Effects of Selenium Administration on Erythrocyte and Blood Plasma Glutathione Peroxidase Activity in Goats

The activity of glutathione peroxidase (GSH-Px, E.G. 1.11.1.9.) was determined in heparinized whole blood, blood plasma and washed erythrocytes from goats before and up to 4 weeks after the administration of selenium (0.4 mg/10 kg BW) and vitamin E (20 mg/10 kg BW) or only vit. E (20 mg/10 kg BW). It was found that Se administration caused a significant increase in enzyme activity in whole blood and washed erythrocytes first detected 2 weeks after the intramuscular injection of Se. No changes were observed in plasma from the treated animals. Minor and insignificant changes were seen in the vit. E treated control animals. It is concluded that GSH-Px activity in blood plasma or serum is of no value as a short-term indicator of the selenium status of goats but whole blood is a good indicator of the long-term status.     

Glutathione Peroxidase Activity in Porcine Blood

Determination of the seleno-enzyme glutathione peroxidase (GSH-Px) in blood from Danish Landrace pigs was done using a quantitative, spectrophotometric method and a simple “spot test”. A close correlation between the net reaction rate measured spectrophotometrically (Δ A/min.) and time for defluores-cence (minutes) was obtained (r² = 0.72—0.77, P < 0.0005). From these results the factors used for a conversion of defluorescence time to u/g hemoglobin were evaluated. The results further showed that the “spot test” can be used as a screening method for detection of subnormal GSH-Px levels in pigs.While red cell GSH-Px seems independent of the sex, an elevation of both plasma and red cell GSH-Px was found with increasing age of pigs. The normal range of red cell GSH-Px activity was wide, contrasting the small variations observed in the individual pig. Some evidence that porcine red cell GSH-Px is under genetical control was found and discussed in relation to the possible use of GSH-Px as an indicator of the pig''s selenium status.     

低硒雏鸡口服亚硒酸钠后机体硒浓度及谷胱甘肽过氧化物酶的活性动态变化规律

低硒雏鸡口服亚硒酸钠后,对不同时间血液（清）、肝、肾、胰、心、脾硒浓度及谷胱甘肽过氧化物酶活性的动态变化规律测定。结果发现随着硒浓度的变化,酶活性也发生相应变化,但１９２ｈ后肾、脾酶活性出现第２次升高而其硒浓度仍降低。值得注意的是酶活性的变化总滞后于硒浓度的变化     

不同硒水平对猪和大鼠的生长性能、组织硒含量、血GSH-Px活性的影响及比较

采用仔猪36头和大鼠144只,在低硒玉米—豆饼基础日粮上,以亚硒酸钠形式添加0、0·02、0.1、0.5、2.5、12.5ppm的硒,分别测定了不同硒水平对猪、大鼠生长性能、组织硒含量和血GSH-Px活性的影响,并在此基础上对两者进行了比较。试验结果表明,高硒和低硒都能影响猪、大鼠的生长性能及各组织硒含量,大鼠的反应较敏感;猪、大鼠血GSH-Px活性的对数值在一定范围内均随饲料硒水平的增加而升高。因此认为,通过大鼠亦能迅速捕捉到猪体试验的某些结果,可作为猪模拟或预备性试验的较为敏感、经济的动物。     

The relationship of erythrocyte glutathione peroxidase to blood selenium in swine

The erythrocyte glutathione peroxidase activity and blood selenium have been investigated in swine fed a Se deficient diet with, and without, selenium supplementation. A highly significant correlation (r = 0.90) between erythrocyte glutathione peroxidase and blood selenium was found.     

微分脉冲催化极谱法测定乳牛全血硒

采用美国２７３Ａ型电化学分析系统,根据ＳｅＳＯ３２－－ＫＩＯ３氧化还原反应原理,用微分脉冲催化极谱法测定了奶牛全血痕量硒。此法最低检出极限０．１μｇ／Ｌ,线性范围０．５～５．０μｇ／Ｌ,回收率９２．６０％～１０３．００％。硒标准溶液和饲料重复测定值的变异系数分别为１．５％和２．２％。奶牛全血硒的测定值符合饲料梯度添加试验,其精密度和准确度均高。     

谷胱甘肽过氧化物抗体酶ScFv的基因构建

特异性单克隆抗体杂交瘤细胞株５Ｃ９所分泌的ＭｃＡｂ经化学修饰后,其抗体酶活性比兔肝谷胱甘肽过氧化物酶活性高２．６倍。在所建成的杂交瘤细胞株基础上,通过提取该细胞总ＲＮＡ,分离ｍＲＮＡ,反转录合成ｃＤＮＡ,以及ＶＨ和ＶＬ基因的ＰＣＲ扩增、组装,成功地构建了谷胱甘肽过氧化物抗体酶ＳｃＦｖ基因。电泳分析证明,ＶＨ和ＶＬ基因长度分别为３４０ｂｐ和３２５ｂｐ;所构建的ＳｃＦｖ基因长度约为７５０ｂｐ,并带有ＳｆｉⅠ和ＮｏｔⅠ切点,可用于ＳｃＦｖ的基因重组及其表达。     

有机硒在猪营养中的研究进展

硒为动物必需微量元素,缺乏和过量对机体都可产生不利影响,甚至死亡。硒的形式多种多样,其中有机硒具有诸多优点,成为近年来硒研究的热点。本文重点综述有机硒在猪体内的代谢和对母猪、公猪繁殖性能、生长育肥猪生产性能及肉质品质的影响。     

不同海拔地区牦牛心肌、骨骼肌GSH-PX的测定

在西宁屠宰场对来自青海省两个不同海拔县牦牛心肌和骨骼肌线粒体内谷胱甘肽过氧化物酶(GSH-PX)活性进行测定。结果表明,海拔4300m左右的玛多县牦牛心肌、骨骼肌GSH-PX分别为20.15U.mg-1±5.43U.mg-1和15.32U.mg-1±4.27U.mg-1,海拔3400m左右的刚察县牦牛心肌、骨骼肌GSH-PX分别为6.67U.mg-1±5.67U.mg-1和7.76U.mg-1±4.83U.mg-1;玛多牦牛的心肌、骨骼肌组织线粒体的GSH-PX活性显著高于刚察牦牛(P<0.05)。在高原低氧环境下,牦牛体内GSH-PX活性与海拔高度呈正相关。     

Glutathione Peroxidase Activity and Erythrocyte Lipid Peroxidation as Indices of Selenium and Vitamin E Status in Young Pigs

A randomized, blocked 2³ factorial experiment was conducted with 48 pigs from sows fed a diet low in selenium and vitamin E. From 3 to 12 weeks of age the piglets were kept in single pens and fed a basic diet consisting mostly of barley, dried skim milk, soybean meal and dried yeast, and containing 55 µg selenium and 3 mg vitamin E per kg. The treatment factors — i.e. feed supplements — were 2 levels of Se (nil, 60 µg/kg), 2 levels of vitamin E (nil, 50 mg/kg), and 2 levels of the feed antioxidant ethoxyquin (nil, 150 mg/kg). Blood samples, collected at termination of the experiment, were examined for glutathione peroxidase activity (GSH-Px) and resistance against erythrocyte lipid peroxidation (ELP) to evaluate Se and vitamin E status, respectively. Analysis of variance showed the GSH-Px activity to be litter-dependent (P < 0.001) and influenced by selenium supplementation (P < 0.001) but not by the other supplements or by interactions between supplements. Resistance against ELP was influenced only by vitamin E supplementation (P < 0.001). GSH-Px and ELP thus seem to be valuable and simple methods for evaluating, respectively, Se status and vitamin E status in growing pigs.     

附睾特异谷胱甘肽过氧化物酶基因调控的研究进展

附睾特异谷胱甘肽过氧化物酶(epididymal specific glutathione peroxidase,GPx5)可保护精子免受氧化应激,维持精子遗传信息的完整性,促进精子发育成熟,其重要生理功能在提高动物繁殖力上有着不可替代的作用,但其基因调控转录表达的机制尚不明确。现作者主要对基因表达特性、表达调控和转录调控等内容进行综述。     

Bioavailability to chicks of selenium in barley, oats and meat meal

Day-old White Leghorn chicks deficient in selenium (Se) were fed a low Se basal diet (containing adequate level of vitamin E) for 2 weeks depletion period before they were given the experimental diets containing different levels of Se for 4 weeks. Dietary treatments contained 0.03, 0.06, 0.09 or 0.12 mg Se/kg as sodium selenite, barley, oats, meat meal or their extracted counterparts. Plasma GSH-Px activity was observed at weekly intervals, while the Se concentration of plasma and liver were determined at the end of the study. The biological availability of Se in the test ingredients was measured by the induction of plasma GSH-Px activity. In comparison to sodium selenite (100 %) it was: 77 % for barley, 80 % for extracted barley, 37 % for oats, 62 % for extracted oats, 20 % for meat meal, and 26 % for extracted meat meal. Using the retention of Se in plasma as a criterion, the following biological availability of Se was observed: barley 151 %; extracted barley 102 %; oats 90 %; extracted oats 107 %; meat meal 40 %; and extracted meat meal 47 %. Similarly, the efficiency of the test ingredients in increasing the Se concentration in liver was: barley 82 %; extracted barley 90 %; oats 67 %; extracted oats 98 %; meat meal 26 %; and extracted meat meal 31 %. The greater biopotency of the natural Se sources for increasing the Se concentration of the chick tissues than for inducing the plasma GSH-Px activity in comparison to sodium selenite, indicated that proportionally less amounts of the Se retained in the chick plasma from the natural sources were incorporated into the metabolic active form of Se, i.e., GSH-Px. Therefore, the plasma GSH-Px activity was suggested as the more reliable criterion to be used for the evaluation of the bioavailability of Se.     

Comparative effect of selenium in wheat, barley, fish meal and sodium selenite for prevention of exudative diathesis in chicks

Groups af White Leghorn chicks obtained from dams deprived on selenium (Se), were fed from hatching a low-Se-vitamin E basal diet alone, or supplemented with 0.02, 0.04, 0.06 or 0.08 mg Se/kg diet, as sodium selenite (Na2SeO₃ · 5H₂O), wheat, barley or fish meal. Prevention of the Se-vitamin E deficiency responsive disease exudative diathesis (ED) as it was clinical observed, induction of the plasma Se dependent enzyme glutathione peroxidase (GSH-Px) activity, and Se concentration in the cardiac muscle were observed to be dietary Se level and source dependent. Slope ratio assay was applied to estimate the biological availability of Se in the natural sources relative to Se in sodium selenite. For the prevention of ED, the bioavailability of Se in wheat, barley and fish meal was 99, 85 and 80 %, respectively. The increase in the plasma GSH-Px activity revealed a bioavailability for Se in wheat, barley and fish meal of 79, 71 and 66 %, respectively. Using retention of Se in the cardiac muscle as the bioassay, a bioavailability of 108, 87 and 100 % was calculated for wheat, barley and fish meal Se, respectively.     

The stability of glutathione peroxidase activity in plasma from cattle,pigs and sheep on storage in the presence and absence of glutathione

Ovine, bovine and porcine plasma glutathione peroxidase (GSH-Px) activity decreased on storage at both 4°C and 20°C. The ovine and bovine enzymes were significantly less stable than the porcine enzyme. The addition of GSH to a final concentration of 2 mmol/L to plasma samples at the commencement of storage retarded the loss of both ovine and bovine plasma GSH-Px activity. The ovine enzyme was unique in that after inactivation by storage at 4°C, incubation with GSH restored the enzyme activity. It is recommended that plasma GSH-Px should be assayed fresh, or otherwise stored at –20°C.     

Serum glutathione peroxidase activity and blood selenium in pigs

Blood serum glutathione peroxidase activity and blood selenium concentration were measured in blood samples from pigs subjected to experimentally induced selenium deficiency and dietary selenium supplementation on graded levels. A highly significant correlation between blood selenium and serum GSH-Px activity in pigs, especially in selenium deficient pigs, was demonstrated. There was also a strong relationship between blood selenium concentration and serum GSH-Px activity in pigs receiving dietary selenium at graded levels. Serum GSH-Px activity exhibited an excellent close-response relationship to dietary selenium. Linear regression analysis showed that the increased serum GSH-Px activity was a function of the dietary selenium concentration. The fitness of serum in monitoring slight changes of the selenium status of pigs with help of the estimation of GSH-Px activity was discussed. The measurement of serum GSH-Px activity seems to provide a useful and rapid means for defining selenium requirements and for identifying selenium deficiency in growing pigs.     

祁连县本地黄牛全血铁含量的测定

对60头祁连县本地黄牛的全血铁含量进行了测定。结果表明：祁连黄牛全血铁含量为0．319g/L。同时发现公、母黄牛间的全血铁含量无显著差异（P＞0．05），而成年黄牛的全血铁含量极显著地高于犊牛（P＜0．01）。     

门源本地黄牛血钾浓度测定

采用火焰光度法对 40头门源县本地黄牛进行了血钾浓度测定 ,其血清钾浓度为 5 .5 2± 0 .82mmol L ,全血钾浓度为 8.90± 3.32mmol L ,红细胞钾浓度为 15 .5 2± 10 .2 5mmol L     

锌硒对后备猪繁殖性能及仔猪发育的影响

本试验研究了锌硒对后备公母猪繁殖性能和哺乳仔猪成活率的影响。在２月龄公母猪和哺３乳仔猪日粮中添加不同剂量的锌和硒,试验与对照组比较,后备母猪排卵率和产仔性能均有明显提高;后备公母初次采精时间提前,睾丸大小,射精量,精子活率和精子密度均显著提高,精子畸形率降低;     

The effects of dietary oxidized fat and selenium source on performance,glutathione peroxidase,and glutathione reductase activity in broiler chickens

Normal or elevated selenium status of broilers, which is influenced by dietary selenium sources, improves the bird’s ability to overcome the adverse effects of reactive oxygen metabolites. The objective of this study was to evaluate the effects of feeding graded levels of peroxidized poultry fat on blood and hepatic glutathione peroxidase (GSH-Px), and hepatic glutathione reductase activity in broiler chickens fed either inorganic sodium selenite (SEL) or organic selenium enriched in the organic selenium yeast product Sel-Plex (SP). Nine starter diets, varying in levels of oxidized fat (0, 3, and 6 mEq/kg) and dietary selenium sources, were fed to 360 male chicks from hatch to 21 d of age. Sel-Plex or SEL was added to the basal diet to provide either 0 or 0.2 ppm of supplemental selenium in the diets. Blood and hepatic samples were obtained for each treatment group at 21 d of age. Neither peroxidized fat nor selenium source significantly altered the activity of hepatic glutathione reductase (P ≤ 0.05). Blood GSH-Px was influenced significantly by both fat and selenium source (P ≤ 0.05), but the fat × selenium source interaction was not significant (P ≥ 0.3). A selenium source effect on the hepatic GSH-Px activity (P ≤ 0.05) was evidenced by higher GSH-Px activity, even in the basal diet with no added peroxidized fat. An increase in GSH-Px activity was seen in the erythrocyte and hepatic samples in both the SEL and SP treatments when peroxidized fat was given at 3 mEq/kg, but in the erythrocytes and in the hepatic tissues from SEL-supplemented birds, there was an apparent inhibition of GSH-Px activity. This inhibition was not seen in the hepatic tissue samples from SP-fed birds. Because elevated GSH-Px activity is indicative of oxidative stress, it was concluded that dietary SP supplementation resulted in better selenium and redox status in broilers than did SEL. These results indicate that the dietary selenium supplied in an organic form (selenium yeast as SP) improved the selenium and redox status in broilers, leading to greater resistance to oxidative stress than when the inorganic form of selenium (SEL) was fed.