东莨菪碱对兔脑缺血再灌注Na+-K+-ATPase活性的影响

目的：观察再灌注损伤时脑组织Ｎａ＾＋－Ｋ＾＋－ＡＴＰａｓｅ活性的发迹及东莨菪碱对缺血再灌注脑组织Ｎａ＾＋－Ｋ＾＋－ＡＴＰａｓｅ活性的影响。方法：以选择性头部低温为阳性对照。通过低压低灌法造成完全性脑缺血模型。将３０只兔分为：假手术组,缺血组,缺血再灌注组,低温治疗组,东莨菪碱治疗组,东莨菪碱低温治疗组,结果：脑组织Ｎａ＾＋－Ｋ＾＋－ＡＴＰａｓｅ活性以Ⅲ组最低;Ⅱ、Ⅳ、Ⅴ、Ⅵ组的Ｎａ＾＋－Ｋ＾＋＝Ａ     

兔大脑缺血再灌流新模型

本文报道了兔大脑缺血再灌流新模型。方法为结扎双侧椎动脉(VA),同时可逆性阻断双侧颈内动脉(ICA)和双侧颈外动脉(ECA),即6-动脉阻断(6AO),60分钟后复流双侧ICA和ECA 120分钟。实验结果显示,脑电活动明显受抑制,脑组织含水量增加至80.41±0.82%,对照组78.13±0.53%((?)±SD),P<0.01。超微结构提示在缺血60分钟时有细胞毒性脑水肿存在,当再灌流120分钟时,细胞毒性和血管源性脑水肿同时存在。与传统的双侧VA和和颈总动脉(CCA)阻断(4AO)模型比较,6AO造成的再灌流损伤较4AO方法更为严重,且不必同时降低全身血压,避免了低血压造成其他重要脏器损伤的可能性。     

磁共振扩散加权成像对兔脑缺血再灌注伤的评价

目的探讨兔脑缺血再灌注后磁共振扩散加权成像（DWI）的特点。方法将成年新西兰兔用线栓法建立兔大脑中动脉闭塞再灌注（MCAO／R）模型,再将成功的兔MCAO／R模型随机分为永久性缺血组和缺血再灌注组;另取同样动物行假手术分别作为缺血组及再灌注组的对照组;观察不同时间DWI像上高信号区范围变化及表观扩散系数（ADC）的演变特点。结果1．缺血组：缺血1h可见到DWI像上明显的高信号伴ADC值的下降,缺血不同时间点DWI像上的高信号区较缺血1h均有增大,24h后趋于稳定。缺血组不同时间点平均ADC值呈先下降后上升的趋势。2．再灌注组：与再灌注前相比,再灌注2h、5h组均表现为DWI像上高信号区缩小及ADC值升高;再灌注11h组表现为高信号范围增大伴ADC值升高;再灌注23h、47h组表现为高信号范围增大而ADC值出现较明显下降。结论急性脑缺血后DWI像高信号区及ADC值的下降经早期再灌注后可明显改善,但持续再灌注可能导致ADC值再次下降。     

旱黑口服液对衰老小鼠心、脑细胞膜Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性的影响

目的观察旱黑口服液对D-gal衰老小鼠心肌细胞膜、脑细胞膜上Na -K -ATP,ase、Ca2 -Mg2 -ATPase活性的影响,探讨旱黑口服液在延缓衰老方面的效应机制。方法以D-gal致亚急性衰老小鼠为模型,同时给予旱黑口服液治疗,6周后测定心、脑细胞膜上Na -K -ATPase、Ca2 -ATPase活性。结果与空白组比较,衰老组心、脑细胞膜上Na -K -ATPase、Ca2 -Mg2 -ATPase活性降低,经旱黑口服液治疗后心、脑细胞膜上Na -K -ATPase、Ca2 -Mg2 -ATPase活性活性明显提高。结论旱黑口服液具有提高D-gal致衰老小鼠心、脑细胞膜上Na -K -ATPase、Ca2 -Mg2 -ATPase活性,延缓衰老的作用。     

兔全脑缺血及再灌注对脊髓酶组织化学的影响

短暂性脑缺血发作(TIA)在临床上较为多见,严重危害人类的健康,降低了人们的生活质量。为探讨全脑短暂性缺血,尤其是椎基底动脉系短暂性缺血发作(VBTIA),对脊髓灰质酶组织化学的影响,探索VB TIA与脊髓损伤(spinal cord injury,SCI)之间的联系,本实验用酶组织化学方法作了研究。     

高频喷射通气治疗PE-SWD兔血气和Na+-K+-ATPase图像分析定量研究

为了探讨高频喷射通气（HFJV）治疗海水淹溺肺水肿（PE－SWD）的作用机理,采用全自动血气酸碱分析仪和计算机图像分析系统,对海水淹溺肺水肿组（PE－SWD－G）、高频喷射通气组（HFJV－G）和正常对照组（Con－trolgropu,CG）兔PaO2、p8CO2、血氧饱和度（SSO2）和兔肺内N －K －ATPase进行自动检测和定量分析。结果表明,PE－SWD经HFJV治疗100min后,HFJV－G中的PaO2、SaO2和肺毛细血管内皮细胞中Na －K －ATPase活性比PE－SWD－G明显升高（P＜0．01或P＜0．05）,并且HFJV－G中Na －K －ATPase的3项参数（D1、D2和G6）几乎恢复到接近CG水平。HFJV－G兔PaO2和SaO2的升高与肺内Na －K －ATPase活性的恢复密切相关。HFJV对PESWD的治疗,关键在于能较好地纠正低氧血症,因而对肺内Na －K －ATPase的恢复有明显的促进作用。     

NGF对兔脑缺血／再灌注损伤半胱氨酸蛋白酶-12的影响

目的探讨神经生长因子(NGF)对兔脑缺血/再灌注损伤半胱氨酸蛋白酶-12(caspase-12)的影响。方法健康雄性新西兰大白兔26只,随机分成假手术组(Sham组,n=6)、缺血/再灌注组(I/R组,n=10)和NGF治疗组(NGF组,n=10)。免疫组化方法检测组织caspase-12及caspase-3的表达;用流式细胞术(FCM)及DNA原位末端缺口标记法(TUNEL法)检测神经细胞凋亡。结果与Sham组相比,I/R组caspase-12及caspase-3表达增加(P<0.01),凋亡细胞数增加(P<0.01);而NGF处理后显著缓解caspase-12与caspase-3的表达增加及凋亡细胞数的增加(P<0.01),但仍高于Sham组。结论抑制caspase-12介导的caspase级联反应性凋亡途径的激活是NGF减少缺血/再灌注损伤细胞凋亡的机制之一。     

脑缺血再灌注对大鼠耳蜗形态学及听觉的影响

目的：为探讨脑缺血再灌注对大鼠耳蜗形态学及听觉的影响。方法：采用闭塞大鼠肮脏了缺血模型,观察了脑缺血３０分钟及再灌注不同时间大鼠耳蜗结构和听阈的动态变化,形态学观察应用光镜、扫描电镜与透射电镜,听力测定采用４０ＨＺ听上关电位（４０ＨＺＡＥＲＰ）技术。结果：缺血３０分钟和再灌注２小时、２４小时、７２小时４０ＨＺＡＥＲＰ反应阈与缺血前比较显著提高（Ｐ〈０．０１）,随或注延长听阈逐渐降低。病理变化特点是     

兔脑缺血再灌注磁共振弥散加权成像与水通道蛋白-4表达的相关性

目的 分析兔脑急性缺血组织磁共振弥散成像（DWI）的影像学表现及其与水通道蛋白-4（AQP-4）表达的关系,探讨DWI成像的病理生理基础。 方法 58只新西兰大白兔随机分为永久缺血组（A组）和再灌注组（B组）,线栓法制作大脑中动脉缺血和缺血1h后再灌注模型。其中A组（A₁~A₆）分为缺血1h、3h、6h、12h、24h、48h组;B组（B₁~B₆）又分为再灌注0h、2h、5h、11h、23h和47h组。每组分别于各自时间点进行MRI弥散成像,分别测量表观弥散系数（ADC）,并计算相对表观弥散系数（rADC）值。显微镜下观察并记录双侧大脑皮层和纹状体区AQP-4阳性细胞数。 结果 缺血1h时DWI高信号区内平均ADC值95％可信区间上限为58.75×10^－5 mm²/s。缺血组DWI高信号区面积随时间延长逐渐增大,rADC值呈先下降后上升的趋势。再灌注组rADC值于再灌注2h趋于正常化,DWI高信号区面积减小;5h rADC值最低;以后rADC值逐渐升高,DWI高信号区面积逐渐扩大。缺血组AQP-4阳性细胞数6h内呈下降趋势,6h后缓慢上升,与rADC值的变化关系密切（r＝.943,P=0.005）;再灌注5h内AQP-4变化平稳,之后也出现上升趋势。 结论 AQP-4表达水平的高低受缺血程度和持续时间的影响,永久缺血组rADC值的变化趋势与AQP-4表达水平的高低有明显的相关性。     

血压对大鼠脑缺血/再灌注损伤的影响

目的： 研究血压变化对大鼠脑缺血/再灌注模型的影响。方法: 44只SD大鼠随机分为低血压组、正常血压组、高血压组及尿激酶/高血压组,制作缺血2 h再灌注24 h脑缺血/再灌注损伤模型,再灌注起始分别应用降压药物或升压药物改变平均动脉压水平（约20 mmHg）持续1 h,观察其神经功能改善、梗死体积、出血性转化的发生。结果: 再灌注24 h,低血压组神经功能恶化,其它各组均有不同程度的恢复;随着血压的升高,大鼠脑梗死体积有逐渐减小的趋势;尿激酶/高血压组出血性转化发生率最高,其次为低血压组及高血压组,而正常血压组最低;尿激酶/高血压组梗死灶周围皮层区MMP-9阳性细胞计数与其它各组比较均有显著差异（P<0.05）。结论: 再灌注期间升高血压有利于脑缺血大鼠神经功能预后的改善。大鼠脑缺血再灌注模型出血性转化发生率随着血压的升高或降低均有增加的趋势,其发生可能与MMP-9的过量表达有关。     

Down-regulated Na+/K+-ATPase activity in ischemic penumbra after focal cerebral ischemia/reperfusion in rats

This study was aimed to examine whether the Na⁺/K⁺ adenosine triphosphatase (Na⁺/K⁺-ATPase) activity in ischemic penumbra is associated with the pathogenesis of ischemia/reperfusion-induced brain injury. An experimental model of cerebral ischemia/reperfusion was made by transient middle cerebral artery occlusion (tMCAO) in rats and the changes of Na⁺/K⁺-ATPase activity in the ischemic penumbra was examined by Enzyme Assay Kit. Extensive infarction was observed in the frontal and parietal cortical and subcortical areas at 6 h, 24 h, 48 h, 3 d and 7 d after tMCAO. Enzyme Assay analyses revealed the activity of Na⁺/K⁺-ATPase was decreased in the ischemic penumbra of model rats after focal cerebral ischemia/reperfusion compared with sham-operated rats, and reduced to its minimum at 48 h, while the infarct volume was enlarged gradually. In addition, accompanied by increased brain water content, apoptosis-related bcl-2 and Bax proteins, apoptotic index and neurologic deficits Longa scores, but fluctuated the ratio of bcl-2/Bax. Correlation analysis showed that the infarct volume, apoptotic index, neurologic deficits Longa scores and brain water content were negatively related with Na⁺/K⁺-ATPase activity, while the ratio of bcl-2/Bax was positively related with Na⁺/K⁺-ATPase activity. Our results suggest that down-regulated Na⁺/K⁺-ATPase activity in ischemic penumbra might be involved in the pathogenesis of cerebral ischemia/reperfusion injury presumably through the imbalance ratio of bcl-2/Bax and neuronal apoptosis, and identify novel target for neuroprotective therapeutic intervention in cerebral ischemic disease.     

家兔急性不完全性脑缺血及重灌流的实验研究

采用低压低灌流方法造成家兔急性不完全性脑缺血60分钟,缺血后进行重灌流。检测了脑电图(EEG)、心输出量、平均动脉血压及脑静脉血乳酸脱氢酶(LDH)、磷酸肌酸激酶(CPK)活性以及大脑皮质水、钠、钾及环核苷酸含量,观察组织形态学改变。实验结果表明通过低压低灌流成功地复制了兔急性不完全性脑缺血模型。其特点为EEG严重抑制、大脑皮质水、钠含量升高、LDH及CPK活性显著升高。并见脑组织出现脑水肿改变。重灌流期间EEG先有所恢复后严重抑制,LDH及CPK活性仍显著升高。大脑皮质cAMP含量进一步升高,水肿程度加重。组织形态学呈现明显的缺血性损伤尤以亚微结构更为严重,表明重灌流后组织损伤加重。作者分析了上述改变发生的可能机制。     

Sarcolemmal Na+-K+-ATPase activity in diabetic rat heart

Heart sarcolemmal membranes were isolated by the hypotonic shock-LiBr treatment from rats with chronic diabetes induced by a streptozotocin (65 mg/kg, iv) injection. Sarcolemmal Mg2+-dependent ATPase activity was elevated, whereas 5'-nucleotidase and K+-p-nitrophenylphosphatase activities in diabetic heart were depressed in comparison to control preparations. Although patent Na+-K+-ATPase and patent ouabain-sensitive Na+-K+-ATPase activities were unaltered, latent Na+-K+-ATPase activities, as determined in membranes after alamethicin or deoxycholate treatments, were found to be significantly depressed in diabetic animals. A depression in the latent Na+-K+-ATPase activity in diabetic preparations was also observed in membranes prepared by the sucrose density gradient method. Insulin-treated diabetic rats were observed to have normalized latent Na+-K+-ATPase activities. Total phospholipid content did not differ, but cholesterol content of the sarcolemmal membranes was significantly increased in diabetic heart preparations. Sarcolemmal Na+-K+-ATPase activity in diabetic heart was more resistant to treatments with filipin, an agent known to bind with cholesterol residues. These results suggest that chronic experimental diabetes is associated with some defects in sarcolemmal enzymatic activities and composition.     

Effects of fatty acid intermediates on Na+-K+-ATPase activity of cardiac sarcolemma

The effect of amphiphilic lipid intermediates on the Na+-stimulatable activity of the Na+-K+-ATPase of sarcolemma from adult canine cardiac myocytes was studied. Sarcolemma (mean Na+-stimulatable ATPase activity of 73 mumol.mg sarcolemmal protein-1.h-1) was preincubated (37 degrees C for 10 min at pH 7.2) or rapidly mixed at 0 degrees C with amphiphilic lipid intermediates prior to dilution and assay of enzyme activity. Their effects were dependent on temperature, initial concentration, and the ratio of bound amphiphile to sarcolemmal protein. In particular, pretreatment of freshly prepared sarcolemma at 0 degrees C with arachidonyl CoA (up to 0.25 mM) caused 110% stimulation above control activity; palmitoyl CoA or palmitoyl carnitine under the same conditions caused no significant effect. Despite strong binding to the sarcolemmal vesicles, palmitoyl carnitine (up to 0.4 mM or 5 mumol/mg protein) and palmitoyl CoA (0.1 mM or 1.0 mumol of membrane-bound palmitoyl CoA/mg protein) were ineffective even with preincubation. Palmitoyl CoA was inhibitory above this level. Preincubation (22 degrees C for 10 min) with lysophosphatidylcholine only produced inhibition (40% at 0.75 mM). Thus fatty acyl thioesters of CoA and lysophosphatidyl choline but not palmitoyl carnitine perturb sarcolemmal Na+-K+-ATPase activity.     

Decreased myocardial Na+-K+-ATPase activity in one-kidney, one-clip hypertensive rats

We have previously shown that Na+-K+ pump activity (ouabain-sensitive 86Rb uptake) is decreased in vascular tissue of animals with various forms of low renin hypertension. In the present study we measured Na+-K+-ATPase activity, the energy source for Na+-K+ pumping, in membrane fractions prepared from myocardial tissue of rats with chronic one-kidney, one-clip hypertension and their one-kidney normotensive controls. Membranes were prepared by two independent methods: microsomal fractions (method 1) and fractions prepared by the hypotonic LiBr method of Dhalla et al. (method 2). In membranes prepared from left ventricles of the hypertensive rats (by method 1) Na+-K+-ATPase activity was decreased, Mg2+-ATPase activity was increased, and the sialic acid content and 5'-nucleotidase activity (two putative membrane markers) were unchanged relative to the control rats. The sensitivity of cardiac Na+-K+-ATPase to inhibition by ouabain was also unchanged. Na+-K+-ATPase activity was also decreased in the right ventricles (method 1) of these hypertensive rats, suggesting that this defect is probably not pressure related. In membranes prepared from the left ventricles of the hypertensive rats by method 2, Na+-K+-ATPase activity was again reduced, whereas the Mg2+-ATPase and 5'-nucleotidase activities were unchanged relative to the controls. These studies suggest that myocardial Na+-K+-ATPase activity is suppressed in rats with this low renin form of hypertension and the possible effect of this suppression on myocardial contractile activity is discussed.     

大鼠脑缺血及再灌流对脑组织血流量、ATP和乳酸水平含量的影响

目的和方法：本研究采用大鼠可逆性阻塞大脑中动脉所致的局灶性脑缺血再灌流模型，观察缺血３ｈ再灌流３ｈ、缺血６ｈ再灌流３ｈ对脑组织脑局部血流量（ｒｅｇｉｏｎａｌｃｅｒｅｂｒａｌｂｌｏｏｄｆｌｏｗ，ｒＣＢＦ）、ＡＴＰ、乳酸及脑水含量的影响。结果：缺血３ｈｒＣＢＦ明显下降（Ｐ＜００１），再灌流３ｈ升至缺血前６５３％（Ｐ＜００１）。缺血３ｈ再灌流３ｈ与缺血６ｈ组比较，ＡＴＰ明显恢复（Ｐ＜００１），乳酸含量明显下降（Ｐ＜００１），脑水含量明显减少（Ｐ＜００５）。缺血６ｈ再灌流３ｈ与缺血９ｈ组比较，尽管ＡＴＰ明显恢复（Ｐ＜００１），乳酸含量下降（Ｐ＜００１），但脑水含量无显著差异（Ｐ＞０１）。结论：缺血３ｈ再灌流３ｈ保护“半暗带”的效果优于缺血６ｈ再灌流３ｈ。     

粉防己碱对大鼠急性全脑缺血再灌注损伤的影响

目的：研究粉防己碱对大鼠急性全脑缺血再灌注时脑血流量的影响。方法：采用改良的大鼠四血管（双侧颈总和锁骨下动脉）结扎法，复制大鼠急性全脑缺血（３０ｍｉｎ）再灌注（５ｍｉｎ，６０ｍｉｎ）损伤模型。结果：粉防己碱能明显增加脑血流量，减少钙积累，减轻脑水肿。结论：粉防己碱对大鼠急性全脑缺血再灌注时神经原有较好的保护作用。