硒螺旋藻拮抗大鼠肝纤维化的作用及机制研究

目的:研究硒螺旋藻(Se enriched Spirulina platensis,Se-SP)拮抗大鼠肝纤维化效应,以及对肝细胞增殖和谷胱甘肽过氧化物酶(GSH-Px)和硫氧还蛋白还原酶(TR)活性的上调作用。方法:在SD大鼠用硫代乙酰胺诱导肝纤维化模型,同期补充Se-SP,取肝进行组织病理分析,检测肝组织脂质过氧化产物丙二醛(MDA)含量及GSH-Px和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3H-TDR掺入水平。结果:Se-SP可明显减轻鼠肝组织纤维化程度,比亚硒酸钠更明显地促进肝细胞硒酶活性和细胞增殖,同时可抑制肝组织胶原的生成和血清透明质酸(HA)含量。结论:Se-SP对肝纤维化具有较强的抗氧化和促肝细胞再生及功能修复作用,其机制主要是Se-SP作为高生物利用度的补硒剂,通过上调硒酶活性,发挥直接或间接的生物效用。     

高海拔地区心血管疾病与微量元素硒及相关生物活性物质的临床研究

目的 :探讨微量元素硒 (Se)及相关生物活性物质在高海拔地区心血管疾病中的作用。方法 :测定 4 7例心血管疾病患者和 2 0例健康人体内血清Se、血浆谷胱甘肽过氧化物酶 (GSH -Px)活力 ,丙二醛 (MDA)含量及相关临床指标。结果 :心血管病组血清Se含量及GSH -Px活力显著下降 (P <0 0 1) ,MDA含量升高 (P <0 0 5 ) ,心肌酶中肌酸磷酸激酶 (CK -MB)和心肌钙蛋白 (CTn -I)明显高于对照组 (P <0 0 5 )。结论 :血清Se减少时 ,高海拔地区心血管疾病患者体内存在着抗氧化能力降低和脂质过氧化反应增强。提示临床可使用亚硒酸钠和抗氧化剂     

氟硒镉对大鼠体内抗氧化酶及微量元素的影响

目的　探讨氟硒镉对大鼠各组织中脂质过氧化物 (LPO)含量和谷胱甘肽过氧化物酶 (GSH Px)活性以及镉硒锌等微量元素含量的影响。方法　采用SD大鼠经饮水染毒 8周 ,实验结束时处死动物测定各组织中LPO和谷胱甘肽过氧化物酶及镉硒锌的含量。结果　氟、硒、镉实验组均可见大鼠血清、肝、肾组织中GSH Px含量与对照组比呈显著降低 ,LPO含量量呈显著增高。其中任意二元素联合组较氟、硒、镉组GSH Px的含量呈明显回升 ,LPO含量量呈明显降低 ,而氟 +硒 +镉组其升高与降低的作用则更明显 ,以至GSH Px、LPO的水平几乎和对照组相同。过量硒和镉能导致肾硒、肝镉成数倍的增长。氟、镉可引起各组织中硒、锌的缺乏 ,硒则可使肝、肾中锌水平普遍提高。氟 +硒、镉 +硒以及氟 +硒 +镉联合可减少肾硒、肝镉的蓄积 ,同时也可减少氟、镉所致锌的损失。结论　提示过量的氟、硒、镉均可促进动物体内脂质过氧化作用增强 ,并抑制GSH Px的活性 ,使机体抗氧化能力降低。但当其中二或三种化学元素共存时 ,可减轻各自所引起的脂质过氧化作用以及对GSH Px的活性的抑制作用 ,同时减轻镉硒在体内的蓄积和氟镉所致引起体内锌水平的降低。     

硒对镉在大鼠肝脏亚细胞分布及脂质过氧化作用的影响

采用给大鼠腹腔注射镉(CdCl_2 1mg/kg)或/和硒(Na_2SeO_3 0.4mg/kg)的方法,研究了硒对镉在大鼠肝脏亚细胞分布及脂质过氧化作用的影响。结果表明,给大鼠连续腹腔注射CdCl_2(1mg/kg)3d,可致大鼠肝微粒体和线粒体脂质过氧化物(LPO)含量显著增加,谷胱甘肽过氧化物酶(GSH-Px)活性显著下降,肝细胞浆还原型谷胱甘肽(GSH)含量显著降低。同时给大鼠腹腔注射Na_2SeO_3(0.4mg/kg),硒可拮抗上述镉的效应。但硒对大鼠肝脏镉含量及镉在肝脏亚细胞分布没有明显影响。     

富硒螺旋藻对大鼠实验性肝纤维化的拮抗效应

目的研究富硒螺旋藻(Se-SP)对大鼠肝纤维化的拮抗作用。方法SD大鼠腹腔注射3%硫代乙酰胺(TAA)溶液复制肝纤维化病理模型,每天灌胃分别补硒(10.8μg)、藻粉(100mg)和富硒藻粉(100mg,其中含硒10.8μg)进行实验干预。实验结束取大鼠血清进行常规肝功能检查,DAN荧光法测定硒(Se)含量,TBA法测定血清过氧化产物丙二醛(MDA)浓度,放射免疫法测定血清透明质酸(HA)水平,比色法检测谷胱甘肽过氧化物酶(GPx)和超氧化物歧化酶(SOD)活性。大鼠肝组织切片HE染色进行病理分析,Masson三色法胶原染色估计肝组织胶原相对含量(RCC%)。结果Se-SP组肝功能指标恢复最好,其血清中Se含量和GPx活性均明显提高(P<0.05),MDA和HA则明显降低(P<0.05)。肝纤维化病理诊断主要为Ⅰ级,肝组织RCC降低了约60%。进一步分析发现血清Se含量与GPx活性呈正相关(r=0.720),与MDA呈负相关(r=0.675)。结论Se-SP对大鼠实验性肝纤维化有较好的拮抗效应,作用机制与增强机体抗氧化水平和增加肝功能贮备有关。     

地方性氟中毒患者内外环境硒水平与机体抗氧化功能的测定

[目的 ]了解地方性氟中毒患者内外环境硒水平 ,探讨氟对抗氧化功能的损伤作用。 [方法 ] 2 0 0 0年选择山东省梁山县氟中毒病村氟斑牙患者 3 0例 ,梁山县及长清县正常对照村健康人群各 3 0人 ,检测土壤、粮食中硒含量和血、尿中硒、氟含量 ,检测血中抗氧化酶类谷胱苷肽过氧化物酶 (GSH Px)活性、超氧化物歧化酶 (SOD)活性和含量及脂质过氧化物 (LPO)含量。 [结果 ]梁山县氟病村、非病村内外环境硒水平均低于长清县正常对照村 ;与 2处对照村健康人群比较 ,氟中毒患者血、尿氟含量升高 ,血中GSH Px、SOD降低 ,LPO升高 ,GSH Px/LPO、SOD/LPO降低。 [结论 ]梁山县氟中毒病区为低硒高氟地区 ;高氟使体内微量元素平衡紊乱 ,抗氧化酶类受损 ,脂质过氧化代谢异常。     

硒精氨酸对衰老小鼠肝损伤的保护作用

<正>硒作为体内重要抗氧化系统谷胱甘肽过氧化物酶(GSH-Px)和磷脂氢谷胱甘肽过氧化物酶(PHG-Px)的必需组分,在拮抗自由基对组织细胞的损害,延缓衰老等方面发挥重要作用[1,2]。动物实验表明,缺硒与肝纤维化,肝功能障碍,肝癌发生密切相关。补硒能显著减轻肝细胞变性及纤维化程度[3,4],起保肝护肝抗癌防癌等作用[5]。     

番茄红素对大鼠体内抗氧化系统功能的影响

目的　观察番茄红素 (lycopene ,LP)对大鼠抗氧化酶系统的影响。方法　大鼠饲喂番茄红素 4周后处死 ,测定血清和肝匀浆的超氧化物歧化酶 (SOD)活性、过氧化氢酶 (CAT)活性、谷胱甘肽过氧化物酶(GSH -Px)活力、总抗氧化能力 (T -AOC)、丙二醛 (MDA)及还原型谷胱甘肽 (GSH)含量。结果　各番茄红素给药组的大鼠血清和肝组织的SOD活性、GSH -Px活力及T -AOC上升 ,MDA含量降低 ,与空白组相比 ,在统计学上差异有显著性 (P <0 0 5 )。结论　番茄红素可以提高大鼠机体的抗氧化能力 ,抑制脂质过氧化     

微量元素与肝癌

1　硒肝癌高发区启东市多次研究表明 ,肝癌发病率 (死亡率 )与机体内外环境的硒水平呈负相关。但世界上有些地区虽低硒但肝癌发病率并不增加 ,提示缺硒可能不是肝癌的直接原因。也只有当环境中存在大量致癌物质时 ,肝癌才高发。据报道 〔1〕硒对 Novikoff肝癌等肿瘤细胞有抑制效应 ,证实硒能阻碍或完全抑制各种移植性癌细胞的增殖。在启东进行的鸭肝癌实验研究表明 ,在饲料中加入 0 .5～ 2 .0 μg/ kg亚硒酸钠 ,明显降低癌前变异肝细胞灶和结节的发生。大鼠在 AFB1 致癌作用下 ,当服用富硒麦芽能使谷胱甘肽硫转移酶 (GST)活性升高而起解…     

褪黑素对低硒饮食大鼠脂质过氧化的影响

目的 :研究褪黑素对低硒粮喂养的大鼠脂质过氧化增强的影响 ,并讨论其可能机制。方法 :将SD大鼠分为 3组 ,分别用低硒饲料、低硒饲料加硒、低硒饲料加褪黑素灌胃饲养 ,12周时检测血Se、血GSH—Px及心肌组织、肝组织匀浆MDA水平。结果 :12周时低硒组大鼠血Se、GSH—Px较加硒组 (对照组 )显著降低 ,心肌组织、肝组织匀浆MDA均明显高于其它两组。加硒组与褪黑素组MDA无显著差异。结论 :褪黑素可以显著抑制低硒饮食大鼠脂质过氧化的增强 ,作用与其抗氧化机制有关     

Toxicity and oxidative stress of different forms of organic selenium and dietary protein in mallard ducklings

Concentrations of over 100 ppm (mg/kg) selenium (Se) have been found in aquatic plants and insects associated with irrigation drainwater and toxicity to fish and wildlife. Composition of diet for wild ducklings can vary in selenium-contaminated environments. Earlier studies have compared toxicities and oxidative stress of Se as selenite to those of seleno-DL-methionine (DL) in mallards (Anas platyrhynchos). This study compares DL, seleno-L-methionine (L), selenized yeast (Y) and selenized wheat (W). Day-old mallard ducklings received an untreated diet (controls) containing 75% wheat (22% protein) or the same diet containing 15 or 30 ppm Se in the above forms except for 30 ppm Se as W. After 2 weeks, blood and liver samples were collected for biochemical assays and Se analysis. All forms of selenium caused significant increases in plasma and hepatic glutathione peroxidase activities. Se as L at 30 ppm in the diet was the most toxic form, resulting in high mortality (64%) and impaired growth (>50%) in survivors and the greatest increase in ratio of oxidized to reduced hepatic glutathione (GSH). Se as both L and DL decreased the concentrations of hepatic GSH and total thiols. Se as Y accumulated the least in liver (approximately 50% of other forms) and had less effect on GSH and total thiols. In a second experiment, in which the basal diet was a commercial duck feed (22% protein), survival was not affected by 30 ppm Se as DL, L, or Y and oxidative effects on GSH metabolism were less pronounced than with the wheat diet.     

克山病病区粮食中补充蛋氨酸对大鼠膳食硒生物利用的影响

为研究在克山病病区粮食中补充蛋氨酸对大鼠组织硒和谷胱甘肽过氧化物酶 (GPX)活性的影响 ,用克山病病区生产的低硒粮食为主配成低硒基础饲料 ,其硒含量为 0 .0 0 7mg/kg。在此基础上添加不同量的硒蛋氨酸 ,使饲料硒水平分别达到 0 .0 0 7、0 .0 6和 0 .5 0 mg/kg。每一硒水平又分别补充或不补充 4g/kg DL -蛋氨酸 ,配制成含不同硒和蛋氨酸的 6种饲料 ,分别喂养雄性 Wistar断乳大鼠 8周。结果在饲料硒水平为0 .0 0 7mg/kg时 ,补充蛋氨酸组动物除肌肉硒含量低于未补充组外 ,其它组织硒含量和各组织 GPX活力与不补充蛋氨酸动物无显著差异 ;在饲料硒水平为 0 .0 6 mg/kg时 ,补充蛋氨酸组动物组织中的硒含量出现了重新分布 ,最明显的是补充蛋氨酸组动物肌肉的硒含量减少 ,而肝脏和血硒含量增加 ,且各组织中 GPX活力显著大于未补充蛋氨酸组的动物 ;在饲料硒水平为 0 .5 0 mg/kg时 ,补充蛋氨酸组动物组织中硒含量有不同程度下降 ,但 GPX活力仍保持不变。研究结果认为病区粮食中蛋氨酸不足时 ,机体首先利用膳食中的硒蛋氨酸(谷类食物中硒的主要形式 )以替代蛋氨酸参与组织蛋白质的合成。补充蛋氨酸后 ,硒蛋氨酸即可发挥其应有生理功能。进一步提示病区粮食中蛋氨酸不足可能是与克山病发病有关的另一因素。     

膳食蛋白质水平对硒利用的影响 Ⅰ、膳食蛋白质水平对大鼠血及组织中硒含量及谷胱甘肽过氧化物酶活力的影响

用低硒(0.03ppm)及高硒(0.30ppm)两类饲料喂养大鼠共三月,每类饲料蛋白质水平从5.3—13.4％,饲料基本成分为玉米和黄豆,实验结果发现,在不同硒水平下,饲料蛋白质水平对机体利用硒的影响大不相同。在低硒(0.03ppm)饲料下,低蛋白组动物血及血、心、肾及胰织组中的含硒量最高,饲养蛋白质水平愈高,各组织中硒含量则显著降低。及肝组织中的谷胱甘肽过氧化物酶活力有相同趋势。在高硒(0.30ppm)饲料组则无此种趋势,相反,蛋白质水平愈高,在肝脏中的贮存愈好。文中并讨论了在我国克山病区单纯补充硒的意义。     

肝癌组织中转化生长因子beta1表达与Treg浸润的关系及临床意义

目的 探讨肝癌组织中转化生长因子beta1表达与Treg浸润的关系及临床意义.方法 采用免疫组织化学染色的方法检测213例肝癌组织、癌旁肝组织中TGF-β和Foxp3表达.结果 肝癌组织中TGF-β低表达组92例,高表达组121例,高表达阳性率为56.81％;癌旁组织中TGF-β低表达组44例,高表达组169例,高表达阳性率为79.34％,癌组织和癌旁高表达率差异有统计学意义(P=0.0000).肝癌组织中Foxp3细胞平均密度为2.76个/HP,癌旁极少见或未见.肝癌组织中TGF-β与Foxp3表达呈正相关(r=0.221,P=0.027).肝癌组织中TGF-β和Foxp3表达在患者血浆AFP浓度高水平组高于低水平组(P=0.017 6, 0.028 1).结论 TGF-β在肝癌瘤旁组织较之肝癌组织表达更为明显,而Treg侵润则与之不相符,在肝癌组织中TGF-β的表达,与肿瘤局部组织中的Treg侵润具有一定的正相关性,与临床特征相关联可见患者血清AFP水平与TGF-β及Foxp3表达具有一定的相关性.     

Influence of dietary methionine on the metabolism of selenomethionine in rats

To determine the influence of methionine on selenomethionine (SeMet) metabolism, weanling male rats were fed for 8 wk a basal diet marginally deficient in sulfur amino acids, containing 2.0 micrograms selenium (Se)/g as DL-SeMet and supplemented with 0, 0.3, 0.6 or 1.2% DL-methionine. Increased dietary methionine caused decreased selenium deposition in all tissues examined but increased glutathione peroxidase (GSHPx, EC 1.11.1.9) activity in testes, liver and lungs. A positive correlation was found between dietary methionine and the calculated percentage of selenium associated with GSHPx. In a second experiment, 75SeMet was injected into weanling male rats which had been fed the basal diet containing 2.0 micrograms selenium as DL-SeMet with or without the addition of 1.0% methionine. The selenoamino acid content of tissues and the distribution of 75Se in erythrocyte proteins were determined. In comparison to the rats fed the basal diet without added methionine, significantly more 75Se-selenocysteine was found in liver and muscle, more 75Se was found in erythrocyte GSHPx and less 75Se was found in erythrocyte hemoglobin of rats fed 1.0% methionine. These data suggest that methionine diverts SeMet from incorporation into general proteins and enhances its conversion to selenocysteine for specific selenium-requiring proteins, such as GSHPx.     

太原市食物硒含量及居民硒摄入量的评价

本文测定了太原市50多种常见食物中硒的含量。结果表明,以动物性食品特别是鱼类、鸡肉、猪肝和鸡蛋中硒含量最为丰富,均在0.1ppm以上。谷类与豆类含硒相近,其中进口小麦加工的面粉为0.14ppm,大多数蔬菜及干果类的含硒量均低于0.01ppm。大部分菌藻类食物含硒较其它植物性食物高。这些测定值为太原市食物硒含量的评价提供了科学依据。可以看出,太原市食物硒水平虽远高于克山病病区但低于北京市。以太原市全年食物消费情况和膳食调查得到的居民每日硒摄入量,刚刚达到生理需要量和适宜供给量的低限水平。     

Bioavailability to rats of selenium in various tuna and wheat products

Bioavailability of selenium (Se) in tuna and wheat at various stages of processing was studied in rats. The protein source of the rat diets was torula yeast with Se supplied by either raw, precooked or canned tuna, or whole wheat flour, whole wheat bread or bran. Sodium selenite was used as the standard. Each Se source was fed at three levels: 0.05, 0.10 and 0.15 ppm. By using increase in glutathione peroxidase (GSH-Px) activity in liver, kidney and whole blood as an indicator of bioavailability, no differences were found among the three tuna products or among the three wheat products tested. However, significantly lower GSH-Px activity was found in the combined tuna groups as compared to the combined wheat groups, suggesting that selenium in wheat was more available than that in tuna. There was a significant increase in the liver Se content of rats fed all levels of Se in canned tuna and in kidney, blood and muscle Se of rats fed 0.10 and 0.15 ppm Se in canned tuna in comparison to the tissue Se content in rats fed these same levels of Se in raw or precooked tuna. Since this did not correspond with an increase in GSH-Px activity it was concluded that it did not represent increased bioavailability of canned tuna. Thus, food processing does not appear to affect Se availability, but Se appears to be more available in wheat than tuna.     

The effect of dietary selenium and vitamin A on biochemical parameters and survival of young among white-tailed deer (Odocoileus virginianus)

Thirty-two adult female white-tailed deer were assigned to four complete pelleted diets (+/- 45 ppm vitamin E; +/- 0.2 ppm selenium). Selenium and vitamin E concentration in the unsupplemented diet was 0.04 and 5.5 ppm, respectively. Biochemical parameters of the erythrocyte (RBC) glutathione peroxidase system and survival of off-spring to weaning were followed for 2 years. At the end of the second year, 12 male young (3 per treatment) and the remaining adults were killed, and liver and muscle parameters of the glutathione system determined. Plasma selenium (Se) and vitamin E (E) were significantly lower among unsupplemented adults within 6 months of treatment and remained essentially constant from 10 months on. In vitro hemolysis and mortality of young were affected by dietary E but not by Se. Tissue glutathione peroxidase (GSH-Px) was correlated with tissue Se in all tissues measured (RBC, liver and muscle). Tissue Se, in turn, was related to dietary Se. Thus, dietary Se deficiency (Se = 0.04 ppm) resulted in biochemical deficiency (depressed GSH-Px). This was not reflected in gross lesions among the adults, nor in increased mortality among young.     

KAI1、E-cadherin 和αvβ3在胃癌中的表达和意义

摘要:目的　探讨KAI1、E-cadherin 和αvβ3与胃癌临床病理特征的关系。方法　应用免疫组化SP法检测52例胃癌组织和30例癌旁组织KAI1、E-cadherin 和αvβ3蛋白的表达。结果　KAI1、E-cadherin 和αvβ3蛋白在胃癌中的表达与癌旁组织有明显差异（P＜0.05）,并与分化程度、淋巴结转移差异显著（P＜0.05）。αvβ3蛋白表达还与病理分期有显著差异（P＜0.05）。KAI1蛋白与E-cad蛋白在胃癌中的表达呈正相关（r＝0.299）,与αvβ3蛋白呈负相关（r＝-0.301）;而E-cad蛋白与αvβ3蛋白无相关性（r＝-0.213,P＞0.05）。结论　KAI1 和E-cad基因低表达而αvβ3蛋白在胃癌中高表达可能是胃癌恶化的一个标志。     

富硒酵母对奶牛抗氧化能力和免疫功能的影响

目的:研究富硒酵母对妊娠奶牛抗氧化能力和免疫功能的影响。方法:选用24头妊娠健康黑白花母牛为受试奶牛,等分为4组。1组为对照(C组),余为受试T1,T2,T3组,分别添加三种硒制剂:即奥特奇公司的富硒酵母(Sel plex 50) 、有机硒无机硒混合物(70% Sel plex 50+30%亚硒酸钠)以及亚硒酸钠组。实验期168 d。在试验期第40、70、125 d时测定血中GSH-Px、SOD活性、MDA含量、硒水平以及淋巴细胞转化率和T细胞计数。结果:在125 d时,GSH-Px活性、SOD酶活性、血清硒浓度,T1、T2、T3组均显著或非常显著高于C组;MDA 水平T1、T2、T3组非常显著低于C组;同时,淋巴细胞转化率和T细胞计数,T1、T2组非常显著高于C组。三个试验组中T1与 T3组比,P<0.01,说明T1组效果优于T2、T3组。结论:富硒酵母(Sel plex 50)改善奶牛的抗氧化能力和免疫功能的效果比无机硒好。