Oxidative Stress and Neutrophil Function in Cats with Chronic Renal Failure

Background: Oxidative stress is an important component in the progression of chronic renal failure (CRF) and neutrophil function may be impaired by oxidative stress. Hypothesis: Cats with CRF have increased oxidative stress and decreased neutrophil function compared with control cats. Animals: Twenty cats with previously diagnosed renal failure were compared with 10 age‐matched control cats. Methods: A biochemical profile, CBC, urinalysis, antioxidant capacity, superoxide dismutase (SOD) enzyme activity, reduced to oxidized glutathione ratio (GSH : GSSG), and neutrophil phagocytosis and oxidative burst were measured. Statistical comparisons (2‐tailed t‐test) were reported as mean ± standard deviation. Results: The CRF cats had significantly higher serum blood urea nitrogen, creatinine, and phosphorus concentrations than control cats, and significantly lower PCV and urine specific gravity than control cats. The GSH : GSSG ratio was significantly higher in the CRF group (177.6 ± 197, 61.7 ± 33; P < .02) whereas the antioxidant capacity was significantly less in the CRF group (0.56 ± 0.21, 0.81 ± 0.13 Trolox units; P < .005). SOD activity was the same in control and CRF cats. Neutrophil oxidative burst after Escherichia coli phagocytosis, measured as an increase in mean fluorescence intensity, was significantly higher in CRF cats than controls (732 ± 253, 524 ± 54; P < .05). Conclusions: The higher GSH : GSSG ratio and lower antioxidant capacity in CRF cats is consistent with activation of antioxidant defense mechanisms. It remains to be determined if supplementation with antioxidants such as SOD beyond the level of control cats would be of benefit in cats with CRF.     

二化性家蚕滞育过程中谷胱甘肽S-转移酶活性的变化

二化性家蚕卵以25℃和15℃催青,可分别诱导成虫产下子代滞育和非滞育卵,而即时浸酸和5℃左右的低温处理可以分别阻止和解除胚胎滞育。利用1-氯-2,4-二硝基苯(CDNB)显色法测定了经上述处理后的胚胎滞育过程中谷胱甘肽S-转移酶(glutathione S-transferase,GST)的活性,结果表明:胚胎发育后期的蚕卵经25℃催青,卵中的GST活性显著高于15℃催青蚕卵;蚕卵即时浸酸未显著改变胚胎滞育发动阶段蚕卵中的GST活性;5℃低温处理显著提高了滞育卵中的GST活性,但是未能显著改变即时浸酸卵的GST活性。上述结果表明,蚕卵中的GST活性变化与二化性家蚕胚胎滞育诱导和解除密切相关。     

Exogenous Application of Glycinebetaine Modulates Activities of Antioxidants in Maize Plants Subjected to Salt Stress

The influence of exogenously applied glycinebetaine (0, 50 and 100 m m ) as a foliar spray at different growth stages, i.e. vegetative, reproductive or both at the vegetative and reproductive stages on gas exchange characteristics, glycinebetaine (GB) and the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) was examined in plants of two maize cultivars, Golden and C-20 grown under saline conditions. Salt stress caused a marked decrease in photosynthetic capacity, chlorophyll contents and SOD activity in both maize cultivars. However, activities of CAT and POD remained almost unchanged in both maize cultivars under salt stress. Accumulation of GB increased with an increase in exogenous level of GB, i.e. 100 m m GB spray caused a greater accumulation of GB in the leaves of maize plants than did 0 or 50 m m . Although exogenously applied GB enhanced photosynthetic capacity of salt-stressed plants of both cultivars, it enhanced the activities of antioxidant enzymes, SOD, CAT and POD, in salt-stressed plants of cv. C-20 only. Overall, the adverse effects of salt stress on maize plants were alleviated by the exogenous application of GB at different growth stages, which up-regulated photosynthetic capacity and the activities of some antioxidant enzymes.     

四川盆地麦冬及其近缘植物的同工酶分析

采用聚丙烯酰胺凝胶电泳技术,作过氧化物(POD)同工酶、酯酶(EST)同工酶分析,并使用SPSS 17.0软件对谱带作相关及聚类分析,以探讨四川盆地不同产地25份麦冬及其近缘植物野生资源间的遗传多样性,为麦冬分类、鉴定和种质资源保护提供生化依据。结果显示,不同产地麦冬及其近缘植物样品的POD同工酶有10种酶谱类型,每种类型具有6~11条酶带;EST同工酶有15种酶谱类型,每种类型有4~8条酶带;同工酶系统聚类分析结果将25个样品被分为4类,并与染色体核型具有同一性。四川盆地麦冬种质资源,具有丰富的遗传多样性,POD、EST同工酶分析可以作为麦冬及其近缘植物种质资源鉴定的重要参考依据,并可将其加以区分,结合形态学、细胞学等经典理论研究,可判断其遗传差异及亲缘关系。     

玉米品种抗感玉米粗缩病毒与过氧化物酶关系的研究

 研究选取对玉米粗缩病毒（MRDV）表现抗病、中感及高感3个不同类型的代表性品种,分析了三叶期、五叶期室内盆栽及抽穗期田间采取的病叶及健康玉米叶片的过氧化物酶（POD）的变化,旨在研究玉米品种抗感病性与过氧化物酶的关系及感染病毒后的诱导抗病性机理。结果表明:玉米三叶期、五叶期及抽穗期,感病品种的POD酶活性大于抗病品种,显示玉米叶片内的POD含量与品种的感病性有相关性。发病后,各品种酶活性均上升,抗病品种上升幅度最大,说明防御酶POD的应激表达与品种的抗病性相关;同工酶研究结果表明:玉米抽穗期,抗病品种健叶具有一条Rf 0.261差异酶带,而感病品种则没有,这一特异蛋白带的组成型表达显示出与品种抗病的相关性,可作为评价品种抗病性的生理生化指标之一。发病后,抗病品种及中感品种又新增一条酶带,Rf为0.471;三叶期及五叶期,抗病品种同样都比感病品种多出现一酶带区,进一步证明了在玉米植株体内存在与抗玉米粗缩病毒相关的POD同工酶,这一结果将为抗病育种提供极有价值的生理生化基础。     

纳米硒对肉鸡肝脏谷胱甘肽过氧化物酶mRNA表达和酶活的诱导作用

为了探讨纳米硒对肉鸡肝脏细胞内谷胱甘肽过氧化物酶 (cGPx)的诱导作用 ,将 1日龄艾维茵肉雏鸡随机分为 1个对照组 (0mg/kg)和 5个剂量组 (0 .1,0 .2 ,0 .3,0 .4和 0 .5mg/kg) ,饲喂到 4 2日龄 ,断头处死。从肉鸡肝脏中提取总RNA ,RT PCR法检测肝脏中的cGPx的表达丰度 ;DTNB法测定肝组织中的cGPx酶活性。试验结果表明 ,各试验组肉鸡肝脏组织cGPxmRNA丰度与对照组相比有显著的差异 (P <0 .0 5 ) ;各试验组肉鸡肝脏组织cGPx活力与对照组相比有显著的差异 (P <0 .0 5 ) ,且二者变化规律一致。本试验结果表明 :纳米硒对肉鸡肝脏cGPxmRNA稳定性具有调控作用 ,并能提高其酶活 ,而且其Weinberg剂量 效应的最适剂量范围较宽     

化学杀雄剂1号对棉花过氧化酶、蔗糖酶活性的研究

采用0.1％的杀雄剂1号分3次处理初花期的棉花,诱导其产生雄性不育,对叶片和花药进行的过氧化物酶、蔗糖酶活性测定结果表明:处理棉株的叶片过氧化物酶活性与对照无明显差异,蔗糖酶活性不断下降且后期低于对照;处理后花药中过氧化物酶和蔗糖酶活性在前期均与对照相似,随后二者均逐渐高于对照。说明处理花药中过氧化物酶、蔗糖酶活性的升高影响着败育花粉的产生。     

花生内生抗虫工程菌的应用研究

研究了带有Bt基因的花生内生菌对花生生物学特性、酶活性及抗虫性的影响。结果表明：3种不同处理方法（浸种、喷施、浸种＋喷施）均能增加花生体内的超氧化物歧化酶（SOD）和过氧化物酶（POD）的活性，提高花生的株高、分枝数、主根长和地上部、地下部鲜重等生物学指标，并对棉铃虫表现出了一定抗性。在3种处理方法中均以浸种＋喷施效果最佳，而浸种或喷施2种处理方法其效果因品种不同而异。     

油茶组培苗不定根形成过程酶的活性变化分析

[目的]分析油茶组培苗不定根发生过程中酶的变化规律,为油茶种苗培育提供参考依据.[方法]以广西主栽油茶无性系岑软2号油茶、桂无1号油茶和桂普24号油茶组培苗为材料,测定其生根过程中过氧化物酶(POD)、多酚氧化酶(PPO)和吲哚乙酸氧化酶(IAAO)活性.[结果]岑软2号和桂无1号油茶组培苗易生根,培养至50 d生根率大于84.0%,而桂普24号油茶组培苗培养至50 d生根率仅52.7%,属难生根无性系.在组培生根过程中,岑软2号和桂无1号油茶的POD、PPO和IAAO活性在根原基诱导期均呈急剧上升的变化趋势,在根原基形成约20 d达最高峰;桂普24号油茶的POD活性在整个生根期变化不明显,PPO活性明显低于岑软2号和桂无1号油茶,IAAO活性前期不断降低,有利于吲哚乙酸(IAA)的累积,容易形成愈伤组织.[结论]油茶组培苗生根诱导前期提高其POD、PPO和IAAO活性,有利于根原基的诱导,生根诱导后期降低其POD、PPO和IAAO活性有利于不定根伸长.生产上培育油茶组培苗时在培养基中调整外源激素和外源酚等物质的用量可提高组培苗的生根率.     

拮抗菌对致病疫霉生长及抗性酶活性的影响

为获得更为有效的致病疫霉拮抗菌并探讨拮抗菌的作用机理,本研究利用对峙培养法、滤纸片法测定了10个待测菌株的活体及发酵液的抑菌作用,用分光光度法测定了受显著抑制后再恢复生长的致病疫霉体内多酚氧化酶(PPO)、过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)的活性。结果表明:活体状态下以核桃细菌的抑制作用最强(抑菌率为84.50%);发酵液中以梨黑斑病菌(Alternaria alternate)的抑制作用最强(抑菌率为76.68%),其次是白菜黑斑病菌(A.brassicae)。将梨黑斑病菌和白菜黑斑病菌的发酵液复配后其抑菌率达到了81.31%。受抑制的致病疫霉菌落中紧靠抑菌带边缘的菌丝不能恢复正常生长,较远的菌丝易恢复正常生长;受抑制的致病疫霉体内PPO、POD、PAL活性均明显降低,与对照相比,PPO活性下降了45%~68%,POD下降了27%~58%,PAL下降幅度最大,约80%~90%,这与植物受病菌抑制或侵染后PPO、POD、PAL活性增加相反。