创伤后应激障碍样情感行为异常大鼠脑组织ATP酶活性的动态变化(英文)

目的:探讨创伤后应激障碍(posttraumaticstressdisorder,PTSD)样精神与行为异常的病理生理基础,为其治疗途径提供新思路。方法:将72只雄性Wistar大鼠随机分组为海马阈下电刺激组(SE,n=32)、海马电极埋植对照组(CE,n=32)和正常对照组(NC,n=8),利用频率25Hz、波宽1ms、串长10s、串隔7min、强度100μA的恒流、单脉冲电流,反复惊厥阈下电刺激海马,并定量检测了实验动物海马组织匀浆及线粒体Na+-K+-ATP酶、Ca2+-ATP酶活性改变。结果:电刺激停止后12h阈下刺激大鼠海马细胞线粒体Na+-K+-ATP酶活性即明显下降为(0.56±0.15)mmol/(kg·s),(F=4.348,P<0.01),48h为(0.61±0.17)mmol/(kg·s),(P<0.05)仍显著低于NC组(0.84±0.22)mmol/(kg·s);24h线粒体Ca2+-ATP酶活性亦明显降低为(0.53±0.14)mmol/(kg·s),(F=4.999,<0.05,72h为(0.60±0.16)mmol/(kg·s)仍显著低于NC组(0.83±0.22)mmol/(kg·s)。结论:海马组织,特别是海马细胞线粒体钠钾泵与钙泵功能受损,在实验动物长时程PTSD样情感行为异常发生发展中可能有重要意义。++2+     

创伤后应激障碍样情感行为异常大鼠脑组织ATP酶活性的动态变化

目的探讨创伤后应激障碍( posttraumatic stress disorder,PTSD)样精神与行为异常的病理生理基础,为其治疗途径提供新思路. 方法将 72只雄性 Wistar大鼠随机分组为海马阈下电刺激组( SE, n=32)、海马电极埋植对照组( CE, n=32)和正常对照组( NC, n=8),利用频率 25 Hz、波宽 1 ms、串长 10 s、串隔 7 min、强度 100 μ A的恒流、单脉冲电流,反复惊厥阈下电刺激海马,并定量检测了实验动物海马组织匀浆及线粒体 Na+-K+-ATP酶、 Ca2+-ATP酶活性改变. 结果电刺激停止后 12 h阈下刺激大鼠海马细胞线粒体 Na+-K+-ATP酶活性即明显下降为 (0.56± 0.15) mmol/( kg· s) ,(F=4.348, P< 0.01), 48 h为 (0.61± 0.17) mmol/(kg· s),(P< 0.05)仍显著低于 NC组 (0.84± 0.22) mmol/(kg· s); 24 h线粒体 Ca2+ ATP酶活性亦明显降低为 (0.53± 0.14 ) mmol/(kg· s),(F=4.999,< 0.05, 72 h为 (0.60± 0.16) mmol/(kg· s)仍显著低于 NC组 (0.83± 0.22) mmol/(kg· s). 结论海马组织,特别是海马细胞线粒体钠钾泵与钙泵功能受损 ,在实验动物长时程 PTSD样情感行为异常发生发展中可能有重要意义.     

自体冷血停跳液对未成熟心肌三磷酸腺苷酶的影响

目的 研究自体冷血停跳液对非紫绀先天性心脏痛患儿心肌细胞ATP酶的影响,探讨自体冷血停跳液对未成熟心肌的保护作用.方法 体重≤8 kg非紫绀先天性心脏病婴幼儿30例,其中室间隔缺损(VSD)2例,VSD伴肺动脉高压(PH)11例,VSD伴房间隔缺损(ASD)伴PH 9例,ASD 2例,VSD伴卵圆孔未闭(FPO)6例.随机分为自体冷血组、冷血组和晶体停跳液组,每组10例.分别于心脏停跳前、复跳后取右心耳心肌,检测心肌ATP酶的活性.结果 手术前、后自体冷血组、冷血组和晶体停跳液组心肌细胞Na+K+-ATPase[(4.84±1.48)μmol/(mg·h)与(3.76±1.42)μmol/(mg·h)、(4.82±1.30)μmol/(mg·h)与(2.56 ±1.32)μmol/(mg·h)、(4.72±1.42)μmol/(mg·h)与(2.12±1.24)μmol/(mg.h)],Ca2+-ATPase[(10.02±1.64)μmol/(mg·h)与(8.56 ±1.45)μmol/(mg·h)、(9.87±1.48)μmol/(mg·h)与(5.87±1.42)μmol/(mg·h)、(10.23 ±1.56)μmol/(mg·h)与(4.91 ±1.36)μmol/(mg·h)]和Ca2+Mg2+-ATPase[(24.23 ±2.01)μmol/(mg·h)与(19.21±1.93)μmol/(mg·h)、(23.18 ±1.86)μmol/(mg·h)与(12.32 ±2.01)μmol/(mg·h)、(24.02 ±2.32)μmol/(mg·h)与(10.12±1.87)μmol/(mg·h)]活性差异均有统计学意义(P均＜0.05);术前自体冷血组与冷血组和晶体停跳液组比较差异均无统计学意义(P均＞0.05),术后冷血组和晶体停跳液组与自体冷血组比较差异均有统计学意义(P均＜0.05).结论 自体冷血停跳液对未成熟心肌ATP酶影响最小,对婴幼儿心肌具有良好的保护作用.     

磷酸肌酸对大鼠心肺复苏后脑能量代谢的影响

目的 观察外源性磷酸肌酸(CP)对大鼠心肺复苏(CPR)后脑损伤的影响.方法 成年雄性SD大鼠160只,随机(随机数字法)分为4组:假手术对照组(A组)、常规复苏组(B组)、小剂量CP组(C组)、大剂量CP组(D组),各组再分别按自主循环恢复(ROSC)后(B、C、D组)或气管切开后(A组)0.5、3、6、12、24h时间点分为5亚组(n=8).B、C、D组采用窒息法建立大鼠CPR模型,ROSC后即刻C组静注CP0.5 g/kg,D组静注CP 1.0 g/kg.A组仅施行麻醉、气管切开、血管穿刺等操作,不行窒息及复苏.各亚组在相应时间点取材大脑额叶.采用高效液相色谱法( HPLC)测定脑组织三磷酸腺苷(ATP)、二磷酸腺苷(ADP)、一磷酸腺苷(AMP)含量,并计算总腺苷酸(TAN)及能倚(EC)值;采用吸光度法测定脑组织Na+ -K+ -ATP酶、Ca2+ - Mg2+ - ATP酶活性;HE染色观察光镜下大脑皮层病理变化.应用SPSS 16.0软件包进行数据统计,组间比较采用方差分析.结果 与A组比较,B组C组各时间点ATP、TAN、EC、Na+-K+-ATPase、Ca2+ -Mg2+ -ATPase均降低(P＜0.05或P＜0.01),D组0.5、3、6、12 h时间点的ATP、TAN、EC、Na+ -K+ -ATPase、Ca2 -Mg2 -ATPase均降低(P＜0.05或P＜0.01),B组各时间点AMP均升高(P＜0.01),C组D组0.5h和3h时间点的AMP升高(P＜0.01);与B组比较,C组D组6、12、24h时间点的ATP、TAN、EC、Na+ -K+ -ATP酶、Ca2+ -Mg2+ -ATP酶均升高(P＜0.05或P＜0.01),C组D组6、12、24h时间点的AMP均降低(P＜0.05或P＜0.01);与C组比较,D组6、12、24h时间点的TAN、Na+ -K+ -ATPase、Ca2 -Mg2 -ATPase以及24h的ATP均升高(P＜0.05或P＜0.01).大脑皮层病理变化B组严重,C组D组较轻.结论 心肺复苏后存在脑能量代谢障碍,CP可以增加CPR后脑组织中的ATP含量,提高Na+ -K+ -ATPase和Ca2 -Mg2+ -ATPase的活性,减轻脑组织病理损伤,具有脑保护作用,在大剂量给药时作用更明显.     

内给氧改善缺血再灌注后脑组织能量代谢的实验研究

目的:探讨内给氧改善大鼠脑组织缺血再灌注后能量代谢障碍,起到脑保护作用的机制。方法:30只Wistar大鼠随机分成3组:假手术组、缺血组、治疗组,制备大鼠脑缺血再灌注损伤模型,予内给氧治疗后,分别测定各组大鼠脑组织中的三磷酸腺苷(ATP)、二磷酸腺苷(ADP)、单磷酸腺苷(AMP),乳酸含量及Na+-K+-ATPase活性,计算能量负荷值。结果:内给氧治疗组的ATP含量(2.3309±0.0866)mg/L、能量负荷值为0.0960±0.0052,Na+-K+-ATPase活性为(0.903±0.117)μkat/g,均高于缺血组犤(0.8199±0.0591)mg/L,0.1663±0.0044,(0.465±0.064)μkat/g犦差异存显著性意义(P<0.05),乳酸含量(16.0342±1.0136)mmol/g低于缺血组(24.2513±4.3571)mmol/g,差异有显著性意义(P<0.05)。结论:内给氧可明显改善大鼠脑缺血再灌注后能量代谢,具有脑保护作用。     

创伤后应激障碍样行为异常大鼠海马钙依赖性反应紊乱

目的探讨情感行为异常大鼠海马钙离子及其相关的钙依赖性反应,进一步认识创伤后应激障碍(PTSD)样行为异常的神经生物学基础。方法将240只雄性Wistar大鼠随机分组为海马阈下电刺激组(SE,n=96)、海马电极埋植对照组(CE,n=96)和正常对照组(NC,n=48),采用频率25Hz、波宽1ms、串长10s、串隔7min、强度100μA的恒流、单脉冲电流,反复刺激大鼠海马以建立PTSD样行为异常动物模型;采用神经生化、流式细胞仪、荧光标记术及Westernblotting等方法,定量观测了实验大鼠海马Na+-K+-ATP酶与Ca2+-ATP酶活性,细胞内游离钙离子含量与钙调素(CaM)相对活性平均通道荧光,以及海马组织总CaM表达的动态变化规律。结果电刺激停止后12h阈下刺激大鼠海马细胞线粒体Na+-K+-ATP酶活性即明显下降犤(0.56±0.17)mmol/(kg·s),F=4.438,P<0.05犦,48h仍显著低于NC组犤(0.61±0.17)mmol/(kg·s),P=0.026犦;24h线粒体Ca2+-ATP酶活性亦明显降低犤(0.53±0.14)mmol/(kg·s),F=4.999,P<0.05犦,72h仍显著低于NC组犤(0.61±0.17)mmol/(kg·s),P=0.027犦。海马细胞内游离钙离子含量于电刺激停止后12～48h明显高于两对照组(F=16.355,P<0.01),72h仍显著高于NC组犤(290±70)nmol/L,P=0.03犦,游离CaM平均通道荧光则同步降低(F=10.655,P<0.05),而海马组     

高渗盐水对大鼠缺血再灌注损伤肾组织Na+-K+-ATP酶活性的影响

目的 探讨高渗盐水对缺血再灌注损伤肾组织Na+-K+-ATP酶活性的影响.方法 56只SD大鼠随机分为假手术组(S组)、缺血再灌注组(IR组)和高渗盐水处理组(H组).肾缺血再灌注损伤模型的建立:左侧肾蒂夹闭45 min后松开,分别于再灌注4 h、6 h、12 h,测定左肾系数、血清肌酐(Cr)、左肾组织Na+-K+-ATP酶(Na+-K+-ATPase)活性和丙二醛(MDA)含量.结果 H组左肾系数、血清肌酐和丙二醛明显低于IR组,而左肾组织Na+-K+-ATP酶活性明显高于IR组.结论 高渗盐水预处理对实验SD大鼠缺血再灌注肾损伤有保护作用.     

热休克蛋白70对大鼠体外心脏细胞功能的影响

目的观察重酒石酸去甲肾上腺素诱导后热休克蛋白70在体外心脏中的表达,并探讨热休克蛋白70对大鼠体外心脏细胞功能的影响.方法实验于2003-03/09在华中科技大学同济医学院药理实验室进行.取成年雄性Wistar大鼠12只,随机分为2组,每组6只[1]生理盐水组腹腔注射生理盐水0.4 mL,注射后24 h取体外心脏,常规建立Langendorff体外心脏灌注模型,灌注15 min转为工作心15 min后停灌45 min,恢复灌注15 min改为工作心30 min.[2]重酒石酸去甲肾上腺素组腹腔注射重酒石酸去甲肾上腺素3.1μmol/kg(0.53 mg/kg),24 h后取体外心脏,方法同生理盐水组.采用Western blot法测定心肌细胞中热休克蛋白70含量及生化指标.结果12只大鼠全部进入结果分析.[1]热休克蛋白70含量(吸光度)重酒石酸去甲肾上腺素组明显高于生理盐水组(t=10.16,P＜0.01).[2]生化指标重酒石酸去甲肾上腺素组三磷酸腺苷含量、超氧化物歧化酶活性、心肌线粒体Ca2+-ATPase活性、心肌线粒体合成三磷酸腺苷能力优于生理盐水组[(13.67±2.60),(5.36±0.89)μmol/g;(2.44±0.14),(4.64±0.29)μkat/g;(6.77±0.90),(2.54±0.28)μkat/g;(124.22±13.58),(61.25±5.84)mmol/g;尸均＜0.01],丙二醛含量、肌酸激酶和乳酸脱氢酶漏出率、心肌细胞内Ca2+含量、心肌线粒体Ca2+含量低于生理盐水组(P＜0.01).结论重酒石酸去甲肾上腺素诱导的热休克蛋白70的高表达对缺血再灌注未成熟心肌细胞功能具有明显的保护效应,可以减轻细胞内和线粒体内Ca2+超载而发挥其细胞保护效应,减轻再灌注损伤.     

尼可地尔含血停搏液对心肌细胞Na+-K+ATP酶的保护作用

目的缺血再灌注损伤会导致心肌细胞Na+-K+ATP酶活性降低,通过对比缺血再灌注后Na+-K+ATP酶活性改变,研究尼可地尔含血停搏液对心肌细胞Na+-K+ATP酶的保护作用。方法采用间生态离体兔心共生支持系统模型。16个心脏随机分为两组,每组8只。分别采用尼可地尔超极化含血停跳液或者高钾去极化含血停跳液灌注。超极化含血停跳液由尼可地尔(100μmol/L),Krebs-Henseleit液和兔血1:2混合配制。去极化停搏液由St.Thomas'液与兔血1:2混合配制,最终K+浓度20mmol/L。心脏停跳后以含血停跳液间断灌注,常温缺血60min。再灌注60min。采用电镜酶化学方法检测缺血前后心脏Na+-K+ATP酶的变化。结果缺血再灌注后两组中酶的活性均明显降低,高钾组较尼可地尔组减少更明显。结论尼可地尔对心肌细胞Na+-K+ATP酶缺血再灌注损伤有保护作用。     

高血压灌注对猪心肺复苏后胃肠组织超微结构和酶学的影响

目的 观察猪心肺复苏(CPR)后高血压灌注对胃肠组织超微结构和酶学的影响.方法 采用直流电致实验猪心室纤颤(室颤)4 min后行CPR.复苏成功的10只猪按随机数字表法分为对照组(n=5)和高血压灌注组(n=5),后者给予去甲肾上腺素升高血压,使平均动脉压(MAP)维持在室颤前基础状态的130％.于复苏前后测定血清二胺氧化酶(DAO)水平及胃肠组织ATP酶活性,并在光镜和电镜下观察组织结构.结果 自主循环恢复(ROSC)后2h、4h高血压灌注组与对照组DAO水平均较室颤前明显升高(高血压灌注组:15.66±2.24、15.76±0.95比8.38±0.70,对照组:14.87±1.34、13.85±0.52比9.92±0.78,均P＜0.05);而两组间均无差异.ROSC后24 h高血压灌注组胃组织Na+-K+-ATP酶(μmol·mg-1·h-1)和Ca2+-ATP酶(μmol·mg-1·h-1)明显高于对照组(Na+-K+-ATP酶:6.07±1.49比2.89±1.48,Ca2+-ATP酶:7.67±1.86比3.07±1.50,均P＜0.05);而两组间肠组织中ATP酶活性无明显差异.在光镜和电镜下观察高血压灌注组胃肠黏膜结构、线粒体损伤均轻于对照组.结论 CPR后出现消化道功能受损、能量代谢异常、血清DAO水平升高、肠微绒毛破坏;高血压灌注能够改善能量代谢、减少黏膜损伤,对消化道具有保护作用.     

A single isoform of the Na+/K+-ATPase α-subunit in Diptera: evidence from characterization of the first extracellular domain

The first extracellular domain of the α-subunit of the Na⁺/K⁺-ATPase (sodium/potassium pump) is functionally important, affecting sensitivity of the enzyme to cardiac glycosides (e.g. ouabain) and being implicated in the transport of K⁺. This domain is also variable among mammalian isoforms of the α-subunit. Using PCR, we have isolated from seven insect species with contrasting physiologies a DNA fragment containing this region, in order to help determine whether tissue-specific expression might be associated with isoforms encoded by a gene family, as it is in mammals. A single sequence (with one ORF) characteristic of Na⁺/K⁺-ATPase was obtained from genomic DNA of each species. Only the fragment from Manduca sexta contained an intron, but at a location different to that found in mammals. For all Diptera so far characterized, the species phylogeny is the same as the α-subunit gene phylogeny (based on the sequences of the first extracellular domain and flanking transmembrane domains). The results strongly indicate a single, ouabain-sensitive isoform of the α-subunit of Na⁺/K⁺-ATPase is present in Diptera.     

Effects of plasma membrane Ca2+-ATPase tyrosine phosphorylation on human platelet function

BACKGROUND: The plasma membrane Ca(2+)-ATPase (PMCA) plays an essential role in maintaining low intracellular Ca(2+) ([Ca(2+)](i)) in resting platelets. Earlier studies demonstrated that platelet activation by thrombin results in tyrosine phosphorylation of PMCA, which inhibits pump activity. OBJECTIVES: The objective was to determine the functional consequences of PMCA tyrosine phosphorylation. METHODS: A decapeptide including the tyrosine phosphorylation site of PMCA and a scrambled version were synthesized and introduced into human platelets using saponin. Fura-2 calcium monitoring and aggregometry were used to characterize the effects of inhibition of tyrosine phosphorylation. RESULTS: Western blot analysis of immunoprecipitates showed that introduction of the inhibitory peptide decreased tyrosine phosphorylation of PMCA by nearly 60% in saponin-permeabilized, thrombin-treated platelets as compared with the scrambled control peptide. Concomitant with inhibition of PMCA tyrosine phosphorylation was a significant decrease in [Ca(2+)](i) during thrombin-mediated platelet activation. The functional consequence of reduced PMCA tyrosine phosphorylation and decreased [Ca(2+)](i) was a significant delay in the onset of thrombin-mediated platelet aggregation. CONCLUSIONS: The results demonstrate that PMCA tyrosine phosphorylation regulates [Ca(2+)](i) during platelet activation, which affects downstream events in the activation process. Moreover, PMCA tyrosine phosphorylation and resultant inhibition of PMCA activity produces a positive feedback loop mechanism by enhancing the increase in [Ca(2+)](i) accompanying platelet activation.     

Effect of inhibition of the electrogenic Na+/K+ pump on the mechanical activity in the rat uterus

Summary— The effects of ouabain and K⁺-free solution were studied in estrogen-primed rat uterine strips under resting tone or repeatedly stimulated with KCl, acetylcholine or oxytocin applied for 20 minutes at 60 minute intervals. These effects were compared with those of the K⁺ channel opener cromakalim. In preparations under resting tone, ouabain (0.1 mM and 0.3 mM) induced rhythmic contractions which disappeared after 20–30 minutes whereas at a higher concentration (1 mM) it evoked a rapid, phasic response followed by a small tonic contraction. Exposure of the strip to a K⁺-free solution induced either rhythmic waves, which ceased after 8–10 minutes, or a single phasic contraction which was followed by a small and slow increase in the resting tone (54 ± 10 mg after 180 min exposure). Nifedipine (0.3 μM) abolished the rhythmic or phasic component of these responses but failed to modify the late small tonic contraction induced by ouabain 1 mM or by K⁺-free solution. Ouabain (0.1–1 mM) or K⁺-free-evoked responses disappeared after short (4 min) or prolonged (60 min) exposure to a Ca²⁺-free, 3 mM EGTA-containing solution. Cromakalim (10 nM ?0.1 mM) did not induce any variation in the resting tone either in the presence or in the absence of Ca²⁺ in the medium. In strips repeatedly stimulated with acetylcholine (0.1 mM) or oxytocin (1 μM), ouabain (0.3 mM), K⁺-free-solution and cromakalim (10 μM) reduced the amplitude of the initial, phasic response and progressively decreased the oscillatory component of the response to these agonists. Conversely, the successive responses evoked by KCl 60 mM in similar experimental conditions were not affected by ouabain or cromakalim. Ouabain (0.3 mM), K⁺-free solution and cromakalim (10 μM) decreased the Ca²⁺-independent, maintained contractions induced by acetylcholine or oxytocin after prolonged exposure to a Ca²⁺-free, EGTA-containing medium. These inhibitory effects were partially or completely reversed in the presence of the non-selective potassium channel blocker tetraethylammonium (10 mM) or in a Ca²⁺-free solution containing 60 mM K⁺. In conclusion, these results suggest that the response induced by ouabain or K⁺-free solution in estrogen-primed rat myometrium involves Ca²⁺ influx through potential-operated calcium channels but not Ca²⁺ release from intracellular stores. In addition, our results show that prolonged exposure to ouabain or K⁺-free medium decreases membrane receptor-mediated responses in rat uterus. This inhibitory effect seems to be the result, at least in part, of a decrease in the cytosolic level of K⁺, due to the inhibition of the electrogenic Na⁺ pump.     

Erythrocyte Na+-H+ exchanger and Na+-Li+ countertransport activity in primary aldosteronism

Abstract. Several authors have described increased Na-H exchanger activity in essential hypertension but no data are available in secondary forms of hypertension such as primary aldosteronism. We measured Na-H exchanger kinetics together with Na-Li countertransport V _max in the erythrocytes of eight patients with primary aldosteronism and in 15 normotensive control subjects. Plasma aldosterone, plasma renin and plasma potassium were also evaluated. Na-H exchanger V _max appear to be increased in patients with primary aldosteronism and Hill's n , an index of co-operativity amongst intracellular proton binding sites, was significantly lower in patients than in controls. No statistically significant differences were found between affinity for intracellular protons (K50%) and for Na-Li countertransport V _max between the two groups studied. We were unable to find any correlations between Na-H exchanger V _max and Na-Li countertransport V _max in the two groups considered as a whole. From the present data Na-H exchanger overactivity would not appear to be a specific feature of essential hypertension but seems to be characteristic in patients with primary aldosteronism.     

Erythrocyte Li+/Na+ and Na+/H+ exchange, cardiac anatomy and function in insulin-dependent diabetics

It has been proposed that an increased activity of cell membrane Na+/H+ exchange, mirrored by increased erythrocyte Li+/Na+ exchange, may facilitate cell hypertrophy and hyperplasia. Patients with insulin-dependent diabetes mellitus may develop a specific cardiomyopathy with systolic and diastolic abnormalities and increased thickness of the left ventricle. Therefore, we have investigated the relationships between erythrocyte Li+/Na+ and Na+/H+ exchange and echocardiographic parameters in 31 male insulin-dependent diabetics (aged 17-68), in good metabolic control. Three had untreated mild hypertension. In all patients the urinary albumin excretion rate was less than 200 micrograms min-1. Ten patients had a Li+/Na+ countertransport higher than 0.37 mmol l-1 cell h-1, the upper normal limit for our laboratory (0.49 +/- 0.10, mean +/- SD). In comparison with the patients with normal countertransport, they had increased interventricular septum thickness and relative wall thickness (h/r). End diastolic volume and cardiac index were reduced while blood pressure and urinary albumin excretion rate were similar. In the whole study group, interventricular septum thickness was significantly correlated to Li+/Na+ exchange (r = 0.61, P less than 0.001) and Na+/H+ exchange (r = 0.35, P less than 0.05), independently of the effect of age and blood pressure. Posterior wall thickness was correlated to Li+/Na+ exchange (r = 0.38, P less than 0.05) and h/r to Li+/Na+ exchange (r = 0.41, P less than 0.05) and to Na+/H+ exchange (r = 0.44, P less than 0.05). Li+/Na+ exchange was negatively correlated to cardiac index (r = -0.37, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

二氮嗪对移植鼠心不同时期心肌组织ATP酶活性的作用

目的探讨二氮嗪对移植鼠心在术后不同时期心肌细胞膜Na^＋-K^＋-ATPase和肌浆网Ca^2＋-ATPase活性的变化及其对心肌缺血再灌注损伤的作用。方法采用改良Heron法大鼠颈部异位心脏移植模型。sD雄性大鼠随机分为实验组、对照组和拮抗组，并在术后不同时间（5min、1周、3个月）留取标本，检测心肌细胞膜Na^＋-K^＋-ATPase和肌浆网Ca^2＋-ATPase活性，及观察心肌超微结构。结果（1）实验Ⅰ、Ⅱ组心肌细胞膜Na^＋-K^＋-ATPase和肌浆网Ca^2＋-ATPase活性均显著高于相应对照Ⅰ、Ⅱ组（P〈0．05）；实验组中Ⅰ、Ⅱ、Ⅲ组心肌细胞膜Na^＋-K^＋-ATPase活性增高呈递减性显著性减弱（P〈0．05），实验Ⅰ组肌浆网Ca^2＋-ATPase活性显著高于实验Ⅱ、Ⅲ组；余差异无显著性。（2）拮抗组取消实验组DE的这一增高作用。（3）中长期各组均有良好的心肌超微结构保护，肌节清，线粒体肿胀不明显，嵴结构尚清楚，排列整齐；仅Ⅲ组偶有空泡变性。结论二氮嗪对移植鼠心长期冷缺血保存后，有更好的保存和提高细胞膜Na^＋-K^＋-ATPase和肌浆网Ca^2＋-ATPase的活性，减轻心肌缺血再灌注损伤，维持心肌能量代谢有效地进行来发挥心肌保护作用。     

人骨髓基质细胞协同外源性细胞因子对脐血CD34+细胞的体外扩增作用

目的探讨人骨髓基质细胞(hBMSC)协同以干细胞因子和FL为主的细胞因子对脐血CD34+细胞的体外扩增作用.方法采用免疫磁珠法分选脐血CD34+细胞,以SCF+IL-3+IL-6+FL+EPO组合高效扩增CD34+细胞[1],并结合该细胞因子组合接种到预先照射(20Gy)的hBMSC上,d10结束培养,收获细胞分别作细胞计数、集落培养和流式细胞术检测CD34+细胞数.结果本法获得的脐血CD34+细胞纯度较高(92±0.04)%,在hBMSC组培养的d2,造血细胞几乎都粘附到hBMSC上,随着培养时间的延长,CD34+细胞比例不断下降.hBMSC组与无hBMSC组相比,除细胞总数扩增倍数外,CFU-GM、BFU-E、CD34+细胞扩增倍数差异有显著性意义(P<0.05).结论①脐血来源的CD34+细胞粘附于滋养层上形成造血灶,且10d后造血细胞仍具有体外集落形成能力,表明骨髓基质细胞可支持并维系体外造血;②hBMSC协同外源性细胞因子可能是扩增造血干/祖细胞的较理想方案.     

Erythrocyte Na+–H+ exchanger kinetics and Na+–Li+ countertransport activity in essential hypertensive patients

The authors measured Na⁺–H⁺ exchanger kinetics together with Na⁺–Li⁺ countertransport V _max in the erythrocytes of 21 subjects with essential hypertension and 16 normotensive control subjects. Na⁺–H⁺ exchanger V _max appeared to be increased in patients with essential hypertension, while the Na⁺–H⁺ exchanger affinity for intracellular proton sites ( K _50%) proved to be unchanged and the index of cooperativity among intracellular proton binding sites as measured by Hill's coefficient (Hill's n ) decreased as compared with normotensive control subjects. Na⁺–Li⁺ countertransport V _max appeared to be higher in patients with essential hypertension than in control subjects. The authors were unable to find any correlations between Na⁺–H⁺ exchanger kinetic parameters and metabolic variables such as parameters of insulin resistance and plasma lipids. On the basis of the data obtained, erythrocyte Na⁺–H⁺ exchanger activity was found to be abnormal in two kinetic variables in essential hypertensive patients and showed no simple linear correlations with the main variables of glucose metabolism, plasma lipids, renin or aldosterone.