维甲酸对转化生长因子β1 诱导的HFL-I细胞Ⅲ型胶原、STAT3和PIAS3表达的影响

目的: 研究全反式维甲酸(ATRA)对转化生长因子β₁(TGF-β₁)诱导的人胚肺成纤维细胞(HFL-I)中Ⅲ型胶原(collagen Ⅲ)、信号转导子和转录激活子3(STAT3)和活化STAT3蛋白抑制剂(PIAS3)表达的影响。方法: 体外培养HFL-I细胞,5 μg/L TGF-β₁诱导0 h、6 h、12 h、24 h、48 h和72 h后,RT-PCR法检测collagen Ⅲ、STAT3和PIAS3 mRNA表达,诱导0 d、1 d、3 d和5 d后,Western blotting法检测STAT3和p-STAT3蛋白表达。不同浓度维甲酸干预,24 h后用RT-PCR法检测collagen Ⅲ、STAT3和PIAS3 mRNA表达,3 d后用Western blotting法检测STAT3和p-STAT3蛋白表达。结果: TGF-β₁诱导后,HFL-I细胞中collagen Ⅲ和STAT3 mRNA表达明显上调,PIAS3 mRNA表达明显下调,STAT3和p-STAT3蛋白表达明显上调(P< 0.05)。各浓度ATRA都下调TGF-β₁诱导的HFL-I细胞中collagen Ⅲ、STAT3 mRNA和STAT3、p-STAT3蛋白的表达,上调PIAS3 mRNA表达(P<0.05)。结论: ATRA可通过抑制TGF-β₁诱导的HFL-I细胞collagen Ⅲ和STAT3表达、上调PIAS3表达而起到抗肺纤维化作用。     

全反式维甲酸对人胚肺成纤维细胞增殖及α-SMA表达的影响

目的: 研究全反式维甲酸(ATRA)对人胚肺成纤维细胞(HFL-I)增殖与分化的影响。方法: 体外培养HFL-I, MTT法检测不同浓度ATRA(0.1 μmol/L、1 μmol/L、10 μmol/L)作用3 d对HFL-I增殖能力的影响。5 μg/L 转化生长因子β₁(TGF-β₁)刺激0 h、6 h、12 h、24 h、48 h、72 h后,RT-PCR法检测α-平滑肌肌动蛋白(α-SMA) mRNA表达,刺激0 d、1 d、3 d、5 d后,Western blotting法检测α-SMA蛋白表达。不同浓度ATRA干预,24 h后RT-PCR方法检测α-SMA mRNA表达,3 d后用Western blotting方法检测α-SMA蛋白表达。结果: (1) MTT法检测显示不同浓度ATRA以浓度依赖性方式抑制HFL-I细胞的增殖(P<0.05)。(2)5 μg/L TGF-β₁诱导后,HFL-I细胞中α-SMA mRNA和蛋白表达均上调(P<0.05)。(3) ATRA以浓度依赖性方式下调TGF-β₁诱导的α-SMA mRNA和蛋白的表达(P<0.05)。结论: ATRA能够抑制HFL-I细胞的增殖和TGF-β₁诱导的分化,该作用可能是通过下调α-SMA mRNA和蛋白的表达实现的。     

糖尿病大鼠局灶脑缺血/再灌注损伤与脑组织TGF-β1mRNA表达

目的:观察糖尿病和对照组鼠脑缺血/再灌注损伤与转化生长因子β₁(TGF-β₁) mRNA表达的异质性。方法:采用逆转录聚合酶链式反应(RT-PCR)检测大鼠中脑动脉阻塞(MCAO)后脑内TGF-β₁ mRNA表达水平,并且应用组织病理进行损伤程度评定。 结果:糖尿病组大鼠脑缺血及缺血/再灌损伤程度明显重于"相应对照组"。糖尿病及对照组大鼠在MCAO 2 h时TGF-β₁ mRNA表达量明显增高,后者增高比前者更为明显。再灌24 h后TGF-β₁ mRNA表达量下降,但仍高于假手术组。结论:糖尿病加重缺血/再灌性脑损伤|MCAO后TGF-β₁ mRNA表达增高可能是机体一种抗损伤反应,糖尿病组抗损伤反应下降。     

富硒螺旋藻对肝叶切除大鼠肝细胞再生的促进作用

目的: 探讨富硒螺旋藻对肝叶切除大鼠肝细胞再生的促进作用。方法: 用Wistar大鼠复制67%肝叶切除动物模型，术前灌胃富硒螺旋藻7 d，于手术时(0 h)及术后12 h、48 h取鼠肝细胞，检测谷胱苷肽过氧化物酶(GPx)和硫氧还蛋白还原酶(TR)活性，免疫组化方法测定肝细胞增生细胞核抗原(PCNA)，放射免疫法测定肝细胞DNA合成率。实验设150(H)、50(M)、15(L) mg·kg^-1·d^-1剂量组以及安慰剂(P)组和假手术对照组(F)。结果: 与P、F组相比，实验组大鼠肝细胞GPx和TR活性及PCNA指数和［³H］-TDR掺入水平均明显升高(P<0.05)。相关分析发现，GPx和TR活性与PCNA表达指数均有明显正相关(r²=0.77和0.87,P<0.05)，与［3H］-TDR掺入水平也具有高度正相关(r²=0.73和0.84,P<0.05)。结论：结果提示Se-SP对肝叶切除大鼠具有明显促肝细胞再生效应，这些硒酶活性上调可能在增强肝细胞再生增殖中起重要作用。     

香烟提取物和脂多糖对人胚肺成纤维细胞TGF-β1 mRNA及蛋白表达的影响

目的:探讨香烟提取物(CSE)和脂多糖(LPS)对体外培养的人胚肺成纤维细胞(HELF)转化生长因子-β₁(TGF-β₁)mRNA及其蛋白表达的影响。方法:应用不同浓度的CSE(1∶50、1∶25和1∶10)、LPS(0.1 mg/L、1 mg/L和10 mg/L)及CSE(1∶25)与LPS(1 mg/L)联合作用于HELF, 37℃作用24 h后, 提取细胞总RNA, 应用逆转录-多聚酶链反应(RT-PCR)及免疫细胞化学技术检测TGF-β₁ mRNA和蛋白表达的变化。结果:CSE低浓度(1∶50和1∶25)时可增加HELF TGF-β₁ mRNA及蛋白的表达(Ｐ＜0.05), 高浓度(1∶10)时未引起TGF-β₁ mRNA及蛋白表达增强(Ｐ＞0.05)。不同浓度的LPS均引起HELF TGF-β₁ mRNA及蛋白表达增强(Ｐ＜0.05)。CSE与LPS联合作用也可增加HELF TGF-β₁ mRNA及蛋白的表达(Ｐ＜0.05)。结论：一定浓度的CSE和LPS可上调肺成纤维细胞TGF-β₁ mRNA及蛋白表达。     

脂氧素A4对肝细胞生长因子诱导HepG2肝癌细胞血管生成相关细胞因子表达的影响

目的: 探讨脂氧素A₄(LXA₄)对肝细胞生长因子(HGF)诱导的HepG2肝癌细胞血管生成相关细胞因子表达的影响。方法: 体外培养HepG2肝癌细胞,实验分为空白组、HGF处理组、HGF+LXA₄处理组、HGF+脂氧素受体激动剂BML-111处理组。RT-PCR检测脂氧素受体(ALX)表达情况,Western blotting检测COX-2、MMP-2、MMP-9、IκBα和NF-κB p65的表达量,ELISA检测TNF-α、IL-1β、VEGF和TGF-β分泌水平, 荧光素酶报告质粒检测NF-κB转录活性。结果: HepG2肝癌细胞表达ALX,LXA₄和BML-111下调COX-2、 MMP-2和MMP-9,抑制TNF-α、IL-1β、VEGF和TGF-β分泌,并且干扰NF-κB转位及其转录活性。结论: 脂氧素抑制HGF诱导HepG2肝癌细胞表达血管生成相关细胞因子,包括VEGF、COX-2、TNF-α、IL-1β、TGF-β、MMP-2及MMP-9,此效应可能通过干扰NF-κB活化实现。     

核心蛋白聚糖对翼状胬肉成纤维细胞增殖的影响

目的: 观察核心蛋白聚糖(DCN)对体外培养人翼状胬肉成纤维细胞(HPF)增殖的影响,并对照观察丝裂霉素C(MMC)对HPF的影响,寻找辅助治疗和预防翼状胬肉复发的新途径。方法: (1)取患者的翼状胬肉体部组织,采用组织块贴壁培养法原代培养HPF。(2)用0.01、0.1、1、5、10 mg/L DCN及 MMC分别作用于体外培养的HPF, 24 h、48 h、72 h后观察2种药物对HPF形态的改变,2种药物不同浓度分别作用12 h、24 h、48 h后 MTT法比较2种药物的作用效果,不同浓度的DCN作用48 h后免疫组织化学染色增殖细胞核抗原(PCNA)法检测细胞生长活性,流式细胞术测定细胞周期时相变化。结果: 10 mg/L DCN或1 mg/LMMC在12 h后均能显著抑制HPF的增殖(P<0.05),呈剂量和时间依赖性。1~10 mg/L DCN 作用48 h使G₀/G₁期细胞百分比上升(P<0.05),5~10 mg/LDCN 作用48 h使G₂/M期和S期百分比(G₂/M%+S%)显著下降(P<0.05),实验组和对照组均未检测到终末期凋亡细胞。1~10 mg/L DCN能浓度依赖性地抑制细胞表达PCNA(P<0.05)。结论: 核心蛋白聚糖能抑制HPF的增殖,阻滞细胞在DNA合成前期。     

大鼠肝再生过程中线粒体外周型苯二氮卓类受体的研究

目的：研究肝细胞线粒体通透性转换（PT）的主要调节蛋白外周型苯二氮卓类受体(PBR)在肝再生过程中的表达及其与专一性配体结合动力学变化，探讨与线粒体PT的关系。〖HTH〗方法：健康成年雄性SD大鼠，随机分为3组：肝部分切除（PH）组，切除肝左叶和中叶约全肝的70%；假处理组，同样麻醉和开腹，但不切肝；正常组。手术后3 h、6 h、12 h、 24 h、 48 h、 72 h、 120 h 和168 h 分别以半定量RT-PCR法检测PBR mRNA表达的动态变化。利用PBR专一的配体［3H］PK11195测定肝再生时线粒体膜上PBR的含量以及受体与配体亲和力的变化。〖HTH〗结果：在肝再生过程中PBR基因表达与假处理组无显著差异；［3H］PK11195与PBR最大结合量(Bmax)显著低于对照组（P <0.05），其中PH后3 h 和120 h非常显著（P<0.01），168 h接近正常水平； 平衡解离常数（Kd）在PH后72 h和168 h明显低于假处理照组（P<0.01）。假处理组之间Bmax和Kd无明显差异。〖HTH〗结论：肝再生过程中肝线粒体PBR mRNA水平无明显变化，而PBR与配体结合动力学明显改变提示PBR与线粒体PT变化有关。     

缝隙连接在TGF-β1 诱导的自发性高血压大鼠血管平滑肌细胞增殖中的作用

目的: 探讨缝隙连接是否参与转化生长因子β₁(TGF-β₁)诱导的自发性高血压大鼠(SHR)血管平滑肌细胞增殖及可能的分子机制。方法: 原代培养SHR胸主动脉平滑肌细胞,细胞分4组:对照组、TGF-β₁组、缝隙连接阻断剂18α-甘草次酸(18α-GA)组和TGF-β₁+18α-GA组。MTT法及流式细胞术检测细胞的增殖活性,免疫荧光技术观察细胞中缝隙连接蛋白(Cx)43和Cx40蛋白表达及定位,Western blotting法检测细胞中Cx43和Cx40蛋白表达, 染料示踪分子传递法(划痕标记染料传输法)检测细胞的缝隙连接功能。结果: (1)与对照组相比,TGF-β₁组MTT法测得A值及细胞周期S期比例增高 (P<0.05),细胞增殖活性增强。18α-GA组降低(P<0.05);与TGF-β₁组比,TGF-β₁+ 18α-GA组A值及S值比例均降低(P<0.05),细胞增殖活性减弱。(2)免疫荧光技术检测细胞中Cx43与Cx40蛋白表达呈阳性,两者共定位于胞浆。(3)与对照组相比,TGF-β₁组Cx43蛋白表达增强(P<0.05),Cx40表达无显著差异(P>0.05),18α-GA组Cx43和Cx40表达均减弱(P<0.05),与TGF-β₁组比,TGF-β₁+18α-GA组Cx43表达减弱(P<0.05),Cx40表达无显著差异(P>0.05)。(4)与对照组相比,TGF-β₁组缝隙连接功能明显增强(P<0.05);18α-GA组缝隙连接功能明显减弱(P<0.05);与TGF-β₁组比,TGF-β₁+18α-GA组缝隙连接功能显著降低(P<0.05)。结论: TGF-β₁主要通过上调SHR血管平滑肌细胞Cx43蛋白表达,引起缝隙连接通讯功能增强,从而促进了SHR血管平滑肌细胞的增殖,而Cx40蛋白表达可能不起主要作用。     

IgA肾病患者血清IgA1诱导正常人肾小球系膜细胞钙离子释放、转化生长因子β表达上调和纤连蛋白分泌

目的:研究IgA肾病患者血清IgA₁对正常人肾小球系膜细胞(HMC)活化及分泌炎症硬化因子的刺激作用,比较与正常人IgA₁的差异,探讨IgA肾病患者血清IgA₁病理生理作用。方法:亲和层析提取血清IgA₁,加热聚合(aIgA₁),激光共聚焦显微镜检测细胞内游离钙离子(Ca²⁺)释放,RT-PCR法检测细胞内TGF-β mRNA表达,间接竞争ELISA法检测细胞上清纤连蛋白(Fn)含量。结果:IgA肾病患者aIgA₁呈时间依赖性诱导正常HMC细胞内游离Ca²⁺释放、TGF-β mRNA表达和Fn分泌,作用趋势与正常人aIgA₁相同,高峰时间分别为孵育后60 s、24-36 h和36-48 h,但作用强度显著高于正常人aIgA₁;在作用高峰时间,患者组和正常人组Fluo-3最大相对荧光强度增加值分别为(95.83±11.43)和(55.88±12.72),TGF-β／GAPDH的比值分别为0.96±0.06和0.74±0.02,Fn含量分别为(6.45±0.18)μg/L和(5.54±0.43)μg/L,均有显著差异(P<0.05)。结论: IgA肾病患者血清IgA₁可以诱导体外培养的正常HMC活化并分泌炎症硬化因子,其作用较正常人IgA₁强,提示患者血清IgA₁分子与肾小球系膜细胞直接相互作用可能是IgA肾病发病机制之一。     

Blunted DNA synthesis and delayed S-phase entry following inhibition of Cdk2 activity in the regenerating rat liver

Activation of the cyclin E/Cdk2 complex may play an important role in mid-G1/S-phase progression in proliferating mammalian cells. We evaluated the effect of targeted inhibition of Cdk2 activity by CYC202 (R-roscovitine) on hepatocytes proliferation in vivo after 70% partial hepatectomy (PH) in rats. In controls, Cdk2 activity and DNA synthesis peaked 24 h after PH. CYC202 abrogated Cdk2 activity, prevented BrdU incorporation and PCNA expression and increased mortality 24 h after PH. Cyclin E and Cdk2 protein expression and complex formation was not affected by CYC202 nor was cyclin D1, Cdk4 and c-ras mRNA expression. Two consecutive injections 8 and 20 h after PH were required to elicit the inhibitory effect of CYC202, which was lost when either the injection at 8 h or at 20 h was withheld. Cdk2 activity and cell progression resumed 48 h after PH in surviving animals suggesting that CYC202 induced a reversible inhibition of the cell cycle. Our results confirm an important role for Cdk2 in hepatocytes proliferation in the regenerating liver. We demonstrate that molecular events, including Cdk2 activation, occurring within the 8th and 24th hour after PH (G1/S-phase transition) are crucial in determining whether or not DNA synthesis and hepatocytes proliferation proceed normally after PH.     

5-羟色胺4受体调节剂对肝部分切除大鼠胃肠5-羟色胺分泌和肝再生的影响

目的 探讨5-羟色胺4(5-HT4)受体调节剂(激动剂和抑制剂)对肝部分切除(PH)后大鼠胃肠道5-羟色胺(5-HT)和肝再生的影响. 方法 60只成年SD大鼠PH后分为对照组、西沙必利(激动剂)组和GR113808(抑制剂)组3组;西沙必利组PH后每12 h按10mg/kg体重的西沙必利灌胃,GR113808组PH后每12 h按3mg/kg体重的GR113808腹腔注射;分别于PH后0 h、24 h、48 h、72 h计算肝/体重比,并取血液、胃、小肠和肝组织;用免疫组织化学技术显示胃肠中5-HT免疫阳性(5-HTIR)细胞,用图像分析系统测定胃肠5-HTIR细胞平均灰度,用酶联免疫吸附法(ELESA)检测血液中的5-HT,用银染技术显示肝细胞核仁组织区相关嗜银蛋白(AgNORs). 结果 与对照组比,1. 西沙必利组胃肠中5-HTIR细胞数于PH后48～72 h显著下降(P<0.05)、细胞的灰度于PH后24～72 h显著上升(P<0.05),血中5-HT的含量于PH后24～72 h显著上升(P<0.05),肝/体重比和肝组织AgNORs颗粒数在PH后48～72 h显著增加(P<0.05);2. GR113808组在PH后24～72 h期间,5-HTIR细胞数较对照组无显著性差异,但细胞的灰度显著下降(P<0.05或P<0.01),血中5-HT的含量显著下降(P<0.05或P<0.01),肝/体重比于48～72 h显著下降(P<0.05或P<0.01),肝中AgNORs颗粒数于24～72 h显著减少(P<0.05或P<0.01). 结论 用5-HT4受体调节剂改变胃肠道5-HT的分泌量,可导致肝/体重比和肝细胞的转录活性发生相应的改变;胃肠道分泌的5-HT具有促进肝细胞增殖的作用.     

Phenylbutyrate exerts adverse effects on liver regeneration and amino acid concentrations in partially hepatectomized rats

Phenylbutyrate is recommended in urea cycle disorders and liver injury to enhance nitrogen disposal by the urine. However, hypothetically there may be adverse responses to the use of phenylbutyrate in the treatment of liver disease because of its role as a histone deacetylase inhibitor and its stimulatory effect on branched‐chain alpha‐keto acid dehydrogenase, the rate‐limiting enzyme in the catabolism of branched‐chain amino acids (BCAA; valine, leucine and isoleucine). We report the effects of phenylbutyrate on liver regeneration and amino acid levels in plasma of partially hepatectomized (PH) rats. Phenylbutyrate or saline was administered at 12‐h intervals to PH or laparotomized rats. Phenylbutyrate delayed the onset of liver regeneration compared to the saline‐treated controls, as indicated by lower hepatic DNA specific activities 18 and 24 h post‐PH, decreased hepatic fractional protein synthesis rates 24 h post‐PH and lowered the increases in liver weights and hepatic protein and DNA contents 48 h after PH. Hepatic DNA fragmentation (a hallmark of apoptosis) was higher in the phenylbutyrate‐treated animals than in controls. Phenylbutyrate decreased the glutamine and BCAA concentrations and the ratio of the BCAA to aromatic amino acids (phenylalanine and tyrosine) in the blood plasma in both hepatectomized and laparotomized animals. In conclusion, the delayed onset of liver regeneration and the decrease in BCAA/AAA ratio in blood suggest that phenylbutyrate administration may be disastrous in subjects with acute hepatic injury and BCAA supplementation is needed when phenylbutyrate is used therapeutically.     

Hepatocyte 'priming' and increase in transforming growth factor-beta1 mRNA expression are delayed in hypothyroid versus euthyroid rats during liver regeneration

Hypothyroidism decreases liver weight and delays the compensatory liver growth after partial hepatectomy (PH) as compared with the euthyroid condition. The aim of this study was to investigate, in hypothyroid rats, the mRNA expression of genes modulating these effects, focusing on c-fos and c-myc, hallmarks of hepatocyte 'priming', and on transforming growth factor-beta1 (TGF-beta1) and its receptor, the transforming growth factor-beta1 receptor-type II (TbetaR-II), negative regulators of liver growth. Euthyroid and hypothyroid male Wistar rats underwent 70% PH and total RNA was isolated from frozen liver samples removed at basal state and during regeneration, 0-144 h after surgery. In this study, we show for the first time that, in the basal liver state, hypothyroidism increased TGF-beta1 and TbetaR-II mRNA levels by 45% and 30%, respectively, as compared with the euthyroid condition and, after PH, resulted in a approximately 12-h delay in the activation of c-fos and c-myc mRNA expression. Moreover, the increase in TGF-beta1 mRNA levels, detected 24-48 h after PH in euthyroid rats, was delayed by 72 h in hypothyroid rats, occurring when a concomitant reduction in TbetaR-II was measured. These results suggest that, in hypothyroid rats, at the basal liver level, the increase in mRNA expression of genes that negatively regulate liver growth might be involved in the decrease in liver weight and that, after PH, the delay of hepatocyte 'priming' and coordinated changes in mRNA expression of negative regulators of liver regeneration might be involved in delaying the regenerative process.     

Protection of hepatotoxic and lethal effects of CCl4 by partial hepatectomy

CCl4 is a hepatotoxic haloalkane, capable of producing hepatocellular fatty degeneration and centrilobular necrosis. Previous reports indicate induction of liver regeneration after 36-48 hr of CCl4 treatment, which is considered as a secondary effect. The present investigation was undertaken to evaluate the primary effects of CCl4 on hepatic DNA synthesis and to correlate liver regeneration with CCl4 toxicity. These studies were conducted in normal and actively regenerating livers using male Sprague-Dawley rats undergoing sham operation (SH), or partial (70%) hepatectomy (PH). Incorporation of 3H-thymidine (3H-T) in hepatocellular nuclear DNA and autoradiographic analyses of liver sections served as indices for hepatocellular regeneration. Initial experiments established that peak regeneration occurs at 2 days post-PH (PH2) and liver regeneration phases out by 7 days post-PH (PH7). SH and PH rats were challenged with a single ip dose of either corn oil vehicle or CCl4 at either 0.1 ml/kg (to represent subtoxic dose) or 2.5 ml/kg (to represent toxic dose). The low dose of CCl4 was not toxic and did not alter 3H-T incorporation and percentage labelled cells at 6 or 24 hours after administration to SH, PH2 or PH7 groups, indicating that there was no interference with PH-stimulated hepatocellular regeneration. The high dose of CCl4 was significantly hepatotoxic and lethal in SH rats, while in PH2 rats both hepatotoxic and lethal effects were significantly decreased. 3H-T incorporation as well as percentage labelled cells, highly stimulated by PH, were significantly decreased by high dose of CCl4. However, hepatocellular regeneration in PH2 rats treated with high dose of CCl4 was still significantly higher than SH or PH7 groups by virtue of the stronger stimulatory effect of PH. In PH7 rats, where hepatocellular regeneration had returned to the SH level, the hepatotoxic and lethal effects of the large dose of CCl4 were also restored. These findings show that the progressive phase of a single high dose of CCl4 injury which normally culminates in hepatotoxic and lethal effects is significantly mitigated by previously stimulated hepatocellular regeneration. High dose of CCl4 suppresses hepatocellular regeneration at early time points after administration in contrast to the smaller subtoxic dose of CCl4. By virtue of the much stronger stimulatory effect, PH results in the protection against the hepatotoxic and lethal effects of CCl4 despite the obtunding effects of the high dose on hepatocellular regeneration.     

Localization and induced expression of fusion genes in the rat lung.

Liposome-mediated gene transfer is useful for DNA transfection into cells in culture. We wondered whether this method could be used to introduce new DNA into the intact lung. Fusion genes containing either the Rous sarcoma virus (RSV) promoter or the mouse mammary tumor virus (MMTV) promoter (which contains glucocorticoid response elements) were linked to the bacterial gene chloramphenicol acetyltransferase (CAT), an enzyme not present in mammalian cells. Plasmids containing the RSV-CAT fusion gene were mixed with cationic liposomes (Lipofectin; BRL, Inc., Grand Island, NY), and single doses were instilled into the cervical trachea of anesthetized rats. Control rats received either liposomes or plasmid. After 24, 48, and 72 h, lungs were perfused free of blood, homogenized, and analyzed for CAT enzyme activity. Liver and kidney tissue were also obtained. We found that rats given either intratracheal liposomes or plasmid had no detectable CAT activity. By contrast, 24 h after instillation of lipid:DNA complexes, lung CAT expression remained elevated for the next 48 h but was barely detectable in liver or kidney. In another group of rats, MMTV-CAT:liposome complexes were instilled intratracheally and then the rats were injected with either dexamethasone or saline. We found that the dexamethasone-treated rats had a 5- to 10-fold higher level of lung CAT expression at 24 and 48 h than the saline-treated controls had; liver and kidney CAT levels were negligible in both groups. Dexamethasone treatment did not increase RSV-CAT expression, indicating that the dexamethasone effect on MMTV-CAT expression was related to the presence of the MMTV promoter.(ABSTRACT TRUNCATED AT 250 WORDS)     

先天性心脏病合并肺动脉高压患儿手术前后血浆硫化氢及血红素氧合酶-1的变化及意义

目的:探讨先天性心脏病(CHD)合并肺动脉高压(PH)患者手术前后硫化氢(H2S)及血红素氧合酶-1(HO-1)变化的临床意义。方法:采集河北医科大学第四医院心脏外科收治的48例左向右分流的CHD患者。48例患者均在静吸复合麻醉中成功实施了根治手术。48例患者经心脏多普勒进行术前测压,按照肺动脉收缩压(PASP)分为3组:A组,无PH组(PASP30mmHg)15例;B组,轻度PH组(PASP30-49mmHg)15例;C组,中重度PH组(PASP≥50mmHg)18例。于手术前、手术后1h及手术后24h采集桡动脉血标本,用吸光度法于酶标仪670nm测定3组各时段血浆H2S含量;用双波长分光光度法测定3组各时段血清HO-1活性。结果:各组患者术后H2S含量呈上升趋势,但只有术后24h与术前比较有显著差异(P0.05)。在术前、术后1h及术后24h:中重度PH组、轻度PH组血浆H2S含量均显著低于无PH组(P0.05),中重度PH组血浆H2S含量均显著低于轻度PH组(P0.05);每组患者在术前、术后1h、术后24h血清HO-1活性无显著差异;3组患者组间血清HO-1活性比较差异无显著。3组患者H2S含量与PASP呈负相关(术前r=-0.66,P0.01;术后1hr=-0.458,P0.01;术后24hr=-0.730,P0.01)。3组患者HO-1活性与PASP无相关性(均P0.05)。结论:H2S在PH形成和肺血管重建中发挥重要作用。HO-1与PASP无相关性,但不能排除HO-1在PH形成和肺血管重建中有重要作用。血浆H2S可作为判断PH严重程度的指标之一。     

HMGB1 translocation and expression is caused by warm ischemia reperfusion injury, but not by partial hepatectomy in rats

Mechanical injury or ischemia/reperfusion (I/R) injury induces high mobility of group box 1 (HMGB1) translocation and release. However, the surgical procedure itself can initiate pathophysiologic processes causing damage to the respective organ. A liver resection, as an example, leads to portal hyperperfusion injury of the remnant liver. Therefore, we aimed to elucidate the impact of different hepatic surgical injury models on cellular localization and expression of HMGB1. Focal warm I/R injury was induced by clamping the vascular blood supply to the median and left lateral liver lobes for 90 min followed by 0.5 h, 6 h and 24 h reperfusion, as reported previously. Liver injury by PH was induced by subjecting rats to 30%, 70% or 90% partial hepatectomy (PH) followed by a 24 h observation period. Additional 12 rats were subjected to 90% PH and sacrificed at 1 h and 6 h to investigate the expression and release pattern of HMGB1. Elevation of serum liver enzymes indicating hepatic injury peaked at 6 h and recovered thereafter in models, warm I/R injury and PH. Liver injury was confirmed by liver histology. HMGB1 was translocated from the nucleus to the cytoplasm in livers subjected to warm I/R; but not in livers subjected to PH. Both protein and mRNA expression of HMGB1 were significantly up-regulated in livers subjected to warm I/R. In contrast, neither 30% PH, 70% PH nor 90% PH caused an elevation of hepatic HMGB1 mRNA and protein expression. High serum levels of HMGB1 (30 ng/ml) were measured at 0.5 h reperfusion period after warm I/R, much lower levels thereafter (< 5 ng/ml). Similar low serum levels were measured at all time points after 90% PH. Subsequently expression levels of TNF-a should be changed to tumor necrosis factor-alpha (TNF-α) reached a peak (26-fold elevation) at 6 h and decreased down to 5-fold at 24 h after warm I/R. TNF-α expression levels after PH never exceeded a 5-fold elevation. In conclusion, HMGB1 translocation and expression depends on the type of liver injury as it is induced by ischemia, but not by liver resection/hyperperfusion. These results suggest that HMGB1 may be used as molecular marker to visualize ischemic damage. Mechanic injury in hepatic surgery is associated with focal warm ischemia, and thereby HMGB1 translocation reflects surgical quality in experimental PH. Expression of hepatic TNF-α follows the kinetic pattern of HMGB1, pointing to a muss less pronounced inflammatory response after successful PH compared to warm I/R injury.     

褪黑素对睡眠剥夺大鼠记忆的影响

目的探讨褪黑素对睡眠剥夺(SD)大鼠记忆的影响及其机制。方法24只大鼠随机分为对照组(SD 生理盐水)和2个实验组(SD 小、大剂量褪黑素),用小平台水环境法建立大鼠SD模型,SD48h和SD72h后用水迷宫测试大鼠的记忆能力,最后检测大鼠大脑皮层和海马中一氧化氮(NO)和丙二醛(MDA)含量。结果实验组大鼠SD48h和SD72h水迷宫反应时均明显小于对照组(F=11.89、5.44,P=0.00、0.012)。实验组大鼠大脑皮层和海马组织中NO和MDA含量明显低于对照组(F=14.31~27.41,P=0.00)。结论褪黑素对睡眠剥夺大鼠记忆障碍有改善作用,这可能与抑制睡眠剥夺大鼠大脑皮层和海马中NO及MDA的升高作用有关。