Histopathological alterations in gill,liver and kidney of common carp exposed to chlorpyrifos

Histopathological alterations in gill, liver and kidney of common carp, Cyprinus carpio, intoxicated with sub-lethal concentrations of chlorpyrifos (O,O,-diethyl-O-3,5,6-trichloro-2-pyridyl phosphorothioate) pesticide (1 and 100 μg/L) for a period of 14 days were analyzed under light microscope. Gill exhibited hyperplasia and hypertrophy of gill epithelium, blood congestion, dilation of marginal channel, epithelial lifting, lamellar fusion, lamellar disorganization, lamellar aneurysm, rupture of the lamellar epithelium, rupture of pillar cells and necrosis. Alterations in hepatocytes were more pronounced, including nuclear and cellular hypertrophy, cellular atrophy, irregular contour of cells and nucleus, cytoplasmic vacuolation, cytoplasmic and nuclear degeneration, cellular rupture, pyknotic nucleus, necrosis and melanomacrophages aggregations. Histopathological lesions in kidney were cellular and nuclear hypertrophy, narrowing of tubular lumen, cytoplasmic vacuolation, hyaline droplet degeneration, nuclear degeneration, occlusion of tubular lumen, tubular regeneration, dilation of glomerular capillaries, degeneration of glomerulus and hemorrhage in Bowman's space. The most significant conclusion drawn from this study was that with the increased concentration and duration the toxicosis of chlorpyrifos would be enhanced as shown through the analysis of mean assessment value (MAV) and degree of tissue changes (DTC) also.     

MC-LR对草鱼肠道显微结构和炎症相关细胞因子表达的影响

微囊藻毒素-LR(MC-LR)是蓝藻水华暴发产生的一种毒素,在水生生态系统中广泛分布.为探讨MC-LR对鱼类的肠道免疫毒性,分别对草鱼经腹腔注射不同剂量的MC-LR(25、75和100μg·kg-1),24、48、72和96 h后取样,分别进行组织病理变化和炎症相关细胞因子表达分析.显微结构结果显示,肠道组织病理变化表现为微绒毛结构破坏并伴随淋巴细胞浸润,肠上皮细胞排列紊乱,杯状细胞数目显著增多,粘膜固有层充血,在高剂量组甚至出现粘膜固有层分离的现象,且有剂量和时间效应.采用荧光定量PCR方法检测了炎症相关细胞因子IL-1β、IL-8、IL-10、TNF-α和TGF-β的mRNA转录水平变化.结果显示促炎性细胞因子IL-1β、IL-8和TNF-α表达在低剂量组显著上升,而在高剂量组的表达多被抑制;而抗炎性细胞因子IL-10 mRNA仅在25μg·kg-1BW处理组表达差异变化显著,但在高剂量组表达变化差异不显著,TGF-β1的表达仅在75和100μg·kg-1处理组分别处理72和24 h后显著降低,其他差异不显著.从以上结果推测MC-LR的肠道免疫毒性主要表现为肠黏膜结构的破坏以及产生炎性反应,其中对肠黏膜结构的破坏具有剂量依赖效应.     

湖北鸭儿湖表层沉积物与鱼体中Hg质量比的相关性研究

采用固/液Hg自动分析仪,对采自湖北鸭儿湖氧化塘的鲢鱼、鳙鱼及表层沉积物(0～20 cm)中Hg质量比进行了检测.1998年采集的畸形鲢鱼鱼肉中Hg的平均质量比为(1.723±0.926) mg/kg (n=5),分别是美国FDA人体健康影响标准(1.0 mg/kg) 和我国食品卫生标准(0.3 mg/kg)的3.2倍和10.6倍,超标率均达100%;2002 年采集的畸形鲢鱼、畸形鳙鱼鱼肉中Hg的平均质量比分别为(0.572±0.118) mg/kg(n=10)和(0.739±0.118) mg/kg (n=10),是我国Hg食品卫生标准的1.9倍和2.5倍,超标率达100%.沉积物中Hg的平均质量比为5.08 mg/kg.两年采集的鸭儿湖氧化塘鱼肉、表层沉积物中总Hg质量比的分析和比较表明,表层沉积物中Hg质量比与鱼体内Hg质量比呈明显的正相关性(R=0.959).研究结果表明,污水养鱼中Hg通过食物链所导致的食品安全问题应引起人们高度关注.     

滴水湖及其鲫鱼体内PAHs分布特征与影响因素分析

通过测定滴水湖水体、颗粒物和沉积物体系PAHs含量,探讨其分布与组成特征、影响因素及污染来源.结果表明,滴水湖水体中溶解态、颗粒态和沉积物中PAHs平均浓度分别为16.78ng/L、33.02ng/g和40.98ng/g.统计分析表明,水体酸碱度以及电导率与溶解态低环PAHs之间存在显著相关性,总有机碳(TOC)与沉积物中高环PAHs浓度之间存在显著相关性.溶解态的PAHs来源主要表现为草、木和煤的高温燃烧,部分样点表现为石油源;颗粒态PAHs则主要表现为高温燃烧以及石油泄漏源;而沉积物PAHs的来源则较复杂,除了草、木及煤的高温燃烧源和石油泄漏源,还有部分样点表现为石油的高温燃烧源.鲫鱼肌肉、卵部以及鳃部PAHs含量的测定结果表明,鲫鱼不同部位对PAHs的富集能力具有较大差异.鳃部总PAHs含量最高,其次为鲫肉部分,鲫卵所含PAHs浓度最少.与国内外其他研究相比较,滴水湖鲫鱼体内PAHs含量处于较低水平,但鲫鱼部分样品的BaP等当量浓度略高于EPA规定的可食性生物器官中PAHs含量的上限值.     

微囊藻毒素在银鲫肠道中的累积及其病理学影响

银鲫(Carassius auratus),杂食性鱼类,是我国淡水主养品种之一。在富营养化湖泊中,它能以有毒微囊藻为主要食物,导致微囊藻毒素(MCs)在其组织中大量累积。为研究MCs在肠道内累积和代谢特征及其对肠道的毒性影响,分别以50和200μg MC-LReq·kg-1剂量的MCs粗提液(主要含MC-RR和MC-LR)对银鲫进行腹腔注射,并在注射后1、3、12、24、48和168 h后取样。MCs的含量用LC-MS和HPLC进行定性和定量测定,结果发现,高低两剂量组银鲫肠中MCs的含量均在注射后1 h达最大值(分别为2.8和181.4 ng·g-1DW),然后随暴露时间的延长迅速下降。相对于毒素的累积,MCs诱导的银鲫肠组织损伤具滞后性,注射后48 h内,高低两剂量组肠道的病理变化呈时间-剂量依赖性的增长,病理特征表现为肠上皮细胞排列紊乱,甚至出现坏死、溶解和脱落,杯状细胞数目显著增多,微绒毛结构破坏并伴随淋巴细胞浸润。实验结果表明,单次染毒后MCs在鲫肠道中迅速累积后降解,并造成时间-剂量依赖性组织损伤,且低剂量组的损伤是可逆的。     

Distribution of persistent organochlorine pesticides in tissue/organ of silver carp (Hypophthalmichthys molitrix) from Guanting Reservoir, China

The concentration of organochlorine pesticides（OCPs） in tissues and organs of silver carp（Hypophthalmichthys mofitrix） from Guanting Reservoir were investigated to evaluate the pollution potential and distribution of OCPs. A total of 16 OCPs were measured and the concentrations were in the range of 1.61-69.01 ng/g wet weight（ww） for total OCPs, 0.16- 0.75 ng/g ww for HCB. 0.75 -26.80 ng/g ww for SHCH（sum of α-,β-, γ- and δ-HCH） and 0.68-35.94 ng/g ww for SDDT（ sum of p, p＇-DDE, p, p＇-DDD, o, p＇-DDT and p, p＇- DDT）. The mean concentrations of total OCPs, HCB, ∑HCH, and ∑DDT were 18.04, 0.96, 7.14 and 9.28 ng/g ww, respectively. Among the organochlorine pesticides, β-HCH and p, p＇-DDE were the most dominant compounds in tissue and organ with the average concentrations of 4.42 and 8.14 ng/g, respectively. The results obtained in this study show that the levels of 16 OCP residues found in silver carps are low and pose no threat to human health and wildlife fed upon them on the basis of existing related quality guidelines. However, recent input of lindane and DDT might still exist in the area investigated and further investigation should be carried on.     

Effect of sub-acute exposure to TiO2 nanoparticles on oxidative stress and histopathological changes in Juvenile Carp (Cyprinus carpio)

Increasing application of nanotechnology highlights the need to clarify and understand nanotoxicity. Mammalian and in vitro studies have raised concerns about the toxicity of titanium dioxide nanoparticles (TiO2-NPs), but there are limited data on ecotoxicity to aquatic organisms. In this work, the sub-acute toxicity of TiO2-NPs to carp (Cyprinus carpio) was assessed. Superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities and lipid peroxidation (LPO) levels in liver, gill and brain tissues of carps varied with concentration of TiO2-NPs suspensions and exposure time (up to 8 d). As a result, 100 and 200 mg/L TiO2-NPs caused statistically significant decrease in SOD, CAT and POD activities and significant increase in LPO levels in tissues (P < 0.05), suggesting that the fish exposed to these two concentrations of TiO2-NPs su ered from the oxidative stress. The extent of depletion of antioxidant enzymes activities and the elevation of LPO in the liver was the greatest, indicating that the liver might be the most susceptible organ to TiO2-NPs exposure. In addition, carps had gill pathologies including edema and thickening of gill lamellae as well as gill filaments, and liver pathologies including necrotic and apoptosis hepatocytes after exposed to 100 and 200 mg/L TiO2-NPs for 20 d. These results indicated a potential risk from TiO2-NPs released into the aqueous environment.     

多溴联苯醚在市场鲫鱼体内分布和食鱼暴露量

利用气质联用仪(GC-NCI-MS)方法定量分析了台州路桥区河流野生鲫鱼肌肉、菜市场养殖鲫鱼肌肉、肝脏、脑、心脏和卵组织中多溴联苯醚(polybrominated diphenyl ethers,PBDEs)的含量及分布特征,并且评估了当地人通过食鱼的PBDEs暴露量.结果表明,电子垃圾拆解点附近河流鲫鱼肌肉中PBDEs含量显著高于没有明显PBDEs污染源的菜场养殖鲫鱼;PBDEs在养殖鲫鱼组织中分布不均,心脏组织中ΣPBDEs含量最高,均值为18.82 ng·g-1(湿重),卵组织中最低,均值为1.97ng·g-1.菜场养殖鲫鱼各组织中PBDEs同系物分布模式相似,BDE-47是最主要同系物,比例均值大于50%,其次是BDE-183(约20%),再次BDE-99和-153;河鱼肌肉组织中PBDEs同系物与养殖鲫鱼不尽相同,河鱼肌肉组织中主要同系物是BDE-47、-153和-99.这些结果可能暗示了来自上游的简单电子垃圾拆解行为是河流鲫鱼中较高PBDEs含量的一个污染来源.台州居民通过食用河流鲫鱼途径的PBDEs日均暴露量约为29.0 ng,稍微高于其他地区.     

渔洞水库pH值异常成因分析及水资源保护建议

酸碱平衡失调是渔洞水库水生生态系统失衡的具体表现形式。文章立足工作实际,分析渔洞水库pH值异常变化成因,藻类的生长与N、P的联系,pH值异常变化与藻类优势种群的出现以及藻类与富营养化之间的关系,鲢鱼、鳙鱼控藻利弊。分析认为:保护好渔洞水库水资源需要在水环境的保护上建立长效机制,在水量和水质方面认真、彻底做好相关的工作,切实把预防突发性水污染事件放在突出位置,把有效去除N、P等(特别是P)营养物质,有效遏制水体富营养化的发展作为根本性任务。