by the inverted fluorescence microscope. The fluorescence quenching kinetic experiment was done to verify the function and effectiveness of the cell model. Then the cell model was utilized to study the physiological characteristics of LRRC8A, such as the characteristics of anion transport, the opening of LRRC8A by osmotic pressure, the effect of anion transport velocity, and the effect of chloride channel inhibitors on LRRC8A anion channel. The results of the inverted fluorescence microscope showed that LRRC8A was expressed on the cell membrane and YFP-H148Q/I152L was expressed in the cytoplasm. The results of fluorescence quenching kinetic test showed that under the condition of low osmotic state, LRRC8A could transport some kinds of anions, such as iodine and chloride ions. Osmotic pressure played a key role in the regulation of LRRC8A volume-regulated anion channel opening. Chloride channel inhibitors inhibited ion transport of LRRC8A channel in a dose-dependent manner. It is suggested that LRRC8A has the characteristics of classic volume-regulated anion channels by using the cell model of FRT cells co-expressing LRRC8A and YFP-H148Q/I152L.

Important progress has been made in the interpretation of subcellular location, ion transport characteristics and biological functions of endosomal Na⁺,K⁺/H⁺ antiporter in Arabidopsis thaliana. The endosomal Na⁺,K⁺/H⁺ antiporter contain two members, AtNHX5 and AtNHX6, whose amino acid sequence similarity is 78.7%. Studies have shown that AtNHX5 and AtNHX6 are functionally redundant, and they are all located in Golgi, trans-Golgi network (TGN), endoplasmic reticulum (ER) and prevacuolar compartment (PVC). AtNHX5 and AtNHX6 are critical for salt tolerance stress and the homeostasis of pH and K⁺. It has been reported that there are conservative acidic amino acid residues that can regulate their ion activity in the endosomal NHXs transmembrane domain, which plays a decisive role in their own functions. The results of the latest research indicate that endosomal NHXs affect vacuolar transport and protein storage, and participate in the growth of auxin-mediated development in A. thaliana. In this paper, the progress of subcellular localization, ion transport, function and application of endosomal NHXs in A. thaliana was summarized.

Ion channels and transporters represent two major types of pathways of transmembrane transport for ions. Distinct from ion channels which conduct passive ionic diffusion, ion transporters mediate active transport of ions. In the perspective of biochemistry, ion transporters are enzymes that catalyze the movement of ions across the plasma membrane. In the present review, we selected the Na(+)/HCO3(-) cotransporter (NBC) as an example to analyze the key biochemical and biophysical properties of ion transporters, including stoichiometry, turnover number and transport capacity. Moreover, we provided an analysis of the electrophysiological principles of NBC based on the laws of thermodynamics. Based on the thermodynamical analysis, we showed how the stoichiometry of an NBC determines the direction of its ion transport. Finally, we reviewed the methodology for experimental determination of the stoichiometry of NBC, as well as the physiological significance of the stoichiometry of NBCs in specific tissues.

Sodium calcium exchanger (NCX), which is widely expressed in the plasma membrane, mitochondrial membrane and secretory vesicles in diverse kinds of cells, belongs to a type of cation translocators. NCX works in two modes, the forward mode and reverse mode, to regulate the intracellular Ca(2+) concentration bi-directionally. In the forward mode, NCX carries Ca(2+) out of the cell against its electrochemical gradients coupled to the influx of Na(+) down its electrochemical gradients; alternatively, Ca(2+) enters through the reverse mode of NCX, and Na(+) is carried out of the cell. Exactly through the two-way modes, NCX can regulate intracellular Ca(2+) concentration fleetly and accurately, and plays a critical role in a series of physiological processes including intracellular signal transduction, growth and development of cells, excitation and its coupled functions of excitable cells. NCX are acknowledged to be involved in myofiber contraction, neurotransmission, migration and differentiation of neurogliocyte, activation of immune cells, secretion of cytokines and hormones etc. Moreover, abnormal activation of the reverse mode of NCX plays a vital role in many pathological processes including cell apoptosis, ischemia-reperfusion injury, insulin secretion, tumor etc. Here we reviewed the research status about the NCX's participation in some physiological and pathophysiological processes, so as to provide comprehensive understanding about its functions.

Objective: To investigate the association of the polymorphisms of rs4961 in alpha-adducin (ADD1) and rs28933400 in Na+/K+ -ATPase a2 (ATP1A2) genes, the products of which are important for sodium transport, with essential hypertension., Methods: Mutagenically separated PCR (MS-PCR) was used to detect the genotypes of the two loci. The subjects were recruited randomly including 196 patients of essential hypertension and 192 healthy controls., Results: The frequencies of genotypes and alleles of in the ADD1 gene were significantly different between the patients and controls respectively (P=0.03, P=0.04). There was significant relationship between the genotypes of rs4961 and systolic blood pressure and blood sodium concentration. However, there was no significant relationship between the rs4961 genotypes and diastolic blood pressure, body mass index, blood kalium and chlorine concentrations. There was no polymorphism at the rs28933400 locus in the subjects analyzed., Conclusion: The rs4961 polymorphism of the ADD1 gene is associated with essential hypertension, but the rs28933400 locus in the ATP1A2 gene may have no association with essential hypertension in the studied population.

We established a cell based high throughput screening model by calcium assay on fluorometric imaging plate reader for finding modulators of TRPV3. The TRPV3 expression vector was transfected into HEK-293 and stable cell line expressing TRPV3 was selected with antibiotics. Upon TRPV3 specific modulators stimulated, pharmacological characteristics of TRPV3 over expression cell line were detected by calcium assay on fluorometric imaging plate reader. Assay conditions were optimized and stability of the model was observed. The reliability and accuracy of application to 96 and 384 well format high throughput screening were also evaluated. A stable HEK-293 cell line highly expressing TRPV3 was established. TRPV3 specific modulators could modulate calcium signal through TRPV3 in dose dependent manner. Optimized screening condition was established by assay development. This model is stable and sensitive, and meets the requirement of high throughput screening by Z'factor validation and Spiking test. This cell model can be applied to screening TRPV3 modulators by calcium assay.

In this paper, GLUT4 vesicles are observed in real-time under TIRF microscopy and a new three-dimensional single particle tracking algorithm according to the unique features of TIRF is put forward. Firstly a fluorescence correction procedure was processed to solve the problem of fluorescence bleaching over time and mobile vesicles were segmented by an adaptive background subtraction method. Kalman filtering was then introduced to track the granules so as to reduce the searching range and to avoid the disturbance of background noise and false targets. In the experiments the algorithm was applied in analyzing the long-distance movement of GLUT4 vesicles. The experimental results indicate that the algorithm has achieved robust tracking of the vesicles in the imaging plane and has effectively calculated the position in the direction orthogonal to the imaging plane.

Sodium ion with high concentration is toxic to living cells, and microorganisms adapt to the environment containing high concentration of salt by the strategies of salt-in-cytoplasm and compatible solutes. The Na+ extrusion system plays important roles in maintaining cytoplasmic Na+ homeostasis and pH level in microbial cells. Two possible mechanisms of Na+ circulation across the cytoplasmic membrane have been proposed, namely primary Na+ pump and secondary Na+/H+ antiporter. Primary sodium pumps coupled the extrusion of Na+ to respiration, and the activity of which was insensitive to uncoupler CCCP ( carbonyl-cyanide m-chlorophenylhydrazone). There were two types of secondary Na+/H+ antiporters-encoding genes designated single gene and multiple subunits, respectively. The types of transportation systems for Na+, possible mechanisms of Na+ extrusion, and projects for further study in bacteria are reviewed.

Objective: To investigate the cardioprotective effects of cariporide as an adjunct in different cardioplegic solutions., Methods: The hearts of 32 young New Zealand rabbits were isolated, hung on the Langendorff perfusion apparatus, arrested with 4 degrees C cardioplegic solutions to cause cardiac ischemia for 120 min, reperfused with 37 degrees C Krebs-Henseleit solution, and randomly divided into 4 equal groups: St. Thomas cardioplegic solution group (perfused with St. Thomas cardioplegic solution every 30 min), histidine-tryptophane-ketoglutarate (HTK) cardioplegic solution group (perfused with HTK solution, St. Thomas solution + cariporide (St + C) group (perfused with St. Thomas cardioplegic solution plus cariporide), and HTK solution plus cariporide (HTK + C) group (perfused with HTK cardioplegic solution plus cariporide). Multichannel physiological record instrument was used to record the left ventricular functions: left ventricular diastolic pressure (LVDP), maximum change rate of left ventricular systolic pressure rise and fall (+dp/dt(max)), maximum change rate of left ventricular diastolic pressure rise and fall (-dp/dt(max)), and coronary flow (CF). Automatic biochemical analyzer was used to measure the creatine kinase (CK)-MB, Then the level of ATP in the cardiac muscle cells was detected by high pressure liquid chromatography, the content of malonyldialdehyde (MDA) was detect by sulfur barbituric acid method. The calcium content (iCa) was measured by atomic absorption spectrophotometry. And the myocardial water content (WC) was measured too., Results: The LVDP, +dp/dt(max), -dp/dt(max), CF recovery rate, and ATP content of the HTK group were all significantly higher than those of the St. Thomas group (all P < 0.05), and the CK-MB, MDA, WC, and iCa of the HTK group were all significantly lower than those of the St. Thomas group (all P < 0.05). The ATP level of the HTK + C group was significantly higher than those of the HTK and St + C groups (both P < 0.05), and the CK-MB, WC, MDA, and iCa of the HTK + C group were all lower than those of the HTK and St + C groups (all P < 0.05). The MDA level of the St + C group was significantly higher than that of the HTK group, and the ATP of the St + C group was significantly lower than that of the HTK group (both P < 0.05), however, there was no significant differences in CK-MB, WC, and iCa between these 2 groups (all P > 0.05)., Conclusion: Cariporide enhances the cardioprotective effects of the St. Thomas and HTK cardioplegic solutions in immature myocardium.

Objective: To investigate the roles of cation-chloride cotransporters-Na, K, 2Cl(-) cotransporter-1 (NKCC1) and K(+)-Cl(-) cotransporter-2 (KCC(2)) in the epileptogenesis of cortical dysplasia., Methods: Six pregnant SD rats were given intraperitoneal injection of 1-3-bis-chloroethyl-nitrosourea (BCNU) on the embryonic day 17 (E17) and gave birth of 56 pups (experimental group) on the day P21. Five pregnant SD rats were given intraperitoneal injection of normal saline and gave birth of 48 pups (control group) on the day E21. Sixty days after birth the brains of 24 male pups in the experimental group and 22 male pups in the control group selected randomly were taken out to isolate the hippocampus. Cresyl-violet staining was applied to observe the histological alterations in the hippocampus. RT-PCR was used to detect the mRNA expression of NKCC1 and KCC2., Results: Cresyl-violet staining revealed heterotopic cell clusters within the hippocampus. RT-PCR showed that the ratio of NKCC1 to beta-actin of the experimental group was 0.70 +/- 0.13, significantly higher than that of the control group (0.48 +/- 0.09, P < 0.01); while the ratio of KCC2 to beta-actin of the experimental group was 0.54 +/- 0.10, significantly lower than that of the control group (0.80 +/- 0.15, P < 0.01)., Conclusion: The upregulation of NKCC1 mRNA and the concomitant downregulation of KCC2 mRNA may be deeply related to the mechanism of epileptogenicity in cortical dysplasias.

Objective: To investigate the changes in renal sodium transport during development of hypertension in ouabain-hypertensive rats (OHR) and further elucidate the role of ouabain in the pathogenesis of hypertension., Methods: Eighty male SD rats weighing 80-100 g were randomized equally into normal control and ouabain groups and treated with intraperitoneal injection of normal saline (1 ml/kg) and ouabain (27.8 microg/kg) once daily, respectively. Systolic blood pressure (SBP) and body weight of the rats were recorded weekly. One week before sacrifice scheduled at weeks 2, 4, 6 and 8, respectively, the rats were individually housed in metabolic cages to determine food consumption twice. Blood and 24-hour urine samples were collected to measure serum and urine concentration of sodium, trace lithium and creatinine. Endogenous creatinine clearance rate (Ccr), fractional excretions of sodium (FENa), fractional excretions of lithium (FELi) and fractional reabsorption of sodium in the distal tubules (FDRNa) were calculated., Results: The body weight and food intake between ouabain groups and control groups were comparable during the experiment (P>0.05). Blood pressure was also comparable in the two groups after 2 weeks (P>0.05). At week 4, however, blood pressure of ouabain group was significantly higher than that of the control group (P<0.001) and increased in a dose-dependent manner. The SBP in ouabain group appeared to reach a plateau at week 7. Ccr and plasma sodium (PNa) were similar in the 2 groups during the experiment (P>0.05). FELi was significantly lower at weeks 2, 4 and 6 in ouabain group than in the control group (P<0.01), and FELi decrement in ouabain group was accompanied by reduced sodium excretion. FENa was significantly lower at week 4 in ouabain group than in the control group (P<0.05), but this difference was not significant in weeks 2 and 6 (P>0.05). At weeks 2, 4 and 6, ouabain group showed significantly lower FDRNa than the control group (P<0.05), suggesting the compensation of the distal nephron segments. After 8 weeks, FENa, FELi and FDRNa were similar between the two groups (P>0.05)., Conclusions: Ouabain can increase renal proximal tubule reabsorption of sodium and consequently decrease renal sodium excretion in OHR, which can contribute to alteration of the pressure-natriuresis relationship in OHR, and play an important role in the development and maintenance of hypertension of OHR.

Objective: To evaluate the capacity of active water and sodium transport of alveolar type II (AT II cells in rats with acute respiratory distress syndrome (ARDS)., Methods: AT II cells were isolated and purified from rats with ARDS, and the distribution of aquaporin-1 (AQP-1) on the cells was observed by immunocytochemistry, immunoelectron microscopy and Western blotting. The sodium currents were detected by patch-clamp technique in whole-cell recording mode., Results: Immunocytochemistry showed staining for AQP-1 in rat AT II cells, and immunoelectron microscope demonstrated the presence of AQP-1, which was decreased as shown by Western blotting in comparison with the control group. The whole-cell currents were also decreased, but remained sensitive to terbutalin treatment., Conclusions: The capacity of active water and sodium transport is damaged, but not totally lost in AT II cells of ARDS rats. Terbutalin can increase the currents even if in pathological conditions. AQP-1 and sodium transport of AT II cells play an important role in pulmonary liquid clearance.

Objective: To observe the changes of sodium transport of alveolar type II cells in oleic acid-induced acute respiratory distress syndrome (ARDS)., Methods: After isolation of the AT II cells as ARDS model induced by oleic acid, the whole cell sodium current was recorded in 5 h with patch-clamp in whole-cell mode. The effect of beta2-agonist terbutaline on the current was also examined., Results: The sodium currents recorded from AT II cells in ARDS were smaller than that of the control cells, but the current could be stimulated to increase obviously by terbutaline., Conclusion: AT II cells can actively transport sodium ion even under conditions of ARDS, but this capacity can not match that of the control cells. Terbutaline can obviously stimulate the sodium current.

Objective: To investigate the relationship between the changes of the L-type calcium current (I(Ca, L)) and the calcium-activated transient outward chloride current (I(Cl, Ca)), and the repolarization characteristic of action potential in phase 1 under isoprenaline (ISO) stimulation in atrium myocytes of rabbit., Methods: Atrium myocytes were obtained by enzymatic dissociation from a section of atrial free wall. The membrane currents and action potential were recorded by the whole-cell patch-clamp technique., Results: After recording I(Ca, L), atrium myocytes were perfused with ISO (1 micromol/L) immediately. Five minutes later, a transient outward current (I(to)) was significantly induced, and the peak of I(to) was gradually increased while I(Ca, L) gradually decreased with increasing in clamp voltage. The I(to) was resistant to 4-AP (3 mmol/L) but sensitive to DIDS (150 micromol/L, Cl(-) channel blocker). This current was blocked by CdCl(2) (200 micromol/L, Ca(2+) channel blocker). The elicited rate of I(to) was 91.67% (P < 0.05). (2) The shape of AP was like an inverse triangle with no plateau in Phase 2 after ISO (1 micromol/L) perfusion. Moreover, compared to the parameters of control group, APD(50) and APD(90) were significantly shortened from (65.4 +/- 4.2) ms and (95.8 +/- 3.8) ms to (12.8 +/- 3.8) ms and (27.0 +/- 4.7) ms, and reduced to 80.46% and 71.87%, respectively (P < 0.01, n = 12). 4-AP (3 mmol/L) had on obvious effect on the shape of AP, however, the plateau of AP in phase 2 was recovered by DIDS (150 micromol/L) perfusion, APD(50) and APD(90) were (41.1 +/- 4.5) ms and (79.6 +/- 3.4) ms respectively. Compared to the parameters of control group, there were no significant differences (P > 0.05, n = 12). These results indicated that ionic transport were changed by ISO perfusion in atrium myocytes and I(to) played an important role in the phase 1 repolarization of AP., Conclusions: Before ISO administration, we could only observe I(Ca, L) in atrium myocytes of rabbit. After isoproterenol intervention, certain intracellular ionic consistency and membrane ionic channels were changed. Calcium activated chloride channel and I(to2) revealed obvious predominance which shorten APD significantly. Action potential showed a triangle with no plateau, suggesting an electrical remodeling in atrium myocytes. The remodeling of ionic channel is related possibly with the opening of Ca(2+)-activated Cl(-) current, which maybe the electrophysiological base of reentrant atrial tachycardia.

The present study was carried out to determine the functional properties of Kv4.2 expressed in mammalian cells in comparison with native transient potassium outward current (I(A)) in the hippocampal neurons. Transient transfection, cell culture and whole cell voltage clamp techniques were used. The results showed that I(A) in cultured rat hippocampal neurons and Kv4.2 expressed in HEK293 cells both displayed "A"-type current properties. The activation curves of I(A) and Kv4.2 were better fitted by simple Boltzmann function with V(1/2) 10.0+/-3.3 mV, k 13.9+/-2.6 mV for I(A) and V1/2 -9.7+/-4.1 mV, k 15.8+/-5.7 mV for Kv4.2, respectively. The steady-state inactivation curves of I(A) had a midpoint of -93.0+/-11.4 mV and a slope of 9.0+/-1.5 mV. The voltage-dependence of inactivation for Kv4.2 exhibited midpoint and slope values of -59.4+/-12.2 mV and 8.0+/-3.1 mV, respectively. The time constants (tau) of recovery from inactivation of I(A) and Kv4.2 were 27.9+/-14.1 ms and 172.8+/-10.0 ms, respectively. These results suggest that Kv4.2 is probably a major isoform contributing to I(A) in hippocampus neurons.

The physiological changes that occur to sperm during the residence in the female tract are collectively referred to as "capacitation". The mechanism of action by which these compounds promote capacitation is poorly understood at the molecular level. However, some molecular events significant to the initiation of capacitation have been identified, such as the correlation of capacitation with cholesterol efflux from the sperm plasma membrane, increased membrane fluidity, modulations in intracellular ion concentrations, hyperpolarization of the sperm plasma membrane and increased protein tyrosine phosphorylation. This review discusses recent progress in elucidation mechanisms which regulate sperm capacitation.

The effects of plasmid pcDNA3 on Ca(2+) transport of sarcoplasmic reticulum (SR) in ischemic skeletal muscle was investigated. The results show that Ca(2+) transport (including Ca(2+) uptake and Ca(2+) release) rate of SR in ischemic skeletal muscle was markedly increased compared with that in non-ischemic muscle (P<0.01 or P<0.05). After plasmid pcDNA3 bound to the DNA binding proteins of SR, Ca(2+) transport of SR was further increased. The results suggest that the effect of plasmid DNA on the ability of Ca(2+) transport in SR of ischemic skeletal muscle is the same as is observed in normal skeletal muscle. The pathophysiological significance of the present finding deserves further exploration.

Objective: To investigate the effects of heredity on transmembrane ion transport in essential hypertension (EH)., Methods: 52 essential hypertensives were divided into two groups, 23 with positive family history (FH(+)) and 29 with negative family history (FH(-)). The rate constant of ouabain-sensitive sodium efflux ((o)K(os)) was measured as the half of the increase in erythrocyte Na(+) concentration during incubation with ouabain for 2 hours, (o)K(os) was calculated by an equation and the maximal rate (Vmax) of red cells Na(+)/H(+) exchange was determined as the Na(+) influx promoted by an outward H(+) gradient. Intracellular Na(+) concentration was measured with flame photometry and (45)Ca(2+) influx in ATP-depleted red cells with liquid scintillation counting., Results: The red cell Na(+)/H(+) exchange and (45)Ca(2+) in-flux were significantly higher but the (o)K(os) lower in both the FH(+) and FH(-) groups than in the controls. FH(+) group demonstrated a significantly higher (o)K(os) and lower Ca(2+) influx as compared with those in FH(-) group. In FH(+) group, systolic blood pressure was positively correlated with age, while diastolic blood pressure positively correlated with (45)Ca(2+) influx., Conclusion: Our data show a genetic contribution to abnormal membrane transport in hypertension. There is a defect in membrane permeability to Ca(2+) and a greater exchangeable pool of cytosolic free Ca(2+) in FH(+) group that participate in the pathogenesis of inherited hypertension.

Whole cell patch-clamp recording techniques were used to compare the electrophysiological properties between delayed rectifier K+ current of rabbit vascular smooth muscle cell (VSMC) and the cloned Kv1.5 channel. When VSMC is clamped at -40 mV, depolarizing the membrane potential at increasing steps of 10 mV could evoke a series of outward potassium currents without any deactivation. The V1/2 of the activation curve was 27.2 mV. The currents decrease obviously after adding 100 mmol/L TEA or 1 mmol/L 4AP in the perfusate. When the concentration of extracellular Ca2+ was decreased from 1.5 mmol/L to 0.5 or 0 mmol/L, the currents did not show much change, while in HBK7 (cloned Kv1.5 channel cell) held at -80 mV, similar steparise depolarization could also produce a series of outward potassium currents without any deactivation decayed. V1/2 of the activation was 0.8 mV. 4AP inhibited the cloned channel current with IC50 of 7.3 mmol/L, showing neither frequency- or use-dependence. TEA (30, 100 and 300 mmol/L) reduced the current by 28.6%, 37.4% and 46.3% respectively. Quinidine (0.1 and 1 mmol/L) decreased it by 29.7% and 37.4%. These results show what we have recorded in isolated rabbit vascular smooth muscle cells is the delayed rectifier potassium currents which are different in electrophysiological and pharmacological properties from those of cloned Kv1.5 channel current.

Reoxygenation is more serious for hypoxic myocardial cells because of the subsequent calcium overload. The calcium overload is known due to augmentation of H(+)-Na+, Na(+)-Ca2+, exchange during pH paradox. But the present experiment showed that, when H(+)-Na+, Na(+)-Ca2+ exchange was inhibited, calcium could still enter myocardial cells after hypoxia or reoxygenation. Similar result was observed after using Na(+)-Free solution, suggesting that calcium entrance into the cell was unrelated to Na+ channel. It was further shown that calcium accumulation was related to pH gradient across the myocardial cell membrane, i.e., being increased with increase of H+ concentration in the cell. Therefore, it appears that, besides H(+)-Na+, Na(+)-Ca2+ exchange, H(+)-Ca2+ exchange is one of the reasons of calcium overload during intracellular pH paradox.

The human hepatic stimulator substance (hHSS) was extracted from abortive fetal liver according to the method of LaBrecque. The intracellular free calciumion was measured by fluorescent probes Fura-2/AM. Rat hepatocytes were isolated from liver by the method of Seglen and intoxicated by CCl4 vapour, then the changes of [Ca2+]i, the leakage of intracellular K+, ALT and viability of hepatocytes were observed. The results were as follows: The hHSS does exist in the human fetal liver, hHSS could increase the viability of intoxicated hepatocytes, maintain the intracellular calcium homeostasis, and decrease the leakage of intracellular potassium and ALT into the culture medium. These results indicate that hHSS could protect hepatocytes against CCl4 through maintaining calcium homeostasis, preventing potassium leakage and sustaining stability of hepatocyte polasmalemma.

Thirty min after stabilization perfusion with oxygenated buffer, hearts were divided in four groups: (1) CONTROL GROUP: 75 min. of aerobic perfusion; (2) Low flow anoxia group: 45 min. of low flow anoxic perfusion (95% N2:5%CO2, 0.15 ml/min.) followed by 30 min. of aerobic perfusion; (3) Ouabain group: protocol same as (2), except that ouabain (200 mumol/L) was added to anoxic perfusate during low flow anoxia; (4) Ouabain+Amiloride group: protocol same as (3) except that amiloride (0.5 mmol/I) was added to perfusate during low flow anoxia. Compared with the low flow anoxia group, ouabain resulted in an additional increase in Na during reperfusion accompanied with a depressed ventricular function. The deleterious effects of ouabain could be significantly combatted by amiloride. It is concluded that a decrease in Na/K ATPase activity may contribute to Na gain in reperfused myocardium, the mechanism of which might result from stimulation of Na/H exchange.