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31.
全氟辛酸对大肠杆菌的氧化胁迫和膜损伤 总被引:1,自引:0,他引:1
全氟辛酸(perfluorooctanoic acid,PFOA)因其具有极高的化学稳定性和良好的疏水疏油性而在工业生产中广泛使用,但近年来被认为是一种在环境中广泛分布的持久性有机污染物.利用流式细胞术等检测技术,研究了PFOA对大肠杆菌(Escherichia coli,E.coli)的氧化胁迫和膜损伤,并对其毒性作用机制进行了初步的探索.结果表明,在PFOA胁迫下,大肠杆菌胞内活性氧(reactive oxygen species,ROS)含量增加,膜脂肪酸不饱和度降低,丙二醛(malondialdehyde,MDA)浓度升高、细胞膜通透性增大、跨膜电位降低,而细胞膜上的Na+K+-ATPase、Ca2+Mg2+-ATPase活性随时间的延长代偿性地先上升后降低.由此说明,在PFOA胁迫下,大肠杆菌细胞内升高的ROS与细胞膜不饱和脂肪酸发生过氧化反应,降低膜脂肪酸的饱和度,使得MDA在细胞内积累,进一步引起细胞膜损伤及其上相关ATPase活性降低,最终导致大肠杆菌细胞失活或死亡.实验结果对研究PFOA胁迫下环境生态毒理提供更多依据. 相似文献
32.
K. N. Chetty D.S.V. Subba Rao L. Drummond D. Desaiah 《Journal of environmental science and health. Part. B》2013,48(5):525-544
Abstract The immuno‐biochemical effects of cobaltous chloride in rats receiving iron‐sufficient and deficient diets were investigated. Rats receiving 100 ppm or more cobalt showed a significant reduction in thymus and body weights along with a marked decrease in hemoglobin, hematocrit, sheep agglutinins and plaque forming cells. These effects were more pronounced in rats receiving cobalt mixed with iron‐deficient diet than those fed on iron‐sufficient diet. The Na+‐K+ and mitochondrial (Oligomycin‐sensitive) Mg2+ATPase activities in brain and liver of rats fed with iron‐deficient diets were decreased significantly. However, the ATPase activities in these tissues from rats fed with cobalt mixed with iron‐sufficient diets were not altered. 相似文献
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In vitro effects of Pb2+, the pyrethroid insecticides cypermethrin, fenvalerate and the syner‐gist piperonyl butoxide on sodium‐potassium‐activated adenosine triphosphatase (Na,K‐ATPase) from dog kidney were determined. Pb2+ with an estimated IC50 value of 5.2 μM was found to be a potent inhibitor of Na,K‐ATPase activity, whereas Na,K‐ATPase was less sensitive to the pyrethroids tested and piperonyl butoxide. Investigation with circular dichroism (CD) spec‐troscopy showed that inhibition occurs through conformational changes of the α‐subunit of the enzyme. The kinetic characteristics of inhibition of Na,K‐ATPase with varying substrate (ATP) concentrations as well as with varying Na+ concentrations exhibited a competitive type of inhibition with Pb2+ in the μM range. With Pb2+ alone in the enzyme assay no conformational changes of the protein could be observed which confirmed the assumption that Pb2+ can bind to the Na+ binding site of the α‐subunit. Uncompetitive type of inhibition occurred with varied K+ concentrations demonstrating that this cation binding site is not affected directly by Pb2+. Complete reversal of Pb2+ by DTT confirms that a possible target for interaction of this heavy metal ion with Na, K‐ATPase are specific SH groups. Synergistic effects could only be determined with higher Pb2+ concentrations of 3, 5 and 7 μM plus piperonyl butoxide while all other combinations with this heavy metal plus organic substances where of the additive type. With CD spectroscopy also only additive effects were observed. These results demonstrate that higher concentrations of piperonyl butoxide favor the binding of Pb2+ to the Na+ binding site by conformational changes of the protein. 相似文献
34.
除草剂苯噻草胺污染对多食鞘氨醇杆菌(Sphingobacterium multivolum)抗氧化酶和ATP酶的影响 总被引:3,自引:0,他引:3
研究了暴露于苯噻草胺中的多食鞘氨醇杆菌Y1菌株中超氧化物歧化酶(SOD)、过氧化物酶(CAT)和ATP酶活性在短期内的变化.结果表明,苯噻草胺对细菌SOD活性诱导作用明显,尤其对处于对数生长期的细菌所产生的影响大于稳定生长期的细菌.苯噻草胺对CAT也有强烈的诱导作用,对处于不同生长阶段细菌的影响类似于对SOD的影响结果.苯噻草胺能激活ATP酶,但在细菌生长阶段影响较小.抗氧化酶和ATP酶相结合作为该类化合物对土壤污染胁迫的敏感生物指示物具有一定的可行性. 相似文献
35.
两个海州香薷种群根对Cu的吸收及Cu诱导的ATP酶活性差异 总被引:3,自引:0,他引:3
通过水培实验,比较分析了分别来自湖北省铜绿山矿区和红安非矿区的海洲香薷种群根对铜的抗性和对Cu的吸收累积差异,同时应用微囊膜技术进行了ATPase的诱导和活性测定.结果发现,来自铜绿山种群植物的铜耐受性明显高于红安种群,在20μmol·L-1 Cu处理时红安种群根尖开始变黑,生长明显受到抑制;而铜绿山种群在80μmol·L-1 Cu处理时仍然能正常生长;在所有Cu处理中,铜绿山种群植物根的Cu含量明显低于红安种群.Cu诱导的ATPase活性在铜绿山种群根质膜有明显的变化,在1μmol·L-1 Cu处理时,其活性显著增加,5μmol·L-1 Cu处理时,其活性先到达高峰而后降低;而红安种群则没有出现Cu诱导的ATPase活性的升高,除了100μmol·L-1 Cu明显降低了ATPase活性外,其它处理则没有显著的变化.在还原型谷光苷肤(GSH)存在的条件下,Cu诱导的ATPase活性在铜绿山种群中显著提高,且有明显的Cu浓度效应,而红安种群虽有提高但没有浓度效应.这些结果表明,矿区种群根细胞中可能存在Cu-ATPase,该酶在根的Cu吸收运输方面可能起重要的调节作用,从而使其具有较高的Cu抗性. 相似文献
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观察香烟水溶性提取物(CSE)和尼古丁对大鼠心肌线粒体的损伤作用.大鼠心肌线粒体分别与CSE或尼古丁于37℃温孵60min,结果表明,CSE明显降低线粒体细胞色素C氧化酶(COX)活性,呈剂量依赖性.但是ATPase活性不受影响.在线粒体呼吸活性受到抑制的同时,过氧化指标无明显变化.CSE对6.5mmol/L钙离子引起的线粒体肿胀反应具有抑制作用,但可加剧250mmol/L钙离子诱导的线粒体肿胀反应.维生素C对CSE造成的线粒体损伤无保护作用.未见尼古丁对体外大鼠心肌线粒体有毒性.CSE对心肌线粒体的损伤可能是由于它对呼吸酶活性的直接抑制作用而与氧自由基机制无关.尼古丁可能不是CSE损伤大鼠心肌线粒体的毒性成分. 相似文献
38.
Zsolt Molnár Regina Pálföldi Anna László Marianna Radács Krisztián Sepp Péter Hausinger László Tiszlavicz Zsuzsanna Valkusz Márta Gálfi 《环境科学学报(英文版)》2015,27(8):165-170
Many environmental chemicals and pesticides have been found to alter neuroendocrine communication in exposed biological objects. The environmental loads have primary and secondary effects that can alter the homeostatic regulation potential. Since it is difficult to avoid human exposition, a potentially important area of research to develop in vivo and in vitro experimental models. In this context, the primary aim of this study was to demonstrate the effects of chlorobenzenes on adrenocorticotrophic hormone (ACTH) release. In our experimental study, male Wistar rats were exposed to 0.1, 1.0 and 10 μg/b.w. (body weight) kg of 1,2,4- trichlorobenzene and hexachlorobenzene (ClB) mix via gastric tube for 30, 60 or 90 days. At the endpoints of the experiment blood samples were taken and animals were decapitated. Primary, monolayer adenohypophysis cell cultures were prepared by enzymatic and mechanical digestion. The ACTH hormone content in serum and supernatant media was measured by immuno-chemiluminescence assay. The Mg2 +-dependent ATPase activity was determined by modified method of Martin and Dotty. Significant differences were detected in the hormone release between the control and treated groups. The hormone release was enhanced characteristically in exposed groups depending upon the dose and duration of exposure. The Mg2 +-ATPase activity enhanced after chronic and subtoxic ClB exposition. Light microscopy revealed that the adenohypophysis seemed to be more abundant. Results indicate that Wistar rats exposed to subtoxic ClB have direct and indirect effects on hypothalamus–hypophysis–adrenal axis. 相似文献
39.
全氟辛酸(PFOA)广泛应用于工业生产中,具有高度的生物毒性及生物蓄积性,然而PFOA对环境微生物的毒性影响仍有待深入开展.通过流式细胞术测定了酵母菌在不同浓度PFOA胁迫下细胞膜通透性、ROS、线粒体跨膜电位的变化,并且测定了MDA含量和Na+K+-ATPase、Ca2+Mg2+-ATPase活性变化.结果显示PFOA可使PI染色细胞比例增高,酿酒酵母细胞膜通透性增大、ROS和MDA含量升高、线粒体跨膜电位降低,且ROS含量、MDA含量与线粒体跨膜电位降幅均与PFOA胁迫浓度和时间呈正相关.Na+K+-ATPase、Ca2+Mg2+-ATPase活性先上升后降低,表明酿酒酵母在PFOA胁迫下,其生理活性受到抑制甚至发生细胞凋亡.证明PFOA对酿酒酵母具有生物毒性,100 mg·L-1PFOA对酿酒酵母具有即时毒性.该结果可为PFOA的影响评价提供更多依据. 相似文献
40.
二氧化硫对大鼠离体心脏功能影响的机制研究 总被引:1,自引:1,他引:1
为了探讨二氧化硫(SO2)对心脏功能影响的机制,分别用10、300和1000μmol·L-1的SO2灌流大鼠离体心脏后,测定心脏组织中一氧化氮(NO)、超氧化物歧化酶(SOD)、丙二醛(MDA)和谷胱甘肽(GSH)含量以及心脏灌流液中肌酸激酶(CK)和乳酸脱氢酶(LDH)活性.结果表明,10、300和1000μmol·L-1的SO2均可使心脏组织中NO和MDA含量以及心脏灌流液中CK和LDH活性明显增加,而使SOD和GSH含量明显减少.较高浓度(300和1000μmol·L-1)的SO2可使心脏组织中Na+K+-ATP酶和Ca2+Mg2+-ATP酶活性明显下降.结论:SO2对大鼠离体心脏功能影响的作用机制与SO2对心脏组织的氧化损伤作用、心肌细胞膜Na+K+-ATP酶和Ca2+Mg2+-ATP酶活性降低及NO-cGMP信号转导通路有关. 相似文献