右美托咪定对大鼠离体肺缺血-再灌注损伤时RIP K3/MLKL介导程序性坏死的影响

目的评价右美托咪定对大鼠离体肺缺血-再灌注损伤(LIRI)时受体相互作用蛋白激酶3(RIPK3)/混合系列蛋白酶样结构域(MLKL)介导的肺组织细胞程序性坏死的影响。方法成年雄性SD大鼠72只,采用随机数字表法随机分成三组(n=24):缺血-再灌注损伤组(IR组)、右美托咪定组(DEX组)和对照组(C组)。IR组采用IL-2型离体肺灌流系统建立大鼠离体LIRI模型; DEX组在复灌开始时于灌流液中加入右美托咪定10 nmol/L;C组只通气和灌流。测定大鼠肺组织湿/干重比(W/D),光镜下观察肺组织病理学并测定肺泡损伤率(IAR)。测定灌流液中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。Western blot法分别检测肺组织中RIPK3和MLKL蛋白含量。结果与C组比较,IR组和DEX组肺组织W/D、IAR和灌流液中MDA含量均明显升高(P0.05),而灌流液中SOD活性均明显降低(P0.05)。与IR组比较,DEX组肺组织W/D、IAR和灌流液中MDA含量均明显降低(P0.05),而灌流液中SOD活性明显升高(P0.05)。光镜显示IR组肺组织形态学结构发生明显损伤,而DEX组则明显减轻。与C组比较,IR组和DEX组肺组织RIPK3和MLKL蛋白含量均明显升高(P0.05);与IR组比较,DEX组肺组织RIPK3和MLKL蛋白含量均明显降低(P0.05)。结论右美托咪定可通过抑制RIPK3/MLKL介导的肺组织细胞程序性坏死来减轻大鼠离体肺缺血-再灌注损伤。     

缝隙连接Cx43在右美托咪定预防缺血-再灌注离体兔心复灌性心律失常中的作用

目的观察右美托咪定对离体家兔心缺血-再灌注(ischemia-reperfusion,IR)损伤后心肌复极不均一性及Cx43表达的影响,探讨Cx43在右美托咪定抑制IR损伤心肌复极不均一性中的作用。方法健康成年家兔18只,体重(2.0±0.5)kg,成功制备Langendorff离体心脏灌注模型,KH液平衡灌流15min后随机均分为三组,每组6只。空白对照组(C组):持续平衡灌注37℃K-H液150min;IR组:K-H液继续灌流15 min后停灌,注射4℃Thomas液10 ml/kg使心脏停搏60min,心脏周围用4℃Thomas液保护,30min半量复灌4℃Thomas液5ml/kg,60min时复灌K-H液;右美托咪定组(DEX组):于K-H液及Thomas液中加入右美托咪定25ng/ml,余同IR组。记录平衡灌流15min(T_0)、继续灌流15min(平衡30min,T_1)、复灌30min(平衡120min,T_2)、复灌60min(平衡150min,T_3)的HR及三层心肌(内膜、中膜、外膜)90%单相动作电位时程(MAPD90)并以此计算跨室壁复极离散度(transmural dispersion of repolarization,TDR),观察心脏复灌时心律失常发生情况、复跳时间,T_3时取左心室组织采用Western blot法、免疫组化法检测左室心肌组织Cx43的表达及分布。结果 DEX组复跳时间明显短于IR组(P0.05);与T_0时比较,T_2、T_3时IR组、DEX组HR明显减慢,TDR明显增大(P0.05);与IR组比较,T_1~T_3时DEX组HR明显减慢,T_2、T_3时DEX组TDR明显减小(P0.05)。与C组比较,IR组、DEX组Cx43表达明显减少(P0.05)且分布不均,且DEX组明显多于IR组(P0.05)。结论右美托咪定抑制IR损伤后心肌复极不均一性,从而起到稳定IR损伤心肌心电传导,降低复灌性心律失常发生率的作用,其机制可能与右美托咪定抑制缝隙连接失偶联、抑制Cx43表达减少及分布紊乱有关。     

右美托咪定预防大鼠创伤后应激障碍的效果及其对海马ERK活性及ARC表达的影响

目的 评价右美托咪定预防大鼠创伤后应激障碍(PTSD)的效果及其对海马细胞外信号调节激酶(ERK)活性及活动调节骨架蛋白(ARC)表达的影响.方法 成年雄性SD大鼠68只,体重250～280 g,采用随机数字表法,将大鼠分为4组(n=17)∶生理盐水组(NS组)、右美托咪定0.3 μg/kg组(D1组)、右美托咪定3.0μg/kg组(D2组)和右美托咪定9.0μg/kg组(D3组).于PTSD模型制备前30 min,NS组腹腔注射生理盐水2 ml,D1组、D2组和D3组分别腹腔注射右美托咪定0.3、3.0和9.0μg/kg.采用应激增强恐惧学习法制备PTSD模型.于模型制备第1天A室电击处理后15 min时采用Western blot法检测海马ERK、磷酸化ERK(p-ERK)的表达水平;第1天A室电击处理后30 min时采用Western blot法检测海马ARC的表达水平.结果 与模型制备第2天比较,3组大鼠模型制备第3天木僵率升高(P＜0.05);与NS组比较,D2组和D3组模型制备第3天木僵率均下降,海马p-ERK和ARC表达降低(P＜0.05),D1组上述指标差异无统计学意义(P＞0.05);D2组和D3组上述指标比较差异无统计学意义(P＞0.05).4组大鼠海马ERK表达差异无统计学意义(P＞0.05).结论 右美托咪定对大鼠PTSD有一定预防作用,且与剂量有关,该作用机制与抑制海马ERK活性,下调ARC表达有关.     

盐酸右美托咪定对缺血-再灌注损伤大鼠心肌Toll样受体4/核因子-κB信号通路的作用

目的研究盐酸右美托咪定对心肌缺血-再灌注损伤大鼠心肌组织中Toll样受体(toll-like receptor,TLR)-4mRNA、核因子(nuclear factor,NF)-κB mRNA的表达,探讨盐酸右美托咪定对心肌缺血-再灌注损伤大鼠心肌TLR-4/NF-κB信号通路的影响。方法健康3个月龄SD雄性大鼠21只,体重250~300g,随机均分为三组:假手术组(sham组)、缺血-再灌注组(IR组)、缺血-再灌注+盐酸右美托咪定组(DEX组)。采用结扎左冠状动脉前降支的方法制备大鼠心肌缺血-再灌注损伤模型,sham组左冠状动脉穿线不结扎。Sham组和IR组在结扎前30min经腹腔注射生理盐水100μg/kg,DEX组在结扎前30min经腹腔注射盐酸右美托咪定注射液100μg/kg(4μg/ml)。实时定量逆转录聚合酶链反应(RT-PCR)方法检测TLR-4mRNA和NF-κB mRNA的表达。结果sham、IR和DEX组的TRL-4mRNA分别为(2.21±0.11)、(7.83±0.35)和(3.91±0.21),sham、IR和DEX组的NF-κB mRNA分别为(0.013±0.166)、(0.051±0.016)和(0.015±0.004),IR、DEX组的TRL-4mRNA和NF-κB mRNA的表达明显高于sham组,且DEX组TRL-4mRNA和NF-κB mRNA的表达明显低于IR组(P0.05)。结论盐酸右美托咪定可降低缺血-再灌注损伤大鼠心肌组织TLR-4mRNA和NF-κBmRNA的表达,盐酸右美托咪定可以调控TLR/NF-κB信号通路的转导,抑制炎症反应,减轻心肌缺血-再灌注损伤,保护心肌。     

右美托咪定对大鼠局灶性脑缺血-再灌注损伤后抗氧化能力的影响

目的观察右美托咪定预先处理对大鼠局灶性脑缺血-再灌注损伤后抗氧化能力的影响。方法健康雄性SD大鼠42只,体重250~280g,随机分为假手术组(Sham组)、缺血-再灌注组(IR组)和右美托咪定组(DEX组),每组14只。采用大脑中动脉线栓法制作大鼠局灶性脑缺血-再灌注损伤模型,具体方法为线栓法栓塞大脑中动脉2h后恢复再灌注。Sham组仅分离血管,不留置线栓;于大脑中动脉栓塞前30 min DEX组给予腹腔注射盐酸右美托咪定注射液100μg/kg(4μg/ml),IR组腹腔注射等量的生理盐水。三组均于再灌注24h后取8只大鼠进行神经功能评分,测定脑梗死体积;剩余6只大鼠取脑组织检测超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSHPX)、谷胱甘肽还原酶(GR)和过氧化氢酶(CAT)活性。结果 IR组和DEX组神经功能评分明显高于Sham组,脑梗死体积明显大于Sham组,SOD、GSH-PX、GR、CAT活性明显低于Sham组(P0.05);DEX组大鼠神经功能评分明显低于IR组,脑梗死体积明显小于IR组,SOD、GSH-PX、GR、CAT活性明显高于IR组(P0.05)。结论右美托咪定有保护内源性抗氧化酶活性作用,可能有助于减轻大鼠脑缺血-再灌注损伤。     

右美托咪定对家兔窦房结细胞动作电位的影响

目的 评价右美托咪定对家兔窦房结细胞动作电位的影响.方法 健康新西兰家兔,雌雄不拘,体重1.5～2.5 kg,开胸取心脏,分离窦房结,60个离体窦房结,采用随机数字表法,将其随机分为6组(n=l0):正常对照组(C组)、0.5 ng/ml右美托咪定组(D1组)、5.0 ng/ml右美托咪定组(D2组)、5.0 ng/ml右美托咪定+α2肾上腺素能受体拮抗剂育亨宾组(D2+Y组)、5.0 ng/ml右美托咪定+非选择性超极化激活环核苷酸门控阳离子电流阻断剂氯化铯组(D2+C组)和50.0 ng/ml右美托咪定组(D3组).6组先用台氏液灌流60 min,C组继续用台氏液灌流40 min,D1组、D2组和D3组分别用含0.5、5.0、50.0 ng/ml右美托咪定灌流40 min,D2+Y组和D2+C组分别用含1 μmol/L育亨宾和2mmol/L氯化铯的台氏液灌流20 min,随后再加入5.0 ng/ml右美托咪定继续灌流20 min.分别于台氏液灌流60 min、育亨宾或氯化铯灌流20 min时和右美托咪定停止灌流时记录最大去极速率(Vmax)、动作电位幅度(APA)、复极化50％的动作电位时程(APD50)、复极化90％的动作电位时程(APD90)、4期自动去极速率(VDD)和起搏放电频率(RPF).结果 与C组比较,D1组、D2组和D3组T2,3时APA、VDD和RPF降低,Dt组、D2组和D3组上述指标依次降低(P＜0.05),4组间Vmax、APD5和APD90差异无统计学意义(P＞0.05).与T1时比较,T2时D2+C组VDD和RPF降低,T3时D2+Y组和D2+C组APA、VDD和RPF降低(P＜0.05),余参数差异无统计学意义(P＞0.05)；与T2时比较,T3时D2+Y组APA、VDD和RPF降低,D2+C组APA降低(P＜0.05),余参数差异无统计学意义(P＞0.05).结论 右美托咪定可呈浓度依赖性地降低家兔窦房结细胞自律性,其机制与抑制超极化激活的环核苷酸门控阳离子电流有关,而与α2肾上腺素能受体无关.     

右美托咪定对家兔离体心脏缺血-再灌注时心肌单相动作电位及跨室壁复极离散度的影响

目的观察右美托咪定对家兔离体心脏缺血-再灌注心肌动作电位及跨室壁复极离散度的影响,探讨其对缺血-再灌注心肌电生理特性的作用。方法健康成年家兔18只,体重(2.0±0.5)kg,成功制备Langendorff离体心脏灌注模型,K-H液平衡灌注15min后,随机分为三组,每组6只:空白对照组(C组):持续平衡灌注37℃K-H液150min;缺血-再灌注组(IR组):K-H液继续灌注15min后停止,注射Thomas液(4℃,10 ml/kg)使心脏停搏60 min,心脏周围用低温(4℃)Thomas液保护,30min半量复灌Thomas液(4℃,5ml/kg),60min时复灌K-H液;右美托咪定组(DEX组):于K-H液及Thomas液中加入右美托咪定(25ng/ml),余同IR组。记录平衡灌注15min(T0)、继续灌注15min/平衡30min(T1)、复灌30min/平衡120min(T2)、复灌60min/平衡150min(T3)的HR及三层心肌[内膜(Endo)、中膜(Mid)、外膜(Epi)]单相动作电位振幅(monophonic action potential amplitude,MAPA),0相最大上升速率(Vmax),90%单相动作电位时程(monophonic action potential duration,MAPD90)并计算跨室壁复极离散度(transmural dispersion of repolarization,TDR),观察心脏复灌时心律失常、复跳时间,均不使用药物恢复心律。结果 DEX组心脏复跳时间(16.67±3.78)s明显短于IR组(46.33±7.29)s(P0.05);心脏复跳时IR组有6例发生心律失常,2min内有2例恢复正常节律;DEX组有2例发生心律失常,2min内有1例恢复正常节律。与T0时比较,T2、T3时IR组,T1~T3时DEX组HR明显减慢(P0.05);与T1时比较,T2、T3时DEX组HR明显减慢(P0.05);与T2时和C组比较,T3时DEX组HR明显减慢(P0.05);T1~T3时DEX组HR明显慢于IR组(P0.05)。与T0时比较,T1时DEX组Mid部位,T2、T3时DEX组Epi、Mid、Endo部位的MAPD90明显延长(P0.05)。与T1时比较,T3时DEX组Epi、Mid、Endo部位的MAPD90明显延长(P0.05);T3时DEX组Mid部位的MAPD90明显长于C组(P0.05);T2、T3时DEX组Epi、Mid、Endo部位的MAPD90明显长于IR组(P0.05)。与T0时和C组比较,T2、T3时IR组,T1~T3时DEX组TDR明显增大(P0.05);T2、T3时DEX组TDR明显小于IR组(P0.05)。结论右美托咪定能够延长MAPD、抑制缺血-再灌注损伤后心肌复极不均一性,具有稳定缺血-再灌注心肌电生理特性的作用。     

右美托咪定预处理对大鼠心肌缺血-再灌注后心室功能和细胞凋亡的影响

目的探讨右美托咪定预处理对大鼠心肌缺血-再灌注损伤后心室功能和心肌细胞凋亡的影响。方法 30只SD大鼠随机分为三组,右美托咪定组(D组),右美托咪定+育亨宾组(D+Y组)和对照组(IR组),D组给予右美托咪定5μg·kg-1·h-1预处理1h,D+Y组静脉注射育亨宾1mg/kg,10min后按5μg·kg-1·h-1输注右美托咪定1h;IR组仅输注等量生理盐水,建立Langendorff缺血-再灌注模型,每10分钟测定左心室舒张末压(LVEDP)、左心室收缩压(LVSP)、左心室内压最大上升速率、下降速率(±dp/dtmax),计算左心室发展压(LVDP)。60min后取下心脏并以TUNEL检测心肌细胞的凋亡,RT-PCR检测Bcl-2mRNA,Bax mRNA的表达。结果与D组比较,再灌注后不同时点IR组和D+Y组大鼠LVDP、±dp/dtmax、Bcl-2mRNA表达明显降低、LVEDP、Bax mRNA表达明显升高(P0.05)。IR组和D+Y组LVDP、LVEDP、±dp/dtmax、Bcl-2mRNA和Bax mRNA表达差异均无统计学意义。IR组细胞阳性率为(36.1±9.2)%、D+Y组为(38.2±6.5)%,明显高于D组为(24.0±8.3)%(P0.05),而IR组和D+Y组细胞阳性率差异无统计学意义。结论右美托咪定预处理可以显著改善大鼠心肌缺血-再灌注损伤后的心室功能,并且可能通过调控凋亡基因Bcl-2mRNA和促凋亡基因BaxmRNA的表达,减少心肌细胞凋亡。     

右美托咪定对脂多糖诱导的脓毒症大鼠全身炎症反应和肺损伤的影响

目的观察脂多糖(LPS)对大鼠血浆和肺组织中的炎性因子和Toll样受体4(TLR4)表达的影响及右美托咪定的干预作用。方法雄性SD大鼠40只,250~300g,随机分为四组。Control组(n=10)生理盐水1ml·kg~(-1)·h~(-1)大鼠尾静脉泵注6h;DEX组(n=10)右美托咪定(负荷量6.5μg·kg~(-1)·h~(-1),10min;5μg·kg~(-1)·h~(-1)维持)大鼠尾静脉泵注6h;LPS组(n=10)经大鼠尾静脉注射7.5mg/kg的LPS后继续生理盐水泵注6h;LPS+DEX组(n=10)经大鼠尾静脉注射7.5mg/kg的LPS后泵注右美托咪定6h。以6h为实验终结点,并于此时行右心室取血和肺组织标本的制备。采用ELISA法检测血浆IL-1、IL-6、TNF-α浓度,Western blot法检测肺组织TLR4、髓样分化因子88(MyD88)、NF-κB蛋白含量;检测大鼠肺组织湿/干比(W/D);并用Murakami法评测肺损伤程度。结果与Control组比较,LPS组大鼠血浆IL-1、IL-6和TNF-α浓度明显升高,肺组织中的TLR4、MyD88、NF-κB蛋白含量明显升高(P0.01),肺W/D明显升高;LPS+DEX组上述指标差异均无统计学意义。Control组和DEX组未见明显肺损伤,LPS组肺间质水肿、炎性细胞浸润明显,LPS+DEX组肺损伤程度明显减轻(P0.01)。结论 LPS的刺激可以明显升高大鼠血浆中炎性因子以及肺组织中TLR4的表达水平,右美托咪定的干预可以减轻这一趋势,缓解大鼠的全身炎症和肺水肿的程度。     

右美托咪定辅助全麻用于胸腔镜手术的效果

目的 评价右美托咪定辅助全麻用于胸腔镜手术的效果.方法 择期进行全麻胸腔镜手术的患者68例,性别不限,年龄45～70岁;ASAⅠ～Ⅱ级;体质量(63.77±5.17)kg.采用随机数字表法分为右美托咪定组(DEX组)和生理盐水组(对照组),各34例.DEX组给予盐酸右美托咪定注射液0.6μg/kg微量泵泵注,10 mi...     

Metabolism of Round Spermatids: Kinetic Properties of Pyruvate Kinase

Round spermatids (steps 1-8) were isolated from rat testes and kinetic properties of pyruvate (PK) in their extract were examined. A plot of PK activity against phosphoenolpyruvate (PEP) or ADP concentration appeared sigmoidal. Km values for PEP and ADP were 0.12 and 0.29 mM, respectively. However, fructose 1,6-bisphosphate (FBP) stimulated the enzyme markedly by increasing its affinity for PEP. FBP (0.35 microM) was required for 50% activation of PK, when the PK activity was measured at 25 microM PEP and 0.2 mM ADP. In contrast, ATP (Ki = 6.5 mM) inhibited the PK activity. On the other hand, in the presence of 5 mM glucose, the level of FBP in spermatids increased markedly, while that of ATP declined rapidly. The level of ADP remained constant. When the activity of PK in spermatid extract was measured at intracellular levels of FBP, ADP and ATP, it was maximum. The results suggest that PK becomes probably fully activated when glucose is metabolized in the glycolytic pathway of spermatids. It seems unlikely that PK is the rate-limiting step in glycolysis of spermatids.     

Expression of growth factor receptors,the focal adhesion kinase,and other tyrosine kinases in human soft tissue tumors

Background: The tyrosine kinases are a family of genes that includes many growth factor receptors and protooncogenes. They appear to have a role in many cancers, but have not been systematically studied in the pathogenesis and progression of human sarcomas. Methods: To characterize the protein tyrosine kinases that are expressed in human sarcomas, we used a polymerase chain reaction (PCR)-based method to construct kinase-specific cDNA libraries from low-grade and high-grade primary tumors. Thereafter, individual tyrosine kinase gene expression was assessed in a panel of sarcoma cell lines and primary tumors using Northern blotting and PCR. Results: We identified 19 species of tyrosine kinase genes, including many growth factor receptors, the human homolog of the focal adhesion kinase (FAK) gene, and a noveltrk-related kinase designated HGK2. Messenger RNA expression analyses showed relative overexpression of the two forms of the platelet-derived growth factor receptors (PDGFRs) with expression of the form restricted to a subgroup of high-grade and metastatic sarcomas. We were unable to demonstrate coexpression of the PDGF isoforms in primary tumors that overexpressed the receptors, suggesting that a PDGF/PDGFR autocrine pathway may not be a central mechanism in the malignant transformation of sarcomas in vivo. FAK expression was observed in a variety of sarcomas, with increased levels in several high-grade and metastatic leiomyosarcomas. Conclusions: When grouped together by histologic cell type and grade, the expression data of the 19 kinases in primary tumors described a greater degree of heterogeneity than is generally appreciated by clinicopathologic classification schemes. This diversity suggests that sarcomas, even those that appear to be clinically similar, arise through a variety of molecular pathways involving tyrosine kinases.Presented at the 46th Annual Cancer Symposium of the Society of Surgical Oncology, Los Angeles, March 18–21, 1993.     

血清心型肌酸激酶对判断电损伤后心脏损害的临床价值

目的探讨电损伤后心脏损害的发病情况及判断电损伤后心脏损害的血清酶学指标。方法研究了３２例电接触性损伤患者的心电图、血清肌酸激酶（ＣＫ）和心型肌酸激酶（ＣＫＭＢ）活性。结果１７例患者有心电图异常（Ａ组）,１５例患者心电图基本正常（Ｂ组）。将测定的血清ＣＫＭＢ减１１％总ＣＫ的差定义为ＣＫＭＢ差值。Ａ组ＣＫ、ＣＫＭＢ、ＣＫＭＢ／ＣＫ比率和ＣＫＭＢ差值明显高于Ｂ组（全部：Ｐ＜００５）。Ａ组８８％的患者ＣＫＭＢ差值大于２５Ｕ／Ｌ,Ｂ组为６７％（Ｐ＜００１）。结论（１）心脏损害是电损伤的常见并发症,高压电更易于导致心脏损害;（２）血清ＣＫＭＢ,特别是ＣＫＭＢ差值可用于评价电损伤患者的心脏损害。     

磷酸肌醇3激酶/蛋白激酶B信号通路在丁苯酞保护心肌缺血再灌注损伤中作用机制的实验研究

目的观察丁苯酞预处理对心肌缺血再灌注损伤的保护作用以及磷酸肌醇3激酶(PI3K)/蛋白激酶B(Akt)通路在此过程中的作用。方法将大鼠心肌细胞(H9C2)随机分为假手术组(Sham组)、缺血再灌注组(I/R组)、丁苯酞预处理组(I/R+NBP组)。通过氧气剥夺以及无糖培养基的更换模拟6 h缺血4 h复灌心肌缺血模型。通过细胞计数检测试剂盒(CCK-8)检测不同药物浓度细胞活性,探索丁苯酞的最佳药物浓度;比色法检测各组乳酸脱氢酶(LDH)以及丙二醛(MDA)含量;蛋白质印迹法(Western blot)检测PI3K、磷酸化蛋白激酶B(p-Akt)和Akt的蛋白表达水平;定量聚合酶链反应(qPCR)技术检测白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)在核糖核酸(mRNA)水平的表达。多组之间比较采用单因素方差分析,两组之间比较采用t检验。结果丁苯酞的最佳用药浓度为100μmol/L;I/R组MDA、LDH的表达量高于Sham组[(172.03±14.99)nmol/L比(38.98±6.49)nmol/L、(195.04±14.50)%比(100.00±0.00)%,t=14.106、11.354,P<0.05];I/R组IL-1β、TNF-α的表达量高于Sham组(22.36±2.71比1.00±0.00、6.20±0.31比1.00±0.00,t=13.660、28.874,P<0.05);I/R组PI3K、p-Akt的表达量也高于Sham组(0.61±0.34比0.34±0.01、0.95±0.04比0.36±0.04,t=13.487、18.392,P<0.05),差异有统计学意义。I/R+NBP组MDA、LDH的表达量低于I/R组[(56.98±4.79)nmol/L比(172.03±14.99)nmol/L、(140.34±4.44)%比(195.04±14.50)%,t=12.661、7.890,P<0.05];I/R+NBP组IL-1β、TNF-α的表达量低于I/R组(6.66±0.60比22.36±2.71、1.76±0.11比6.20±0.31,t=9.798、23.352,P<0.05),差异有统计学意义;I/R+NBP组PI3K、p-Akt的表达量高于I/R组(1.00±0.05比0.61±0.34、1.27±0.04比0.95±0.04,t=11.440、10.432,P<0.05),差异有统计学意义。结论丁苯酞可以通过减少细胞损伤、抑制氧化及炎性反应进而减轻心肌缺血再灌注损伤,该过程可能有PI3K/Akt通路的参与。     

Mitogen-activated protein kinase cascade and cell cycle-related genes in the kidney

Recent studies have shown that mitogen-activated protein kinase (MAPK) consists of at least 3 subfamilies, including the classical MAPK, stress-activated protein kinase/c-Jun N-terminal kinase, and p38 kinase. Transforming growth factor (TGF)-β-activating kinase-1 (TAK1) is a novel MAP kinase kinase (MAPKK) that is reported to stimulate the p38 kinase and/or c-Jun N-terminal kinase pathway. TAKdN, the active form of TAK1, inhibits [³H]-thymidine uptake, and reduces the percentages of cells in the S and G₂/M phases of the cell cycle. TAKK63W, the negative, or inactive form of TAK1, ameliorates the inhibition of³H-thymidine uptake and the percentages of cells in S and G₂/M phases induced by TGF-β. Overexpression of TAKdN inhibits cyclin D1 gene promoter activity and protein expression. In contrast, constitutive active MKK1, the classical p42/44 MAPK activator, increases cyclin D1 promoter activity and protein level. Overexpression of the active form of MKK1 increases [³H]-thymidine uptake, while the inactive form decreases the uptake. To elucidate the mechanisms of the cell cycle of mesangial cells, we produced adenovirus vectors containing the coding sequences of cyclin D1 (AxCAD1), p16^INK4 (AxCAp16), and p21^CIP1 (AxCAp21), and investigated whether transfer of these genes changes platelet-derived growth factor-and endothelin-1-induced proliferation of rat mesangial cells. AxCAp16 and AxCAp21 inhibits [³H]-thymidine incorporation and the mitogen-induced increase in cyclin-dependent kinase-4 activity, and reduces the percentage of cells in the S phase as well. Overexpression of cyclin D1 increases the percentage of the cells in the S and G₂ phases, and reduces cell size. These findings suggest that p16^INK4 and p21^CIP1 function as inhibitors of the proliferation of mesangial cells, induced by growth-promoting factors, and that deregulated expression of cyclin D1 causes disturbances in the cell cycle. This review was presented at the 40th Annual Meeting of the Japanese Society of Nephrology and received an Oshima Award for Young Investigators.     

长链非编码RNA-XIST对脊髓损伤大鼠神经元凋亡影响及其机制的实验研究

目的:探讨长链非编码核糖核酸-X染色体失活基因(lncRNA-XIST)对脊髓损伤大鼠神经元凋亡过程的影响及其作用机制。方法:将成年SD大鼠(北京中国科学院实验动物中心提供)随机分为假手术组、脊髓损伤组、观察组,假手术组接受椎板切除术,脊髓损伤组和观察组椎板切除后使用脊髓打击器损伤脊髓。假手术组和脊髓损伤组脊髓内注射空...     

鞘内注射吗啡加可乐定对切口痛大鼠脊髓背角蛋白激酶A催化亚单位表达的影响

Objective To observe the effect of intrathecal clonidine plus morphine on expression of protein kinase A (PKA) catalytic subunit in the spinal dorsal horn in a rat model of incisional pain. Methods Eighty male Sprague-Dawley rats were divided randomly into five groups: sham group, control group, pre-incisional morphine 2.5 μg group, pro-incisional clonidine 5 μg group and preincisional morphine 2.5 μg plus clonidine 5 lag group (n=16). lntrathecal catheter and the model of incisional pain were pro-duced according to Yaksh and Brennan's described method respectively. Changes of pain behavior were assessed by mechanical with-drawal threshold (MWT) and thermal withdrawal latency(TWL). The expressions of PKA catalytic subunit in the spinal dorsal horn were assessed by immunohistochemical method and western blotting analysis. Results Compared with sham group, MWT and TWL in control group were decreased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were increased significantly in control group (P<0.01). Compared with control group, MWT and TWL in pre-incision morphine 2 μg plus clonidine 5 lag group were increased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were decreased significantly in pre-incision morphine 2 μg plus clonidine 5 μg group (P<0.01). However, MWT, TWL and the number of positive cells and pro-tein expression of PKA catalytic subunit in the spinal dorsal horn changed with no statistical significance in pre-incisional morphine 2.5 μg group and pre-incisional clonidine 5 μg group compared with control group. Conclusion lntrathecal clonidine significantly enhances the antinociceptive effect of intrathecal morphine in a rat model of incisional pain, which might be associated with inhibi-tion of the increased expression of PKA catalytic subunit in spinal cord.     

鞘内注射吗啡加可乐定对切口痛大鼠脊髓背角蛋白激酶A催化亚单位表达的影响

Objective To observe the effect of intrathecal clonidine plus morphine on expression of protein kinase A (PKA) catalytic subunit in the spinal dorsal horn in a rat model of incisional pain. Methods Eighty male Sprague-Dawley rats were divided randomly into five groups: sham group, control group, pre-incisional morphine 2.5 μg group, pro-incisional clonidine 5 μg group and preincisional morphine 2.5 μg plus clonidine 5 lag group (n=16). lntrathecal catheter and the model of incisional pain were pro-duced according to Yaksh and Brennan's described method respectively. Changes of pain behavior were assessed by mechanical with-drawal threshold (MWT) and thermal withdrawal latency(TWL). The expressions of PKA catalytic subunit in the spinal dorsal horn were assessed by immunohistochemical method and western blotting analysis. Results Compared with sham group, MWT and TWL in control group were decreased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were increased significantly in control group (P<0.01). Compared with control group, MWT and TWL in pre-incision morphine 2 μg plus clonidine 5 lag group were increased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were decreased significantly in pre-incision morphine 2 μg plus clonidine 5 μg group (P<0.01). However, MWT, TWL and the number of positive cells and pro-tein expression of PKA catalytic subunit in the spinal dorsal horn changed with no statistical significance in pre-incisional morphine 2.5 μg group and pre-incisional clonidine 5 μg group compared with control group. Conclusion lntrathecal clonidine significantly enhances the antinociceptive effect of intrathecal morphine in a rat model of incisional pain, which might be associated with inhibi-tion of the increased expression of PKA catalytic subunit in spinal cord.     

鞘内注射吗啡加可乐定对切口痛大鼠脊髓背角蛋白激酶A催化亚单位表达的影响

Objective To observe the effect of intrathecal clonidine plus morphine on expression of protein kinase A (PKA) catalytic subunit in the spinal dorsal horn in a rat model of incisional pain. Methods Eighty male Sprague-Dawley rats were divided randomly into five groups: sham group, control group, pre-incisional morphine 2.5 μg group, pro-incisional clonidine 5 μg group and preincisional morphine 2.5 μg plus clonidine 5 lag group (n=16). lntrathecal catheter and the model of incisional pain were pro-duced according to Yaksh and Brennan's described method respectively. Changes of pain behavior were assessed by mechanical with-drawal threshold (MWT) and thermal withdrawal latency(TWL). The expressions of PKA catalytic subunit in the spinal dorsal horn were assessed by immunohistochemical method and western blotting analysis. Results Compared with sham group, MWT and TWL in control group were decreased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were increased significantly in control group (P<0.01). Compared with control group, MWT and TWL in pre-incision morphine 2 μg plus clonidine 5 lag group were increased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were decreased significantly in pre-incision morphine 2 μg plus clonidine 5 μg group (P<0.01). However, MWT, TWL and the number of positive cells and pro-tein expression of PKA catalytic subunit in the spinal dorsal horn changed with no statistical significance in pre-incisional morphine 2.5 μg group and pre-incisional clonidine 5 μg group compared with control group. Conclusion lntrathecal clonidine significantly enhances the antinociceptive effect of intrathecal morphine in a rat model of incisional pain, which might be associated with inhibi-tion of the increased expression of PKA catalytic subunit in spinal cord.