细胞外信号调节激酶在失血性休克后活性变化及其在血管反应性调节中的作用

目的 观察失血性休克后细胞外信号调节激酶(ERK)的活性变化及其对休克血管反应性的影响.方法 采用72只健康成年SD大鼠,复制失血性休克模型,观察休克后不同时期大鼠肠系膜上动脉(SMA)血管组织中ERK活性的变化,同时测定血管反应性的变化;并观察改变ERK活性对休克血管反应性的影响.结果 失血性休克后,大鼠肠系膜上动脉血管组织中ERK活性升高,在休克30 min时达到最高点(为正常组的2.6倍,P＜0.01),随着休克时间的延长,ERK的活性逐渐降低,在休克后2 h降低为正常对照组的56.1%(P＜0.05);失血性休克大鼠的血管反应性变化也呈现休克早期升高、休克晚期降低的趋势.给予AngII处理可使休克2 h血管组织内ERK活性升高为休克2 h组的1.9倍(P＜0.01),同时休克血管反应性明显升高,而ERK的抑制剂PD98059可拮抗AngII诱导ERK活性增加和血管反应性升高的作用.结论 ERK在失血性休克大鼠血管反应性调节中具有重要作用.

Abstract：

Objective To investigate the changes of extracellular signal-regulated kinase (ERK) activity and its role in regulation of vascular reactivity following hemorrhagic shock. Methods In 72 SD rats, the hemorrhagic shock model was adopted, the activity of ERK in the superior mesenteric artery ( SMA) of rats after shock was measured, and the vascular reactivity of SMA after shock was observed. The effect of altered ERK activity on the regulation of vascular reactivity of SMA after shock was investigated.Results After shock, the activity of ERK in SMA was increased about 2. 6 folds as compared to normal group ( P ＜0. 01) , and it reached the peak at 30 min after shock. The activity of ERK 2 h after shock was reduced to 56. 1 % of normal group ( P ＜ 0. 05 ). At the same time, the vascular reactivity of SMA was also increased at early shock and decreased at late shock. Angiotensin II ( AngII) increased the activity of ERK to 1. 9 folds as compared to shock 2-h group (P ＜0. 01) , and AngII also increased the vascular reactivity of SMA at 2 h shock. PD98059, the ERK antagonist, antagonized the effect of AngII on ERK activity and vascular reactivity of the SMA. Conclusion ERK may play an important role in the regulation of vascular reactivity after hemorrhagic shock.     

细胞外信号调节激酶介导血管生成素-1、2对休克血管低反应性的调节

目的 观察细胞外信号调节激酶( Erk)在血管生成素-1(Ang-1)、血管生成素-2(Ang-2)调节失血性休克血管反应性双相变化中的作用 方法 采用SD大鼠152只和混合培养的血管内皮细胞(VEC)、血管平滑肌细胞(VSMC),观察失血性休克后肠系膜上动脉(SMA)中Erk蛋白表达和磷酸化变化,Erk抑制剂对Ang-1和Ang-2调节缺氧早期和晚期血管反应性作用的影响,以及给予Ang-1、Ang-2和Tie-1抑制剂后缺氧混合细胞中Erk蛋白表达和磷酸化的变化 结果 (1)失血性休克后SMA中Erk磷酸化逐渐增高,休克lh、2h和4h分别增高至正常对照组的2.72、3.32和3.46倍(P＜0.01).(2)Erk抑制剂可恢复缺氧4h血管反应性并拮抗Ang-2( 200μg/L)降低缺氧4 h血管低反应性的作用,去甲肾上腺(NE)的最大收缩力(Emax)分别由5.875 mN升高至9.681 mN 和由3.444 mN增高至9.003mN (P ＜0.01).(3) Ang-1和Tie-2抑制剂可抑制缺氧4h的Erk磷酸化增高,使其由0.6258分别降低至0.2643和0.2578 (P＜0.01).结论 Erk磷酸化介导休克晚期Ang-2降低血管反应性的调节作用     

老年鼠失血性休克时睾丸糖皮质激素受体的变化

目的与方法：应用放射配体结合法，测定老年鼠失血性休克时睾丸细胞液糖皮质激素受体（GR）的最大结合量（R0）和平衡解离常数（Kd）。结果：老年鼠4、8h休克组睾丸细胞液GR的R0分别是41．86±6．47fmol／（mg·蛋白）、27．74±5．87fmol／（mg·蛋白），显著低于各自对照组（P均＜0．01），Kd值显著高于各自对照组（P均＜0．01）。结论：GR的功能可能与失血性休克有关。     

Postshock mesenteric lymph drainage ameliorates vascular reactivity and calcium sensitivity through RhoA

Background

Vascular hyporeactivity plays an important role in the pathogenesis of severe shock. Previous studies have shown that postshock mesenteric lymph (PSML) blockage ameliorates the vascular reactivity and calcium sensitivity, and RhoA is involved in the regulation of vascular reactivity after hemorrhagic shock. Therefore, the present study tested whether small GTPase RhoA mediates the improvement of the vascular reactivity and calcium sensitivity in superior mesenteric artery (SMA) of rats with PSML drainage.

Materials and methods

The hemorrhagic shock model (blood pressure to 40 ± 2 mm Hg) was established, and PSML was drained from immediate hypotension for 3 h, after which SMA was isolated, and the vascular reactivity and calcium sensitivity were tested in the presence of RhoA agonist (U-46619) or inhibitor (C3 transferase). The protein expressions of small GTPase RhoA and phospho-RhoA were also examined in SMA.

Results

The hemorrhagic shock resulted in a significant decrease in the SMA reactivity and calcium sensitivity, which was enhanced by the application of U-46619 to the SMA. In contrast, the PSML drainage ameliorated the deleterious effect of the hemorrhagic shock on the SMA. This beneficial effect of the PSML drainage was abolished by C3 transferase. Western blotting revealed that the expressions of the RhoA and phospho-RhoA in SMA tissue obtained from the shock group were significantly decreased, and the PSML drainage markedly enhanced these protein expressions.

Conclusions

RhoA is an important contributor to the PSML drainage-induced amelioration of the vascular reactivity and calcium sensitivity in rats with hemorrhagic shock.     

RheA对失血性休克大鼠血管反应性的调节作用

目的 观察Rhea在失血性休克大鼠血管反应性调节中的作用.方法 采用sD大鼠复制休克模型,取离体血管环和原代血管平滑肌细胞(VSMC),观察在休克不同时期血管反应性的变化以及RheA活性调节剂对失血性休克后大鼠离体血管环和VSMC收缩反应性的影响.结果 在休克早期和短暂缺氧后,离体血管环和VSMC对NE收缩反应性均有所升高,其Emax和60 min累计渗透率分别为(1.684±0.101)S/mg组织和68.99±6.83,RhoA的激动剂U-46619可进一步升高休克早期或短暂缺氧后血管反应性,RhoA特异性抑制剂C3enzyme可明显降低休克早期和短暂缺氧所引起的血管收缩反应性的升高,其Emax和60 min累计渗透率分别为(0.736±0.112)g/mg组织和53.91±5.53.而在休克晚期或长时间缺氧后,离体血管环和VSMC对NE收缩反应性明显降低,其Emax和60 min累计渗透率分别为(0.608±0.045)g/mg组织和38.53±4.87,RhoA激动剂U-46619可明显升高休克晚期或长时间缺氧所致血管反应性的降低,Emax和60 min累计渗透率分别为(0.934±0.110)g/mg组织和57.99±6.83,U-46619的这一作用可被RheA抑制剂C3enzyme所拮抗.结论 休克后血管反应性呈双相变化,休克早期升高,休克晚期降低,Rhea参与了休克血管反应性的调节.     

右美托咪定通过腺苷A1受体调节大鼠压力反射敏感性

目的观察腺苷A1受体在右美托咪定调节压力反射敏感性(baroreflex sensitivity,BRS)中的作用。方法健康成年雄性SD大鼠32只,体重240~280g,按随机数字表随机分为四组:对照组(C组)、选择性腺苷A1受体阻断剂组(P组)、右美托咪定组(D组)、选择性腺苷A1受体阻断剂+右美托咪定组(PD组),每组8只。C组泵注生理盐水40 ml·kg~(-1)·h~(-1)负荷量15 min,维持泵注10 ml·kg~(-1)·h~(-1);P组腹腔注射选择性腺苷A1受体阻断剂8-环戊基-1,3-二丙基黄嘌呤(DPCPX)1mg/kg,泵注同C组方案的生理盐水;D组右美托咪定负荷量100μg/kg,维持量100μg·kg~(-1)·h~(-1)持续泵注;PD组腹腔注射DPCPX 1mg/kg并泵注右美托咪定,泵注剂量同D组。采用苯肾上腺素升压法于泵注前(T_0)、泵注后60min(T_1)和泵注后120min(T_2)测定BRS。结果与T_0时比较,T_1和T_2时D组和PD组BRS明显升高(P0.05)。与C组和P组比较,T_1和T_2时D组和PD组BRS均明显升高(P0.05)。与D组比较,T_1和T_2时PD组BRS明显降低(P0.05)。结论右美托咪定可能通过腺苷A1受体增加大鼠BRS。     

Role of non-MLC20 phosphorylation pathway in the regulation of vascular reactivity during shock

Background

Studies have shown that shock-induced vascular hyporeactivity is associated with the decrease in 20-kDa myosin light chain (MLC20) phosphorylation. Whether and how a non-MLC20 phosphorylation pathway participates in the regulation of vascular reactivity after shock is not known.

Methods

With superior mesentery artery (SMA) obtained from rats in hemorrhagic shock and hypoxia-treated SMA, the regulatory effect of platelet-derived growth factor (PDGF) on vascular reactivity and the roles of caldesmon, 27-kDa heat shock protein (HSP27), extracellular signal–regulated protein kinase (Erk), and p38 mitogen–activated protein kinase (MAPK), the main molecules that are involved in the non-MLC20 phosphorylation pathway of the regulation of smooth-muscle contraction, were investigated.

Results

PDGF (40–100 ng/mL) increased the vascular reactivity after shock in a dose-dependent manner, whereas it did not increase the MLC20 phosphorylation in a dose-dependent manner. PDGF with concentration more than 60 ng/mL did not further increase the MLC20 phosphorylation, whereas upregulated the phosphorylation of HSP27, Erk, and p38MAPK, and the activity of myosin adenosine triphosphatase in SMAs, and downregulated the phosphorylation of caldesmon. p38MAPK antagonist, SB203580, not only antagonized PDGF-induced increase in the phosphorylation of HSP27, but also antagonized PDGF-induced decrease in the phosphorylation of caldesmon, whereas Erk antagonist, PD98059, only antagonized PDGF-induced decrease in the phosphorylation of caldesmon.

Conclusions

These findings suggested that a non-MLC20 phosphorylation pathway participated in the regulation of vascular reactivity after shock. Caldesmon- and HSP27-mediated change in myosin adenosine triphosphatase activity and Erk and p38MAPK played an important role in this process. These findings may provide some potential targets for the treatment of vascular hyporeactivity after shock.     

Edaravone improves the survival of rats subjected to hemorrhagic shock without resuscitation

Our aim in this study was to find out whether edaravone (3-methyl-1-phenyl-pyrazolin-5-one, MCI-186), a novel free radical scavenger, improved the survival rate in a rat hemorrhagic shock (HS) model. Fifty male Sprague-Dawley rats were divided randomly into an edaravone group and a saline group. Both groups were subjected to HS by inducing a mean arterial pressure of 30 mmHg for 60 min without resuscitation. The edaravone group was divided into four subgroups based on when edaravone was given: 0, 15, 30, or 60 min after HS. The saline group was given saline immediately after HS. We evaluated the 24-h survival rate in each group. The survival rate of the edaravone subgroup given edaravone immediately after HS was significantly better than that of the saline group. Edaravone improved the survival rate in a rat HS without resuscitation model. Edaravone was most effective when given immediately after HS.     

转录因子Egr-1在失血性休克复苏后肝脏损伤中的作用

目的研究转录因子Egr-1在失血性休克复苏（HS/R）后肝脏损伤中的作用.方法利用Egr-1野生型（WT）和基因封闭型（KO）小鼠复制失血性休克复苏模型.取肝组织,RT-PCR法测定肝组织中TNF-α、IL-6、G-CSF、ICAM-1 mRNA的表达变化.通过检测肝组织中MPO的含量、血清ALT水平和组织学检查,评估肝脏炎症细胞浸润和损伤程度.结果失血性休克2.5 h＋复苏4 h后,Egr-1 KO小鼠肝组织中TNF-α、IL-6、G-CSF、ICAM-1 mRNA的表达水平明显低于Egr-1WT组;Egr-1 KO组失血性休克复苏后肝组织炎性浸润和损伤程度减轻,表现为血清ALT水平低,肝组织中MPO含量低,病理损伤轻.结论本实验结果表明转录因子Egr-1参与了失血性休克复苏后肝脏炎症反应基因表达的调节,在失血性休克复苏后的肝脏损伤中起一定的作用.     

The effect of various resuscitative regimens on hemorrhagic shock in puppies

Since shock secondary to hemorrhage is not infrequently encountered in the pediatric patient, a puppy model was devised to help measure and monitor cardiovascular and metabolic changes that occur before and after resuscitation from hypovolemic shock (mean arterial pressure of 50 mm Hg for 1 hr). Three resuscitation protocols were compared: whole blood (replacement: shed) 1:1, 5% albumin in Ringer's lactate 1:1, and Ringer's lactate 3:1. All dogs survived the experiment and responded similarly during the shock period. Thermal dilution cardiac output rose in all groups after resuscitation; however, in the Ringer's lactate and 5% albumin groups, cardiac output was statistically greater than that observed in the blood group. In all groups, pH and blood pressure approached but did not return completely to baseline levels after resuscitation. In addition, early resuscitation demonstrated a further decrease in pH (“hidden acidosis”) before it began to return toward normal as resuscitation progressed. This study suggests that the infusion of large volumes of Ringer's lactate or 5% albumin in Ringer's lactate are equally efficacious in the treatment of hemorrhage. However, 5% albumin seems to be preferable because it allows infusion of a smaller quantity of electrolyte solution with equivalent physiologic benefits.     

腺苷A2A受体激活缺血后处理保护皮瓣作用研究

目的：缺血后处理需要反复夹闭血管蒂,可能对血管造成机械性损伤。药物缺血后处理成为缺血后处理的发展方向。腺苷A2A是调控皮瓣炎症的关键靶点,进行相关研究进一步探究腺苷A2A激活缺血后处理对皮瓣有否保护作用。方法：健康成年新西兰大白兔,分为3组。A组为假手术组;B组为缺血再灌注损伤组;C组,再灌注前5min注射腺苷A2A激活剂。分别进行皮瓣存活率检测和ELISA检测TNF以及IL-6。结果：腺苷A2A激活剂组皮瓣存活率高,炎症因子检测活性低于缺血再灌注损伤组。结论：腺苷A2A激活剂缺血后处理可以抑制炎症因子,具有保护皮瓣作用。运用腺苷A2A受体激活缺血后处理可能成为保护皮瓣的新措施。     

丙酮酸腹膜透析液对大鼠失血性休克静脉液体复苏后腹腔脏器的保护作用

目的：研究丙酮酸腹腔透析液对大鼠失血性休克静脉液体复苏后腹腔脏器的保护作用。方法：雄性SD大鼠40只,随机分为4组（n=10）。大鼠按全身血容量的45％经股动脉放血制作失血性休克模型。单纯静脉复苏组（VR组）于休克1h后回输失血及2倍失血量的乳酸钠林格液行静脉复苏,其余3组在上述静脉复苏基础上,分别腹腔注射生理盐水（DPR组）、乳酸钠透析液（L组）、丙酮酸钠透析液（P组）20ml行腹腔复苏,时间30min。分别于休克前（O时）及休克后60（静脉复苏前）、180（腹腔复苏后1h）、360rain（腹腔复苏后4h）用PICCO心肺容量监测仪监测大鼠平均动脉压（MAP）;激光多普勒血流仪测定休克后180min和360min肝、肾和小肠黏膜血流量;生化法测定休克前及休克后180、360min血丙氨酸转氨酶（ALT）、二胺氧化酶（DAO）活性和肌酐（cr）水平;干／湿比重法测定休克后180、360min肝、肾、肠各组织含水率。结果：失血性休克后各组MAP骤降至（35±5）mmHg;休克后60min时,各组大鼠MAP无明显差异（P〉0．05）。腹腔复苏后,与VR组比较,L和P组均能显著提高失血性休克大鼠MAP（P〈0．05）,降低血ALT、Cr和DAO水平,减轻肝、肾、肠组织含水率,提高腹腔脏器血流量（P〈0．05或P〈0．01）,在失血后360min时,P组的上述变化较其余复苏组更为显著。结论：丙酮酸腹腔透析液对大鼠失血性休克静脉液体复苏后腹腔脏器具有保护作用。     

高晶体-高胶体渗透压混合液对失血性休克大鼠不同组织中血管紧张素原表达的影响

目的 研究高晶体—高胶体渗透压混合液(HHS)复苏失血性休克时不同组织中血管紧张素原(angiotensinogen，ANG)表达的变化，探讨组织中的肾素—血管紧张素系统(renin-angiotensin system，RAS)活性的变化。方法 选取成年SD大鼠30只，随机平均分为复方乳酸钠(LRS)组和HHS组。制作失血性休克动物模型，分别用LRS或HHS复苏。采用逆转录酶—多聚酶链反应(reverse-transcrlptase-polymerase chain reaction，RT—PCR)的方法半定量测定各组大鼠休克前、休克后和复苏后30min的下丘脑、垂体前叶、肾上腺中的ANG基因表达水平，采用β—actin为内对照。结果 失血性休克后各组织中ANG表达水平均明显升高。只有HHS可降低各组织中的升高的ANG的表达水平。结论 HHS可抑制失血性休克时组织中的RAS的激活。     

限制性液体复苏对失血性休克大鼠网状内皮系统的影响

目的探讨限制性液体复苏对失血性休克大鼠网状内皮系统的影响。方法60只SD大鼠制成未控制性重度失血性休克模型,随机分成对照组、NF组(无液体复苏组)、NS40组(限制性液体复苏组)和NS80组(常规大量液体复苏组),检测和比较休克复苏后各组存活大鼠肝脏枯否细胞和腹腔巨噬细胞的吞噬功能。结果重度失血性休克大鼠失血后150min存活率NF组、NS40组和NS80组比对照组明显提高,NS40组较NS80组显著改善(P0.05);NS40组大鼠肝脏枯否细胞和腹腔巨噬细胞的吞噬功能较NS80组明显改善(P0.05)。结论限制性液体复苏可以显著改善失血性休克大鼠的网状内皮系统的吞噬功能,提高大鼠的免疫功能,降低死亡率。     

失血性休克大鼠血浆及腹腔巨噬细胞释放细胞因子改变

目的：研究大鼠失血性休克前后血浆及腹腔巨噬细胞释放细胞因子的变化。方法：将30只大鼠分为失血性休克组（20只）和对照组（10只）,观察大鼠休克前后血浆和腹腔巨噬细胞释放肿瘤坏死因子（TNF）－α,白细胞介素（IL）－1β,IL－6和IL－8改变。结果：失血性休克90min后大鼠腹腔巨噬细胞释放TNF－α,IL－1β,IL－6和IL－8显著减少（P＜0．01）,而血浆中这些细胞因子水平明显升高（P＜0．01）。结论：失血性休克对大鼠细胞免疫功能有抑制作用。     

吡那地尔诱导失血性休克大鼠血流动力学保护

目的 观察吡那地尔诱导失血性休克大鼠血流动力学的保护及与线粒体ATP激活钾通道( KATP)的关系.方法 采用失血性休克复苏大鼠,观察吡那地尔预处理对大鼠存活时间、血流动力学指标[平均动脉压(MAP)、左室收缩压(LVSP)、左室舒张末压(LVEDP)、左室压最大上升/下降速率(±dp/dtmax)、心率(HR)]的影响,以及线粒体KATP关闭剂5-羟基癸酸(5-HD)和格列本脲对其效应的作用.结果 吡那地尔预处理显著延长大鼠存活时间,恢复血流动力学,MAP、LVSP、LVEDP、+dp/dtmax、- dp/dtmax、HR分别增高5.9％、11.6％、32.9％、28.0％、28.1％和13.4％(P＜0.01),5-HD和格列本脲可显著抑制其保护效应(P＜0.01).结论 吡那地尔开放线粒体KATP,保护失血性休克大鼠血流动力学,提高存活率.     

鸟苷酸结合蛋白在失血性休克大鼠心肺组织中的表达

目的研究失血性休克大鼠心肺组织鸟苷酸结合蛋白(G蛋白)的变化.方法颈总动脉放血,使平均动脉压降至45 mm Hg(1 mm Hg=0.133kPa)稳定1 h致大鼠中度失血性休克模型,6 h后用Western blot法测定心肺组织Gsa、Gia、Gqa、Goa的含量.结果休克后心脏膜组织Gsa两条带(84.2±5 8)%;(84.6±4.2)%较对照组(100%)显著降低.Gia(159.4±7.7)%和Gqa(130.4±20.9)%带较对照组(100%)则显著升高,Goa(90.6±4.9)%降低(P＜0.05).肺膜组织Gsa两条带较正常对照组显著降低.Gia和Gqa较正常对照组织也下降(P＜0.05).结论大鼠心肺组织G蛋白的变化可能参予了失血性休克时信号转导系统功能障碍的发生.     

腺苷A1受体在全身麻醉中的作用研究进展

背景 由于腺苷在睡眠方面的作用与全身麻醉所产生的作用非常相似,近年来关于腺苷及其受体在全身麻醉过程作用的研究越来越多,但其机制尚无定论.目的 综述腺苷A1受体与全身麻醉的关系及在全身麻醉过程中可能的作用机制.内容 简述全身麻醉与腺苷A1受体在睡眠方面的相似之处以及全身麻醉相关的重要受体γ-氨基丁酸A型(γ-amino butyric acid A,GABAA)受体、N-甲基-D-天冬氨酸(N-methyl-D-aspartic acid,NMDA)受体与腺苷A1受体的关系,总结目前腺苷A1受体在全身麻醉中作用的研究结果.趋向 腺苷A1受体在全身麻醉中的作用机制尚不完全清楚,有待进一步的研究证实,研究腺苷A1受体和全身麻醉之间的关系对于临床麻醉工作及药物的研究应用有一定的指导意义.     

高渗氯化钠羟乙基淀粉复合液对失血性休克肺的保护作用

目的观察用高渗氯化钠羟乙基淀粉复合液(7.5%氯化钠 6%羟乙基淀粉200/0.5,HHS)小容量复苏对失血性休克后肺损伤的影响。方法雄性SD大鼠随机分为五组:正常对照组(CON组,n=6):不放血不补液;其他大鼠通过放血使MAP降至45mmHg并维持120min,然后分为:休克组(SH组,n=6),不补液复苏;HHS组(n=8),用HHS5ml/kg静脉滴注;7.5%氯化钠高渗溶液组(HTS组,n=6),用7.5%NaCl5ml/kg静脉滴注;复方乳酸钠组(LR组,n=7),用3倍失血量的复方乳酸钠静脉滴注。观察休克2h末、补液结束即刻、15、30、60、120、180min时MAP、CVP的变化,测定补液结束2、24h存活动物的氧合指数和肺水含量、肺髓过氧化物酶(MPO)水平、肺损伤评分。结果在补液结束120、180min,HTS组MAP、CVP低于HHS和LR组(P<0.05);在补液结束24h,HHS组氧合指数、肺水含量、肺MPO水平、肺损伤评分优于HTS和LR组(P<0.05)。结论用HHS小容量复苏失血性休克,维持血流动力学稳定时间更长;对肺组织的保护作用优于7.5%氯化钠高渗溶液或复方乳酸钠。     

失血性休克大鼠血管扩张刺激磷蛋白磷酸化在肠屏障功能障碍中的作用

目的 观察失血性休克大鼠血管扩张刺激磷蛋白(VASP)磷酸化在肠屏障功能障碍中的作用.方法 采用40只Wister大鼠,观察不同休克时相点(1、2、4 h)VASP磷酸化和肠屏障功能变化(以小肠黏膜组织形态、血浆D-乳酸含量反映),及VASP磷酸化激动剂环磷腺苷(cAMP)对休克2 h肠屏障功能的影响.结果 (1)正常组VASP磷酸化水平很低(0.021 ±0.004),休克1 h时增高(0.145 ±0.011)(P＜0.01),2 h后降低(0.108 ±0.010)(P＜0.01);休克1 h肠屏障功能变化不明显,2 h后肠屏障功能显著降低.(2)VASP磷酸化激动剂cAMP可增强休克2 h小肠上皮组织VASP磷酸化(0.169 ±0.030)(P＜0.01),减轻肠屏障功能损伤.结论 VASP磷酸化可能对失血性休克大鼠肠屏障功能有保护作用.