Protective Effects of Selenium,Zinc, or Their Combination on Cadmium-Induced Oxidative Stress in Rat Kidney

The present study was conducted to investigate whether the combined treatment with Se and Zn offers more beneficial effects than that provided by either of them alone in reversing Cd-induced oxidative stress in the kidney of rat. For this purpose, 30 adult male Wistar albino rats, equally divided into control and four treated groups, received either 200 ppm Cd (as CdCl₂), 200 ppm Cd + 500 ppm Zn (as ZnCl₂), 200 ppm Cd + 0.1 ppm Se (as Na₂SeO₃), or 200 ppm Cd + 500 ppm Zn + 0.1 ppm Se in their drinking water for 35 days. The results showed that Cd treatment decreased significantly the catalase (CAT) and glutathione peroxidase (GSH-Px) activities, whereas the superoxide dismutase (SOD) activity and the renal levels of lipid peroxidation (as malondialdehyde, MDA) were increased compared to control rats. The treatment of Cd-exposed rats with Se alone had no significant effect on the Cd-induced increase in the MDA concentrations but increased significantly the CAT activities and reversed Cd-induced increase in SOD activity. It also partially prevented Cd-induced decrease in GSH-Px activity. The treatment of Cd-exposed animals with Zn alone increased significantly the CAT activity and partially protected against Cd-induced increase in the MDA concentrations, whereas it had no significant effect on the Cd-induced increase in SOD activity and decrease in GSH-Px activity. The combined treatment of Cd-exposed animals with Se and Zn was more effective than that with either of them alone in reversing Cd-induced decrease in CAT and GSH-Px activities and Cd-induced increase in MDA concentrations. Results demonstrated beneficial effects of combined Se and Zn treatment in Cd-induced oxidative stress in kidney and suggest that Se and Zn can have a synergistic role against Cd toxicity. I. Messaoudi and J. El Heni have equally contributed to this work.     

Copper/zinc and copper/selenium ratios,and oxidative stress as biochemical markers in recurrent aphthous stomatitis

ProjectRecurrent aphthous stomatitis (RAS) is a common oral mucosal disorder characterized by recurrent, painful oral aphthae, and oxidative stress presumably contributes to its pathogenesis. The aim of this study is to scrutinize the relationship between oxidative stress and serum trace elements (copper, Cu; zinc, Zn; selenium, Se), and to evaluate the ratios of Cu/Zn and Cu/Se in this disorder.ProcedurePatients with RAS (n = 33) and age- and sex-matched healthy control subjects (n = 30) were enrolled in this study. Malondialdehyde (MDA) concentrations in plasma and the activities of superoxide dismutase (SOD1; CuZnSOD), glutathione peroxidase (GPx) and catalase (CAT) in erythrocyte were determined as spectrophotometric. Also, the levels of Se, Zn and Cu in serum were determined on flame and furnace atomic absorption spectrophotometer using Zeeman background correction.Results and conclusionsOxidative stress was confirmed by the significant elevation in plasma MDA, and by the significant decrease in CAT, SOD1, and GPx (p < 0.05). When compared to controls, Zn and Se levels were significantly lower in patients, whereas Cu levels was higher in RAS patients than those in controls (p < 0.05). In addition, the correlation results of this study were firstly shown that there were significant and positive correlations between Se–CAT, Se–GPx, and Cu–MDA parameters, but negative correlations between Se–Cu, Se–MDA, Cu–CAT, Cu–SOD1 and Cu–GPx parameters in RAS patients. Furthermore, the ratios of Cu/Zn and Cu/Se were significantly higher in the patients than the control subjects (p < 0.05). Our results indicated that lipid peroxidation associated with the imbalance of the trace elements seems to play a crucial role in the pathogenesis of RAS. Furthermore, the serum Cu/Zn and Cu/Se ratios may be used as biochemical markers in these patients.     

Circadian rhythms of biomarkers of oxidative stress and their characteristics in broiler chickens reared under natural light/dark cycle

For the purpose of studying circadian rhythms of biomarkers of oxidative stress in broiler chickens maintained under natural photoperiod, we collected blood from the wing veins of 10 matured broiler chickens every three hours for a period of 24 h. The blood samples were analyzed for superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA). The fitting in of single cosinor procedure showed that CAT and MDA exhibited clear circadian rhythms, while SOD did not. The amplitude of daily rhythms for the parameters was small, while the acrophases were all restricted to the light phase of the light:dark cycle. In conclusion, to our knowledge, this is the first time investigation of the circadian rhythms of antioxidants in broilers chickens, reared under natural photoperiod in the tropics. The result may be exploited for a more precise targeting of reactive oxygen species, thereby offering better protection for the cells to combat oxidative stress.     

低温胁迫下嫁接对黄瓜叶片SOD和CAT基因表达与活性变化的影响

研究了低温胁迫下嫁接和自根黄瓜叶片Mn-SOD、Cu/Zn-SOD和CAT mRNA基因表达和酶活性变化及其与抗冷性的关系.结果表明:低温胁迫下,嫁接与自根黄瓜叶片Cu/Zn-SOD、Mn-SOD mRNA基因相对表达量变化分别与其Cu/Zn-SOD、Mn-SOD活性变化相吻合,而CATmRNA相对表达量变化与其CAT活性变化并不一致;嫁接黄瓜叶片Cu/Zn-SOD和Mn-SOD mRNA相对表达量及SOD、Cu/Zn-SOD和Mn-SOD活性均高于自根黄瓜,MDA含量和电解质渗漏率均低于自根黄瓜,嫁接黄瓜较高的SOD基因表达量调控的较高SOD活性是其抗冷性强于自根黄瓜的主要因素;嫁接黄瓜的功能叶CAT mRNA相对表达量略高于自根黄瓜,而幼叶CAT mRNA相对表达量低于后者,但两者CAT活性差异不大,说明低温胁迫对嫁接黄瓜叶片CAT mRNA相对表达量及CAT活性的影响不大.     

Effect of Supplemental Trace Minerals on Hsp-70 mRNA Expression in Commercial Broiler Chicken

The effects of supplementing the organic forms of selenium (Se), chromium (Cr), and zinc (Zn) on Hsp-70 mRNA expression and body weight in broiler chickens were evaluated. 200 chicks were equally distributed into stainless steel battery brooders at the rate of 5 birds per pen and reared under heat stress condition up to 42^nd day. The chicks were fed with three experimental diets supplemented with organic forms of Se (0.30?mg/kg), Cr (2?mg/kg), and Zn (40?mg/kg) during the starter and finisher phases and a control diet without any supplementation. On the 21st and 42nd day, 20 birds from each period were sacrificed and samples were collected for analysis. Organic Se, Cr, and Zn supplementation significantly (P?Hsp-70 mRNA levels. The Hsp-70 mRNA expression levels were significantly (P?Hsp-70 mRNA expression level was not affected by age of the birds. The study concluded that organic trace mineral (oTM) supplementation resulted in low Hsp-70 mRNA expression, indicating reduced heat stress in broilers.     

氯化钠胁迫下嫁接黄瓜叶片SOD和CAT mRNA基因表达及其活性

研究了NaCl胁迫下嫁接和自根黄瓜叶片Cu/Zn-SOD、Mn-SOD和CAT mRNA的表达与其酶活性变化及其MDA含量和电解质渗漏率变化.结果表明：在NaCl胁迫条件下,嫁接黄瓜叶片Cu/Zn-SOD mRNA、Mn-SOD mRNA和CAT mRNA的相对表达量均高于自根黄瓜,SOD、Cu/Zn-SOD、Mn-SOD和CAT活性也均高于自根黄瓜,说明与自根黄瓜相比,嫁接黄瓜叶片较高的Cu/Zn-SOD mRNA、Mn-SOD mRNA和CAT mRNA相对表达量是其维持较高Cu/Zn-SOD、Mn-SOD和CAT活性的重要原因;随着NaCl胁迫时间的延长,嫁接和自根黄瓜叶片Cu/Zn-SOD- mRNA、Mn-SOD mRNA和CAT mRNA的相对表达量均呈上升趋势,但其酶活性变化并不完全一致,说明还有其他因素参与相关酶活性的调控;嫁接黄瓜叶片MDA含量和电解质渗漏率均低于自根黄瓜,说明嫁接黄瓜具有较高的活性氧清除系统,可以减少活性氧物质的危害,提高其耐盐性.     

Alterations of serum selenium, zinc, copper, and iron concentrations and some related antioxidant enzyme activities in patients with cutaneous leishmaniasis

The aim of this study was to measure the alterations in serum selenium (Se), copper (Cu), zinc (Zn), and iron (Fe) concentrations and their carrier proteins, ceruloplasmin (Cp), transferrin (Tf) albumin, and related antioxidant enzyme activities, erythrocyte Cu-Zn Superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities in patients with cutaneous leishmaniasis (CL). Erythrocyte Cu-Zn SOD activities, serum Cu concentrations, and Cp levels were found to be significantly higher in the patients group than those of controls. However, GSH-Px and CAT activities and Se, Zn, Fe, and Tf levels were lower in patients than in the control subjects. There were positive important correlation’s between Cu-Zn SOD and Cp, Cu-Zn SOD and Cu, Cp and Cu, GSH-Px and Se, and Fe and CAT in the patients group. Our results showed that serum essential trace elements Se, Zn, Cu, and Fe concentrations and their related enzymes Cu-Zn SOD, GSH-Px, and CAT activities change in CL patients. The changes may be a part of defense strategies of organism and are induced by the hormonelike substances.     

Effects of free and dipeptide forms of methionine supplementation on oxidative metabolism of broilers under high temperature

Our previous studies have shown that methionine supplementation could help to attenuate the effects of heat stress on the metabolism of broiler chickens. Here we investigated for the first time the effects of methionine supplementation in the form of DL-methionyl-DL-methionine on broilers subjected to heat stress during the growth phase. Broilers were divided into two groups; one group was reared under thermoneutral conditions and the other under continuous heat stress (30 ± 1 °C, 60% relative humidity). Both groups were subdivided into three dietary treatments: a methionine-deficient (MD) diet, a diet supplemented with free methionine (DL-M), and a diet supplemented with methionine dipeptide (DL-MM). Broilers raised under chronic heat stress had lower feed intake and weight gain than broilers raised under thermoneutral conditions (P < 0.05). There were no differences in animal performance between methionine-supplemented diets (DL-M and DL-MM). Heat-stressed birds had significantly higher heterophil/lymphocyte (H/L) ratio than thermoneutral birds. Under heat stress, broilers fed DL-M and DL-MM diets had lower H/L ratio than birds fed the MD diet. Higher concentrations of carbonylated proteins and lower concentration of reduced glutathione were observed in broilers raised under heat stress. In comparing heat-stressed broilers, we found that birds fed the DL-M diet had lower concentrations of thiobarbituric acid-reactive substances and carbonylated proteins than those fed the MD diet (P < 0.05). Higher expression of glutathione peroxidase (GPX) and glutathione synthetase (GSS) genes was observed in heat-stressed broilers (P < 0.05). Under heat stress, the MD diet increased GPX expression compared with other diets. Under thermoneutral conditions, the DL-M diet resulted in the highest GSS expression. There was a negative correlation between DNA methylation and GPX and GSS expression. Our results showed that supplementation of broiler diets with free methionine or methionine dipeptide may help attenuate the effects of heat stress through enhanced activation of genes related to the glutathione antioxidant system. Methionine effects were found for gene regulation, gene expression, and post-translational processing.     

Alterations in plasma essential trace elements selenium, manganese, zinc, copper, and iron concentrations and the possible role of these elements on oxidative status in patients with childhood asthma

The aim of the present study is to evaluate the status of plasma essential trace element selenium (Se), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) concentrations and the effect of these elements on oxidative status in patients with childhood asthma. Plasma Se, Mn, Cu, and Zn concentrations were determined by atomic absorption spectrophotometry (AAS) and Fe concentrations, malondialdehyde (MDA), and total antioxidant capacity (TAC) were determined by the colorimetric method. The plasma MDA/TAC ratio was calculated as an index of oxidative status. Plasma albumin levels were measured to determine nutritional status. Plasma Fe concentrations, MDA levels and the MDA/TAC ratio were significantly higher (p<0.001, p<0.001, and p<0.01, respectively) and Se and Mn concentrations and TAC were lower (p<0.01, p<0.05, and p<0.01, respectively) in patients when compared to the healthy subjects. Plasma Zn, Cu, and albumin levels were not found to be significantly different in patients and controls (p>0.05). There were positive relationships between plasma MDA and Fe (r=0.545, p<0.001) and TAC and Se (r=0.485, p<0.021), and a negative correlation between TAC and MDA values (r= −0.337, p<0.031) in patients with childhood asthma. However, there was no correlation between these trace elements and albumin content in patient groups. These observations suggest that increased Fe and decreased Se concentrations in patients with childhood asthma may be responsible for the oxidant/antioxidant imbalance.     

Protective role of supplemental vitamin E and selenium on lipid peroxidation, vitamin E, vitamin A, and some mineral concentrations of Japanese quails reared under heat stress

This study was conducted to determine the effects of vitamin E and selenium (Se) on lipid peroxidation (MDA), serum and liver concentration of antioxidant vitamins, and some minerals of Japanese quails reared under heat stress (34°C). One hundred twenty 10-d-old Japanese qualis (60 males, 60 females) were randomly assigned to 4 treatment groups, 3 replicates of 10 birds each. The experiment was designed in a 2×2 factorial arrangement using two levels of vitamin E (125 and 250 mg/kg of diet) and two levels of selenium (0.1 and 0.2 mg/kg of diet). Greater dietary vitamin E and selenium inclusions resulted in a greater (p=0.001) serum vitamin E and vitamin A, but lower (p=0.001) MDA concentrations. Liver vitamin E and vitamin A concentrations increased (p=0.001) and MDA concentrations decreased (p=0.001) when both dietary vitamin E and selenium increased. No interactions between vitamin E and selenium were detected (p≥0.11) for any parameters. Increasing both dietary vitamin E and selenium caused an increase in serum concentrations of Fe and Zn (p=0.001), but a decrease in serum concentration of Cu (p=0.001). Results of the present study showed that dietary vitamin E and selenium have synergistic effects and that supplementing a combination of dietary vitamin E (250 mg/kg of diet) and selenium (0.2 mg/kg of diet) offers a good management practice to reduce heat stress-related depression in performance of Japanese quails.     

Effects of Dietary Selenium, Vitamin E, and Their Combination on Growth, Serum Metabolites, and Antioxidant Defense System in Skeletal Muscle of Broilers Under Heat Stress

This experiment was conducted to evaluate the effects of dietary vitamin E, selenium (Se), and a combination of the two, on the performance, serum metabolites and oxidative stability of skeletal muscle of broilers during heat stress. The broilers raised in either a thermoneutral (23.9°C constant) or heat stress (23.9°C to 37°C cycling) environment were assigned to 6 dietary treatments (0, 0.5, or 1 mg/kg Se; 125 and 250 mg/kg vitamin E; or 0.5 mg/kg Se plus 125 mg/kg vitamin E) from 1 to 49 days of age. At the end of the experiment, blood samples were collected from chicks, the chicks sacrificed, and pectoralis superficialis muscle was used for measurement of malondialdehyde (MDA) concentration and enzyme activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD). The heat-stressed chicks consumed less feed, gained less weight, and had higher feed conversion ratio when compared to thermoneutral chicks (P<0.05). Serum concentrations of iron (Fe) and zinc (Zn) were decreased by heat stress (P<0.05), whereas the serum concentrations of copper (Cu), glucose, and uric acid were significantly increased under heat stress (P<0.05). The chicks that received supplemental of vitamin E exhibited significantly higher serum concentrations of Zn (P<0.05) and significantly lower concentrations of Cu, glucose, and uric acid (P<0.05) when exposed to heat stress. Dietary Se also caused a significant decrease in serum glucose, uric acid, and Cu concentrations of heat-stressed broilers (P<0.05), but had no significant effect on Zn concentration (P>0.05). The GPx activity remained relatively constant (P>0.05), though SOD activity and MDA levels in skeletal muscle were enhanced on exposure to heat stress (P<0.05). The heat-stressed chicks that received the combined supplementary level of vitamin E and Se had the lowest concentration of MDA and the highest activity of SOD in the skeletal muscle (P<0.05). Dietary Se also caused a significant increase in enzyme activity of GPx in the skeletal muscle (P<0.05). These results indicate that the derangement of blood parameters and oxidative stability in broilers under heat stress are improved by supplemental vitamin E and Se.     

Supplemental zinc and vitamin A can alleviate negative effects of heat stress in broiler chickens

This experiment was conducted to evaluate the effects of zinc (ZnSO₄H₂O) and vitamin A (retinol) supplementation on performance, carcass characteristics, and serum concentrations of glucose, cholesterol, total protein, and malondialdehyde (MDA) as an indicator of lipid peroxidation in broiler chickens (Ross) reared at a high temperature (34°C). One hundred twenty 10-d-old male broilers were randomly assigned to 4 treatment groups, 3 replicates of 10 birds each. The birds were fed either a basal diet or the basal diet supplemented with either 30 mg Zn/kg diet, 4.5 mg (15,000 IU) retinol/kg diet, or 30 mg Zn+4.5 mg retinol/kg diet. Supplemental zinc and vitamin A significantly increased live weight gain and improved feed efficiency (p<0.05). However, a combination of zinc and vitamin A, rather than each separately, provided a greater performance. Hot and chilled carcass weights and yields and the weights of internal organs with the exception of abdominal fat were greater for each supplement (p<0.05) compared to the control group. Abdominal fat decreased (p<0.05) upon dietary zinc and vitamin A supplementation. Supplemental treatments resulted in an increased total serum protein but decreased glucose, cholesterol, and MDA concentrations. The results of the study show that, separtely or as a combination, zinc and vitamin A supplementation resulted in an improved live weight gain, feed efficiency, and carcass traits, as well as a decrease in serum MDA concentrations. The results of the present study also suggest that zinc and vitamin A have similar effects and that a combination of zinc and vitamin A may offer a potential protective management practice in preventing heat-stress-related depression in performance of broiler chickens.     

Effects of Se and Cd Co-treatment on the Morphology,Oxidative Stress,and Ion Concentrations in the Ovaries of Laying Hens

This study aims at revealing the effects of the combined treatment of selenium and cadmium on ovary morphology, oxidative stress, and 28 kinds of ion concentrations in laying hens. In this experiment, 128 healthy 31-week-old chickens were selected and divided into four treatment groups, three of which were separately fed the basic diets supplemented with either Se or Cd or both Se and Cd for 90 days, and the remaining group was fed the basic diet and treated as a control. The chickens were sacrificed for collecting ovarian tissues. Morphological structure and ultrastructure analysis of ovaries in the Cd-treated group revealed ovarian damage, with decreased activities of SOD and GPx, along with increased levels of MDA and H₂O₂. Cd treatment also resulted in disturbances in ion balance. The concentrations of Ca, Ti, Cu, Zn, and Ba were significantly reduced, while the concentrations of Fe, Mo, and Cd were significantly increased when compared with the control group. Interestingly, the damages caused by cadmium were alleviated in the Se+Cd-treated group. These results indicate that selenium can alleviate cadmium-induced ovarian damages.     

Effects of dietary genistein on nutrient use and mineral status in heat-stressed quails.

Genistein is a powerful antioxidant and plays a role in calcium and bone metabolism. We evaluated the efficacy of dietary supplementation with genistein on the nutrient use and mineral concentrations in tibia and serum of quails reared at high environmental temperature (34 degrees C). Two hundred and forty Japanese quails (10 days old) were randomly assigned to 8 treatment groups consisting of 10 replicates of 3 birds. The birds were kept in a temperature-controlled room at 22 degrees C (Thermoneutral, TN groups) or 34 degrees C (for 8 h/d; 09.00 am-05.00 pm; Heat stress, HS groups). Birds were fed either a basal diet (TN and HS) or the basal diet supplemented with 200, 400 or 800 mg of genistein/kg of diet. Heat exposure decreased apparent nutrient digestibility and bone mineralization when the basal diet was fed (P < 0.001). Apparent digestibility of dry matter (DM) (P < 0.05), crude protein (CP) (P < 0.05) and ash (P < 0.01) was significantly improved by genistein supplementation. However, this improvement was not in direct proportion to increased doses of supplement since there was no difference when diets included either 400 or 800 mg genistein/kg of diet (P < 0.05) in birds reared under heat stress. The amounts of Ca, P, Mg, Mn, Zn, Fe and Cu in the excreta decreased (P < 0.01), while Ca, P, Mg, Mn, Zn and Cu concentrations in tibia ash increased in quails reared under heat stress conditions (P < 0.01) with genistein supplementation. Ca and P concentrations in tibia ash were also increased in birds kept under thermoneutral conditions with genistein supplementation. Increased serum alkaline phosphatase activity (P < 0.01) was associated with increasing dietary genistein in all groups. In conclusion, genistein supplementation to the basal diet improved digestibility of CP, DM and ash and levels of Ca and P and bone mineralization in quails reared under heat stress conditions.     

Metabolism and Tissue Distribution of Trace Elements in Broiler Chickens' Fed Diets Containing Deficient and Plethoric Levels of Copper,Manganese, and Zinc

Supplementation of broiler diets with copper, manganese, and zinc at levels higher than that stipulated by the National Research Council 1994 reportedly improved live weight, feed conversion, and cured leg abnormality supposedly caused by inadequate intake of Mn and Zn. The objective of the study was to ascertain the effects of plethoric supplementation of copper (Cu), manganese (Mn), and zinc (Zn) on performance and metabolic responses in broiler chickens. The study also aimed to discriminate the responses of the birds when the mineral elements were supplemented either in an inorganic or in an organic form. Cobb 400 broiler chickens (1-day old, n = 300) were assigned to three dietary treatments each containing nine replicates with ten birds for 39 days. The treatments included a control in which the diet was devoid of supplemental trace elements and treatments supplemented with an inorganic trace element premix (ITM) and supplemented with a combination of the inorganic and an organic trace element premix (OTM). The ITM contained (per kilogram) copper, 15 g; iron, 90 g; manganese, 90 g; zinc, 80 g (all as sulfated salts); iodine (as potassium iodide), 2 g; and selenium (as sodium selenite), 0.3 g. The OTM on the other hand, contained copper, 2.5 g; iron, 15 g; manganese, 15 g; zinc, 13.33 g; and chromium, 0.226 g (all as protein chelates). Plethoric supplementation of trace elements improved live weight gain and feed/gain ratio (p < 0.05). Leg abnormality developed in the 16% of the control group of birds but not in the supplemented group. Metabolizability of dry matter, organic matter, and protein was higher (p < 0.01) in the ITM and OTM groups. Excretion of Cu, Fe, and Zn decreased (p < 0.1) due to supplementation of the trace elements leading to increased apparent absorption of the said mineral elements (p < 0.01). Concentration of the concerned trace elements in serum, liver, and composite muscle samples was higher (p < 0.05) in the ITM and OTM dietary groups indicating an increased deposition of the said mineral elements due to supplementation. Although the study revealed subtle difference between the inorganic and organic mineral premixes with regards to the parameters mentioned above, it became apparent that it is possible to reduce excretion of these trace elements by a judicious escalation in the level of supplementation. The results of the present investigation further revealed that the trace mineral requirement of broiler chickens suggested by the National Research Council may not be optimum to support the maximum growth potential of the high yielding strains, and it is reasonable to consider a review of the current NRC recommendations to meet the needs of the modern birds.     

铜锌复合污染对铜富集植物大聚藻抗氧化酶活性的影响

以前期筛选的铜富集植物大聚藻为材料,采用两因素随机区组试验设计,通过盆栽试验研究了不同浓度铜锌复合污染对大聚藻抗氧化酶活性的影响,以揭示铜富集植物大聚藻对重金属的耐性机理,为芦溪河及其它类似污染河流的生态恢复与植被重建提供参考依据。结果表明:(1)铜锌复合污染条件下,大聚藻生物量都表现出低促高抑现象。(2)铜锌复合污染时,大聚藻MDA含量随铜锌浓度升高表现出先升高后降低的变化。(3)铜锌复合污染对大聚藻抗氧化酶系统活性均有不同程度的影响,低浓度铜锌复合污染对SOD(超氧化物歧化酶)、POD(过氧化物酶)和CAT(过氧化氢酶)有促进作用,而随浓度的升高则表现出不同的规律。研究发现,铜锌胁迫下,大聚藻细胞应急防御系统被启动,SOD、POD和CAT发挥作用,体内过量自由基及时被清除,使大聚藻能够保持高的耐性。     

刺芹侧耳两种保护酶基因的克隆、分析及温度对其表达量的影响

为了探究温度胁迫下刺芹侧耳中过氧化氢酶和铜锌超氧化物歧化酶基因的作用,本研究通过RT-PCR方法对刺芹侧耳转录组数据库检索得到的过氧化氢酶（CAT）和铜锌超氧化物歧化酶（Cu/Zn-SOD）基因进行克隆,并利用荧光定量PCR分析在高低温胁迫下CAT和Cu/Zn-SOD基因的表达量,以探讨刺芹侧耳中这两种保护酶基因在高、低温胁迫下的响应特征。结果表明,克隆得到的CAT和Cu/Zn-SOD基因开放阅读框长度分别为1 581bp和582bp,分别编码526个和193个氨基酸,分子量分别为59.6kDa、19.62kDa,等电点分别为6.35、6.31。在高温（35℃）和低温（4℃）两组处理中,CAT和Cu/Zn-SOD基因的表达量及酶活均在处理48h时达到最高且与对照组呈现显著差异,说明两种基因在刺芹侧耳抵御高低温胁迫的过程中具有重要作用。本研究结果初步研究了温度胁迫下刺芹侧耳中CAT与Cu/Zn-SOD基因的生物学功能,为进一步解析刺芹侧耳抵抗温度胁迫的机理奠定基础。     

Relation between blood levels of heavy metals and some markers of oxidative stress among boys with neuropathic bladder and posterior urethral valve

BackgroundThe status of heavy metals in children with lower urinary tract pathology that may harm the upper tract, e.g., neuropathic bladder and posterior urethral valve and its relationship with oxidative stress has not been adequately investigated. Therefore, the object of the current work was to evaluate the concentrations of copper, zinc, cadmium and lead and their relations with levels of catalase (CAT), malondialdehyde (MDA) and glutathione (GSH) in boys with neuropathic bladder and posterior urethral valve.MethodsThirty-six children with neuropathic bladder, 35 children with posterior urethral valve and 33 health controls were included in the study. In addition to routine laboratory tests, blood samples were collected from patients and controls to assess levels of Cu, Zn, Cd and Pb in addition to plasma concentrations of CAT, MDA and GSH.ResultsSignificantly elevated levels of Cu, Pb, CAT, MDA and GSH and significantly lower concentration of blood Zn were found in the studied groups compared to the controls. In the posterior urethral valve group, blood level of Cu was positively correlated with GSH while a significantly negative relation was observed between blood Zn and CAT activity among the neuropathic bladder patients.ConclusionNeuropathic bladder and posterior urethral valve may lead to abnormalities in the blood levels of heavy metals (i.e. Cu, Pb and Zn) and markers of oxidative stress (CAT, MDA and GSH). Therefore, the levels of theses metal ions should be monitored during the treatment course of neuropathic bladder and posterior urethral valve patients to prevent or minimize long-term oxidative injury.     

Metabolic characteristics and oxidative damage to skeletal muscle in broiler chickens exposed to chronic heat stress

Emerging evidence has shown that acute heat exposure affects metabolic characteristics and causes oxidative damage to skeletal muscle in birds. Little is known, however, about such phenomena under chronic heat stress conditions. To address this, we designed the present study to determine the influence of cyclic (32 to 24 to 32 °C: 32 °C for 8 h/d, 32–24–32HS ), and constant (32 and 34 °C, 32HS and 34HS, respectively) heat exposure on the metabolic and peroxide status in skeletal muscle of 4-wk-old male broiler chickens. Heat stress, particularly in the 32HS and 34HS groups, depressed feed intake and growth, while cyclic high temperature gave rise to a less severe stress response in performance terms. Malondialdehyde (MDA) levels in skeletal muscle were enhanced (P < 0.05) by constant heat treatment; the degree of enhancement was not as large as the changes observed in our previous ‘acute’ heat stress model. The 3HADH (3-hydroxyacyl CoA dehydrogenase related to fatty acid oxidation) and CS (citrate synthase) enzyme activities were lowered (P < 0.05) by both the cyclic and constant 34HS treatments, and constant 34HS group, respectively. These results suggest that chronic heat exposure decreases metabolic oxidation capacity in skeletal muscle of broiler chickens. On exposure to chronic heat stress, GPx activity remained relatively constant, though a temperature-dependent elevation in Cu/Zn-SOD activity was observed, implying that anti-oxidation ability was disturbed by the chronic stress condition. From these results it can be concluded that chronic heat stress did not induce oxidative damage to a major extent. This may probably be due to a decrease in metabolic oxidation capacity or due to a self-propagating scavenging system, though the system was not fully activated.