PC12细胞化学缺氧复氧损伤与缺氧诱导因子1表达的关系

目的 研究缺氧诱导因子1(HIF1)在PC12细胞化学缺氧复氧损伤中的作用。方法 在培养液中加入和去除氯化钴模拟化学缺氧和复氧，以乳酸脱氢酶(LDH)漏出和细胞超微结构改变作为细胞损伤指标，观察化学缺氧和复氧后不同时间细胞损伤和HIF1 α蛋白变化。结果 在氯化钴模拟化学缺氧实验中，LDH漏出明显增加，8h达高峰，随后逐渐下降，电镜结果与LDH改变相一致，HIF1 α蛋白表达在化学缺氧后2，4，8和12h均明显增加，8h达高峰，提示化学缺氧8h后细胞损伤逐渐减轻可能与HIF1 α蛋白水平升高有关。在模拟复氧实验中，LDH和细胞形态学改变都显示化学复氧8h细胞损伤最为严重，而HIF1 α蛋白表达在化学复氧4和8h均明显下降，提示细胞化学复氧损伤可能与HIF1 α蛋白水平下降有关。结论 HIF1对神经细胞化学缺氧复氧损伤具有保护作用。     

重组hCGPx腺病毒对人肾小管上皮细胞(HK-2)缺氧再复氧损伤的保护作用

目的:研究重组腺病毒介导的人胞质型谷胱甘肽过氧化物酶(hCGPx)转染对人肾小管上皮细胞缺氧再复氧损伤的保护作用。方法:将含hCGPXcDNA的质粒pGEM-T-hCG-Px和重组腺病毒穿梭质粒pACCMV-pLpA重组,构建pACC-MV-hCGPx穿梭质粒后,与包装质粒pJM17共转染293细胞,构建重组腺病毒AdCMV-hCGPx。以重组腺病毒载体AdCMV-hCGPx转染体外培养的人肾小管上皮细胞株HK-2,以转染空载体的HK-2细胞为对照组,检测转染细胞中CGPx的表达水平。将HK-2细胞经缺氧再复氧损伤处理后,分别检测细胞的存活率、凋亡率及死亡率。结果:各转染组细胞中CGPx的表达率显著高于对照组(P<0.01)。经缺氧再复氧损伤处理后,AdCMV-hCGPx转染组细胞的存活率较对照组明显增强,死亡细胞明显减少,细胞凋亡明显受到抑制。结论:重组腺病毒介导的hCGPx转染人肾小管上皮细胞可保护缺氧再复氧引起的损伤。     

前列地尔对培养乳鼠心肌细胞缺氧复氧损伤的保护作用

目的 :观察前列地尔对培养乳鼠心肌细胞缺氧复氧损伤的保护作用。方法 :采用纯化培养的心肌细胞建立缺氧复氧损伤模型 ,观察不同浓度前列地尔 (5 ,15 ,4 5 μg·L- 1)剂量组细胞的形态学变化 ,黄嘌呤氧化酶法测定细胞内超氧化物歧化酶(SOD)活力 ,硫代巴比妥酸显色法测定细胞内丙二醛 (MDA)含量 ,并测定缺氧复氧后细胞培养液中乳酸脱氢酶 (LDH)活性 ,透射电镜观察细胞超微结构改变。结果 :与正常组比较 ,模型组细胞SOD下降 ,MDA和LDH升高 (均P <0 .0 1)。前列地尔各剂量组与模型组比较 ,心肌细胞SOD(除小剂量组 )活性提高 ,MDA和LDH含量降低 (P <0 .0 1)。且心肌细胞形态及超微结构改善。结论 :前列地尔具有明显的抗缺氧复氧损伤、保护心肌细胞的作用。     

大鼠鼠胚海马神经元缺氧复氧致细胞凋亡模型的建立

目的建立大鼠鼠胚海马神经元缺氧复氧致细胞凋亡模型。方法在大鼠鼠胚海马神经元培养基础上,给予不同时间的缺氧复氧,应用Wright-Giemsa染色、TUNEL法检测细胞凋亡情况。结果随着缺氧和复氧时间的延长神经细胞凋亡数逐渐增加,其中缺氧4 h复氧48 h大鼠海马神经细胞凋亡最为显著。结论缺氧复氧可诱导培养的大鼠海马神经细胞发生凋亡,缺氧4 h复氧48 h可作为细胞凋亡模型。     

Effects and mechanism of glucagon-like peptide-1 on injury of rats cardiomyocytes induced by hypoxia-reoxygenation

Background Although the insulinotropic role of glucagon-like peptide-1 （GLP-1） in type 2 diabetes mellitus has been substantiated, its role in cardioprotection remains largely unknown. This study aimed to determine the effects of GLP-1 on injury of rats cardiac myocytes induced by hypoxia-reoxygenation （H/R） and the possible mechanisms.
Methods The cultured neonatal rats cardiac myocytes were randomly divided into seven groups： the normal control group, the H/R group, the GLP-1＋H/R group, the GLP-1＋H/R＋UO126 （the p42/44 mitogen-activated protein kinase （MAPK） inhibitor） group, the GLP-1＋H/R＋LY294002 （phosphatidylinositol 3-kinase （PI3K） inhibitor） group, the H/R＋UO126 group, and the H/R＋LY294002 group. The lactate dehydrogenase （LDH） activity, apoptosis rate of cardiac myocytes, and caspase-3 activity were detected after the injury of H/R.
Results Compared with the normal control group, the activity of LDH, cardiac myocyte apoptosis rate, and caspase-3 activity all increased significantly in the H/R group （P 〈0.01）. Compared with the H/R group, these three indices all decreased in the H/R＋GLP-1 group （P 〈0.01）. However, the changes of LDH activity, apoptosis rate, and caspase-3 activity were inhibited by LY294002 and UO126 respectively.
Conclusions GLP-1 can directly act on cardiac myocytes and protect them from H/R injury mainly by inhibiting their apoptosis. Its mechanism may be through the PI3K-Akt pathway and the MAPK signaling pathway.     

梓葛冻干粉针剂对人脐静脉内皮细胞体外缺血再灌注模型损伤的保护作用

目的:研究中药单体组方梓葛冻干粉针剂对人脐静脉内皮细胞(HUVECs)体外缺血再灌注模型损伤的保护作用。方法:体外培养HUVECs,采用氧糖剥夺(Krebs液)方法建立缺氧-复氧模型以模拟体内缺血再灌注损伤。分为正常组、模型组、尼莫地平组、梓葛低、中、高剂量组,复氧时正常组及模型组给予生理盐水,余组给予相应的药物干预后,测定细胞活力、细胞内超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、一氧化氮(NO)含量、细胞外乳酸脱氢酶(LDH)释放量;分析细胞凋亡相关蛋白Bcl-2、Bax、Caspase-3的表达。结果:与正常组相比,模型组A值、SOD活性显著性降低(P<0.05);MDA和NO含量以及LDH释放量均显著性升高(P<0.05),Caspase-3和Bax蛋白表达显著升高,Bcl-2蛋白表达显著下降,Bcl-2/Bax显著降低(P<0.01)。与模型组比较,梓葛低剂量组A值显著升高(P<0.05);梓葛低、中剂量组MDA和LDH含量显著降低(P<0.05),Bcl-2蛋白表达水平显著升高(P<0.05,P<0.01);梓葛低剂量组NO含量显著降低(P<0.05);梓葛冻干粉针剂的各剂量组SOD活性均显著提高(P<0.05),Bax蛋白水平显著降低(P<0.05,P<0.01),Bcl-2/Bax均显著提高(P<0.05,P<0.01);梓葛中、高剂量组Caspase-3蛋白表达水平显著降低(P<0.01)。结论:梓葛冻干粉针剂可显著拮抗缺氧-复氧对人脐静脉内皮细胞的损伤,其机制与抑制细胞自由基的产生、提高抗氧化能力及调节凋亡相关蛋白表达密切相关。     

Effects of hypoxia-reoxygenation on isolated liver nonparenchymal cells

To clarify the relationship between Kupffer cells (KC) and hepatocytes in hepatic ischemia-reperfusion injury, isolated liver nonparenchymal cells (NPC), including a large proportion of KC, from C3H/HeN and C3H/HeJ mice were utilized in an in vitro hypoxia-reoxygenation system which enabled precise control of the oxygen concentration in the circumferential air during incubation. The viability of NPC, concentrations of cytokines and superoxides released from NPC, and the effects of antioxidants on hypoxiareoxygenation were investigated. The results were: (1) The deterioration of NPC was slow under hypoxia, but a significant decrease in their viability was observed with reoxygenation. These results were virtually identical in C3H/HeN and C3H/HeJ mice. (2) The concentration of tumor necrosis factor (TNF)-α from NPC of C3H/HeJ was much lower than that from NPC of C3H/HeN, and production of O₂^? was lower in the NPC of C3H/HeJ than in C3H/HeN, but changes in the viability of NPCs which were reoxygenated following various intervals of hypoxia were almost identical in both types of mice. (3) Viability after reoxygenation was improved by the addition of catalase or superoxide dismutase (SOD), and further improved with the combined use of catalase and SOD. These results suggested that the changes in KC function after reoxygenation decreased the viability of the cells, due predominantly to the release of reactive oxygen metabolites, not to the release of TNF-α.     

柴胡注射液对小鼠灌流肝脏缺氧复氧损伤的保护作用

采用小鼠离体肝灌流术在Krebs－Henseleit（K－H）灌流液中加入柴胡注射液，观察柴胡对肝缺氧（1h）复氧（1h）的影响。结果表明：柴胡组与缺氧组相比，光镜电镜下肝组织损伤较轻，且肝组织乳酸脱氢酶（LDH）漏出量显著减少，脏／体比、还原型谷胱甘肽（GSH）及黄嘌呤氧化酶（XOD）含量有显著性差异，丙二醇（MDA）生成延迟。揭示柴胡对小鼠离体灌流肝缺氧复氧损伤有明显拮抗作用，其机制与抑制氧自由基形成有关。