异氟醚预处理通过激活蛋白激酶C-δ诱发心肌纤维膜ATP敏感性钾通道持久敏感化

背景：吸入麻醉药预处理的心肌保护作用机制涉及到心肌纤维膜A胛敏感性钾通道（sarcKATP）的激活，本实验通过研究短暂麻醉药预处理是否能产生持久sarcKATP敏感化，及其是否是通过蛋白激酶C（PKC）介导，进而研究麻醉药预处理的记忆时相。     

异氟醚预处理对大鼠全脑缺血再灌注损伤的保护作用

目的 探讨异氟醚预处理对大鼠全脑缺血再灌注损伤的作用。方法 采用四动脉阻断法制作全脑缺血模型。选择雄性Wistar大鼠78只(250～300g)。随机分为四组:假手术组(SH,n=15)、缺血再灌注组(ISC,n=21)、缺血预处理组(IPC,n=21)、异氟醚预处理组(ISOPC,n=21)。每组按缺血后再灌注时间分为三个亚组:6h、24h、72h。脑组织标本切片后行HE染色观察海马CA1存活细胞数目、原位末端标记(TUNEL)法测定凋亡细胞。结果 HE染色:ISC组随再灌注时间延长CA1区存活的细胞数(个)由90±2(6h)减少至46±5(72h),P<0.01。与ISC组比较,IPC组和ISOPC组72h后CA1区大部分细胞存活,分别为82±4和80±5,P<0.01。TUNEL:ISC组再灌注6h后在CA1区起始段即开始有凋亡细胞,且数量随时间增加。而IPC组和ISOPC组在再灌注24h后出现少量凋亡细胞,再灌注72h后凋亡细胞百分数显著低于ISC组(P<0.01)。结论 异氟醚预处理通过抑制缺血诱导的神经细胞凋亡而产生保护作用。     

地氟醚、七氟醚和异氟醚预处理对缺氧/复氧心肌细胞损害的保护作用

目的　研究地氟醚、七氟醚和异氟醚预处理对心肌细胞缺氧／复氧损害的保护作用。方法　原代培养乳鼠心肌细胞，随机分为对照、单纯缺氧／复氧及 １．５ＭＡＣ地氟醚、七氟醚和异氟醚预处理５组。实验结束测定乳酸脱氢酶（ＬＤＨ）和肌酸激酶（ＣＫ）活性、细胞存活和凋亡率。结果　与对照组比，单纯缺氧／复氧使ＬＤＨ、ＣＫ和细胞凋亡率升高及细胞存活率显著下降（Ｐ＜０．０１）；１．５ＭＡＣ地氟醚、七氟醚和异氟醚预处理显著减轻ＬＤＨ、ＣＫ和细胞凋亡率升高及细胞存活率下降，其中七氟醚减轻作用最强。结论　地氟醚、七氟醚和异氟醚预处理对心肌细胞缺氧／复氧损害有一定的保护作用，七氟醚的保护作用可能更强。     

JNK信号通路在异氟醚预处理和七氟醚预处理减轻大鼠海马脑片缺氧无糖损伤中的作用

目的 评价c-Jun氨基末端激酶(JNK)信号通路在异氟醚预处理和七氟醚预处理减轻大鼠海马脑片缺氧无糖(OGD)损伤中的作用.方法雄性成年SD大鼠,体重270～290 g,断头处死,剥离海马,制备海马脑片.取大鼠海马脑片96张,采用随机数字表法,将其随机分为8组(n=12):对照组(C组)、OGD组、异氟醚预处理组(Iso组)、七氟醚预处理组(Sevo组)、SP600125+异氟醚预处理组(SP+Iso组)、SP600125+七氟醚预处理组(SP+Sevo组)、二甲基亚砜(DMSO)+异氟醚预处理组(DMSO+Iso组)和DMSO+七氟醚预处理组(DMSO+Sevo组).采用电生理技术,细胞外记录CA1区群锋电位(PS)波幅,计算PS恢复程度.采用碘化丙啶染色法,测定细胞活力.结果 与C组比较,其余各组PS恢复程度和细胞活力降低(P＜0.01);与OGD组比较,Iso组、Sevo组、SP+Iso.组、SP+Sevo组、DMSO+Iso组和DMSO+Sevo组PS恢复程度和细胞活力升高(P＜0.01);与180组比较,SP+Iso组PS恢复程度和细胞活力升高(P＜0.01),DMSO+Iso组PS恢复程度和细胞活力差异无统计学意义(P＞0.05);与Sevo组比较,SP+Sevo组PS恢复程度和细胞活力升高(P＜0.01),DMSO+Sevo组PS恢复程度和细胞活力差异无统计学意义(P＞0.05).结论 异氟醚预处理和七氟醚预处理可通过抑制JNK信号通路,减轻大鼠海马脑片缺氧无糖损伤.

Abstract：

Objective To evaluate the role of c-Jun N-terminal kinase (JNK) signaling pathway in the protective effect of isoflurane preconditioning and sevoflurane preconditioning against oxygen-glucose deprivation (OGD) injury in rat hippocampal slices. Methods Male adult SD rats weighing 270-290 g were anesthetized with ether and decapitated. The hippocampi were removed and sagittally sliced (400 μm thick) and placed in artificial cerebral spinal fluid aerated with 95% O2-5% CO2 . Ninety-six hippocampal slices were randomly divided into 8 groups (n = 12 each): control group (group C), OGD group, isoflurane preconditioning group (group Iso),sevoflurane preconditioning group (group Sevo) , SP600125 + isoflurane preconditioning group (group SP + Iso),SP600125 +sevoflurane preconditioning group (group SP + Sevo), DMSO + isoflurane preconditioning group (group DMSO + Iso) and DMSO + sevoflurane preconditioning group (group DMSO + Sevo). Electrophysiological technique was used to record the amplitude of population spike ( PS) in the stratum pyramidale of CA1 region and the degree of recovery of PS was calculated. The cell viability was determined by propidium iodide staining. Results Compared with group C, the degree of recovery of PS and cell viability were significantly decreased in the other groups ( P ＜ 0.01) . Compared with group OGD, the degree of recovery of PS and cell viability were significantly increased in groups Iso, Sevo, SP+Iso, SP+Sevo, DMSO+ Iso and DMSO + Sevo (P＜ 0.01). Compared with group Iso, the degree of recovery of PS and cell viability were significantly increased in group SP+Iso ( P ＜ 0.01) , while no significant change was found in group DMSO + Iso ( P ＞ 0.05) . Compared with group Sevo, the degree of recovery of PS and cell viability were significantly increased in group SP + Sevo ( P ＜ 0.01) , while no significant change was found in group DMSO + Sevo ( P ＞ 0.05). Conclusion Isoflurane preconditioning and sevoflurane preconditioning can attenuate the OGD injury to rat hippocampal slices through inhibiting JNK signaling pathway.     

地氟醚、七氟醚和异氟醚预处理对缺氧-复氧心肌细胞内游离Ca2+的影响

目的 观察地氟醚，七氟醚和异氟醚预处理对缺氧-复氧心肌细胞内Ca^2 的影响。方法 将原代培养乳鼠心肌细胞随机分为对照，缺氧-复氧及1.5MAC地氧醚，七氟醚和异氟醚预处理后缺氧-复氧五组，用Fra-2标记细胞内Ca^2 ，荧光光度计进行测定。结果 与对照组比，复氧20分钟时，其余四组细胞内Ca^2 均显著升高；而地氟醚，七氟醚和异氟醚预处理组的升高幅度明显低于缺氧-复氧组；三个吸入麻醉药组间无差异，复氧60分钟，缺氧-复氧组虽有明显下降，但仍显著高于对照组，地氟醚，七氟醚烽异氟醚预处理组则降至对照组水平。结论 地氟醚，七氟醚和异氟醚预处理，可明显减轻缺氧-复氧心肌引起的细胞内游离Ca^2 升高。     

异氟醚预处理对大鼠局灶性脑缺血损伤的保护作用

目的探讨异氟醚预处理能否诱导脑缺血耐受产生。方法30只雄性SD大鼠(350～400g)，随机分为三组对照组(n＝10)，动物不接受任何处理；Iso/5d／1h组(n＝10)，动物每天接受1h的异氟醚预处理(2％异氟醚，98％氧)，连续5d；O2／5d／1h组(n＝10)，动物每天接受1h的吸氧处理(98％氧，无异氟醚)，连续5d。所有动物均采用右侧颈动脉丝线栓塞大脑中动脉致局灶性脑缺血120min，观察再灌注后1，3，6，12，16，24h动物神经行为学改变及24h时脑梗死容积。结果术后各时间点神经行为学评分Iso／5d／1h组明显低于对照组和O     

异氟烷预处理对大鼠离体心脏缺血再灌注损伤的保护作用

目的探讨异氟烷预处理对大鼠离体心脏缺血再灌注损伤的保护作用。方法50只SD大鼠随机分为5组：对照组（C组）、缺血再灌注组（Ⅰ组）、0．5％、1．0％、2．0％异氟烷预处理组（P1、P2、P3组），每组10只。采用Langendorff离体心脏灌注模型，经主动脉用K-H液平衡灌注。除C组外，其余组均全心缺血30min再灌注60min。P1、P2、P3组在缺血前分别用含相应浓度异氟烷的KH液灌注15min，再用K-H液冲洗15min。记录平衡灌注末、缺血前即刻、再灌注30、60min时左室舒张末压（LVEDP）、左室收缩压（LVSP）、左室内压下降最大速率（dp／dtmin）、左室内压上升最大速率（dp，dtmax）、心率（HR）。再灌注60min时，计算心肌梗死面积百分比、线粒体和胞浆的细胞色素C水平。结果与C组比较，再灌注期间Ⅰ组LVEDP升高，LVSP、dp／dtmax、dp／dtmin降低，P1、P2、P3组LVEDP升高，I、P1组心肌梗死面积百分比升高，I、P1、P2组线粒体细胞色素C水平降低，胞浆细胞色素C水平增高；与Ⅰ组比较，P1、P2、P3组LVEDP及心肌梗死面积百分比降低，线粒体及胞浆细胞色素C水平增高，胞浆细胞色素C水平降低（P〈0．05或0．01）。P2组胞浆细胞色素C水平高于P1组；与P1、P2组比较，P3组线粒体细胞色素C水平增高，胞浆细胞色素C水平降低（P〈0．05）。结论通过抑制线粒体细胞色素C释放到胞浆。异氟烷预处理对大鼠离体心脏缺血再灌注损伤有一定的保护作用。     

异氟醚预处理对沙士鼠脑缺血再灌注损伤的保护作用

目的探讨异氟醚预处理对沙士鼠脑缺血再灌注损伤的保护作用及可能的机制。方法75只雄性沙士鼠，随机分5组，每组15只。假手术组（SHAM组）；I／R组：夹闭双侧颈总动脉5min后开放造成缺血再灌注；异氟醚预处理组（ISO组）：缺血前60min吸入1．2％．1．5％异氟醚30min；5．羟葵酸盐组（5-HD组）：缺血前30min腹腔内注射线粒体ATP敏感性钾通道抑制剂5-HD 10mg／kg；5．HD＋ISO组：腹腔内注射5-HD10mg／kg，30min后同ISO组。再灌注24h，取鼠前脑，透射电镜下观察线粒体超微结构，用荧光分光光度计测定线粒体游离Ca^2＋浓度，用紫外分光光度计测定线粒体通透转运通道（MPTP）开放程度。结果I／R组、5-HD和5-HD＋ISO组线粒体肿胀，嵴断裂、溶解，内呈空泡状，ISO和SHAM组线粒体结构较完整，嵴及内膜间隙仍清晰可见。I／R、5．HD、5．HD＋ISO组线粒体游离Ca^2＋浓度及MFrP开放程度均高于SHAM组，ISO组线粒体游离Ca^2＋浓度及MPTP开放程度低于I/R组（P〈0．05）。结论异氟醚预处理对沙士鼠脑缺血再灌注损伤有保护作用，可能是通过激活线粒体ATP敏感性钾通道，减轻Ca^2＋超载，从而抑制MPTP开放而产生的。     

异丙酚和异氟醚在体感通路上的作用部位

目的：应用正中神经体感诱发电位（MnSSEP)监测初步判断异丙酚和异氟醚在体感传导通路上的作用部位。方法：26例ASA I－Ⅱ级病人随机分为异丙酚（I）和异氟醚（Ⅱ）组。测定两组不同麻醉深度时的MnSSEP。结果：I组N9、N13‘无改变；随着血药浓度的增高，逐步出现N60、P45、N35、N20、P25、潜伏期延长、波幅降低。Ⅱ组N9无改变；随着吸入浓度的增高逐步出现P45、N60、N35、N20、P25、潜伏期延长、波幅降低；N13‘波幅降低，N13‘-N20、N13‘-P25峰间期延长。结论：不同浓度的异丙酚，异氟醚在体感通路上的作用部位不同、浓度越高，作用范围越广。     

乳化异氟醚预处理对兔缺血再灌注心肌血流动力学的影响

近年来研究表明吸入麻醉药异氟醚可模拟缺血预处理发挥心肌保护作用，减轻再灌注期心肌功能抑制。以脂肪乳为载体静脉注射的乳化异氟醚可产生麻醉作用，但是否也具有心肌保护作用，尚无报道。为了进一步研究乳化异氟醚预处理对心肌缺血的保护效应，本实验在兔心肌缺血再灌注模型上测定不同时点血流动力学的有关指标，旨在探讨乳化异氟醚预处理对兔缺血再灌注心肌的血流动力学影响。     

Trypsin stimulates the phosphorylation of p42,44 mitogen-activated protein kinases via the proteinase-activated receptor-2 and protein kinase C epsilon in human cultured prostate stromal cells

BACKGROUND: The pathogenesis of benign prostatic hyperplasia (BPH) is not well understood. It involves the proliferation of prostate stromal cells. The proteinase-activated receptor subtype 2 (PAR-2) receptor is expressed by human prostate tissue and can be stimulated by serine proteases. Prostate epithelial cells secrete serine proteases such as trypsin, prostate specific antigen (PSA), and human glandular kallikrein (hK2). The p42,44 mitogen activated protein kinase (MAP kinase) pathway regulates cell proliferation. Trypsin can stimulate this pathway via the PAR-2 receptor and protein kinase C (PKC) in other tissues. Serine proteases secreted by prostate epithelial cells may interact with PAR-2 receptors expressed by prostate stromal cells causing them to proliferate. The aim of the present study was to establish whether functional PAR-2 receptors are expressed by human prostate stromal cells (HPSCs) and to determine whether PAR-2 stimulation can activate p42,44 MAP kinase via a pathway involving PKC. METHODS: HPSCs were cultured from patients undergoing trans urethral resection of the prostate (TURP). HPSCs were stimulated with PAR agonists. Immunoblotting of HPSC lysate with anti-p42,44 MAP kinase and -PKC isoforms. Data were analyzed with densitometry. RESULTS: Trypsin and the PAR-2 synthetic peptide SLIGKV caused significant increases in MAP kinase phosphorylation and calcium mobilization in HPSCs. The MAP kinase response was attenuated by pertussis toxin (PTX), phorbol 12,13 dibutyrate, Go6983, and Ro 318220. The PKC isoforms alpha, delta, epsilon, and zeta were detected in HPSCs. Trypsin caused the translocation of PKC(epsilon) from the cytosol to the membrane in HPSCs and was able to stimulate cellular proliferation. CONCLUSIONS: The PAR-2 selective serine protease trypsin activates p42,44 MAP kinase phosphorylation via PKC(epsilon). This may be an important mechanism of BPH pathophysiology.     

Heparin-binding epidermal growth factor-like growth factor functionally antagonizes interstitial cystitis antiproliferative factor via mitogen-activated protein kinase pathway activation

OBJECTIVE

To delineate the mechanism underlying the potential functional relationship between interstitial cystitis antiproliferative factor (APF) and heparin‐binding epidermal growth factor‐like growth factor (HB‐EGF), as APF has previously been shown to decrease the proliferation rate of normal bladder epithelial cells and the amount of HB‐EGF produced by these cells.

MATERIALS AND METHODS

APF‐responsive T24 transitional carcinoma bladder cells were treated with high‐pressure liquid chromatography‐purified native APF with or without HB‐EGF to determine the involvement of signalling pathways and proliferation by Western blot analysis, p38 mitogen‐activated protein kinase (MAPK) and extracellular signal‐regulated kinase (Erk)/MAPK assays, and 3‐(4,5‐dimethylthiazolyl‐2)‐2,5‐diphenyltetrazolium bromide (MTT) assay.

RESULTS

Cyclic stretch induced the secretion of HB‐EGF from T24 cells overexpressing the HB‐EGF precursor, resulting in enhanced proliferation. T24 cells treated with APF had increased p38MAPK activity and suppressed cell growth, events that were both reversed by treatment with a p38MAPK‐selective inhibitor. Activation of Erk/MAPK by HB‐EGF was inhibited by APF, and APF did not stimulate p38MAPK in the presence of soluble HB‐EGF or when cells overexpressed constitutively secreted HB‐EGF. Lastly, APF inhibitory effects on cell growth were attenuated by HB‐EGF.

CONCLUSIONS

These results indicate that HB‐EGF and APF are functionally antagonistic and signal through parallel MAPK signalling pathways in bladder cells.     

Isoflurane preconditioning induces neuroprotection that is inducible nitric oxide synthase-dependent in neonatal rats

BACKGROUND: Perinatal stroke is a common human disease. Neonatal brains are immature and engaged in active synaptogenesis. Preconditioning adult rats with the volatile anesthetic isoflurane induces neuroprotection. Whether isoflurane preconditioning induces neuroprotection in neonates is not known. METHODS: Seven-day-old Sprague-Dawley rats had left common carotid arterial ligation followed by hypoxia with 8% oxygen for 1, 2, or 2.5 h at 37 degrees C. Isoflurane preconditioning with 1 or 1.5% isoflurane for 30 min was performed at 24 h before the brain hypoxia/ischemia. The inducible nitric oxide synthase inhibitor aminoguanidine (200 mg/kg, intraperitoneally) was administered 30 min before the isoflurane pretreatment. The weight ratio of left to right cerebral hemispheres at 7 days after the brain hypoxia/ischemia was calculated. The mortality during the period from cerebral hypoxia/ischemia to 7 days afterwards was monitored. In another experiment, 6-day-old rats were exposed to 1.5% isoflurane for 30 min. The cerebral hemispheres were removed at various time points for Western analysis of inducible nitric oxide synthase. RESULTS: The mortality was about 40% in neonates with brain hypoxia/ischemia for 2 h or 2.5 h and was not altered by isoflurane preconditioning. The weight ratio of left/right cerebral hemispheres in the survivors was 0.99 +/- 0.02, 0.65 +/- 0.19, and 0.86 +/- 0.15 (n = 7-18) for the rats in control, brain hypoxia/ischemia for 2.5 h, and isoflurane preconditioning plus brain hypoxia/ischemia for 2.5 h groups, respectively (P < 0.05 for the comparisons between control versus brain hypoxia/ischemia and brain hypoxia/ischemia versus isoflurane preconditioning plus brain hypoxia/ischemia). This isoflurane preconditioning-induced neuroprotection was abolished by aminoguanidine (the weight ratio was 0.61 +/- 0.18, n = 12). Isoflurane induced a time-dependent increase in the inducible nitric oxide synthase proteins. CONCLUSIONS: Isoflurane preconditioning induces neuroprotection in neonatal rats. This neuroprotection is inducible nitric oxide synthase-dependent.     

Differential activation of mitogen-activated protein kinases in ischemic and anesthetic preconditioning

BACKGROUND: Accumulating evidence pinpoints to the pivotal role of mitogen-activated protein kinases (MAPKs) in the signal transduction underlying cardiac preconditioning. METHODS: PD98059, an inhibitor of extracellular signal-regulated protein kinase (MEK-ERK1/2), and SB203580, an inhibitor of p38 MAPK, were used to evaluate the role of MAPKs with respect to postischemic functional recovery in isolated perfused rat hearts subjected to ischemic preconditioning (IPC) and anesthetic preconditioning (APC). Western blot analyses were used to determine the degree of ERK1/2 and p38 MAPK activation after the application of the preconditioning stimulus and after ischemia-reperfusion. Immunohistochemical staining served to visualize subcellular localization of activated MAPKs. RESULTS: PD98059 and SB203580 abolished postischemic functional recovery in IPC but not in APC. IPC but not APC markedly activated ERK1/2 and p38 MAPK, which were abrogated by coadministration of the specific blockers. Conversely, IPC and APC enhanced ERK1/2 activity after ischemia-reperfusion as compared to nonpreconditioned hearts, and IPC in addition enhanced p38 MAPK activity. Coadministration of PD98059 and SB203580 during IPC but not during APC inhibited postischemically enhanced MAPK activities. Moreover, chelerythrine and 5-hydroxydecanoate, effective blockers of IPC and APC, annihilated IPC- and APC-induced enhanced postischemic responses of MAPKs. Finally, administration of PD98059 during ischemia-reperfusion diminished the protective effects of IPC and APC. Immunohistochemistry revealed increased ERK1/2 activity primarily in intercalated discs and nuclei and increased p38 MAPK activity in the sarcolemma and nuclei of IPC-treated hearts. CONCLUSIONS: Although MAPKs may orchestrate cardioprotection as triggers and mediators in IPC, they are devoid of triggering, but they may have mediator effects in APC.     

丝裂原活化蛋白激酶家族在局麻药神经毒性中的作用

背景 局麻药(local anesthetic,LA)广泛用于神经阻滞、镇痛,其可能引起的神经毒性引起了麻醉医生的关注,其中关于此种毒性作用机制的研究取得了较大的进展. 目的 分析总结各种丝裂原活化蛋白激酶家族(mitogen-activated protein kinases,MAPKs)成员在LA神经毒性中的作用. 内容 越来越多的证据证明LA的神经毒性作用可能与细胞凋亡有关.MAPKs是一种广泛存在细胞内的丝氨酸/苏氨酸蛋白激酶,在细胞凋亡过程中发挥重要作用.故MAPK信号通路逐渐成为LA毒性作用研究中的重点,其中关于细胞外信号调节激酶(extracellular signal-regulated kinase,ERK),c-Jun N-末端激酶(c-jun nterminal kinase,JNK)以及p38MAPK信号转导通路的研究较为成熟. 趋向 MAPKs在LA神经毒性的具体机制中发挥重要作用,这为LA的临床应用及毒性作用防治提供依据和理论指导.     

丝裂原活化蛋白激酶家族与病理性疼痛

病理性疼痛包括炎性痛和神经病理性痛。炎性痛是由创伤、细菌或病毒感染及外科手术等引起的外周组织损伤导致的炎症而引起的疼痛;神经病理性疼痛是由于外周或中枢神经系统的直接损伤或功能紊乱引起的疼痛,其共同的临床表现有自发性疼痛、痛觉过敏、触诱发痛等。许多脊髓或高级中枢神经病理生理的改变都可引起或参与病理性神经痛的形成。目前的研究认为,脊髓背角神经元及脊髓胶质细胞丝裂原活化蛋白激酶家族活化与病理性疼痛有关[1,2]。现就MAPKs在病理性疼痛的发生、发展过程中所起的作用作一综述。1 MAPKsMAPKs在所有真核细胞中均有表…     

丝裂原活化蛋白激酶参与骨癌痛的研究进展

背景丝裂原活化蛋白激酶（mitogen-activated protein kinases,MAPKs）是细胞内重要的信号转导系统,在调控神经元可塑性及骨癌痛中发挥重要作用。近年来,发现在中枢和外周神经系统,MAPKs信号通路参与调控了骨癌痛的发生和维持。目的回顾和总结MAPKs信号通路调控骨癌痛中的机制。内容MAPKs家族成员及其上下游信号分子在骨癌痛中的表达及其作用机制。趋向明晰MAPKs信号系统参与癌痛过程的机制,为更好地治疗肿瘤相关疼痛提供理论依据。     

Decreased expression of mitochondrial aldehyde dehydrogenase‐2 induces liver injury via activation of the mitogen‐activated protein kinase pathway

The aim of this study was to determine the role of ALDH2 in the injury of liver from brain‐dead donors. Using brain‐dead rabbit model and hypoxia model, levels of ALDH2 and apoptosis in tissues and cell lines were determined by Western blot, flow cytometry (FCM), and transferase (TdT)‐mediated biotin‐16‐dUTP nick‐end labeling (TUNEL) assays. After the expression of ALDH2 during hypoxia had been inhibited or activated, the accumulations of 4‐hydroxynonenal (4‐HNE) and molecules involved in mitogen‐activated protein kinase (MAPK) signaling pathway were analyzed using ELISA kit and Western blot. The low expression of phosphorylated ALDH2 in liver was time‐dependent in the brain‐dead rabbit model. Immunohistochemistry showed ALDH2 was primarily located in endothelial, and the rates of cell apoptosis in the donation after brain‐death (DBD) rabbit groups significantly increased with time. Following the treatment of inhibitor of ALDH2, daidzein, in combination with hypoxia for 8 h, the apoptosis rate and the levels of 4‐HNE, P‐JNK, and cleaved caspase‐3 significantly increased in contrast to that in hypoxic HUVECs; however, they all decreased after treatment with Alda‐1 and hypoxia compared with that in hypoxic HUVECs (P < 0.05). Instead, the levels of P‐P38, P‐ERK, P‐JNK, and cleaved caspase‐3 decreased and the ratio of bcl‐2/bax increased with ad‐ALDH2 (10⁶pfu/ml) in combination with hypoxia for 8 h, which significantly alleviated in contrast to that in hypoxic HUVECs. We found low expression of ALDH2 and high rates of apoptosis in the livers of brain‐dead donor rabbits. Furthermore, decreased ALDH2 led to apoptosis in HUVECs through MAPK pathway.     

Isoflurane neuroprotection in hypoxic hippocampal slice cultures involves increases in intracellular Ca2+ and mitogen-activated protein kinases

BACKGROUND: The volatile anesthetic isoflurane reduces acute and delayed neuron death in vitro models of brain ischemia, an action that the authors hypothesize is related to moderate increases in intracellular calcium concentration ([Ca2+]i). Specifically, the authors propose that during hypoxia, moderate increases in [Ca2+]i in the presence of isoflurane stimulates the Ca2+-dependent phosphorylation of members of the mitogen-activated protein kinase (MAP) kinase Ras-Raf-MEK-ERK pathway that are critical for neuroprotective signaling and suppression of apoptosis. METHODS: Death of CA1, CA3, and dentate neurons in rat hippocampal slice cultures was assessed by propidium iodide fluorescence 48-72 h after 60-75 min of hypoxia. [Ca2+]i in CA1 neurons was measured with fura-2 and fura-2 FF. Concentrations of the survival-signaling proteins Ras, MEK, MAP kinase p42/44, and protein kinase B (Akt) were assessed by immunostaining, and specific inhibitors were used to ascertain the role of Ca2+ and MAP kinases in mediating survival. RESULTS: Isoflurane, 1%, decreased neuron death in CA1, CA3, and dentate gyrus neurons after 60 but not 75 min of hypoxia. Survival of CA1 neurons required an inositol triphosphate receptor-dependent increase in [Ca2+]i of 30-100 nm that activated the Ras-Raf-MEK-ERK (p44/42) signaling pathway. Isoflurane also increased the phosphorylation of Akt during hypoxia. CONCLUSIONS: Isoflurane stimulates the phosphorylation of survival signaling proteins in hypoxic neurons. The mechanism involves a moderate increase in [Ca2+]i from release of Ca from inositol triphosphate receptor-dependent intracellular stores. The increase in [Ca2+]i sets in motion signaling via Ras and the MAP kinase p42/44 pathway and the antiapoptotic factor Akt. Isoflurane neuroprotection thus involves intracellular signaling well known to suppress both excitotoxic and apoptotic/delayed cell death.