首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
目的 探讨丙泊酚对大鼠前脑缺血/再灌注(ischemia reprfnsion,I/R)诱导线粒体损伤及解耦联蛋白2(uncoupling protein 2,UCP 2)表达的影响.方法 45只健康雄性Wistar大鼠,体重250 g~300 g,按随机数字表法分为3组(n=15).采用二血管阻断法制备大鼠前脑I/R损伤模型.假手术组(C组):暴露双侧颈总动脉后,侧脑室注射生理盐水1 mg/kg;缺血/再灌注(I/R组):脑缺血后侧脑室注射生理盐水1 mg/kg;丙泊酚干预组(P组):脑缺血后侧脑室注射丙泊酚1 mg/kg.各组分别于再灌注后24 h断头取海马组织,提取海马组织线粒体,加入CaCl2于37℃下孵育5 min.透射电镜下观察线粒体形态学改变(n=3);紫外分光光度计法检测线粒体通透性转换孔(mitochondrial permeability transition pore,MPTP)活性(n=6);Western blotting法检测解耦联蛋白2的表达(n=6).结果 电镜下C组线粒体结构完整,I/R组可见线粒体显著肿胀、嵴断裂、膜破裂,P组损伤程度轻于I/R组.C组、I/R组和P组线粒体吸光度值均下降;与C组相比,I/R组和P组线粒体吸光度值明显下降(p<0.05);与I/R组(0.028±0.007)相比,P组(0.017±0.007)吸光度值下降幅度减小(P<0.05).与C组(0.62±0.05)相比,I/R组(0.88±0.14)和P组(1.32± 0.10)UCP2蛋白表达上调(P<0.05);P组UCP2蛋白表达高于I/R组(P<0.05).结论 丙泊酚能够改善大鼠前脑t/R后线粒体形态,促进神经细胞线粒体UCP2表达上调,抑制线粒体经ca2+诱导后MPTP开放,从而改善线粒体功能,这可能是丙泊酚减轻脑I/R损伤的机制之一.  相似文献   

2.
This prospective randomised controlled study evaluated the effects of postoperative sedation with propofol and midazolam on pancreatic function. We studied 42 intensive care unit patients undergoing elective major surgery who were expected to be sedated postoperatively. Patients were randomly assigned to a propofol group (n = 21) or a midazolam group (n = 21). To assess pancreatic function, the following parameters were measured: pancreatitis-associated protein, amylase, lipase, cholesterol and triglyceride prior to start of sedation on the intensive care unit, 4 h after the sedation was started and at the first postoperative day. Patients in the propofol group received on average (SD) 1292 (430) mg propofol and were sedated for 9.03 (4.26) h. The midazolam group received 92 (36) mg midazolam and were sedated for 8.81 (4.68) h. Plasma cholesterol concentrations did not differ significantly between groups. Triglyceride plasma levels 4 h after the start of infusion were significantly higher in the propofol group (140 (54) mg.dl(-1)) than the midazolam-treated patients (81 (29) mg.dl(-1)), but were within normal limits. There were no significant differences between the two groups regarding amylase, lipase and pancreatitis-associated protein plasma concentrations at any time. No markers of pancreatic dysfunction were outside the normal range. We conclude that postoperative sedation with propofol induced a significant increase of serum triglyceride levels but that pancreatic function is unchanged with standard doses of propofol.  相似文献   

3.
The effects of propofol 2 mg/kg, methohexital 2 mg/kg or midazolam 0.3 mg/kg were studied on the QT interval of the ECG corrected by the heart rate (QTc), heart rate and arterial pressure during induction of anaesthesia in 87 ASA class I-(II)-patients. The patients were randomly allocated to one of the three anaesthetic groups. The incidence of the patients with a prolonged QTc interval (= more than 440 ms) ranged from 29 to 41% between the groups. In each group these patients were treated separately. After all anaesthetics, the QTc interval was significantly prolonged in the patients with a normal control QTc interval, whereas in the patients with a prolonged control QTc interval, it tended to be shortened both after propofol and methohexital and it was significantly shortened after midazolam. After injection of suxamethonium, no significant QTc interval changes occurred in the patients with a normal control QTc interval in either the propofol or the methohexital groups, whereas in the patients with a prolonged control QTc interval treated with propofol the QTc interval decreased significantly 60 s after suxamethonium when compared with the corresponding preceding values. The mean values in the propofol group in the patients with a normal control QTc interval were always below the upper limit of the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

4.
脑缺血再灌注后脑损伤的发病机制较复杂,其所致病理损伤包括细胞坏死和凋亡。细胞凋亡与脑缺血再灌注损伤关系密切,是神经元迟发性死亡的主要形式。研究提示与凋亡密切相关的Bcl-2、Caspase-3蛋白等参与了这种迟发性死亡,它们表达的量决定了细胞的生存。本实验采用流式细胞仪、  相似文献   

5.
AIM: Interaction with the gamma-aminobutyric acid receptor (GABA(A)R) complex is recognized as an important component of the mechanism of many anaesthetic agents, including propofol. The aims of this study were to investigate the effect of propofol on GABA(A)R, to determine whether exposure of neurones to propofol influences the localization of GABA(A)R within the cell and to look for cytoskeletal changes that may be connected with activation, such as the mitogen-activated protein kinase (MAPK) pathway. METHODS: Primary cortical cell cultures from rat, with and without pre-incubation with the GABA(A)R antagonist bicuculline, were exposed to propofol. The cells were lysed and separated into membrane and cytosolic fractions. Immunoblot analyses of filamentous actin (F-actin), the GABA(A)beta(2)-subunit receptor and extracellular signal-regulated kinase-1/2 (ERK-1/2) were performed. RESULTS: Propofol triggers an increase in GABA(A)R, actin content and ERK-1/2 phosphorylation in the cytosolic fraction. In the membrane fraction, there is a decrease in GABA(A)beta(2)-subunit content and an increase in both actin content and ERK-1/2 phosphorylation. The GABA(A)R antagonist bicuculline blocks the propofol-induced changes in F-actin, ERK and GABA(A)beta(2)-subunit content, and ERK-1/2 phosphorylation. CONCLUSION: We believe that propofol triggers a dose-dependent internalization of the GABA(A)beta(2)-subunit. The increase in internal GABA(A)beta(2)-subunit content exhibits a close relationship to actin polymerization and to an increase in ERK-1/2 activation. Actin contributes to the internalization sequestering of the GABA(A)beta(2)-subunit.  相似文献   

6.
BACKGROUND: Non-competitive N-methyl-D-aspartate (NMDA) receptor antagonists, including ketamine, have psychotomimetic activities and cause neuronal damage in the posterior cingulate and retrosplenial cortices (PC/RS), which are suggested to be the brain regions responsible for their psychotomimetic activities. We previously demonstrated that ketamine induced marked c-Fos (c-fos protein) expression in the rat PC/RS, which was inhibited by propofol, and the expression was closely related to ketamine-induced abnormal behavior. In the present study, we investigated whether the inhibition by propofol was mediated by GABAA receptor receptor activation. METHODS: Using Wistar rats, propofol alone, propofol with bicuculline or propofol with flumazenil was injected intravenously and then continuously infused. Fifteen minutes later, 100 mg kg-1 of ketamine or normal saline was injected intraperitoneally. Two hours after the ketamine or saline injection, the brain was extracted and brain sections were prepared, and c-Fos expression was detected using immunohistochemical methods. RESULTS: Ketamine induced marked c-Fos expression in the PC/RS (171 +/- 9/0.4 mm2), which was significantly inhibited by propofol (5 +/- 5/0.4 mm2). The inhibition by propofol was disinhibited dose-dependently by both bicuculline (0.5 and 1.0 mg kg-1 bicuculline groups: 46 +/- 15 and 143 +/- 16, respectively) and flumazenil (0.1 and 1.0 mg kg-1 flumazenil groups: 79 +/- 6 and 130 +/- 15, respectively). CONCLUSION: These results demonstrate that the inhibitory effect of propofol on ketamine-induced c-Fos expression in the PC/RS is mediated by GABAA receptor activation, and suggests that ketamine-induced psychoneuronal adverse effects may be suppressed by propofol via the activation of GABAA receptors.  相似文献   

7.
目的 观察异丙酚、咪唑安定和硫喷妥钠对鼠局灶脑缺血/再灌注后的神经功能和病理结果的影响。方法 雄性SD大鼠,采用可逆性大脑中动脉内线栓法诱发局灶脑缺血。缺血3h,再灌注24h后,作神经功能缺陷评估,然后取脑,TTC染色,用Image软件系统作图像分析,计算脑梗塞和脑水肿容积,电镜下观察梗塞边缘组织的细胞超微结构。动物分五组:缺血组、再灌注组、用药组(异丙酚、咪唑定安和硫喷妥钠)结果 异丙酚和咪唑安定明显改善鼠神经功能缺陷程度,降低脑梗塞和脑水肿容积,并减少梗塞边缘组织细胞死亡。异丙酚的脑保护效应强于咪唑安定。结论 异丙酚和咪唑安定有拮抗鼠局灶脑缺血/再灌注损伤的作用。  相似文献   

8.
目的观察异丙酚、咪唑安定和硫喷妥钠对鼠局灶脑缺血/再灌注后缺血部位氨基酸类神经递质含量的影响.方法采用大脑中动脉(MCA)内线栓法诱发局灶脑缺血.雄性SD大鼠随机分为5组,每组6~7只.缺血组仅经历3 h MCA阻塞;再灌注组经历3 h MCA阻塞和3 h再灌注;三个用药组于再灌注前即刻分别腹腔内注射异丙酚、咪唑安定和硫喷妥钠50 mg@kg-1,再灌注3h后,处死鼠,迅速取脑,用高效液相色谱法测脑组织兴奋性氨基酸类含量.结果异丙酚、咪唑安定明显减少再灌注期缺血部位门冬氨酸、谷氨酸堆积;异丙酚增强,而咪唑安定减小GABA堆积;硫喷妥钠无明显作用.结论异丙酚和咪唑安定可能通过加快再灌注期兴奋性氨基酸的清除而产生脑保护效应.  相似文献   

9.
目的 观察异丙酚和地西泮对氯胺酮诱导的大鼠大脑皮质Glu(谷氨酸)释放和c-fos基因表达的影响,探讨异丙酚抑制氯胺酮中枢神经系统副作用的基因机制。方法 将28只Wistar大鼠随机分为生理盐水3 ml-生理盐水1 ml组,生理盐水3 ml-氯胺酮 100 mg/kg组,异丙酚100 mg/kg-氯胺酮100 mg/kg组,地西泮10 mg/kg-氯胺酮:100 mg/kg组。于用药后30 min,检测c-fos mRNA水平。另取大鼠,用药注射后2 h取大脑皮质检测Glu含量、组织含水量和Fos蛋白阳性细胞率。结果 氯胺酮注射后30 min引起大脑皮质c-fos mRNA表达增高,2 h时大脑皮质Glu、水含量和Fos阳性细胞率与生理盐水组相比增加(P<0.01)。异丙酚和地西泮预处理抑制了c-fos基因表达以及组织谷氨酸、水含量的增加,且抑制程度不同。结论 c-fos基因参与了异丙酚和地西泮抑制氯胺酮引起的精神症状和神经元损害的基因机制;异丙酚抑制作用强于地西泮。  相似文献   

10.
The effect of nitrous oxide on myogenic motor evoked potentials(MEPs) after multipulse stimulation is controversial. We investigatedthe effects of propofol in this paradigm. MEPs were elicitedelectrically by a single pulse and by trains of three and fivepulses in rabbits anaesthetized with ketamine and fentanyl.Nitrous oxide 30–70% was given and MEPs were recorded.After washout of nitrous oxide, propofol was given as a bolusof 10 mg kg1 followed by 0.8 (n=9) or 1.6 mg kg1 min1(n=8) as a continuous infusion. Nitrous oxide was then readministeredand MEPs were recorded. Without propofol, nitrous oxide significantlyreduced the amplitude of MEPs dose-dependently, but this effectwas reversed by multipulse stimulation. Administration of low-dosepropofol enhanced nitrous oxide-induced suppression, and thiseffect was reversed by five-pulse stimulation. However, high-dosepropofol produced a greater increase in suppression, such thateven five-pulse stimulation did not overcome the suppression.The results suggest that the degree of reversal of nitrous oxide-inducedMEP suppression produced by multipulse stimulation is affectedby the administration of propofol. Br J Anaesth 2001; 86: 395–402  相似文献   

11.
不同干预措施对大鼠体外循环后急性肺损伤的影响   总被引:1,自引:0,他引:1  
目的观察异丙酚、咪达唑仑及吡咯烷二硫代氨基甲酸酯(PDTC)对大鼠体外循环(CPB)后急性肺损伤(ALI)的影响。方法成年SD大鼠26只,随机分4组:咪达唑仑组(CPBMZ组)、咪达唑仑 PDTC组(CPBPDTC组)、异丙酚组(CPBPROP组)和假手术组(Sham组),Sham组不实施CPB。CPBPROP组腹腔注射异丙酚、芬太尼行麻醉诱导,其它三组腹腔注射咪达唑仑、芬太尼行麻醉诱导, CPBPDTC组转流前30 min腹腔注射PDTC 100 mg·kg-1。CPB转流量为100 ml·kg-1·min-1,转流时间60 min。分别于转流前(T1)、转流结束时(T2)及停转流后60 min(T3)进行动脉血气分析,计算T1、T3时呼吸指数(RI),测定中性粒细胞(PMN)CD11b表达。CPB后60 min测定支气管肺泡灌洗液(BALF)中PMN计数、IL-8及总蛋白浓度,取肺组织,进行病理学检查并测定丙二醛(MDA)含量。结果CPBMZ组T3时RI高于T1(P<0.01)。与CPBMZ组相比,其它三组BALF中PMN计数、IL-8浓度及肺组织MDA含量降低(P<0.05)。CPBMZ组肺组织炎症反应程度最重。各组间及组内PMN上CD11b表达比较差异无统计学意义(P>0.05)。结论异丙酚和PDTC能减轻CPB后ALI,其机制与抗氧化作用和抑制PMN肺内积聚有关。  相似文献   

12.
目的评价脑电图双频谱指数(BIS)、95%边缘频率(95%SEF)对异丙酚、咪唑安定或氯胺酮麻醉病人镇静深度监测的准确性。方法择期行胸、腹部手术病人45例,ASAⅠ或Ⅱ级,年龄30-59岁,随机分为3组:异丙酚组(P组)、咪唑安定组(M组)和氯胺酮组(K组),每组15例。P、M、K组分别以8、0.5、4mg·kg-1·h-1的速率静脉输注药物,每3min行进行警觉/镇静(OAA/S)评分一次,直到OAA/S评分达1分停止给药。记录每次评分即刻的BIS及95%SEF。分析BIS、95%SEF与OAA/S评分的相关性,计算病人意识消失时BIS50、95%SEF50、相应95%可信区间及BIS、95%SEF预测镇静深度的概率(Pk)。结果P、M组BIS、95%SEF与OAA/S评分间具有相关性,K组BIS和95%SEF与OAA/S评分间无相关性。P、M组BIS50分别为65.9、70.7,但是无法计算K组相应的BIS50和95%SEF50。P、M组BIS和95%SEF的Pk均高于0.5(P<0.01),K组BIS和95%SEF的Px与0.5比较差异无统计学意义(P>0.05);P组BIS及95%SE'的Pk均高于M组(P<0.05);P、M组BIS的Pk均高于95%SEF的Pk(P<0.05)。结论BIS和95%SEF可以准确地监测异丙酚的镇静深度,对咪唑安定镇静深度监测的准确性稍差,而对氯胺酮镇静深度无法监测,BIS对麻醉药镇静深度监测的准确性较95%SEF高。  相似文献   

13.
Objectives: To clarify the mechanism by which chronic bladder ischemia causes bladder functional changes, and to investigate the involvement of oxidative stress and pro‐inflammatory cytokines, and the effects of the phytotherapeutic drug, Eviprostat, on these biochemical marker levels and bladder function. Methods: Male Sprague–Dawley rats aged 15 weeks were divided into three groups. Arterial injury was experimentally induced by balloon endothelial injury of the iliac arteries, and a 2% cholesterol diet was given for 8 weeks. Rats in the arterial‐injury group were given daily oral vehicle or Eviprostat, whereas sham‐operated animals on a regular diet (0.09% cholesterol) were given vehicle for the last 2 weeks. Eight weeks after surgery, the levels of bladder pro‐inflammatory cytokines, as well as bladder and urinary oxidative‐stress markers, were determined. Cystometrograms were carried out without anesthesia or restraint. Results: Bladder and urinary oxidative‐stress markers, and bladder pro‐inflammatory cytokine levels were significantly increased in the arterial‐injury group, and Eviprostat markedly suppressed these increase. The cystometrograms showed that arterial injury decreased the intermicturition interval without affecting the micturition pressure. This decrease was reversed by Eviprostat treatment. Conclusions: Oxidative stress and pro‐inflammatory cytokines might be involved in the development of overactive bladder by atherosclerosis‐induced chronic bladder ischemia. Eviprostat might provide an attractive treatment option for individuals with bladder dysfunction due to chronic bladder ischemia because of its anti‐oxidant and anti‐inflammatory properties.  相似文献   

14.
The new non–NMDA (N–methyl–D–aspartate) receptor antagonist NBQX (2, 3–dihydroxy–6–nitro–7–sulfamoyl–benzo(F)quinoxaline) has previously been shown to exert a neuroprotective effect in animal models of cerebral ischemia when administered in the post–ischemic phase. In this investigation the effect of NBQX on acidosis and energy recovery in early reperfusion after 10 min of transient forebrain ischemia with the 2–vessel occlusion model in the rat was studied with 31P NMR spectroscopy. In the intervention group the animals received a bolus dose of NBQX 30 mg kg-1 iv at the start of reperfusion. 31P NMR spectroscopy was used to measure intracellular pH, ATP and phosphocreatine continuously in–vivo during, and after, the ischemic event. The recovery of high energy phosphates and pH was followed during 30 min of reperfusion. Pre–ischemic levels of phosphocreatine were reached after approximately 9–10 min in both groups. Although a slight improvement could be seen in the intervention group there was no significant difference in the rate of recovery between the two groups. ATP reached 90% of preischemic levels after about 8 min without significant difference between the two groups. With respect to the recovery of intracellular pH, no difference could be shown. Our results do not contradict previously published results, but suggest that the potential protective effect of NBQX is not mediated through improved recovery of energy metabolism in early reperfusion.  相似文献   

15.
16.
目的 探讨异丙酚对肝缺血再灌注大鼠心肌损伤的影响及磷脂酰肌醇-3激酶/蛋白质丝氨酸苏氨酸激酶(PI3K/Akt)信号通路在其中的作用.方法 清洁级雄性SD大鼠102只,体重250~280g,采用结扎肝蒂30 min后再灌注的方法制备肝缺血再灌注模型.随机分为5组:假手术组(S组,n=6)仅分离肝门,不结扎;缺血再灌注组(I/R组,n=30)制备肝缺血再灌注模型;异丙酚组(P组,n=30)缺血前10 min股静脉注射异丙酚12 mg/k异的负荷剂量,随后以30 mg·kg-1·h-1的速率静脉输注直至处死;异丙酚+PI3K抑制剂组(P+LY组,n=18)缺血前10 min股静脉注射PI3K特异性抑制剂LY294002 1.5mg/kg(溶于二甲亚砜0.5 ml);溶剂对照组(P+DMSO组,n=18)缺血前10 min股静脉注射二甲亚砜0.5 ml.I/R组和P组于再灌注即刻、30、60、120和240 min(T1-55)时,P+LY组和P+DMSO组于T3-5时取6只大鼠,处死后快速取左心室壁心肌组织,测定总Akt(t-Akt)和磷酸化Akt(p-Akt),并于T3时测定Bcl-2的表达和心肌细胞凋亡情况,取肝左外叶组织,光镜下观察肝组织病理学结果.S组于T1相应时点处死大鼠,测定上述指标.结果 与S组比较,其余各组心肌p-Akt表达水平和心肌细胞凋亡率升高(P<0.05),P+LY组心肌Bcl-2表达差异无统计学意义(P>0.05),其他各组心肌Bcl-2表达均上调(P<0.05);与I/R组比较,P组和P+DMSO组心肌p-Akt和Bcl-2表达上调,心肌细胞凋亡率降低(P<0.05),P+LY组上述指标差异无统计学意义(P>0.05);与P组比较,P+LY组心肌p-Akt和Bcl-2表达下调,心肌细胞凋亡率升高(P<0.05),P+DMSO组上述指标差异无统计学意义(P>0.05);各组心肌t-Akt表达比较差异无统计学意义(P>0.05).P组和P+DMSO组肝组织病理学损伤较I/R组和P+LY组减轻.结论异丙酚可减轻大鼠肝缺血再灌注诱发心肌损伤,该作用与激活PI3K/Akt信号通路有关.  相似文献   

17.
目的 研究咪达唑仑对神经干细胞(neural stem cells,NSCs)增殖、分化及凋亡的毒性作用及右美托咪定(dexmedetomidine,Dex)能否缓解咪达唑仑的神经毒性作用. 方法 分离培养孕14~15 d大鼠胚胎大脑皮质NSCs,将NSCs接种于培养板中,培养24 h后,将其按照完全随机分组法分为3组:对照组(C组)、咪达唑仑组(M组)、Dex联合咪达唑仑组(M+D组).分别采用咪达唑仑、Dex联合咪达唑仑处理培养的第一、二代NSCs 24 h,采用噻唑蓝[3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide,MTT)]比色法检测细胞活力,溴脱氧尿苷(5-bromo-2-deoxyuridine,BrdU)掺入法检测细胞增殖,免疫细胞化学法观察NSCs分化情况,原位末端标记法(terminal dUTP nick-end labeling,TUNEL)检测细胞凋亡. 结果 与对照组比较,咪达唑仑干预NSCs 24 h可降低细胞活力(对照组0.214±0.006,咪达唑仑组0.187±0.002)、减少细胞增殖[(对照组(35.7±1.0)%,咪达唑仑组(27.6±1.0)%]、增加细胞凋亡[对照组(5.7±0.8)%,咪达唑仑组(7.8±1.1)%](P<0.01),但对NSCs分化没有显著影响(P>0.05);与咪达唑仑处理比较,Dex联合咪达唑仑干预NSCs 24 h,可增加细胞活力[M+D组0.233±0.007]和细胞增殖[M+D组(35.7±1.1)%]、减少细胞凋亡[M+D组(5.3±1.0)%](P<0.01),但对NSCs向神经元和星形胶质细胞分化无明显影响(P>0.05). 结论 Dex可缓解咪达唑仑抑制NSCs增殖、促进细胞凋亡的作用,但不影响其向神经元和星形胶质细胞方向分化.  相似文献   

18.
BACKGROUND: BNIP3 is a hypoxia-induced protein involved in cell death and survival but its role in human tumors is unclear. This study investigated the role of BNIP3 in prostate cancer. METHODS: The expression of BNIP3, the androgen receptor (AR), hypoxia inducible factor (HIF)-1alpha, HIF-2alpha and the hypoxia regulated gene GLUT1 were assessed in tissue microarrays constructed from 149 radical prostatectomy specimens. Statistics compared expression of these factors between each other, conventional clinicopathological parameters and PSA recurrence. Since an association between BNIP3 and AR and the HIFs was observed, the influence of hypoxia, dihydrotestosterone and the AR blocker, Casodex, was also investigated in prostate cell lines. RESULTS: BNIP3 was expressed in the nucleus and cytoplasm. Eight of 149 (5.5%) tumors showed no expression, 44/149 (29.5%) cases showed exclusively cytoplasmic expression, 17/149 (11.5%) cases showed exclusively nuclear expression and 80/149 (53.5%) cases showed both cytoplasmic and nuclear expression. There was a significant correlation between cytoplasmic BNIP3 expression and Gleason score (P=0.005), age (P=0.02), AR (P=0.001), and GLUT1 (P=0.006). There was a significant correlation between nuclear BNIP3 expression and HIF-1alpha expression (P=0.006) and HIF-2alpha expression (P=0.013) but no correlation between BNIP3 and pre-operative PSA, tumor volume, margin positivity or capsular invasion (all P>0.05). There was an increase in BNIP3 expression under conditions of hypoxia (0.1% 0(2)) but not with dihydrotestosterone stimulation or with Casodex treatment. CONCLUSIONS: These findings suggest that BNIP3 is directly regulated by hypoxia but that there may be a hormonal independent mechanism coordinating the expression of BNIP3 in prostate tumors.  相似文献   

19.
It is generally considered that the genesis of myelopathy associated with the degenerative conditions of the spine may result from both mechanical compression and circulatory disturbance. Many references about spinal cord tissue ischemic damage can be found in the literature, but not detailed studies about spinal cord microvasculature damage related to congestion or blood permeability. This study investigates the effect of ischemia and congestion on the spinal cord using an in vivo model. The aorta was clamped as an ischemia model of the spinal cord and the inferior vena cava was clamped as a congestion model at the 6th costal level for 30 min using forceps transpleurally. Measurements of blood flow, partial oxygen pressure, and conduction velocity in the spinal cord were repeated over a period of 1 h after release of clamping. Finally, we examined the status of blood‐spinal cord barrier under fluorescence and transmission electron microscope. Immediately after clamping of the inferior vena cava, the central venous pressure increased by about four times. Blood flow, oxygen tension and action potential were more severely affected by the aorta clamping; but this ischemic model did not show any changes of blood permeability in the spinal cord. The intramedullar edema was more easily produced by venous congestion than by arterial ischemia. In conclusions, venous congestion may be a preceding and essential factor of circulatory disturbance in the compressed spinal cord inducing myelopathy. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:139–146, 2012  相似文献   

20.
BACKGROUND: This study was directed to evaluate the immunoexpression of markers for cell proliferation, apoptosis, nuclear androgen receptors, and Glutathione-S-Transferase P1 (GSTP1), in preneoplastic changes induced by cadmium chloride (Cd) and cadmium plus zinc chloride (Cd + Zn) in rat prostate. METHODS: The following parameters were calculated in ventral prostate of normal rats and rats that received Cd or Cd + Zn in drinking water during 24 months: numerical densities of columnar, basal, and GSTP1 immunoreactive epithelial cells; percentages of cells immunoreactive to: PCNA, (LI(PCNA)), androgen receptors (LI(AR)), and of apoptotic cells. RESULTS: The LI(PCNA) was significantly increased in the animals exposed to Cd + Zn, whereas the numerical densities of both columnar (N(V) columnar cells), and GSTP1 immunoreactive (N(V) GSTP1+) cells were significantly increased in the animals treated with metals in comparison with the controls. No significant differences between the two sources of dysplasias (Cd and Cd + Zn) respecting to LI(PCNA), N(V) columnar cells, and N(V) GSTP1+ were observed. The two types of dysplasias considered together showed a significant increase for the N(V) basal, N(V) columnar, and N(V) GSTP1+ cells in comparison with normal acini of treated and controls. The percentage of apoptotic nuclei did not show significant differences among the three groups studied. CONCLUSIONS: (1) The zinc has little influence in the development of the dysplastic changes of the rat prostate mediated by cadmium. (2) The decrease of apoptosis has little influence in the development of dysplasia. (3) GSTP1 could play a role in the response to the oxidative stress in the dysplastic changes caused by cadmium.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号