克山病病区人群和用病区粮饲养的动物血中谷胱甘肽过氧化物酶活力的研究

1.比较了用病区和非病区玉米、大米饲料饲养的大白鼠的全血中GSH-px活力,并与吃常备饲科的大白鼠血GSH-px活力进行对比。结果是:常备饲料组的酶活力大于非病区??粮组和病区粮组的,非病区粮组的酶活力大于病区粮组的。同时测定体外用维生素C氧化血红蛋白生成的高铁血红蛋白,胆绿蛋白和Heinz小体的百分数,所得结果是:常备饲料组小于非病区粮组和病区粮组,非病区粮组小于病区粮组。2.给喂以病区玉米饲料三个月造成乏硒的大白鼠补充硒(Na_2SeO_3)50天后,血硒和红细胞GSH-px活力均上升到接近喂以常备饲料的大白鼠的水平。3.测定了非病区儿童和成人及病区的克山病患儿和非克山病儿童和成人的全血GSH—px活力,结果是:职工户儿童大于农业户儿童,非病区儿童大于病区儿童。病区的非克山病儿童的酶活力与克山病患儿的无明显差别。4.克山病地区的儿童按规定服用亚硒酸钠后,GSH-px活力明显上升,达到70单位左右。5.人群的GSH-px活力与血硒和发硒有非常显著的相关性。     

补硒对克山病病区粮饲养大鼠心肌线粒体单胺氧化酶活性的影响

90只断乳两周的Spragul-Dawley纯种大鼠,随机分为低硒、补硒及常备饲料三组,分别饲以克山病病区低硒粮(含Se 0.009ppm)、克山病病区低硒粮补亚硒酸钠(含Se 0.232ppm)及常备饲料(含Se 0.169ppm),观察硒对心肌线粒体单胺氧化酶活性(MAO)的影响,结果表明:与补硒和常备饲料组相比,低硒组心肌线粒体MAO活性明显下降。饲喂30,60,90天血浆硒含量和红细胞GSH-Px活性显著下降,补硒组心肌线粒体MAO和红细胞GSH-Px活性接近常备饲料组水平。     

克山病病区饲料对大白鼠组织中脂质过氧化物的积蓄和线粒体膨胀收缩的影响

1.用克山病病区粮食,非病区粮食,病区粮食补硒及常备用的四种饲料饲养大白鼠三个月后,观察到常备组动物生长最好,其余三组之间无差别。心脏和肝脏的脏体比值以病区组为最大,常备组显著小于其他三组。2.测定了全血,心和肝线粒体及其上清液中的硒水平和GSH—Px活力,二者均与饲料硒水平呈正相关。无论是心或是肝上清液中的硒含量和GSH—Px活力均较线粒体高。肝线粒体中的GSH—Px活力低于心线粒体。缺硒时,其变化最大。3.自发膨胀时心线粒体以常备组膨胀最小,肝线粒体则病区组最小。用GSH—Px诱发后,心线粒体的膨胀四组无差别;而肝线粒体膨胀时,病区组显著小于常备组与补硒组。除病区组的肝线粒体外,GSH诱发膨胀时,膨胀速度随GSH浓度增加而增加。无论是心或肝的线粒体膨胀后,加ATP收缩程度各组之间均无统计学的差别。4.全血、心匀浆、心线粒体和肝线粒体的TBA值经t测验无显著差别,而喂养160天以后的动物肝匀浆的TBA值似乎有差异,并与GSH—Px活力呈相反的变化。在膨胀时,线粒体的TBA值较膨胀前高,GSH诱发膨胀后,其膨胀速度较自发膨胀快,其TBA也较自发膨胀高。心线粒体在4mMGSH诱发膨胀后,病区组与非病区组的TBA值显著高于常备组与补硒组。     

模拟克山病病区低钙饲料对大鼠生长、代谢的影响

本文研究了模拟克山病病区易感人群膳食组成的饲料及在这种饲料中补充钙和硒对大鼠生长、代谢的影响。结果表明,模拟病区膳食的饲料中除低硒外低钙特别突出,所饲大鼠血清钙水平及全血GSH-Px酶活性明显低于常规饲料组;大鼠的生长状态、血清总蛋白及血清和心肌几种酶(GOT,GPT,LDH,α-HBDH,CK)活性均偏离常规饲料组。在模拟病区膳食的饲料中单纯补充钙可明显改善大鼠的生长状态和酶活性的偏移,呈规律性趋向常规饲料组。表明低钙在喂养病区膳食的大鼠所造成的生长迟缓、代谢偏移中起重要作用。补充钙同时补充硒效果更好。结合流行病学资料表明在低硒环境下合并有明显的低钙,可引起克山病发病。     

克山病病区粮对甲状腺激素代谢及过氧化脂质的影响

用低晒的克山病病区粮喂养大鼠并补充不同剂量的硒，观察了硒对心肌甲状腺激素（ＴＨ）代谢调节作用的影响。结果表明，低晒饲料组血清和心肌谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性；心肌Ｔ４５’－脱单碘酶活性；心肌线粒体α－磷酸甘油脱氢酶（α－ＧＰｕ）活性均明显低于富硒的非病区和常备饲料组。血及心肌脂质过氧化物（ＬＰＯ）含量则相反。在单纯补硒后上述指标均有明显改善。表明晒在心肌甲状腺激素代谢调节作用中起着重要作用。     

硒和维生素E对喂克山病病区粮大鼠胰岛素、C肽水平的影响及其发生机制

饲以克山病病区粮对大鼠胰岛B细胞分泌功能的影响及补充硒和维生素E(VE)的保护作用研究结果表明,病区粮组大鼠血清胰岛索、C肽水平显著下降,胰岛B细胞C肽分泌贮备减少,胰腺谷胱甘肽过氧化物酶(GSH-Px)活力明显降低,脂质过氧化物(LPO)含量升高。在病区粮内分别加入0.44mg/kg亚硒酸钠和500mg/kg VE及联合补充上述剂量硒和VE可明显提高血清胰岛素、C硒水平,增加C肽分泌贮备,升高胰腺GSH-Px活力及降低LPO含量。此结果提示,克山病病区粮可引起大鼠胰岛B细胞功能受损,胰岛素分泌不足,此改变在克山病时可能成为加重心肌损害的原因之一。     

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 Ⅱ、膳食蛋白质水平影响实验动物血和组织中硒含量和谷胱甘肽过氧化物酶活力原因的探讨

<正> 硒是谷胱甘肽过氧化物酶(GSH-Px)的必需组成部分。动物实验证明血和组织中GSH-Px活力与摄入硒量有密切关系。因此,测定血和组织中GSH-Px活力可作为评定机体中硒营养状况的一个指标。作者等在前报告中报导了大鼠饲料硒含量在0.03ppm时,动物血和组织中硒含量和GSH-Px活力随蛋白质水平上升而下降。由于血和组织中GSH-Px活力对评定硒营养状况的重要意义,本文将进一步探讨产生这一现象的原因。     

克山病病区粮饲养大鼠~(75)Se代谢的实验观察

以克山病病区和非病区粮饲养大鼠(饲料号为13和35)6—13周进行~(75)Se示踪代谢实验,观察11种组织脏器(褐脂、胸腺、血液、心脏、肺、肌肉、骨、肾、脾、肝、肠)~(75)Se(Na_2SeO_3)的吸收量和体内分布状况。结果表明,自由进食条件下,病区饲料组动物~(75)Se吸收量高于非病饲料组。其中以13号莜麦饲料组差异最为明显(A实验)。对饲条件下病区组动物~(75)Se的吸收量仍高于非病区组。但是差异程度较自由进食组为小(B实验)。各组动物体内不同组织脏器~(75)Se的分布梯度呈现一定规律性。皆以肾脏的吸收量为最高,其次是肝、脾脏及胸腺等,吸收量最低的是肌肉、心脏及骨骼。 在观察的一周之内,随时间的增加,~(75)Se于组织脏器中的含量,病区饲料组与非病区饲料组有不同的动态变化。 病区与非病区组间~(75)Se吸收量规律性差别,反映了病区组动物在病区出产的饲料影响下,体内硒不足或缺乏,表明病区与非病区出产的粮食存在着质的差异,证实了病区水土——食物链因素对动物机体硒代谢有明显影响。     

膳食中维生素E对克山病区粮饲养的大鼠硒代谢的影响

用除去维生素E的克山病病区粮配成的基础饲料,利用在该低硒低维生素E的基础饲料中补充α-生育酚和/或硒的饲料饲养大鼠,观察维生素E对硒代谢的影响。结果表明: (1)饲料硒水平相同时,维生素E可使肝组织中硒水平明显升高,对其它组织影响不大。 (2)不论硒缺乏时或是补充硒时,维生素E缺乏组动物的全血、心和肝谷胱甘肽过氧化物酶活力均低于补充维生素E组。心和肝中的差异较为明显。 (3)当相应两组大鼠的硒摄入量无明显差别时,不论是补硒组或是缺硒组,在饲料中补充维生素E均可使尿硒排出明显降低,硒在体内存留率增高。     

大鼠谷胱苷肽过氧化物酶发挥最佳活性所需的最低饲料硒水平

目的　测定大鼠谷胱苷肽过氧化物酶活性达到最高时所需的饲料硒水平。方法　以低硒酵母配制低硒基础饲料 ,在此基础上加不同剂量的亚硒酸钠配成 8种不同硒水平的饲料来喂养雄性 Wistar断乳大鼠。饲料硒水平分别为 0 .0 1、0 .0 2、0 .0 3、0 .0 4、0 .0 5、0 .0 6、0 .1 0和 0 .2 0mg/kg。 2 0周时处死大鼠 ,分别对各种组织中的硒 ( Se)、细胞内谷胱苷肽过氧化物酶 ( c GPX)、细胞外谷胱甘肽过氧化物酶 ( e GPX)、磷脂氢谷胱甘肽过氧化物酶 ( PHGPX)活性进行测定。结果　在Wistar大鼠的各种组织中 c GPX发挥最佳活性时的最低饲料硒水平高于其它两种硒蛋白。雄性Wistar大鼠发挥最佳 c GPX活性所需最低饲料硒水平为 0 .2 0 mg/kg,e GPX和 PHGPX发挥最佳活性所需的最低饲料硒水平分别为 0 .0 4和 0 .0 5mg/kg。结论　确保满足雄性大鼠 c GPX、e GPX和 PHGPX三种硒蛋白合成的饲料硒水平为 0 .2 0 mg/kg。     

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。     

不同硒水平饲料对大鼠肝脏谷胱甘肽过氧化物酶和脱碘酶活性的影响

为了解不同饲料硒水平对大鼠肝脏中谷胱甘肽过氧化物酶和脱碘酶活性的影响及确定它们发挥最佳活性时的最低饲料硒水平。５４只体重为５０～６０ｇ的雄性断孔Ｗｉｓｔａｒ大鼠分成９组，分别喂以９种含硒水平为０．０１，０．０２，０．０３，０．０４，０．０５，０．０６，０．１，０．２和５ｍｇ／ｋｇ的不同饲料。实验持续２０周。９组动物２０周的体重增长除５ｍｇ／ｋｇ饲料组与０．１、０．２ｍｇ／ｋｇ饲料组之间有差异外，其余均没有显著性差异。谷胱甘肽过氧化物酶的活性随着饲料硒水平的升高而升高，当饲料硒含量为０．１，０．２和５ｍｇ／ｋｇ饲料时，活性达到最高。因此它发挥正常活性范围的最低饲料硒需要量为０．１ｍｇ／ｋｇ。９个组脱碘酶的活性（ｎｍｏｌ／ｍｉｎ．ｇ）在０．０５至０．２ｍｇ／ｋｇ饲料时活性最高，在５ｍｇ／ｋｇ饲料时酶活性降低，发挥最佳活性最低饲料硒需要量为０．０５ｍｇ／ｋｇ。     

Growth, reproduction rates and mammary gland selenium concentration and glutathione-peroxidase activity of BALB/c female mice fed two dietary levels of selenium

This research was designed to determine the effect of various levels of dietary selenium on growth of BALB/c female mice. The selenium concentration and glutathione peroxidase (GSH-Px) activity in different developmental stages of the mammary gland was determined in the female mice fed 0.03 and 1.5 ppm Se. The development stages studied were: virgin (at 20 and 26 weeks of age), pregnant, lactating and involuted mammary gland. Also, the effect of the two levels of dietary selenium (0.03 and 1.5 ppm Se) on second generation reproductive rates were determined. There was no effect of dietary selenium (0.03, 0.20 or 2.00 ppm Se) on the growth rate of the mice except during pregnancy. The pregnant mice fed the 1.5 ppm Se diet had a greater growth rate than the mice fed the 0.03 ppm diet. Selenium levels in the mammary glands were higher in mice fed the 1.5 ppm Se diet than those fed the 0.03 p]pm Se diet. However, only in the mice with the highest growth rate, 10-week-old virgins, pregnant and lactating mice, was there an effect of dietary selenium on mammary gland GSH-Px activity. The reproductive rates for the second generation mice fed the two diets were similar to rates of mice fed stock diet. When both mating pairs (male and female) consumed the 0.03 ppm Se diet, the reproductive rates were lower than all other mating pairs. Thus, two conclusions can be made from these studies. First, as measured by growth and reproductive capabilities there were no signs of toxicity in mice fed the 1.5-2.0 ppm Se diet. Secondly, the differentiative states of the mammary gland influenced the selenium requirement for GSH-Px activity     

鱼油豆油对饲低硒粮大鼠体内含硒酶活力的影响

目的：研究富含多不饱和脂肪酸的鱼油和豆油对低硒大鼠体内含硒酶活力的影响。方法：饲大鼠低硒粮四周后添加鱼油或豆油（５０ｇ／ｋｇ）继续饲养四周，观察对大鼠肝、肾Ｔ４５－脱单碘酶（ＩＤ－Ｉ）和全血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活力的影响。结果：低硒粮添加鱼油或豆油后，大鼠肝、肾ＩＤ－Ｉ活力降低，全血中ＧＳＨ－Ｐｘ活力亦明显降低；补充０．１μｇ／ｇ硒后可预防ＰＵＦＡｓ对二种酶活性的改变。结论：ＰＵ－ＦＡｓ（鱼油或豆油）可使机体缺硒状态加重。     

Type I iodothyronine deiodinase activity after high selenium intake, and relations between selenium and iodine metabolism in rats.

Type I iodothyronine deiodinase (I-D), which catalyzes the production of the thyroid hormone 3,3',5-triiodothyronine from thyroxine, has recently been identified as a selenoenzyme. It is therefore of interest to investigate the relationships between selenium and iodine metabolism. In the livers of Se-deficient rats I-D activity was inhibited; the production of 3,3',5-triiodothyronine and 3,3'-diiodothyronine from added thyroxine was decreased by greater than 95% relative to Se-adequate controls. The hepatic I-D activity was also reduced in rats fed a diet with a low iodine concentration. Unaltered glutathione peroxidase activities in liver and plasma of these rats suggest, however, that with normal Se intake this metabolic pathway of Se is not affected by iodine depletion. When rats were administered 75Se-labeled selenium at levels equal to the amounts ingested from diets with Se concentrations of 0.3 or 2 mg Se/kg, greater Se concentrations were found in the thyroid and liver of the animals receiving the higher dosage. The thyroidal 3,3',5-triiodothyronine and thyroxine concentrations, however, were comparable in rats fed diets with 0.3 mg Se/kg diet as selenite and 2 mg Se/kg as selenite or L-selenomethionine. The measurement of the hepatic I-D and glutathione peroxidase activities in these animals showed that excessive Se supply does not elevate the activities of the two enzymes but might even have the opposite effect. At high Se intake tissue Se concentration cannot therefore be used as indicator of the selenoenzyme activities.     

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。     

Dietary selenium requirement of fingerling channel catfish

Two experiments were conducted in aquaria to determine the minimum dietary selenium requirement of fingerling channel catfish (Ictalurus punctatus). Casein-gelatin diets containing graded levels of supplemental selenium (as Na2SeO3) ranging from 0 to 15 mg/kg were fed to catfish for 15 weeks in experiment 1 to broadly define their selenium requirement and toxicity levels. Although growth of catfish was affected by dietary selenium level, significant differences in weight gain were not easily discernible due to variability among the groups of fish. Weight gain data generally indicated that the basal diet containing 0.06 mg Se/kg diet caused growth depression, and a supplemental selenium level of 15 mg/kg also caused a reduced growth response, which indicated selenium toxicity. Selenium concentrations in edible muscle tissue increased almost linearly with increasing dietary selenium levels. Liver and plasma selenium-dependent glutathione peroxidase (Se GSH-Px) activities indicated the selenium requirement of fingerling channel catfish was between 0.1 and 0.5 mg Se/kg diet. In experiment 2, casein-gelatin diets containing incremental levels of supplemental selenium were fed to catfish for 14 weeks to more precisely determine their minimum dietary selenium requirement. Growth data and liver and plasma Se GSH-Px activities indicated that the minimum selenium requirement of fingerling channel catfish fed adequate vitamin E was 0.25 mg Se/kg dry diet. Based on these data, it appears that selenium supplementation of commercial catfish feeds is warranted.     

Relative bioavailability of seleno-compounds in the lactating rat

Bioavailability of the organic forms of selenium (Se), selenomethionine (Se-methionine) and Se-yeast was determined relative to that of an inorganic form, selenite, in the lactating rat. A purified, casein-based diet without added Se was fed to nine groups of rats throughout pregnancy to produce a marginal Se deficiency. During lactation, groups (n = 8) were fed experimental diets containing either 0.1, 0.25 or 0.5 ppm Se as selenite, Se-methionine, or Se-yeast. On d 18 of lactation, tissue Se and glutathione peroxidase (GSH-Px) activities of dams and pups were determined. Based on slope-ratio analyses, the bioavailability of Se-methionine and Se-yeast was greater than that of selenite in both lactating dams and their nursing pups. The greater availability of organic Se to pup tissues may be a direct result of the greater concentration of Se in the milk of dams fed organic Se. A dietary level of 0.25 ppm Se as Se-methionine ensured maximal GSH-Px activity in both dam and pup tissues, but 0.5 ppm Se was necessary when selenite or Se-yeast was fed. These results indicate that, regardless of form, the National Research Council recommendation for growing rats of 0.1 ppm Se is not adequate to replete lactating dams and maintain maximal tissue GSH-Px in nursing pups.