亚硒酸钠对果蝇谷胱甘肽过氧化物酶活力及寿命的影响

为探讨亚硒酸钠对果蝇体内谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活力和寿命的影响。将未来配果蝇随机分成４组,给予含不同浓度亚硒酸钠培养基喂养,采用ＤＴＮＢ比色法测定ＧＳＨ－Ｐｘ的活力;采用生存实验计算果蝇寿命。结果显示随亚硒酸钠摄入量的增加,雌雄果蝇体内ＧＳＨ－Ｐｘ活力明显上升（Ｐ〈０．０５）;雌雄果蝇的平均寿命和平均最高寿命也显著延长（Ｐ〈０．０５）。雄蝇的ＧＳＨ－Ｐｘ活力和寿命的变化对亚硒酸钠浓度的     

补硒对低硒居民血小板活化状态的影响

应用１２５Ｉ标记放免法测定血浆血栓素（ＴＸＡ２）、前列环素（ＰＧＩ２）和血小板ＴＸＡ２生成，以比浊法和ＥＬＩＳＡ分别测定血小板聚集性和β－血小板球蛋白（βＴＧ），电镜观察血小板形态，对比研究补硒（２００μｇＳｅ／ｄ，亚硒酸钠，１２周）和未补硒低硒居民上述参数的变化。用２，３－二氨基萘荧光法和谷胱甘肽还原酶偶联法测定硒含量和谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性。结果表明，补硒使红细胞硒和ＧＳＨ－Ｐｘ活性显著增高（Ｐ＜０．０１）；血浆ＴＸＡ２、ＴＸＡ２／ＰＧＩ２比值及血小板ＴＸＡ２生成和聚集性均显著低于未补硒组（Ｐ＜０．０１或０．０５），但血浆ＰＧＩ２和βＴＧ含量以及血小板βＴＧ含量和释放率无显著改变（Ｐ＞０．０５）；补硒可明显减轻病区低硒居民血小板的形态变化，使α－颗粒数显著高于未补硒组（Ｐ＜０．０１）；红细胞硒或ＧＳＨ－Ｐｘ活性分别与血浆ＴＸＡ２和血小板ＴＸＡ２生成呈显著负相关（ｒ＝－０．６９６，－０．７８０；－０．６７６和－０．７９６，Ｐ＜０．０１），与ＡＤＰ诱导的血小板聚集性显著负相关（ｒ＝－０．３９０，－０．３７２，Ｐ＜０．０５）；与凝血酶诱导的聚集性呈不显著的负相关（ｒ＝－０．２７９，－０．３０９?     

膳食维生素B_6对硒的生物利用率影响的研究 Ⅱ．对大鼠组织谷胱甘肽过氧化物酶活性的影响

实验用４周龄断乳雄性大鼠观察膳食维生素Ｂ６（ＶＢ６）对饲亚硒酸钠（ＳｅＬ）或ＤＬ－硒蛋氨酸（ＳｅＭｅｔ）大鼠组织中ＧＳＨ－Ｐｘ活性的影响，实验期为４周。实验证明：与补ＶＢ６各组相比，缺ＶＢ６各组血浆ＧＳＨ－Ｐｘ活性较高，而在红细胞中的结果相反（Ｐ＜０．０５）；缺ＶＢ６各组动物的骨骼肌、心肌和脾脏中ＧＳＨ－Ｐｘ活性都显著低于补Ｂ６各组（Ｐ＜０．０５），上述结果与给硒的化学形式无关。在用ＳｅＭｅｔ的处理组，缺Ｂ６大鼠的肝脏中ＧＳＨ－Ｐｘ活性显著低于补ＶＢ６的大鼠；而在用ＳｅＬ的处理组则没有观察到ＶＢ６的这种影响。本研究结果提示，硒掺入ＧＳＨ－Ｐｘ是通过一个ＶＢ６依存的过程。     

硒酸酯多糖对化疗致癌症患者脂质过氧化的拮抗作用

为了解硒酸酯多糖对肿瘤患者体内过氧化脂质（ＬＰＯ）及谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性的影响，对６０例肿瘤病人随机分成三组：不服硒组、服硒４００μｇ／ｄ组及８００μｇ／ｄ组，并与１５名正常人对照比较。结果为癌患者血清ＬＰＯ明显高于正常人（Ｐ＜０．０１），血清Ｓｅ明显低于正常人（Ｐ＜０．０１），而全血ＧＳＨ含量及ＧＳＨ－Ｐｘ活性明显低于正常人（Ｐ＜０．０５）。服硒酸酯多糖者化疗后血清Ｓｅ较不服者明显升高（Ｐ＜０．０５），ＧＳＨ及ＧＳＨ－Ｐｘ活性明显升高（Ｐ＜０．０１，Ｐ＜０．０５），而ＬＰＯ含量显著下降（Ｐ＜０．０５）。服硒酸酯多糖４００μｇ／ｄ组与８００μｇ／ｄ组之间上述各指标均无明显差异。提示肿瘤病人摄入适量（４００μｇ／ｄ）硒酸酯多糖可增加体内ＧＳＨ－Ｐｘ活性，减轻化疗药物对正常细胞的过氧化损伤。     

氟与硒对离体大鼠肝酶和氧自由基代谢的影响

观察了０．０５～１０００ｍｍｏｌ／Ｌ氟化钠与０．００１～２０ｍｍｏｌ／Ｌ亚硒酸钠单独或联合对大鼠离体肝匀浆和肝细胞碱性磷酸酶（ＡＫＰ）和谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性以及肝细胞内活性氧代谢全过程的影响。结果表明，硒可消除或减轻氟对ＡＫＰ的抑制作用；氟未改变硒对ＧＳＨ－Ｐｘ的激活作用；硒对肝细胞内活性氧代谢的诸多有利作用，如羟自由基（ＯＨ＊）产生量减少、脂质过氧化物（ＬＰＯ）含量下降等，并未因氟的共有而减弱。     

硒和维生素E缺乏对大鼠胰岛功能的影响

以低硒酵母（Ｔｏｒｕｌａｙｅａｓｔ）及低硒玉米淀粉为主要成分配成低硒、低ＶＥ及硒和ＶＥ联合缺乏饲料喂饲大鼠，引起血清胰岛素、Ｃ肽水平显著下降（Ｐ＜０．０１），胰岛内胰岛素与Ｃ肽分泌贮备明显减少（Ｐ＜０．０１），并伴有血及胰腺组织ＧＳＨ－Ｐｘ活性显著降低（Ｐ＜０．０１），ＬＰＯ含量明显上升（Ｐ＜０．０５～０．０１），在饲料中补０．２ｍｇ／ｋｇ硒或５００ｍｇ／ｋｇＶＥ，可明显提高血清胰岛素、Ｃ肽水平（Ｐ＜０．０１），增加胰岛素与Ｃ肽分泌贮备（Ｐ＜０．０１），同时伴有血及胰腺ＧＳＨ－Ｐｘ活性水平升高与ＬＰＯ含量降低（Ｐ＜０．０５～０．０１），提示硒和ＶＥ缺乏是胰岛损害的重要病因之一。     

贻贝及其富硒提取物硒生物活性的比较研究

方法：用基本缺硒饲料或该饲料分别添加亚硒酸钠，胎贝和贻贝提取物饲料饲雄性鼠８周。实验４周后测每组鼠体重并进行代谢实验；收集７２ｈ尿及粪，测定硒含量；实验８周后处死大鼠，分析血及肝谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性和硒含量。结果：贻贝提取物组和贻贝组鼠血及肝ＧＳＨ－Ｐｘ活性和硒水平高于缺硒组，差异极显著；饲贻贝提取物、贻贝对提高ＧＳＨ－Ｐｘ活性的影响无较大差异；但饲贻贝提取物组鼠血及肝硒含量显著高于贻贝组和亚硒酸钠组，且贻贝提取物能有效地促进大鼠的生长。     

硒的化学形态对大鼠肝T45‘—脱单碘酶活力的影响

用低硒地区施硒肥（Ｎａ２ＳｅＯ３）粮饲料（Ｓｅ０．１００ｍｇ／ｋｇ）和硒含量相近的补硒（Ｎａ２ＳｅＯ３）粮饲料（Ｓｅ０．０９９ｍｇ／ｋｇ）分别喂养大鼠８周，观察不同化学形态硒对动物肝Ｔ４５＇－脱单碘酶（ＩＤ－Ｉ）活力、肝含量及血谷胱甘肽地氧化物酶（ＧＳＨ－Ｐｘ）活力的影响。结果表明，硒肥粮组与补硒粮组相比较，肝ＩＤ－Ｄ活性明显高（Ｐ＜０．０１），肝硒含量亦主同，但没有显著意义，而血ＧＳＨ－Ｐｘ活力     

维生素B6对硒的生物利用率影响的研究Ⅳ．对大鼠体内不同化学形式硒利用率及脂质过氧化物的影响

４周龄雄性大鼠饲缺维生素Ｂ６（ＶＢ６）缺硒酪蛋白蔗糖基础饲料，３周后按体重把动物分成１０组，即基础饲料组、基础饲料中补充含硒０．２５ｍｇ／ｋｇ饲料的硒酸钠组、亚硒酸钠组、ＤＬ－硒蛋氨酸组或硒胱氨酸组，在此基础上每种饲料又分成补充或不补充盐酸吡哆醇２．５０μｇ／ｇ饲料两组。实验期为４周。补ＶＢ６各组的红细胞、骨骼肌和心肌中硒水平和谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性均显著高于相应缺ＶＢ６各组，ＶＢ６对饲硒酸钠、亚硒酸钠和硒胱氨酸大鼠肝硒和ＧＳＨ－Ｐｘ水平没有影响；但当补充硒蛋氨酸时，与补ＶＢ６大鼠相比缺ＶＢ６大鼠的肝硒水平较高而ＧＳＨ－Ｐｘ活性显著降低。本研究结果进一步证明，ＶＢ６与血浆硒的转运和利用有关，并且参与了硒蛋氨酸在肝脏中的代谢过程     

亚砷酸钠对大鼠肝线粒体和微粒体酶的影响

研究了亚砷酸钠在体内、体外对大鼠肝线粒体丙酮酸脱氢酶（ＰＤＨ）、琥珀酸脱氢酶（ＳＤＨ）和微粒体酶细胞色素Ｐ－４５０、ｂ５、ＮＡＤ（Ｐ）Ｈ－细胞色素Ｃ还原酶、谷胱甘肽硫转移酶（ＧＳＴ）的影响；并通过观测亚砷酸钠与亚硒酸钠的作用及其对肝谷胱甘肽过氧化物酶、谷胱甘肽含量和线粒体脂质过氧化的影响，探讨亚砷酸钠的作用机理。结果表明：连续７天腹腔注射２０ｍｇ／ｋｇ的亚砷酸钠，线粒体ＰＤＨ、ＳＤＨ被抑制，分别相当于对照组的５１％和５８％。而亚硒酸钠可有效拮抗砷对ＰＤＨ、ＳＤＨ的抑制作用。亚砷酸钠显著降低肝ＧＳＨ的含量，并增强线粒体膜脂质过氧化作用（Ｐ＜０．０５）。在体内试验中，亚砷酸钠对谷胱甘肽过氧化物酶和肝微粒体酶无明显影响。亚砷酸钠在体外实验中，浓度在１０－７～１０－３ｍｏｌ／Ｌ的范围内，抑制ＳＤＨ的活力，提高ＧＳＨ的含量，且呈剂量－效应关系。结果提示，亚砷酸钠对机体的作用与其对ＬＰＯ和体内巯基的影响有关     

黑木耳硒多糖对小鼠血脂、血硒及过氧化物酶的影响

目的　探讨黑木耳硒多糖对血脂、血硒浓度及谷胱甘肽过氧化物酶活性的影响。方法昆明系雄性小白鼠随机分成四组 :正常对照组 ( )、高脂对照组 ( )、亚硒酸钠组 ( )、硒多糖组( )。 和 组饲喂高脂饲料。并每日每鼠分别灌胃亚硒酸钠或硒多糖水溶液 1 ml(1 .95μg Se/ml) ,共 2 1 d。结果　与 组比 , 、 组小鼠血清 TC显著降低 (P<0 .0 0 1 ) ,GSH- Px活性显著增强 (P<0 .0 0 1 ) ; 组小鼠血清 TG显著降低 (P<0 .0 5) ,血硒浓度显著提高 (P<0 .0 1 ) ; 组小鼠血清 TG显著降低 (P<0 .0 1 ) ,血硒浓度显著提高 (P<0 .0 0 1 ) ;与 组比 , 组硒血浓度显著提高(P<0 .0 0 1 ) ,GSH- Px活性显著增强 (P<0 .0 1 )。结论　硒多糖较亚硒酸钠具有更好的降血脂、提高血硒浓度和增强 GSH- Px活性的作用 ,对高血脂症有一定的预防作用     

纳米红色元素硒的急性毒性和生物利用性

纳米红色元素硒是以蛋白质为分散剂的元素硒的纳米粒子,粒径在60nm 以内。体外研究证实,纳米红色元素硒能够与谷胱甘肽反应,其反应能力约为亚硒酸钠的1/20至1/10。急性毒性实验证实以口服硒元素的量计,纳米红色元素硒的LD50 = 112.98(89.95～141.90)m g/kgBW,亚硒酸钠的LD50= 15.72(13.38～18.47)m g/kgBW,显示出纳米红色元素硒的毒性低。生物利用性试验证实:小鼠分别口服纳米红色元素硒和亚硒酸钠(Se 50μg/kg BW)30天,与对照组比,2种硒都能显著提高小鼠血硒和肝硒浓度,血中谷胱甘肽过氧化物酶活性升高。这说明纳米红色元素硒能被小鼠较好利用     

Influence of different sources of injected selenium on certain enzymes, glutathione and adenosylmethionine concentration in buffalo (Bubalus bubalis) calves.

Sodium selenite and selenomethionine were investigated as possible causative factors for the induction of Degnala disease syndrome in twelve buffalo (Bubalus bubalis) calves divided into three groups of four. Group 1 was the control group and received no additional selenium. Sodium selenite and selenomethionine were given daily as intramuscular injections on a selenium-equivalent basis, with a weekly increment in the dose of 0.05 mg Se/kg live weight from 0.05 to 0.20 mg Se/kg live weight per day, in groups 2 and 3 respectively. Only one animal from group 3 manifested the lesions of Degnala disease. The blood Se concentration and erythrocyte glutathione peroxidase (EC 1.11.1.9; GSH-Px) activity were both greater in groups 2 and 3 than in control group 1. The overall blood Se concentration was 0.22 (SE 0.01), 0.38 (SE 0.12) and 0.77 (SE 0.20) micrograms Se/ml in groups 1 to 3 respectively with corresponding GSH-Px activities of 63.84 (SE 7.38), 88.37 (SE 12.38) and 165.32 (SE 40.62) enzyme units/mg protein. Erythrocyte glutathione reductase (NAD(P)H) (EC 1.6.4.2) activity was not affected by treatment but reduced glutathione content was lower in groups 2 and 3. Liver adenosylmethionine, estimated at autopsy, was lowest (22.87 (SE 6.17) mumol/g) in group 3, and greatest (102.63 (SE 9.39) mumol/g) in group 1 (P less than 0.01). Organic Se sources seemed to accumulate in tissues more than inorganic sources, and might be the causative toxic factors of Degnala disease.     

大鼠对富硒平菇硒的生物利用率

本实验用低硒大鼠对人工栽培富硒平菇作了硒生物利用率观察。大鼠按体重随机分为9组,其中1组为低硒对照组,2～5组补充Na_2SeO_3,饲料内硒含量分别为:0.51、0.75、1.91、3.18ppm;6～9组补充富硒平菇,硒为0.45、0.72、1.59、3.41ppm。3周后处死大鼠,采血、肝、测定硒含量,并测定红细胞GSH-Px酶活性。结果表明:血、肝硒值及红细胞GSH-Px酶活性均随补硒浓度的增加而增加,以亚硒酸钠为基准,富硒平菇硒生物利用率,按血硒指标为66.66％;按肝硒指标为125％;按红细胞GSH-Px酶活性指标为123.42％,说明人工栽培富硒平菇可作为极好的食物硒来源。     

Bioavailability of selenium from raw and cooked ground beef assessed in selenium-deficient Fischer rats.

The literature on the bioavailability of selenium (Se) from meats, especially beef, is meager, and that which existed when this research began suggested that Se was not highly bioavailable. In addition, much of the analytical values for Se in beef predated the Food and Drug Administration's 1973 approval of Se as an additive to feeds and mineral premixes of livestock.

One hundred and thirty-six weanling female Fischer 344 rats were divided into two dietary groups: the selenium deficient group in which animals were fed a torula yeast (TY) basal diet which contained 0.008 mg/kg Se and the control group in which animals were fed the TY diet to which was added 0.10 mg/kg Se as sodium selenite.

After 6 weeks of dietary treatment liver glutathione peroxidase (GSHPx) activity had fallen in the Se-deficient rats to 2.4% of that of control rats. At this time (week 6) rats from the Se-deficient TY diet were refed diets containing 0.10 mg/kg Se as selenite, selenate, raw or cooked ground beef that had been freeze-dried. During the Se-repletion period rats were sacrificed at weeks 1, 3, 5 and 8. Liver GSHPx activity and total Se levels in liver and muscle tissue were the criteria of Se bioavailability. After 8 weeks of Se resupplementation the recovery of liver GSHPx activity compared to the control animals (set at 100%) were selenite (98%, p > 0.05), selenate (117%, p < 0.05), raw beef (127%, p < 0.05) and cooked ground beef (139%, p < 0.05). Total Se in both liver and muscle tissue reflected the liver GSHPx activity with the total Se concentration in tissues being highest for cooked beef.

The data suggest that bioavailability of Se from ground beef is greater than that from either selenite or selenate.     

Selenium from selenium-rich Spirulina is less bioavailable than selenium from sodium selenite and selenomethionine in selenium-deficient rats

The bioavailabilty of selenium (Se) from selenium-rich Spirulina (SeSp) was assessed in Se-deficient rats by measuring tissue Se accumulation and glutathione peroxidase (GSH-Px) activity. For 42 d, rats were subjected to dietary Se depletion by consumption of a Torula yeast (TY)-based diet with no Se; controls were fed the same diet supplemented with 75 microg Se/kg diet as sodium selenite. Se-deficient rats were then repleted with Se (75 microg/kg) by the addition of sodium selenite, selenomethionine (SeMet) or SeSp to the TY basal diet. Selenium speciation in SeSp emphasized the quasi-absence of selenite (2% of total Se); organic Se comprised SeMet (approximately 18%), with the majority present in the form of two selenoproteins (20-30 kDa and 80 kDa). Gross absorption of Se from SeSp was significantly lower than from free SeMet and sodium selenite. SeMet was less effective than sodium selenite in restoring Se concentration in the liver but not in kidney. SeSp was always much less effective. Similarly, Se from SeSp was less effective than the other forms of Se in restoring GSH-Px activity, except in plasma and red blood cells where no differences were noted among the three sources. This was confirmed by measuring the bioavailability of Se by slope-ratio analysis using selenite as the reference form of Se. Although Se from SeSp did not replenish Se concentration and GSH-Px activity in most tissues to the same degree as the other forms of Se, we conclude that it is biologically useful and differently metabolized due to its chemical form.     

大鼠硒耗竭过程中不同组织硒蛋白利用硒的优先性

以低硒酵母配制的低硒基础饲料（含硒量为０．０１ｍｇ／ｋｇ）和在此基础上加亚硒酸钠配成硒水平为０．５０ｍｇ／ｋｇ的足硒饲料来喂养雄性Ｗｉｓｔａｒ断乳大鼠。于０、１、２、４、６、８、１２、１５、１７、１９、２０和２４周时处死大鼠取其组织,分别对各种组织中的硒、细胞内谷胱甘肽过氧化物酶（ｃＧＰＸ）、细胞外谷胱甘肽过氧化物酶（ｅＧＰＸ）、磷脂氢谷胱甘肽过氧化物酶（ＰＨＧＰＸ）、Ⅰ型脱碘酶（ＩＤⅠ）和Ⅱ型脱碘酶（ＩＤⅡ）活性进行动态观察。结果发现睾丸中的硒和脑垂体中的ｃＧＰＸ在耗竭过程中降低速度较其它组织慢,且降低幅度较小;而硒蛋白中ＩＤⅠ和ＰＨＧＰＸ对硒的利用优先于ｃＧＰＸ和ｅＧＰＸ,ＰＨＧＰＸ和ＩＤⅠ的功能可能比ｃＧＰＸ和ｅＧＰＸ更重要。     

小儿弱视与微量元素硒的关系及其临床意义

目的:观察微量元素硒及相关生物活性物质对小儿弱视影响以及硒治疗的效果。方法:将弱视患儿随机分为两组:在常规使用遮盖加精细目力训练的基础上,A组37例患儿口服亚硒酸钠0.5 mg/d,连服1周,以后每周0.5 mg,疗程6个月;B组31例患儿未服用亚硒酸钠。观察对象分别于治疗前和治疗6个月后抽血检测血清硒(Se)、血浆谷胱甘肽过氧化物酶(GSH-PX)活力及丙二醛(MDA)含量等指标,随访1年,以观察远期疗效。结果:治疗后A组血清Se(0.034±0.016)mg/L明显高于治疗前(0.013±0.008)mg/L,差异有显著性(P<0.01);A组血浆GSH-PX活力为(87.12±13.61)IU/L,较治疗前(53.62±18.70)IU/L明显增加,差异有显著性(P<0.01)。A组MDA含量(6.46±1.55)nmol/m l,较治疗前(8.68±1.49)nmol/m l明显降低,差异有显著性(P<0.05)。血清Se与血浆GSH-PX呈正相关(r值=0.781,P<0.01),与MDA呈负相关(r值=-0.385,P<0.05)。患儿视力恢复正常者A组22例(59.46%),B组11例(35.48%);视力进步者A组12例(32.43%),B组12例(38.71%);视力恢复率A组明显高于B组(2χ值=3.896,P<0.05),远期疗效较好。结论:用亚硒酸钠治疗该地区弱视患儿有明显的治疗效果;Se水平低表明该地区小儿弱视可能与缺硒有关。提示补充适量硒可提高该地区因低硒引起的弱视患儿的视力。