镉对长江华溪蟹精巢抗氧化酶活性及脂质过氧化的影响

在实验条件下,将健康性成熟雄性长江华溪蟹Sinopotamon yangtsekiense暴露于0、7.25、14.5、29、58和116 mg/L浓度的镉(Cd2+)溶液中,分别于1 d、3 d、5 d和7 d时测定精巢中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氧酶(CAT)活性及脂质过氧化产物丙二醛(MDA)的含量.结果显示,不同时间段3种酶活性和MDA含量均具有浓度和时间效应关系,表明急性镉暴露对精巢有明显的毒性作用,其作用机制与抗氧化酶活力变化和脂质过氧化加剧有关.     

镉对长江华溪蟹免疫相关酶活性的影响

采用浸浴法研究了镉(Cd2+)对长江华溪蟹Sinopotamon yangtsekiense免疫系统相关酶的影响.Cd2+处理组浓度分别为7.25 mg/L、14.5 mg/L、29mg/L、58 mg/L和116 mg/L,同时设对照组.分别在Cd2+处理24 h、48h、72 h和96 h取血清进行酚氧化酶(PO)、超氧化物歧化酶(SOD)、酸性磷酸酶(ACP)和碱性磷酸酶(AKP)活力测定.结果显示,在相同处理时间,随着cd2+浓度增加,PO和SOD活力均呈现先升后降的趋势,且分别于24 h、7.25 mg/L和96 h、14.5 mg/L时达到最大值.当处理浓度相同、作用时间延长时,ACP活力先升后降,且在48 h、58 mg/L时升至最高,AKP活力则持续上升.表明Cd2+对长江华溪蟹免疫相关酶活力具有不同程度的影响,且其作用和效果具有浓度及时间效应.PO和SOD活力变化能够灵敏反映Cd2+对水生动物的胁迫程度,可作为指示镉污染的生物学指标.     

镉对长江华溪蟹心肌细胞超微结构的影响

应用透射电镜方法,研究了镉在24h内对长江华溪触心肌细胞超微结构的影响。结果表明：注射镉后0.5h,心肌细胞超微结构即出现变化,且随着时间的延长,变化渐趋明显,主要表现在细胞核和线粒体。细胞核核膜肿胀、弥散、最后解体。线粒体嵴部分解体、直至全部解体;线粒体内室部分肿胀、明显肿胀、直至高度肿胀。此外,溶酶体的数量和类型随镉处理时间的延长而增多,肌原纤维出现断裂。     

镉对长江华溪蟹精子发生的影响

分别于1999年3－5月和10－12月,利用透射电镜方法,按1.5μg/g体重的剂量体腔注射Cd^2 于长江华溪蟹（Sinopotamon yangtsekiense)体内,在10min至24h之间的若干时间段取材,观察精子发生过程中不同发育阶段生殖细胞的变化。结果表明：镉注射后0.5h,各级生精细胞就开始出现超微结构的变化,主要表现为线粒体肿胀与空泡化,高尔基体变形,内质网扩张和膜结构损伤等。其中线粒体损伤出现最早,是最易受损伤的一个敏感细胞器。     

镉对长江华溪蟹肝胰腺线粒体抗氧化酶活力和脂质过氧化水平的影响

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镉对长江华溪蟹肝胰腺抗氧化酶活力的影响

重金属对环境的污染已成为全球面临的首要问题之一,其中镉(Cd2 )是一种广泛存在的毒性污染物,能通过消化道和呼吸道进入生物体,对机体造成损伤(Zyadah and Abdel-Baky,2000)。研究表明,Cd2 可以通过Ca2 通道穿过细胞膜进入机体(Roesijadi and Robinson,1994),诱导产生大量自由基和活性氧(ROS),从而形成氧胁迫(Toppi andGabbrielli,1994;Hegedus et al.,2001)。ROS可以与体内脂质、蛋白质和核酸反应,导致脂质过氧化、细胞膜损伤并且影响多种酶的活力,对生物体造成威胁。由于在水生生态系统中生物富集污染物的作用明显,故相对于陆地生…     

镉对尖紫蛤抗氧化酶活性及脂质过氧化的影响

为阐明镉(Cd2+)对尖紫蛤消化盲囊和鳃抗氧化酶的毒性影响程度,研究了不同浓度的Cd2+(0.005、0.05、0.5 mg/L)在不同暴露时间(24h、72h、120h)对尖紫蛤鳃和消化盲囊中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-PX)的活性以及丙二醛(MDA)含量的影响。结果表明,在Cd2+浓度为0.005 mg/L时,在整个实验期间Cd2+对消化盲囊和鳃内的SOD、CAT、GSH-PX活性并无显著影响。在Cd2+浓度为0.05 mg/L和0.5 mg/L时,SOD、CAT、GSH-PX在鳃和消化盲囊中的活性都呈现出明显的时间剂量依赖关系。在0.05 mg/L暴露时,鳃和消化盲囊中的SOD、CAT和GSH-PX的活性随时间逐渐增强,在72h时达到最大值,但在120h时略有降低。在0.5 mg/L暴露时,消化盲囊中SOD、CAT及鳃中CAT活性在24h时上升达到最大值,但鳃中SOD直到72h才达到最大值,并均在120h下降到最低,其中消化盲囊中SOD和CAT活性在120h低于对照组,这可能与消化盲囊对Cd2+的敏感性高于鳃有关。在0.5 mg/L暴露的鳃中,GSH-PX在24h、72h活性并不上升,在120h甚至低于正常水平,0.5 mg/L暴露的消化盲囊中,24h时迅速增高,然后逐渐下降到正常值。这可能与Cd2+结合了GSH-PX的活性中心,降低了GSH-PX的活性有关。与3种酶活性随着时间延长和剂量的增加,酶活性会降低的变化趋势不同,鳃和消化盲囊中的MDA的含量随时间延长和剂量的增加而增加,并不出现下降,这表明尖紫蛤鳃和消化盲囊中的MDA含量可以灵敏的反映机体内的氧化损伤程度,但不能敏感的反映水体中Cd2+的污染情况。     

镉对河南华溪蟹副性腺抗氧化酶活性及脂质、蛋白质和DNA的影响

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板蓝根多糖对中华鳖小肠抗氧化酶活性和脂质过氧化的影响

研究了腹腔注射板蓝根多糖(IRPS)对中华鳖小肠抗氧化酶活性和脂质过氧化的影响.24只中华鳖分成4组,每天注射1.5 mg/只、 3 mg/只、 6 mg/只处理组和注射生理盐水对照组,连续注射3 d.结果 表明,3个IRPS处理组均能显著提高SOD、GSH-PX酶活性,极显著降低MDA含量,而且小肠SOD活性随注射剂量的增大而增强,MDA含量随注射剂量的增大而降低.3 mg/只注射组对GSH-PX酶活性提高最显著,1.5 mg/只剂量组能显著提高CAT酶活性,但3 mg/只、 6 mg/只剂量组对CAT酶活性无显著性影响.     

铁镉互作对水稻脂质过氧化及抗氧化酶活性的影响

利用营养液培养方法,以‘沈农265’为供试品种,研究不同Fe(0、0.1、0.25、0.5mmolFe2+·L-1)、Cd(0、0.1、1.0μmolCd2+·L-1)处理对水稻植株体内脂质过氧化及抗氧化酶活性的影响.结果表明:单独供应Fe显著降低了水稻地上部和根系生物量,同时供应Cd后生物量不再下降;单独供应Cd降低了根系中丙二醛(MDA)和可溶性蛋白含量,而同时供应Fe时这种降低作用消失.Fe处理降低了水稻地上部和根系Cd含量,Cd处理也降低了Fe含量,两者表现出明显的相互抑制作用.高Cd(1.0μmol·L-1)和Fe互作,增加了水稻根系中MDA和可溶性蛋白含量,降低了超氧化物岐化酶(SOD)和过氧化氢酶(CAT)活性.表明在低Cd环境中为水稻提供一定数量的外源Fe能降低植株Cd含量;但高Cd胁迫将降低水稻对Fe的吸收,并导致植株体内产生脂质过氧化.     

Effects of cadmium on carbohydrate and protein metabolisms in the freshwater crab Sinopotamon yangtsekiense

The physiological impact of Cd(2+) on Sinopotamon yangtsekiense was evaluated through changes of selected parameters considered as key elements of carbohydrate and protein metabolisms. Crab were exposed to 0.725, 1.45, 2.9mg·L(-1) Cd(2+) for 7, 14 and 21 days. A time- and/or concentration- dependent decrease in muscle glycogen and increase in LDH activity suggested that glycolysis was accelerated during the treatments. Increased protease activity, lowering of FAA and the initially increased and subsequently decreased aminotransferase activities suggest an enhanced protein mobilization during early Cd(2+) exposure followed by a metabolic impairment during late exposure. Decreased hemolymph glucose level was observed in the crabs treated with 2.9mg·L(-1) Cd(2+) for 21d, suggesting an impaired gluconeogenesis. Ammonia level barely changed during the 14d Cd(2+) exposure most likely due to the increased urea and glutamine production; After 1.45 and 2.9mg·L(-1) Cd(2+) treatment for 21d, ammonia was observed increased followed by an exclusive increase in glutamine. Taken together, our results indicate that carbohydrate and protein are mobilized to a varying degree as a compensatory metabolism to response to the energy stress during acute Cd(2+) exposure. As the time lapsed, some symptoms on metabolism obstacle reflect the toxic effect of sublethal Cd(2+).     

厚壳贻贝抗氧化酶活性和脂质过氧化物含量对Cd和Aroclor 1254胁迫的响应

以厚壳贻贝(Mytilus coruscus)为目标生物,研究了不同浓度Cd2+(0.194、0.388、0.775 mg·L-1)、Aroclor 1254(0.005、0.01、0.05 mg·L-1)单一和复合胁迫对其消化盲囊抗氧化酶活性及脂质过氧化产物丙二醛(MDA)含量的影响。结果表明:(1)单一和复合胁迫均可导致厚壳贻贝抗氧化酶的活性先升高后抑制。高浓度组(0.775 mg·L-1Cd2+、0.05mg·L-1Aroclor 1254)在单一胁迫第1天时,抗氧化酶的活性即达峰值。抗氧化酶活性的下降幅度和速率与胁迫物质作用时间和浓度呈正相关。(2)SOD、GSH-Px对胁迫的敏感性高于CAT。(3)各胁迫处理组MDA含量随胁迫时间延长均显著升高(P0.01)。单一胁迫的效应与剂量和时间呈正相关。(4)复合胁迫的效应强于单一胁迫。推测高于环境水平的Cd2+、Aroclor 1254对厚壳贻贝可产生明显氧化胁迫,抗氧化防御系统可以作为海洋环境重金属-有机物复合污染监测的潜在生物标志物。     

Comparative antioxidant enzyme and lipid peroxidation study in erythrocytes and liver of some freshwater fish

1. Superoxide dismutase (SOD), catalase (C), peroxidase (P) and glutathione peroxidase (GSH-Px) were estimated in the erythrocytes and liver of the carp, the tench and the crucian carp during a two-years period, 1983-1984 (autumn). 2. The lipid peroxidation (LP) of the erythrocytes and liver homogenates was also compared. 3. The activities of the enzymes examined showed significant interspecies variations. 4. Significant differences were observed between enzyme activities (except for SOD in the liver) and lipid peroxidation in erythrocytes and liver of investigated fish species. 5. The very high values of peroxide enzyme activities in fish erythrocytes and SOD in fish liver suggest the predominant role of these enzymes in protection of polyunsaturated acids against uncontrolled oxidative processes.     

Cadmium-induced oxidative stress and apoptotic changes in the testis of freshwater crab, Sinopotamon henanense

Cadmium (Cd), one of the most toxic environmental and industrial pollutants, is known to exert gonadotoxic and spermiotoxic effects. In the present study, we examined the toxic effect of Cd on the testis of freshwater crab, Sinopotamon henanense. Crabs were exposed to different Cd concentrations (from 0 to 116.00 mg·L(-1)) for 7 d. Oxidative stress and apoptotic changes in the testes were detected. The activities of SOD, GPx and CAT initially increased and subsequently decreased with increasing Cd concentrations, which was accompanied with the increase in malondialdehyde (MDA) and H(2)O(2) content in a concentration-dependent manner. Typical morphological characteristic and physiological changes of apoptosis were observed using a variety of methods (HE staining, AO/EB double fluorescent staining, Transmission Electron Microscope observation and DNA fragmentation analysis), and the activities of caspase-3 and caspase-9 were increased in a concentration-dependent manner after Cd exposure. These results led to the conclusion that Cd could induced oxidative damage as well as apoptosis in the testis, and the apoptotic processes may be mediated via mitochondria-dependent apoptosis pathway by regulating the activities of caspase-3 and caspase-9.     

Antioxidant enzyme activity and lipid peroxidation in liver of female rats co-exposed to lead and cadmium: Effects of vitamin E and Mn2+

The oxidative status of liver of female rats exposed to lead acetate and cadmium acetate either alone or in combination at a dose of 0.05?mg/kg body wt intraperitoneally for 15 days was studied. After the administration of lead alone, the activity of superoxide dismutase (SOD) decreased in liver, whereas no changes were observed in catalase (CAT) activity, and glutathione (GSH) and thiobarbituric acid (TBARS) levels. Cadmium exposure and combined exposure to lead and cadmium led to decrease in GSH content and increased TBARS levels. Moreover, animals exposed to either cadmium alone or in combination with lead showed a decrease in SOD activity and an increase in CAT activity. The in vitro experiments showed that vitamin E failed to restore the antioxidant enzyme activities in metal treated postmitochondrial supernatant fraction of liver. But Mn²⁺ ions protected the mitochondria from lipid peroxidation and could completely restore Mn-superoxide dismutase (Mn-SOD) activity following metal intoxication. The results of this study indicate that despite the ability of lead and cadmium to induce oxidative stress the effect in liver is not intensified by combined exposure to both lead and cadmium. The observed changes in various oxidative stress parameters in the liver of rats co-exposed to lead and cadmium may result from an independent effect of lead and /cadmium and also from their interaction such as changes in metal accumulation and content of essential elements like Cu, Zn and Fe. These results suggest that when lead and cadmium are present together in similar concentrations, cadmium mediates major effects due to its more reactive nature.     

Phylogeography of the Chinese endemic freshwater crab Sinopotamon acutum (Brachyura,Potamidae)

Phylogeographical inferences based on multiple molecular markers from different modes of inheritance (i.e. mtDNA and nucDNA) can help to explore drivers of current species divergence over different timescales and allow a deeper understanding of evolutionary processes. River systems and mountains, owing to their drainage networks and complex topography, are often a high priority when inferring external causes of phylogeographical patterns. Here, we selected the Chinese endemic freshwater crab Sinopotamon acutum inhabiting drainage networks across the Qinling–Daba Mountains, a watershed that divides northern from southern fauna in China, as a model species (1) to investigate whether river networks and mountain systems act as barriers in shaping the phylogeography of freshwater crabs and (2) to test the impact of historic environments and ecological habitats on crab distribution. Phylogenetic tree and network analyses based on mtDNA revealed divergence between eastern and western populations, but microsatellite DNA did not recover this. Frequent and male‐biased gene flow is evident. The adjacent tributaries, such as Weihe River 1 and Hanjiang River 1, although isolated by Qinling Mts, have low genetic variation in mtDNA. In addition, microsatellite DNA showed low variation between all rivers. Frequent gene flow, genetic variation and mitochondrial genetic structure in S. acutum indicated that the Qinling–Daba Mountains have had no effect on divergence in this species; instead, hydrological networks across these mountains serve as a continuous migration corridor for these crabs. Glacial refugia are probably responsible for the initial isolation of the eastern and western clades, and local adaptations after dispersal have further driven divergence. Cytonuclear discordance in phylogeographical patterns may be attributable to ongoing male‐biased gene flow.