Pb2+对大蒜SOD,POD的影响及Ca2+的解毒作用

用不同浓度的Pb^2＋及Pb^2＋＋Ca^2＋处理大蒜,测定其超氧化物歧化酶（SOD）、过氧化物酶（POD）活性,研究Pb^2＋对大蒜SOD、POD的影响及Ca^2＋的解毒作用。结果表明：一定浓度的Pb^2＋能诱导SOD、POD活性,超过此浓度,SOD、POD活性下降,破坏其抗氧化防御系统;随着时间的延长,SOD、POD的活性先升后降,这是大蒜对逆境胁迫的一种适应;50mg／m^3的Ca^2＋对Pb^2＋有一定程度的解毒作用。     

Intra-peritoneal application of catechins and EGCG as in vivo inhibitors of ozone-induced oxidative stress

Oxidative stress is considered as a prominent feature of many acute and chronic diseases as well as of the normal aging process. We examined the effects of intra-peritoneal administration of catechins and EGCG as in vivo inhibitors of oxidative stress induced by ozone administration in two groups of Wistar rats. The first group was treated by intra-peritoneal administration of catechins and EGCG after the administration of ozone and the second group was pretreated by intra-peritoneal administration of catechins and EGCG prior to ozone administration. We determined in blood the activity of the enzymes superoxide dismutase and glutathione peroxidase, total antioxidant capacity, levels of copper and zinc and in urine malonaldehyde contents. Ozone administration resulted in significant reduction of glutathione peroxidase activity, plasma zinc levels and plasma and Red Blood Cells antioxidant capacity. Catechins and EGCG upregulate superoxide dismutase activity and maintain plasma and Red Blood Cells antioxidant capacity. Malonaldehyde levels at the end of the study were significantly increased only in the first group. Our data demonstrate that treatment with catechins and EGCG cannot reverse or prevent the effects of oxidative stress although some modulation occurs.     

MSP hormonal control of the oocyte MAP kinase cascade and reactive oxygen species signaling

The MSP domain is a conserved immunoglobulin-like structure that is important for C. elegans reproduction and human motor neuron survival. C. elegans MSPs are the most abundant proteins in sperm, where they function as intracellular cytoskeletal proteins and secreted hormones. Secreted MSPs bind to multiple receptors on oocyte and ovarian sheath cell surfaces to induce oocyte maturation and sheath contraction. MSP binding stimulates oocyte MPK-1 ERK MAP Kinase (MAPK) phosphorylation, but the function and mechanism are not well understood. Here we show that the Shp class protein-tyrosine phosphatase PTP-2 acts in oocytes downstream of sheath/oocyte gap junctions to promote MSP-induced MPK-1 phosphorylation. PTP-2 functions in the oocyte cytoplasm, not at the cell surface to inhibit multiple RasGAPs, resulting in sustained Ras activation. We also provide evidence that MSP promotes production of reactive oxygen species (ROS), which act as second messengers to augment MPK-1 phosphorylation. The Cu/Zn superoxide dismutase SOD-1, an enzyme that catalyzes ROS breakdown in the cytoplasm, inhibits MPK-1 phosphorylation downstream of or in parallel to ptp-2. Our results support the model that MSP triggers PTP-2/Ras activation and ROS production to stimulate MPK-1 activity essential for oocyte maturation. We propose that secreted MSP domains and Cu/Zn superoxide dismutases function antagonistically to control ROS and MAPK signaling.     

海水处理对向日葵幼苗生长及叶片一些生理特性的影响

采用海水水培的方法,比较了淡水、20%和40%海水处理对向日葵(Helianthus annuus L.)幼苗生长速率、根冠比、脯氨酸、丙二醛(MDA)含量和保护性酶超氧歧化酶(SOD)及过氧化物酶(POD)活性的影响.结果表明:20%海水处理显著地促进根系生长和根冠比的增加,大大地缓解了叶片的膜脂过氧化作用(使之降至与对照相当的水平),而40%海水明显抑制向日葵生长;脯氨酸在处理4 d后显著积累,40%海水处理后脯氨酸与MDA变化曲线相关性较强,表明脯氨酸的积累在本实验中表现为活性氧伤害的结果;40%海水处理对食葵叶片造成的过氧化伤害比油葵大,但食葵比油葵的自身修复受伤害膜系统的能力强.     

Requirements for Sod Mimics Operating In Vitro to Work Also In Vivo

When an efficient SOD mimic operating in vitro is introduced into cells, the following requirements are needed in order that this compound will catalyze O^?₂ dismutation efficiently: it should be non toxic, stable, has a long metabolic half life, does not form ternary complexes with the cell components, its reduced form reacts slowly with molecular oxygen. should be able to cross cell membranes and also to reach lipophilic or hydrophobic regions. Thus, it seems that finding an efficient compound that has high SOD-like activity in vivo will not be easily achieved.     

镉和增强紫外线-B辐射复合作用对大豆生长的影响

研究了Cd^2+和增强紫外线-B(UV-B)辐射以及二者复合胁迫(Cd+UV-B)对大豆生长、光合作用、抗氧化酶活性和吲哚乙酸(IAA)氧化酶活性的影响,结果表明,UV-B辐射对大豆生长较CA^2+有更明显的抑制作用,主要是降低了光合作用,生物量减小;抑制节间的分化和伸长,节间减少,株高降低。UV-B辐射对POD、SOD活性有显著诱导作用,而Cd^2+明显颉颃UV-B对POD活性的诱导并抑制IAA氧化酶活性．在复合作用下,植物体内IAA氧化酶和POD活性较UV-B单独作用下显著降低,这两种酶活性降低会引起植物体内IAA含量升高,同时光合作用略有升高,这是株高和生物量较UV-B作用下有所增加的重要原因,复合胁迫还增强了对根伸长生长的抑制作用,根长度较对照显著降低(P<0．05)。IAA氧化酶和POD活性变化以及光合强度变化与大豆株高和生物量变化密切相关,这也是复合胁迫影响大豆生长状况的重要因素。     

串叶松香草的新用途---提取SOD开发叶蛋白

串叶松香草（Silphium Perfolialum）系菊科多年生草本植物,栽培简单,产量高,可达亩产鲜草10-12吨/年。从其营养成分的分析表明：串叶松香草含17种氨基酸,叶蛋白含量高,是一种值得得推广的重要经济作物。本文就以从该植物中提取SOD开发叶蛋白的可行性及前景作一简要介绍。     

微囊藻毒素缓解过氧化氢胁迫下铜绿微囊藻损伤的初步研究

过氧化氢可抑制藻类生长, 同时会导致微囊藻毒素(Microcystins, MCs)的释放, 实验设置4个处理组探讨了外源微囊藻毒素MC-LR对H2O2胁迫下铜绿微囊藻生理生化变化的影响。结果表明: 在H2O2胁迫下, 微囊藻的生长和光合活性受到显著抑制, 藻细胞存活率降低, ROS含量明显增加, SOD活性上升。与单独H2O2胁迫相比, 加入MC-LR能增加微囊藻细胞的存活率。250 mol/L H2O2处理24h和48h后, 在培养基中加入200 ng/mL MC-LR可以缓解H2O2对铜绿微囊藻光合系统PSII活性的抑制作用。当微囊藻暴露于250 mol/L H2O2环境中时, 添加了MC-LR处理组藻细胞中的ROS含量明显减少(P0.05)。在相同浓度H2O2且加入了外源MC-LR后藻细胞SOD活性下降(P0.05)。因此, 微囊藻毒素MC-LR可缓解250 mol/L H2O2引起的氧化损伤并增强微囊藻自身的生存能力。研究结果有利于阐明H2O2胁迫影响产毒蓝藻生长代谢的途径及MCs生物学意义。       

Association of AdipoQ gene variation (rs1501299) and oxidative stress with cardiovascular disease in North West Indian population of Punjabi women

BackgroundTill to date whether adiponectin AdipoQ gene variation (rs 1501299) is associated with cardiovascular disease, still remains controversial. Therefore, we aimed to relate the SNP (rs1501299) of adiponectin gene and oxidative stress in context to CVD in Punjabi women of North West India.MethodsIn the present case-control study menopausal women with CVD as cases (n=265) and menopausal women without CVD as controls (n=258) were recruited. Genotyping of rs1501299 single nucleotide polymorphism of adiponectin gene was carried out by RFLP-PCR analysis. Biochemical parameters were analyzed according to the standard procedures.ResultsDistribution of homozygous TT genotype of normolipidemic (p=0.001) and hyperlipidemic (p=0.001) women with CVD was significantly more frequent as compared to women without CVD. rs1501299 T allele carriers with CVD also showed significant (p=0.001) higher frequency distribution as compared to women without CVD. Under recessive model of inheritance TT mutant type homozygotes conferred ~9 fold higher risk [p=0.001; OR= 9.60 (2.92-31.58)] towards CVD susceptibility for MDA>1.50; ~11 fold higher risk [p=0.007; OR= 11.11 (1.49-82.83)] towards CVD for LDL carbonyl protein>15.04 and ~9 fold higher risk [p=0.001; OR= 9.75 (2.30-41.22)] towards CVD susceptibility for SOD≤5.55. Under logistic regression analysis oxidative stress and TT genotype were significantly correlated with CVD.ConclusionsOur study revealed significant association of AdipoQ (rs1501299) gene polymorphism and oxidative stress with cardiovascular disease in Punjabi women of North West India. However, additional studies are required to support these findings.