Effects of combination of irbesartan and perindopril on calcineurin expression and sarcoplasmic reticulum Ca^(2+)-ATPase activity in rat cardiac pressure-overload hypertrophy

Aim： To observe effects of angiotensin （Ang） II receptor antagonist （ATI） irbesartan and angiotensin-converting enzyme （ACE） inhibitor perindopril on rat myocardium calcineurin expression and sarcoplasmic reticulum Ca^2＋-ATPase activity in the model of pressure-overload cardiac hypertrophy. Methods： Forty male adult Sprague Dawley rats were divided into 5 groups One group was treated by sham operation; four groups were myocardium hypertrophy cases caused by banding aortic above renal artery. Drugs were given one week after operation. Group 1： sham group, rats （n=8） were gavaged with normal saline 2 ml/（kg·d） （ig）; Group 2： control group, rats （n=8） were treated with normal saline 2 ml/（kg·d） （ig）; Group 3： rats （n=8） were given perindopril 2 mg/（kg·d） （ig）; Group 4： rats （n=8） were treated with irbesartan 20 mg/（kg·d） （ig）; Group 5： rats （n=8） were given irbesartan 20 mg/（kg·d） plus perindopril 2 mg/（kg·d） （ig）. Morphometric determination, calcineurin expression and sarcoplasmic reticulum Ca^2＋-ATPase activity were done at the end of 6 week of drug intervention. Expression of calcineurin in myocardium was detected by immunohistochemistry. Results： Left ventricular mass index （LVMI）, transverse diameter of myocardial cell （TDM）, calcineurin activity were remarkably decreased after drug intervention and this decrease was most remarkable in the combination drug therapy group. Sarcoplasmic reticulum Ca^2＋-ATPase activity was increased after drug intervention, especially in the combined drug therapy group. Calcineurin expression in myocardium was remarkably decreased after drug intervention. LVMI was positively correlated with TDM and calcineurin, negatively correlated with sarcoplasmic reticulum Ca^2＋-ATPase. Conclusion： These data suggest that irbesartan and perindopril inhibit cardiac hypertrophy through the increased activity of sarcoplasmic reticulum Ca^2＋-ATPase and decreased expression of calcineurin. Their combination had better effects on regressing of ventricular hypertrophy.

The Relationship Between Senescence and Ca^(2+)-ATPase Activity of Microsomal Membrane and Lipid Peroxidation in Harvested Peach Fruit

Peach fruit easily soften and have a short storage time at normal temperature. In this study, peach fruit （Prunus persica sieb et Zucc cv. Yingqing） were picked and stored at 25 and 4℃ to investigate the senescence in correlation with Ca^2＋- ATPase activity of microsomal membrane and lipid peroxidation during ripening and senescence. In comparison with that stored at 25~C, the fruit stored at 4℃ exhibited a higher flesh firmness, lower respiration rate, and generated the late bigger peak value of Ca^2＋-ATPase activity as well as maintained the higher activity of the enzyme. Meanwhile, the lower levels of super oxygen radical （O2^-.） production and content of malondialdehyde （MDA）, a product of membrane lipid peroxidation were observed. Sodium orthovanadate （SO） and erythrosin B （EB）, as Ca^2＋-ATPase inhibitors, could stimulate the respiration rate. The results suggested that the slower senescence rate of peach fruit was closely related to the higher peak value and longer duration of Ca^2＋-ATPase activity in microsomal membrane, with the slighter membrane lipid peroxidation and lower O2^-. production rate.

The investigation for the relationship among serum leptin, erythrocyte membrane Ca^(2+)-ATPase activity and hypertensive disorder complicating pregnancy

Objective： To study the significance of Leptin and the activity of erythrocyte membrane Ca^2＋-ATPase（EMCA） in the development of hypertensive disorder complicating pregnancy. Methods： Radioimmunoassay was used to test the level of serum Leptin, and the activity of EMCA was determined chemically in 38 pregnant women with hypertensive disorder complicating pregnancy and 36 normotensive pregnant women. Results： The level of serum Leptin in hypertensive disorder complicating pregnancy（gestational hypertension： 13.76 ± 3.46 ng/ml; preeclampsia： 15.76 ± 5.47 ng/ml; eclampsia： 18.32 ± 6.38 ng/ml）was significantly higher than that in normotensive pregnant women （11.33 ± 2.93 ng/ml） ,respectively. The average EMCA activity of patients with hypertensive disorder complicating pregnancy （gestational hypertension： 1.65 ± 0.24 μmol·pi/mg.h ; preeclampsia： 1.37 ± 0.19 μ mol·pi/mg·h;eclampsia：1.12 ± 0.14 μmol·pi/mg·h） was significantly lower than that of normotensive pregnant women（1.83 ± 0.38 μ mol·pi/mg·h）,respectively. There was a negative correlation between the level of serum Leptin and the activity of RMCA in hypertensive disorder complicating pregnancy （r = -0.63）. Conclusion： Inhibition of EMCA activity of erythrocyte in hypertensive disorder complicating pregnancy may increase cytoplasmic free calcium, which contributes to the development of hypertensive disorder complicating pregnancy. The negative correlation between the level of serum Leptin and the activity of EMCA, also suggested that serum Leptin and the activity of EMCA may play a role in the development of hypertensive disorder complicating pregnancy.

Phospholamban Antisense RNA Improves SR Ca^(2+)-ATPase Activity and Left Ventricular Function in STZ-induced Diabetic Rats

Objective To study the effect of phospholamban antisense RNA （asPLB） on sarcoplasmic reticulum Ca2＋-ATPase activity and cardiac function in rats with diabetes mellitus （DM） mediated by recombinant adeno-associated virus （rAAV） vector. Methods Six weeks after the induction of DM by streptozotocin injected intraperitoneally, the rats were divided into three groups, namely： DM-rAAV-asPLB group, DM-saline group and DM group （control group）. The rats in the DM-rAAV-asPLB group were intramyocardially injected with rAAV-asPLB, the rats in the DM-saline group were injected with saline, and those in the control group did not receive any treatment. Six weeks after gene transfer, the expressions of PLB protein and PLB phosphorylation were detected by Western-blot, while the activity of sarcoplasmic reticulum （SR） Ca2＋-ATPase and left ventricular function were measured. Results The PLB protein expression level was significantly higher whereas the PLB phosphorylation, SR Ca2＋-ATPase activity and left ventricular function were significantly lower in the DM-saline group than in the control group. No significant difference was found in PLB protein expression level, PLB phosphorylation or SR Ca2＋-ATPase activity between the DM-rAAV-asPLB group and the control group. The left ventricular function in the DM-rAAV-asPLB group was poorer than in the control group and was better than in the DM-saline group. Conclusion rAAV-asPLB can down-regulate PLB protein expression and up-regulate phosphorylation and SR Ca2＋-ATPase activity, thus contributing to the improvement of in vivo ventricutar function. PLB left

Relationship Between Tonoplast H^+-ATPase Activity, Ion Uptake and Calcium in Barley Roots Under NaCl Stress

Under NaCl stress for 2 d, H+-ATPase activity increased, and H+-PPase activity decreased in the tonoplast of salt-tolerant barley ( Hordeum vulgare L. cv. 'Tanyin 2') roots. La3+ (1 mmol/L), an inhibitor of Ca2+ channel in plasma membrane, and EGTA (5 mmol/L), a Ca2+ chelator, inhibited this NaCl-induced increase in H+-ATPase activity but stimulated the H+-PPase activity. Treatment of barley roots with CaM antagonist (trifluoperazine, TFP, 20 mumol/L) also diminished the increase of H+-ATPase activity induced by NaCl. La3+, TFP or La3+ + TFP increased Na+ uptake and decreased K+ and Ca2+ uptake in barley roots under NaCl stress. These results suggested that the activation of tonoplast H+-ATPase and the regulation of Na+ and K+ uptake under NaCl stress may be related to Ca2+-CaM system.

Effect of Huoxuequyu Recipe on Erythrocyte Membrane Ca^(2+)-ATPase Activity in Pregnant Rats with Asymmetrical Intrauterine Growth Retardation Induced by Passive Smoking

The effect of Huoxuequyu recipe on erythrocyte membrane Ca2+-ATPase activity in pregnant rats with passive smoking induced asymmetrical intrauterine growth retardation(IUGR)was observed.The rats were divided into three groups:control group,model group and treated group.The fetal mean birth weight and erythrocyte membrane Ca2+-ATPase activity were found to be decreased in the model group as compared with the control and treated groups.There was a significant difference between the model group and the control group(P<0.01),while no significant difference existed between the treated group and the control group(P>0.05).Furthermore,the findings indicated that the erythrocyte membrane Ca2+-ATPase activity seem to be positively correlated with the birth weight(P<0.05).On the basis of our observation,it is believed that the Huoxuequyu decoction could increase erythrocyte membrane Ca2+-ATPase activity and promote blood circulation, thereby exerting a beneficial effect on fetal development.

Biochemical Evidences for Scopoletin Inhibits Ca^(2+)-ATPase Activity in the Carmine Spider Mite,Tetranychus cinnabarinus(Boisduval)

[Objective] This study aimed to investigate the acaricidal lffect of scopo- letin, and provide the biochemical evidences of scopoletin influencus Ca2＋-ATPase activity and gene expressions in the Carmine Spider Mite, Tetranych＇us cinnabarinus. in increased protein contents; kinetic analysis showed that the catalytic capability of Ca2＋-ATPase was significantly reduced by scopoletin. [Conclusion] Scopoletin exhibits a significant inhibitory effect on Ca2＋-ATPase, and its acaricidal effect against T. cinnabarinus might be due to the direct inhibition of Ca2＋-ATPase.

Effects of fructose-1,6-diphosphate on concentration of calcium and activities of sarcoplosnic Ca^(2+)-ATPase in cardiomyocytes of Adriamycin-treated rats

Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) and activity of sarcoplosnic Ca2+-ATPase (SRCa2+-ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5 mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnl. CK-MB was detected by monoclonal antibody, Myo[Ca2+] was detected by fluorescent spectrophotometry and the activity of SRCa2+-ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnl and CK-MB, while at the same time decreased calcium concentration and increased SRCa2+-ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2+-ATPase activity in cardiomyocytes.

EFFECTS OF CALDESMON, CALPONIN, AND TROPOMYOSIN ON THE MG^(2+)-ATPase ACTIVITIES OF SMOOTH MUSCLE MYOSIN

Objective To test whether in the absence of actin, actin-binding proteins such as caldesmon, calponin, and tropomyosin interact with the myosin of unphosphorylation, Ca 2+ -dependent phosphorylation (CDP), and Ca 2+ -independent phosphorylati-on (CIP) and stimulate myosin Mg 2+ -ATPase activities. Methods Mg 2+ -ATPase activities were measured to evaluate the effects of caldesmon, calponin, and tropomyosin on the myosin in unphosphorylation, CDP by myosin light chain kinase (MLCK), and CIP by MLCK. Results (1) At different incubation-time, i.e., 5, 10, 20, 40, and 60 minutes, the highest Mg 2+ -ATPase activity was ob-served when myosin was in the state of CDP, the medium was CIP of myosin, and the lowest was the unphosphorylated myosin. (2) In the absence of caldesmon, calponin, and tropomyosin, the Mg 2+ -ATPase activities from high to low were in the following order: CDP, CIP, and unphosphorylated myosin. However, in the presence of caldesmon, calponin, and tropo-myosin, the order of relative value of Mg 2+ -ATPase activities from high to low was unphosphorylated, CIP, and CDP of myosin respectively compared to the corresponding controls. Conclusions The results propose that caldesmon, calponin, and tropomyosin are capable of stimulating Mg 2+ -ATPase activity of smooth muscle myosin in Ca 2+ -independent manner, since Ca 2+ is not obligating for the stimulating effects of the three proteins. The common characteristic of the three proteins is that when myosin activities are low, their activations are relatively strong and this property might be involved in smooth muscle tension keeping.

四神丸对慢性复发型结肠炎大鼠结肠组织LDH、SDH、Na+-K+-ATPase和Ca2+-Mg2+-ATPase活力的影响

目的:探究四神丸对慢性复发型结肠炎大鼠结肠组织乳酸脱氢酶(LDH)、琥珀酸脱氢酶(SDH)、Na+-K+-ATPase和Ca2+-Mg2+-ATPase活力的影响。方法:参考文献复制慢性复发型SD大鼠结肠炎模型,将60只大鼠按随机数字表法分为正常组、模型组、四神丸高、中、低剂量组和美沙拉嗪对照组,观察大鼠一般情况并进行结肠肉眼下及镜下损伤评分,分别采用考马斯亮蓝法检测结肠黏膜总蛋白量、定磷法及分光光度法检测LDH、SDH、Na+-K+-ATPase和Ca2+-Mg2+-ATPase活力变化。结果:与模型组比较,四神丸各组大鼠结肠质量明显减轻,结肠长度增长,以及结肠肉眼下及镜下损伤评分均明显降低,同时SDH、Na+-K+-ATPase和Ca2+-Mg2+-ATPase活力均显著提升,但LDH活力出现明显降低。结论:四神丸可能通过恢复结肠黏膜局部能量代谢水平而达到减轻慢性复发型UC大鼠的目的。

香蕉Ca^(2+)-ATPase的基因克隆与表达分析

Ca2+-ATPase是植物逆境胁迫反应中的一种重要调节器。通过设计兼并引物,首次从香蕉果实中克隆得到Ca2+-ATPase基因,命名为MaCA。进一步通过Northern杂交方法检测了MaCA基因在低温胁迫和热激下的表达。结果表明,冷害温度(7℃)下,MaCA基因在冷害症状出现时(第4 d)表达最强。热激(52℃、3 min)处理后0.5~6 h迅速诱导了MaCA基因表达增强,之后逐渐减弱。研究结果说明,香蕉MaCA基因在增强对温度胁迫的适应性中起到了关键作用。

博落回对大鼠心肌Ca^(2+).Mg^(2+)-ATPase与SDH活性的影响及超微结构观察

目的探讨博落回对心肌作用的机制。方法SD大鼠36只分为2个实验组和1个对照组,每组12只;2个实验组分别按1/6LD50、1/3LD50剂量的博落回水煎液灌胃,对照组以蒸馏水灌胃。各组大鼠处死后,每组10只取心肌组织制成匀浆,检测Ca2+.Mg2+-ATPase与SDH(琥珀酸脱氢酶)的活性;另2只大鼠心肌行超微结构观察。结果1/6LD50组大鼠心肌内Ca2+.Mg2+-ATPase与SDH活性较对照组有显著性升高(P<0.05);1/3 LD50组大鼠心肌内Ca2+.Mg2+-ATPase与SDH活性同对照组比较无显著性差异(P>0.05),但呈下降趋势。超微结构观察到实验组大鼠心肌细胞发生凋亡及1/3 LD50组大鼠出现心肌排列紊乱、断裂等征象。结论博落回对大鼠心肌内Ca2+.Mg2+-ATPase与SDH的活性有影响作用,并能诱导心肌细胞凋亡。

钙对苹果果实钙调蛋白含量和Ca^(2＋)-ATPase活性及其基因表达的影响

研究不同浓度钙(0、1和10 mmo1/L CaCl2;5 mmo1/L EGTA)对苹果果实钙调蛋白(CaM)含量和Ca2+-AT-Pase活性及其基因表达的影响。利用同源克隆方法分离CaM和Ca2+-ATPase基因,采用荧光定量PCR方法研究它们表达特征。结果表明,果实切片外源补钙,可溶性Ca2+及CaM含量在高钙处理12 h达到高峰;高钙处理12 h质膜Ca2+-ATPase活性显著增加,与胞内CaM含量增加时间一致;高钙处理24 h液泡膜Ca2+-ATPase活性显著增加;随着质膜和液泡膜Ca2+-ATPase活性显著增加,可溶性Ca2+含量在加钙处理48 h显著下降。研究基因表达发现,加钙处理6 h苹果CaM基因的表达量显著增加;加钙处理12 h苹果Ca2+-ATPase基因的表达量显著增加,与CaM含量及质膜Ca2+-ATPase活性变化一致。果实缺钙处理显著增加CaM基因表达量,而苹果Ca2+-ATPase基因的表达量没有显著变化。上述研究表明,苹果补钙可以提高细胞内可溶性Ca2+和CaM含量以及CaM基因的表达量,有效启动钙信使系统;质膜及液泡膜Ca2+-ATPase是调控胞内Ca2+关键的酶,通过提高质膜及液泡膜Ca2+-ATPase的活性及Ca2+-ATPase基因的表达量,维持胞内Ca2+的稳态水平。

2℃低温下抗寒冬小麦与冷敏感春小麦幼苗细胞质膜Ca^(2+)-ATPase活性比较

通过氯化铈 (Ce Cl3)沉淀的电镜细胞化学法 ,对比观察了抗寒冬小麦幼苗和冷敏感春小麦幼苗质膜 Ca2 + -ATPase活性的变化 ,结果显示 :2 0℃下生长的冬小麦幼苗 ,Ca2 + - ATPase活性主要定位于质膜上。2℃下 ,随处理时间的延长 (3h、12 h) ,质膜 Ca2 + - ATPase活性反应逐步增强。2℃下处理 3d,质膜上仍存在酶反应产物 ,质膜 Ca2 + - ATPase活性高于对照。2 0℃下生长的春小麦幼苗 ,其质膜 Ca2 + - ATPase活性水平高于同样条件处理下的冬小麦幼苗的酶活性水平。2℃处理 3h,春小麦幼苗质膜上酶活性反应明显增强。2℃处理 12 h,酶活性反应迅速降低。2℃下处理 3d,春小麦幼苗质膜上酶反应产物明显少于对照 ,质膜 Ca2 + - ATPase已接近失活。结果表明 ,低温逆境下质膜 Ca2 + - ATPase活性的大小及其稳定性 。

南美白对虾贮藏期间Ca^(2+)-ATPase活力变化规律与机制

为了阐明南美白对虾肉在贮藏期间品质变化机制,提高虾肉的贮藏稳定性,以水分含量分别为6.5%、18.0%与76.5%的纯虾肉(PV)与按虾肉质量添加质量分数5%麦芽糊精的虾肉(PV-MD)为对象,研究了其在-78、-35、-18、5℃贮藏条件下,贮藏期间Ca^(2+)-ATPase活力变化规律,建立了Ca^(2+)-ATPase活力随温度与时间变化的动力学模型。通过分析Ca^(2+)-ATPase活力变化的反应速率常数k与水分活度、玻璃化转变温度之间的关系,阐明虾肉在贮藏期间品质变化的机制。结果表明:Ca^(2+)-ATPase活力随温度升高、虾肉水分含量增加而降低;PV-MD的Ca^(2+)-ATPase活力下降速率低于PV。Ca^(2+)-ATPase活力变化遵循2级反应动力学,即1/C-1/C0=kt,k随温度升高、水分含量增加而增加,但是随麦芽糊精的添加量增加而降低。虾肉冷冻/冻藏过程中,蛋白质变性的速率、程度与玻璃化转变理论密切相关;而在5℃冷藏过程中,蛋白质变性的速率与程度则受到水分活度保藏理论和玻璃化转变理论的双重制约。

毛白杨花粉败育过程中Ca^(2+)-ATPase的异常变化

为研究木本植物花粉败育过程中Ca2+-ATPase的影响,本文利用氯化铈沉淀和电镜细胞化学方法,对不同育性毛白杨花药在小孢子发生发育过程中Ca2+-ATPase进行了定位。结果表明:Ca2+-ATPase在可育花药小孢子母细胞时期大量分布于小孢子母细胞质膜、液泡膜及内膜系统,花药内壁细胞内膜系统和绒毡层细胞质膜,随后Ca2+-ATPase在上述细胞中均减少甚至消失,并于小孢子时期和成熟花粉时期分别在小孢子和花药内壁细胞中再次沉积;不育花药小孢子母细胞以及此时期绒毡层细胞质膜上并无明显Ca2+-ATPase,花药表皮、药室内壁以及中层的Ca2+-ATPase都高于同一时期的可育花药,其绒毡层细胞解体不完全。由上述结果推测:毛白杨不育花药内小孢子母细胞和药壁中Ca2+-ATPase分布异常,影响细胞内钙离子的主动转运,可能导致钙离子异常累积,进而通过影响小孢子母细胞和药室内壁细胞的正常代谢、绒毡层细胞的及时降解而导致花粉败育。

草莓果实成熟过程中细胞Ca^(2+)-ATPase活性的变化

‘春星’草莓果实成熟时 ,总糖和花青苷含量增加 ,呼吸速率也显著升高 ;同时 ,细胞溶质Ca2 + _ATPase活性和微粒体膜的Ca2 + _ATPase总活性变化具有相似的特点 ,即先升高 ,至粉红期达到高峰 ,全红期又下降 ,在微粒体膜中以质膜Ca2 + _ATPase占的比例最高。抑制质膜Ca2 + _ATPase活性的Na3 VO4能促进草莓果实花青苷积累、降低可溶性总糖含量 。

脱硫废弃物对碱胁迫下油葵幼叶细胞钙分布及Ca^(2+)-ATPase活性的影响

利用脱硫废弃物改良盐碱地对于确保国家粮食安全和生态安全,发展循环经济具有重要意义。为了探索脱硫废弃物提高植物抗盐碱机理,采用盆栽试验法,研究了施入不同量脱硫废弃物和CaSO4对碱胁迫下油葵叶片细胞钙分布、总钙含量以及质膜和液泡膜Ca2+-ATPase活性的影响。结果表明:在碱胁迫下(CK),Ca2+与焦锑酸钾结合成黑色颗粒成团零星分布于叶绿体和液泡中,叶绿体超微结构受到不同程度的破坏。施入脱硫废弃物和CaSO4,叶绿体结构完整,细胞间隙、细胞壁和液泡中的钙颗粒逐渐增多,同时,质膜和液泡膜Ca2+-ATPase活性随脱硫废弃物和纯品硫酸钙施量的增加而增加,其中液泡膜Ca2+-ATPase活性无论是对照(CK)还是处理的活性均高于质膜Ca2+-ATPase活性。叶片细胞内总钙含量也随脱硫废弃物和CaSO4施用量的增加呈升高趋势。说明脱硫废弃物和CaSO4通过增加Ca2+-ATPase活性,有利于钙通过质膜和液泡膜进入细胞内,维持膜结构的稳定性,缓解碱对油葵的胁迫。

加工条件对淡水鱼肌原纤维Ca^(2+)-ATPase稳定性的影响

对几种淡水鱼加工过程中Ca2+-ATPase稳定性进行了探讨,分析原料鱼死后不同存放条件下肌原纤维Ca2+-ATPase及肌肉组织pH值的变化规律,结果表明几种鱼的肌原纤维Ca2+-ATPase活性均随处理温度上升而降低,其中温度20℃以后为明显的下降点;中性条件有利于保持鱼肉Ca2+-ATPase活性;原料鱼死后存放于低温条件下,有利于Ca2+-ATPase的稳定。

孕酮处理对蛋鸡蛋壳钙化过程中Ca^(2+)-ATPase基因表达的影响

为了解孕酮对蛋鸡产蛋过程中钙离子ATP酶(Calcium-ATPase,Ca2+-ATPase)基因表达的影响,本研究以产蛋高峰期蛋鸡作为实验动物,进行孕酮处理后,利用实时荧光定量PCR技术(QRT-PCR),测定在蛋壳形成过程中输卵管子宫部Ca2+-ATPase、孕酮受体(progesterone receptor,PGR)的表达量。同时对血液中钙离子和孕酮浓度变化进行测定。结果表明:孕酮处理后,血液中钙离子浓度显著降低(P<0.05),输卵管子宫部Ca2+-ATPase表达量极显著降低(P<0.01),PGR mRNA表达量则显著降低(P<0.05)。结果提示,在蛋壳钙化过程中,孕酮对钙离子转运和Ca2+-ATPase表达起抑制作用。