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壬基酚、辛基酚、二氯酚和双酚A是水环境中普遍存在的酚类污染物,由于其内分泌干扰活性和致癌性近年来受到广泛的关注.本研究以菲律宾蛤仔(Ruditapes philippinarum)为受试生物,研究4种典型酚类污染物暴露对其内脏组织和鳃组织中抗氧化酶包括超氧化物歧化酶(SOD)和过氧化氢酶(CAT)以及解毒酶谷胱甘肽硫转移酶(GST)活性的影响.研究结果表明:壬基酚低浓度处理组(0.05～0.2 mg/L)3种酶活性无显著变化,高浓度处理组(0.4 mg/L),SOD、CAT和GST 3种酶活性均受到显著抑制,抑制率分别为56.6％,59.0％和35.5％.在实验浓度范围(0.05～0.4 mg/L)内,二氯酚能够显著抑制内脏组织CAT活性,双酚A能够显著抑制鳃组织GST活性.3种酶活性变化对于酚类污染物的响应呈现较好的规律性,因此可以作为生物标志物联合指示水体中的酚类污染. 相似文献
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Glutathione S-transferases (GSTs) are a class of enzymes that facilitate the detoxification of xenobiotics, and also play important roles in antioxidant defense. We identified two glutathione S-transferase isoforms (VpGSTS, sigma GST; VpGSTO, omega GST) from Venerupis philippinarum by RACE approaches. The open reading frames of VpGSTS and VpGSTO were of 612 bp and 729 bp, encoding 203 and 242 amino acids with an estimated molecular mass of 22.88 and 27.94 kDa, respectively. The expression profiles of VpGSTS and VpGSTO responded to heavy metals and benzo[a]pyrene (B[a]P) exposure were investigated by quantitative real-time RT-PCR. The expression of VpGSTS and VpGSTO were both rapidly up-regulated, however, they showed differential expression patterns to different toxicants. Cd displayed stronger induction of VpGSTS expression with an approximately 12-fold increase than that of VpGSTO with a maximum 6.4-fold rise. Cu exposure resulted in similar expression patterns for both VpGSTS and VpGSTO. For B[a]P exposure, the maximum induction of VpGSTO was approximately two times higher than that of VpGSTS. Altogether, these findings implied the involvement of VpGSTS and VpGSTO in host antioxidant responses, and highlighted their potential as a biomarker to Cd and B[a]P exposure. 相似文献
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过氧化氢酶(CAT)和硒谷胱甘肽过氧化物酶(Se-GPx)在抗氧化防御体系中扮演重要的角色,在清除多余的活性氧自由基(ROS)防止机体氧化损伤方面具有重要的作用.本文利用RACE-PCR方法首次从脊尾白虾肝胰腺组织中克隆获得了CAT cDNA全长序列,该基因全长2649 bp,包括5′非编码区(UTR) 78 bp、开放阅读框(ORF)1554 bp和3′非编码区(UTR) 1017 bp,共编码517个氨基酸,预测分子量为58.46 kDa,理论等电点为6.64,利用PROSITE tools预测CAT基因的功能位点,发现该氨基酸序列包括酶活性中心序列“FDRERIPERVVHAKGAG”,亚铁血红素结合信号序列“RLFSYPDTH”和 3个催化位点残基His71,Asn144和Tyr354.同源性分析表明,脊尾白虾CAT氨基酸序列与其他物种的相似性为68%-92%.荧光定量PCR分析结果表明,CAT基因在肝胰腺、血细胞、心脏、肌肉、卵巢、鳃、胃和眼柄均有表达,其中在肝胰腺中表达量最高.低盐胁迫后脊尾白虾鳃和肝胰腺中CAT和GPx基因分别在48 h和6 h达到最大值,且与对照组差异显著(P< 0.05),表明CAT和GPx基因参与了低盐胁迫反应,并表现出一定时间效应关系.综合分析结果指出脊尾白虾CAT基因是CAT家族主要成员之一,可能在低盐环境胁迫过程中具有重要的作用. 相似文献
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饲料中添加还原型谷胱甘肽对牙鲆生长和抗氧化能力的影响 总被引：1，自引：0，他引：1
以酪蛋白、明胶为主要蛋白源配制精制基础饲料,添加不同浓度梯度的还原型谷胱甘肽(GSH),饲料中GSH的含量分别为0、97.96、189.92、371.84、688.72和1 063.56 mg.kg-1,在流水式养殖系统中分别投喂初始体质量为(9.49±0.22)g的牙鲆(Paralichthys olivaceus)幼鱼,8周后观测各组牙鲆的生长情况及机体的抗氧化状态。结果表明,饲料中添加外源的GSH对牙鲆成活率没有显著影响(P>0.05);牙鲆增重率(WGR)在饲料GSH含量为371.84 mg.kg-1时达到最大值,显著高于其它各组(P<0.05);饲料GSH添加组牙鲆肝脏中GSH的含量显著高于零添加组(P<0.05);各处理组肝脏中丙二醛(MDA)的含量没有显著差异(P>0.05);肝脏中谷胱甘肽还原酶(GR)的活力随饲料中GSH含量的升高呈现先降低后上升的趋势,并在饲料中GSH含量为371.84 mg.kg-1时达到最低值;肝脏中超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GPx)活力没有受到饲料中GSH含量的显著影响(P>0.05);饲料中GSH含量为371.84 mg.kg-1时,肝脏中总抗氧化力(T-AOC)显著高于1 063.56 mg.kg-1组(P<0.05),谷胱甘肽-S-转移酶(GST)活力显著低于其它各组(P<0.05)。根据WGR的实验数据,利用折线模型得到牙鲆幼鱼饲料中GSH的适宜含量为368.92 mg.kg-1,过高或过低都会对生长造成负面影响,抑制机体抗氧化能力,增加机体氧化压力。 相似文献
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重金属胁迫下厚壳贻贝谷胱甘肽S-转移酶基因表达分析 总被引：2，自引：0，他引：2
谷胱甘肽S转移酶(Glutathione S-transferase,GST)因对环境污染反应灵敏,且具有降解毒物、抗氧化等作用常被作为水体污染的指示分子;厚壳贻贝对环境污染物具有很强的耐受性,是重要的海洋环境污染监测生物,因此研究厚壳贻贝GST分子及其表达特征,对正确使用其进行海洋环境污染预警具有重要价值。本文通过同源克隆法获得厚壳贻贝GST部分序列(Gene Bank序列号为KC176684),经序列比对和系统进化分析初步推断所得到的GST基因为pi型。鉴于铜和镉是目前海水中主要的重金属污染源,进一步利用实时荧光定量PCR技术检测铜和镉胁迫后GST在厚壳贻贝血液中的表达水平,结果显示铜(Cu2+浓度为20μg/L)和镉(Cd2+浓度为200μg/L)胁迫均造成GST高水平表达,但最高表达量出现的时间略有差别,Cu2+出现在刺激后第10 d,表达量为对照组的6.95倍,Cd2+则出现在第15 d,约为对照组的6.11倍,说明GST参与了厚壳贻贝重金属的解毒过程,且对于不同重金属胁迫的解毒能力稍有不同。鉴于厚壳贻贝GST对重金属刺激的敏感作用,可将其作为海水养殖环境污染监测的生物指示基因。 相似文献
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Simple prediction methods are proposed to estimate the wave induced pressures on smooth impermeable seawalls. Based on the physics of the wave structure interaction, the sloped seawall is divided into a total of five zones (zones 1, 2 and 3 during run-up (corresponding pressures are called as positive pressures) and zones 4 and 5 during run-down (corresponding pressures are called negative pressures)) (Fig. 1). Zone 1 (0<z<d−Hi/2), where the wave pressure is governed by the partial reflection and phase shift; Zone 2 (d−Hi/2<z<d), where the effect of wave breaking and turbulence is significant; Zone 3 (d<z<Run-up height), where the pressure is induced by the run-up water; Zone 4 (Run-down<z<d), where the wave pressure is caused by the run-down effect and Zone 5 (0<z<d-Run down), where the negative wave pressures are due to partial reflection and phase shift effects. Here d is the water depth at the toe of the seawall, Hi is the incident wave height and z is the vertical elevation with toe of the seawall as origin and z is positive upward. For wave pressure prediction in zones 1 and 5, the empirical formula proposed by Ahrens et al. (1993) to estimate the wave reflection and Sutherland and Donoghue's recommendations (1998) for the estimation of phase shift of the waves caused by the sloped structures are used. Multiple regression analysis is carried out on the measured pressure data and empirical formulas are proposed for zones 2, 3 and 4. The recommendations of Van der Meer and Breteler (1990) and Schüttrumpf et al. (1994) for the prediction of wave run-down are used for pressure prediction at zone 4. Comparison of the proposed prediction formulas with the experimental results reveal that the prediction methods are good enough for practical purposes. The present study also shows a strong relation between wave reflection, wave run-up, wave run-down and phase shift of waves on wave pressures on the seawalls. 相似文献
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《Comptes Rendus Geoscience》2018,350(4):173-179
The aim of the present study was to test biomarker responses in an edible mollusk, Donax trunculus L. (Mollusca, Bivalvia) associated with environmental pollution in the Gulf of Annaba (northeastern Algeria). The biomarkers selected were glutathione S-transferase (GST), acetylcholinesterase (AChE) and metallothioneins (MTs). Samples were collected seasonally (September 2014, and January, April and July 2015) from two sites located over the Gulf of Annaba: El Battah and Sidi Salem. The results obtained reveal that autumn and winter were the two seasons that show an increase in GST activity, an inhibition of AChE activity and a high rate of MT. In addition, a decrease in AChE activity, an increase in both GST activity and MT levels in D. Trunculus collected from Sidi Salem in comparison with those of El Battah were observed. The biomarker responses at the Sidi Salem site reflect the presence of certain pro-oxidative compounds such as metals (Cd, Cu, Pb, Zn, Mn and Fe) determined in sediments in winter (January) 2015. Moreover, metal concentrations, except Fe, were higher at Sidi Salem than at El Battah. Overall, the Gulf of Annaba remains contaminated by heavy metal. However, this metallic contamination is relatively low and the risks for local population via this edible species were also low. 相似文献
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Information regarding antioxidant enzymes in amphioxus remains lacking, and this study was carried out to examine the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in different genders and tissues of amphioxus Branchiostoma belcheri tsingtauense. Results show that (1) CuZn-SOD, CAT and GPX activities in the whole amphioxus B. belcheri tsing- tauense were basically at the same levels in male and female amphioxus, whereas both T-SOD and Mn-SOD activities in male amphioxus were significantly higher than that in the female (P<0.05); (2) The testis had significantly higher T-SOD and CuZn-SOD activities than the ovary (P<0.05); (3) CuZn-SOD activity was undetectable in the guts of male and female amphioxus; (4) For both male and female am- phioxus, the activities of CAT and GPX in the gonads including testis and ovary were the lowest (P<0.05) among the tissues examined; (5) The gut and gill had the same level GPX activities while the gut had a higher CAT activity; (6) There was no clear difference in CAT and GPX activities in the corresponding tissues between male and female amphioxus. The study on SOD, CAT and GPX activities in different genders and tissues of the protochordate provides data for future comparison of amphioxus antioxidant enzymes with those of invertebrates and vertebrates. 相似文献