Functional properties of transgenic mouse hearts overexpressing both calsequestrin and the Na(+)-Ca(2+) exchanger

Overexpression of calsequestrin (CSQ) induces severe cardiac hypertrophy, whereas overexpression of Na(+)-Ca(2+) exchanger (NCX) does not affect cardiac weight. To investigate a possible beneficial effect of NCX in hypertrophy, we produced transgenic mice overexpressing both NCX and CSQ (NCX/CSQ). Surprisingly, these mice developed severe heart failure. The heart/body weight ratio was enhanced and the mRNA expression of ANF, as a marker of hypertrophy, was highest in double transgenic mice. In isolated muscle strips, the basal relaxation time was prolonged in CSQ and NCX/CSQ mice. Moreover, in the presence of caffeine, force of contraction was increased only in CSQ and NCX/CSQ and was accompanied by elevated diastolic tension. In some respects, however, additional overexpression of NCX altered the CSQ phenotype into the wild-type phenotype. The expression of sarcoplasmic reticulum (SR)-Ca(2+)-ATPase and phospholamban, proteins involved in the Ca(2+) uptake of the SR, were only increased in CSQ, indicating a possible influence of NCX in the regulation of SR-Ca(2+) uptake proteins. The Ca(2+) transients and the L-type Ca(2+) currents in the presence of caffeine were very large in CSQ, but smaller increases were noted in double transgenic mice. Therefore, the successful co-overexpression of CSQ and NCX in these mice provides a novel model in which to investigate the interaction of proteins tightly linked to maintain Ca(2+) homeostasis.     

Oxygen Free Radicals and Endotoxic Shock: Effect of Flaxseed

BACKGROUND: Cardiac dysfunction and tissue injury during endotoxemia may be caused by increased levels of oxygen free radicals. METHODS AND RESULTS: We therefore investigated the effects of endotoxic shock on cardiac function and contractility, plasma creatine kinase (CK) activity and lactate concentration, oxyradical-producing activity of polymorphonuclear leukocytes (PMNL-CL) and white blood corpuscles, antioxidant reserve (cardiac chemiluminescence [LV-CL]), antioxidant enzyme activity (superoxide dismutase, catalase, glutathione peroxidase), cardiac malondialdehyde (MDA) concentration, a lipid peroxidation product, and hemodynamics in the absence or presence of flaxseed treatment in anesthetized dogs. Flaxseed contains lignans that have antioxidant activites and inhibit platelet-activating factor (PAF). The dogs were assigned to three groups: group I, sham control; group II, endotoxin (ET) treated (5 mg/kg intravenously); group III, ET + flaxseed (2 gm/kg/day orally) for 6 days. ET produced a decrease in cardiac function and contractility and antioxidant enzyme levels, and an increase in cardiac MDA and LV-CL, PMNL-CL, and plasma CK and lactate. Pretreatment with flaxseed attenuated the ET-induced cardiac dysfunction and cellular damage. Protection was incomplete for cardiovascular function, plasma CK, and lactate. CONCLUSIONS: These results suggest that oxyradicals and/or PAF may be involved in the deterioration of cardiovascular function and cellular integrity during ET shock and that antioxidant and anti-PAF agents may be effective in the treatment of ET shock.     

Inhibition of canine (NCX1.1) and Drosophila (CALX1.1) Na(+)-Ca(2+) exchangers by 7-chloro-3,5-dihydro-5-phenyl-1H-4,1-benzothiazepine-2-one (CGP-37157)

The electrophysiological effects of the benzothiazepine 7-chloro-3,5-dihydro-5-phenyl-1H-4,1-benzothiazepine-2-one (CGP-37157) (CGP) were investigated on the canine (NCX1.1) and Drosophila (CALX1.1) plasmalemmal Na+-Ca2+ exchangers. These exchangers were selected for study because they show opposite responses to cytoplasmic regulatory Ca2+, thereby allowing us to examine the role of this regulatory mechanism in the inhibitory effects of CGP. CGP blocked Na+-Ca2+ exchange current mediated by both transporters with moderate potency (IC50 values = approximately 3-17 microM) compared with other recently reported blockers of Na+-Ca2+ exchange [e.g., 2-[4-[2,5-difluorophenyl) methoxy]phenoxy]phenoxy]-5-ethoxyaniline (KB-R7943) and 2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea (SEA0400)]. Experiments using alpha-chymotrypsin to remove autoregulation of Na+-Ca2+ exchange showed that block by CGP was reduced, suggesting that part of the effects of this drug may require intact ionic regulatory mechanisms. For NCX1.1, the inhibition produced by CGP was greater for outward Na+-Ca2+ exchange currents compared with inward currents. When CALX1.1 was examined, the extent of inhibition was similar for both inward and outward exchange currents. Although the extent and potency of CGP-mediated inhibition of Na+-Ca2+ exchange are less than those observed with SEA0400 and KB-R7943, our data demonstrate that CGP constitutes a novel class of plasmalemmal Na+-Ca2+ exchange inhibitors. Moreover, the widespread use of CGP as a selective mitochondrial Na+-Ca2+ exchange inhibitor should be reconsidered in light of these additional inhibitory effects.     

白血病病人与健康人白细胞氧自由基及耗氧量的比较

利用电子自旋共振（ESR）自旋捕集与探针技术,观察白血病病人与健康人白细胞氧代谢过程释放活性氧自由基的种类及其耗氧量的变化。结果发现,白血病病人白细胞经豆蔻酰佛波醇乙酯（PMA）刺激只捕集到微弱的羟自由基（OH）信号,刺激前后耗氧量差别不显;健康人白细胞可得到超氧阴离子自由基（O^-2）的ESR波谱信号,耗氧量较正常呼吸即未受PMA刺激时大大增加（P＜0.001)。两组白细胞耗氧量比较,未受刺激时两无明显差别;刺激后,健康组明显高于白血病组（P＜0.001)。结论说明白血病病人白细胞缺乏呼吸爆发功能,因此耗氧量明显低于健康人白细胞。     

氧自由基清除剂对缺血性沙土鼠脑组织损伤的保护作用的研究

本文利用夹闭沙土鼠双侧颈总动脉并再灌注形成缺血再灌注动物模型,观察氧自由基清除剂,超氧化物歧化酶和过氧化物酶对缺血再灌注的沙土鼠的脑组织中过氧化物和水份含量的变化的影响的研究,探讨自由基在脑缺血性损伤过程中的作用。结果表明自由基所致缺血性脑损伤反应主要出现在再灌注期,自由基清除剂对这一损伤作用具有抑制作用。     

奥曲肽对兔肝缺血再灌后小肠超微结构、细胞因子、氧自由基的影响

[目的]探讨兔肝缺血再灌后小肠超微结构、细胞因子、氧自由基的变化及奥曲肽的保护作用.[方法]采用Pring's兔肝脏再灌注模型,将24只新西兰大白兔随机分为三组:A组(假手术组)、B组(肝脏缺血再灌注生理盐水组)、C组(奥曲肽预适应组).三组动物再灌240 min试验结束时取小肠组织行电镜检查超微结构的改变,同时取小肠...     

电针足三里对大鼠氧自由基和前列腺素的影响

目的　观察电针对应激大鼠血浆超氧化物歧化酶 ( SOD)、丙二醛 ( MDA)和前列腺素 E2 ( PGE2 )的影响 ,以探讨电针对胃黏膜保护作用的机理。方法　将 72只大鼠平均分为空白对照组、应激组和电针组 ,每组再按实验时间 1 ,3,5 d平均分为 3小组 (每小组 8只 )。利用生化比色法和放免分析法测定各组大鼠血浆 SOD、MDA和 PGE2 含量并计算各组溃疡指数 ( UI)。结果　应激组较空白对照组大鼠血浆 SOD明显下降 ( 1 7.0± 2 .9) N.L-1→ ( 1 1 .9± 3.4) N.L-1;MDA明显上升 ( 4 .85± 2 .38) N.L-1→ ( 7.5 6± 2 .48)N.L-1;PGE2 明显下降 ( 2 .74± 0 .77) ng.L-1→ ( 1 .5 4± 0 .2 5 ) ng.L-1,P<0 .0 5。 UI明显上升 ( 1 .1± 0 .4)→ ( 2 8.0± 4.1 ) ,P<0 .0 1。电针组较应激组血浆 SOD明显上升 ( 1 1 .9± 3.4) N.L-1→ ( 1 7.7± 4.8) N.L-1;MDA明显下降 ( 7.5 6± 2 .48) N.L-1→ ( 4 .1 4± 1 .78) N.L-1;PGE2 明显上升 ( 1 .5 4± 0 .2 5 ) ng.L-1→( 3.2 1± 0 .38) ng.L-1,UI明显下降 ( 2 8.0± 4.1 )→ ( 1 9.0± 2 .3) ;P<0 .0 1。电针组 PGE2 实验 5 d组较实验 1 d组明显上升 ( 3.2 1± 0 .38) ng.L-1→ ( 4 .5 2± 1 .0 6) ng.L-1,P<0 .0 5。结论　电针对胃黏膜的损伤具有保护作用 ,其机制与其影     

针刀结合手法治疗KOA的疗效及对血浆氧自由基代谢的影响

目的:观察针刀结合手法治疗膝关节骨性关节炎(KOA)的临床疗效及对血浆氧自由基代谢的影响。方法:100例KOA患者随机分为2组各50例,观察组采用针刀结合手法治疗,每5 d 1次。对照组采用口服双氯芬酸钠片25 mg,每日3次。结果:治疗15 d后,2组氧自由基超氧化物歧化酶(SOD)浓度与治疗前比较明显上升,血浆过氧化脂质(LPO)与丙二醛(MDA)浓度均下降,观察组表现更明显(均P0.05,0.01)。观察组痊愈率及总有效率均明显高于对照组(64.0%、98.0%与44.0%、86.0%,P0.05)。患膝关节评分(JOA评分),2组均较治疗前提高,观察组更显著(均P0.05,0.01)。结论:针刀结合手法治疗能明显改善KOA患者的临床症状及体征,并能抑制氧自由基对软骨细胞及基质的损害,延缓KOA的发展,达到防治KOA的目的。     

金水宝胶囊对清除老年虚证者氧自由基的临床与实验研究

报道了３３例老年虚证者服用金水宝胶囊前后，及停药四个月后的红细胞超氧化物歧化酶（ＳＯＤ）活性和血浆丙二醛（ＭＤＡ）含量变化，并以４０只老龄大白鼠分设金水宝胶囊治疗组、淀粉胶囊对照组，并设２０只年轻大白鼠进行空白对照进行与临床观察指标相同的项目研究。结果表明：与对照组比较治疗组用药后与服药前比较，ＳＯＤ活性明显上升，ＭＤＡ含量明显下降（Ｐ值均＜０．０１）。金水宝胶囊能够明显改善畏寒、头晕、腰膝酸软和减轻夜尿频和耳鸣症状的作用。停药四个月后仍能部分降低血浆ＭＤＡ含量，保持药物一定的远期效应。老龄大白鼠金水宝胶囊实验组喂药后较喂药前的ＳＯＤ活性明显升高，ＭＤＡ含量则显著降低（Ｐ值均＜０．０１），与临床观察结果一致。提示：老年虚证与氧自由基代谢失衡直接有关。金水宝胶囊具有提高ＳＯＤ和降低ＭＤＡ含量的作用，有一定延缓衰老和防治老年虚证的作用。     

三种剂型生脉制剂对氧自由基清除作用的比较研究

目的探讨生脉注射液、生脉饮、生脉胶囊三种制剂的抗氧自由基作用 ,并对其作用作了比较。方法用邻二氮菲-Fe2 +氧化法测定羟自由基 (·OH ) ;用改进的邻苯三酚自氧化法测定超氧阴离子自由基 (O-·2 )。结果三种剂型生脉散均有清除O-·2 和·OH的能力 ,与对照管比较差异均有高度显著性 (P <0 .0 1) ,各剂型之间无显著差异 ( P >0 .0 5 )。结论三种剂型生脉制剂均有较强的清除氧自由基作用     

门静脉阻断及复流对肝功能及氧自由基变化的影响

目的:探讨不同程度不同时间段阻断门静脉对肝脏转氨酶及氧自由基变化的影响。为确定门静脉阻断时限提供实验依据。方法:健康成年日本大耳白兔40只,随机分为1个对照组A和4个实验组:分别半阻断门静脉30 min(B1组)、45 min (C1组)及全阻断门静脉30min(B2组)、45 min(C2组),每组8只。各实验组在术前1 h及按上述预定的门静脉阻断时间、解除阻断后30min、60 min各取腔静脉血2 ml;对照组(A组)在相应时间段也各取腔静脉系统血1次。测定各标本丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)及脂质过氧化物(LPO),谷胱甘肽过氧化物酶(GSH-Px)活性并予以对照分析。结果:A组在不同时间段各指标检测结果均无显著差异,实验组与对照组在相应时间段各指标的比较:B1、C1组均无显著差异;B2组阻断30 min时亦无显著差异,而在解除阻断后30 min、60min时AST、LPO明显升高;C2组阻断45 min时ALT、AST明显升高,解除阻断后30 min时另有LPO升高,随后均再升高;B2、C2组解除阻断后60min时尚有GSH-Px下降。结论:门静脉半阻断45 min内对转氨酶及氧自由基损伤指标的变化影响不明显,完全开放前后无显著差异;全阻断30min时对以上酶类活性影响也不大,但复流后要注意再灌注损伤;全阻断45 min要慎重。     

应变率成像评价缺血后处理对犬局部心肌收缩功能的保护作用及与氧自由基的关系

目的 采用心肌应变率成像(SRI)评价缺血后处理(IPostC)对犬局部心肌收缩功能的作用,及与氧自由基的相关性.方法 14只犬左冠状动脉前降支(LAD)阻断180min,再灌注120min,随机分两组:对照组(Con组),无干预;IPostC组,再灌注开始前进行3次再灌注30s,缺血30s.在基础状态、缺血后和再灌注后进行SRI检查,并检测血清丙二醛(MDA)和超氧化物岐化酶(SOD)活性.结果 再灌注后IPostC组心肌收缩期纵向峰值应变率(LSRs)和径向峰值应变率(RSRs)显著大于Con组,同时MDA含量小于Con组,SOD活性则大于Con组(P<0.001). LSRs和RSRs与MDA显著负相关,与SOD显著正相关.结论 SRI可准确评价IPostC对犬心肌缺血再灌注后局部心肌收缩功能的保护作用,其作用与降低氧自由基活性有关.     

氧自由基与阻塞性睡眠暂停低通气综合征患者细胞因子相关性

目的 阻塞型睡眠呼吸暂停低通气综合征（OSAHS）患者细胞因子与氧自由基相关性及对呼吸暂停低通气指数（AHI）和最低SaO2%的影响.方法 选自2008年6月～2009年5月门诊和住院的OSAHS患者,根据AHI将38例OSAHS患者分为轻、中、重度三组,健康体检者15名作为对照.采用双抗体夹心ELISA法检测血清中白介素-6（IL-6）、白介素-8（IL-8）、肿瘤坏死因子（TNF-α）的质量浓度.细胞色素C还原法测外周血中性粒细胞释放超氧阴离子（O2-）水平.并分析O2-水平与细胞因子及AHI和最低SaO2%的关系.结果 重、中度组IL-6、IL-8、TNF-α水平及外周血中性粒细胞释放O2 -量显著高于轻度和正常对照组（P＜0.01）.重、中、轻度组患者外周血中性粒细胞释放O2 -水平与AHI水平呈明显正相关（r 分别为0.659、0.651、0.642,P均＜0.01）、与最低SaO2%水平呈明显负相关（r分别为-0.536、-0.529、-0.518,P均＜0.01）.重、中度组患者外周血中性粒细胞释放O2-水平与血浆IL-6、IL-8、TNF-α浓度呈线性正相关（重度组r分别为0.795、0.776、0.792,中度组r为0.548、0.585、0.686,P均＜0.01）.结论 OSAHS重、中度组患者炎症细胞在细胞因子等刺激下活化,释放氧化物质增多,导致OSAHS重、中度组患者肺功能恶化,内分泌、心血管系统损害可能起重要作用.     

不同吸入氧浓度对剖宫产术母体与婴儿氧合及脂质过氧化物的影响

目的:探讨剖宫产术中不同吸入氧浓度对母体及婴儿的氧合和自由基的影响。方法:44例ASAⅠ～Ⅱ级在脊麻-硬膜外联合阻滞麻醉下行择期剖宫产患者,随机分为两组:空气组(围术期吸21％的氧)、氧气组(围术期吸50％的氧)。记录麻醉前及从吸氧到娩出时间段的母体动脉血气值、SOD和LPO值;以及胎儿首次呼吸前的脐动、静脉血气和LPO、SOD值。分析吸氧与各指标间的相关性。结果:两组新生儿Apgar评分无明显差异。母体术中及娩出时血PO_2及脐静脉血PO_2吸氧气组明显高于吸空气组(P<0.01);胎儿娩出时母体动脉及脐静脉LPO值氧气组均明显高于空气组(P<0.05);但SOD值在两组间无统计学差异。结论:剖宫产期间给予高浓度的氧,虽能改善新生儿的氧合,但能显著增加自由基和脂质过氧化物的含量,影响机体氧化和抗氧化平衡。     

Failure of spermatogenesis in mouse lines deficient in the Na(+)-K(+)-2Cl(-) cotransporter

The Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) carries 1 molecule of Na(+) and K(+) along with 2 molecules of Cl(-) across the cell membrane. It is expressed in a broad spectrum of tissues and has been implicated in cell volume regulation and in ion transport by secretory epithelial tissue. However, the specific contribution of NKCC1 to the physiology of the various organ systems is largely undefined. We have generated mouse lines carrying either of 2 mutant alleles of the Slc12a2 gene, which encodes this cotransporter: a null allele and a mutation that results in deletion of 72 amino acids of the cytoplasmic domain. Both NKCC1-deficient mouse lines show behavioral abnormalities characteristic of mice with inner ear defects. Male NKCC1-deficient mice are infertile because of defective spermatogenesis, as shown by the absence of spermatozoa in histological sections of their epididymides and the small number of spermatids in their testes. Consistent with this observation, we show that Slc12a2 is expressed in Sertoli cells, pachytene spermatocytes, and round spermatids isolated from wild-type animals. Our results indicate a critical role for NKCC1-mediated ion transport in spermatogenesis and suggest that the cytoplasmic domain of NKCC1 is essential in the normal functioning of this protein.     

脑梗死患者氧自由基浓度变化对血液流变性的影响

目的　探讨脑梗死时氧自由基浓度变化对血液流变学的影响。方法　测定 41例急性脑梗死 (ACI)患者和 30例健康人血浆丙二醛 (MDA)、氧化修饰低密度脂蛋白 (ox LDL)浓度及全血粘度 ( ηb) ,血浆粘度 ( ηp)、红细胞压积 (HCT)、血沉 (ESR)、纤维蛋白原 (FIB)、血小板粘附率 (FAD)等指标 ,进行统计学分析。结果　脑梗死组MDA、ox LDL及 ηb、ηp、HCT、ESR、FIB、FAD等指标均明显升高 ,与对照组比较均有显著性差异 (P <0 .0 1或P <0 .0 5 ) ;直线相关分析显示 :MDA与ox LDL、ηb( 2 0 0s-1)、ηb( 3s-1)、ηp及FAD呈显著正相关 (r1=0 .412 9,P <0 .0 1;r2 =0 .472 6 ,P <0 .0 1;r3=0 .5 0 12 ,P <0 .0 1;r4 =0 .316 7,P <0 .0 5 ;r5=0 .30 76 ,P <0 .0 5 )。结论　脑梗死急性期氧自由基的过度形成可引起血液粘度增高 ,其对血液粘度的影响是多途径的。