Cd2+-B[α]P复合污染对菲律宾蛤仔急性毒性和解毒代谢酶活力的影响

文章研究了Cd2+-B[α]P复合污染对菲律宾蛤仔的急性毒性和鳃丝、消化盲囊解毒代谢酶活力的影响。结果表明:Cd2+对菲律宾蛤仔48、72、96h LC50分别为50.41、24.12、14.68 mg/L,Cd2+-B[α]P对菲律宾蛤仔的联合急性毒性48—96h表现为协同作用。Cd2+、B[α]P单一与复合污染对菲律宾蛤仔鳃丝、消化盲囊谷胱甘肽(GSH)含量、谷胱甘肽硫转移酶(GST)和超氧化物歧化酶(SOD)活力的影响显著(P<0.05),而对照组无显著变化。单一染毒组组织GSH含量在12d内呈峰值变化,分别于1d、3d达到最大值,12d后保持稳定,表现为恢复至对照组水平或被诱导;复合污染处理组组织GSH含量除Cd2++B[α]P(15μg/L+0.01μg/L)处理组在3d内呈峰值变化外,其他处理组均呈逐渐下降趋势,均于12d后稳定,被显著抑制。各染毒处理组组织GST、SOD活力在12d内呈峰值变化,分别于1d、3d达到最大值,12d后各处理组GST、SOD活力趋于稳定,GST活力与对照组无明显差异,而SOD活力明显高于对照组水平。由此可见,菲律宾蛤仔在Cd2+-B[α]P复合胁迫下急性毒性效应明显,组织解毒代谢酶活力表现出明显的时间、剂量效应性,鳃丝、消化盲囊GSH含量和SOD活力可作为菲律宾蛤仔Cd2+-B[α]P复合污染评价的潜在生物标志物。     

硫化物对栉孔扇贝线粒体的损伤研究

硫化物是含有-2价硫离子化合物的统称,会抑制复合体IV活性,是水产养殖中常见的有毒物质。以水产养殖动物栉孔扇贝为研究对象,评估硫化物对线粒体的损伤。研究结果显示硫化物能显著降低栉孔扇贝各组织线粒体活力和SOD酶活,增加线粒体的肿胀度和MDA含量,影响线粒体的功能,造成线粒体的损伤,进而对栉孔扇贝产生毒害作用。     

桑沟湾栉孔扇贝生物沉积的现场测定

运用沉积物捕集器于桑沟湾对栉孔扇贝 (Chlamysfarreri)的生物沉积进行了现场测定 ,以评价贝类养殖对近岸生态环境的影响。结果表明 :桑沟湾栉孔扇贝具有相当高的生物沉积速率。壳高 68 1～77 9mm、软体干重 2 75～ 3 91g的栉孔扇贝 ,其生物沉积速率为 0 93～ 6 97g ind·d,平均 3 99g ind·d ;而壳高 40 8～ 67 4mm、软体干重 0 5 9～ 1 85g的栉孔扇贝生物沉积速率的变化范围为 0 5 2～ 6 42g ind·d,平均为 2 3 8g ind·d ;另外 ,壳高为 2 5 8～ 2 8 3mm、软体干重 0 1 2～ 0 1 7g的栉孔扇贝 ,其生物沉积速率在2 0 0 2年的 1 1和 1 2月以及 2 0 0 3年的 1月分别为 0 74、1 1 1和 0 1 5g ind·d。在桑沟湾 ,影响栉孔扇贝生物沉积的主要因素包括水温、悬浮颗粒物、扇贝个体大小和年龄。高密度、大规模的近岸浅海贝类养殖所产生的大量生物沉积物可能会对海区的物理、化学和生物环境产生影响。     

盐度变化对克氏原螯虾渗透调节影响机制的初步研究

本文研究了克氏原螯虾在盐度变化下血淋巴渗透压、鳃丝Na+-K+-ATPase活力和生物胺的变化过程和特征。结果显示：盐度变化（0－20‰）对克氏原螯虾血淋巴渗透压、鳃丝Na+-K+-ATPase活力和生物胺含量影响显著(p<0.05),而对照组无明显变化。在实验时间内各处理组血淋巴渗透压随盐度变化增大而升高,1－2d后趋于稳定,鳃丝Na+-K+-ATPase活力逐渐降低,6d后保持稳定,且渗透压正相关性,酶活力与盐度呈负相关性;各处理组在实验时间内血淋巴和鳃丝多巴胺、去甲肾上腺素、5-羟色胺含量均呈峰值变化,血淋巴中多巴胺、5-羟色胺含量分别在1d和3d时达到最小值和最大值,且变化过程分别与盐度变化值呈负和正相关性,并分别在6d和9d后趋于稳定,而各处理组的NE含量（除盐度为4的处理组）在0.5d内迅速升高,0.5－3d内略有波动,然后呈下降趋势,至15d时保持稳定;各处理组鳃丝多巴胺、去甲肾上腺素和5-羟色胺含量均于2d时达到最大值,且变化过程均与盐度变化值呈正相关性,均在9d后趋于稳定;稳定后各处理组血淋巴和鳃丝生物胺含量均与对照组无显著性差异。这些结果表明,在外界盐度变化下生物胺作为一种神经内分泌因子,在甲壳动物的渗透压调节过程中发挥重要作用,可引发甲壳动物产生的渗透调节过程,如激活鳃丝已有的Na+-K+-ATPase活力、调节血淋巴渗透压效应物含量以适应外界环境的变化。     

中国东海和南海有害赤潮高发区麻痹性贝毒素研究

用小白鼠生物检测法和高效液相色谱法对采自浙江舟山和广东深圳海域贝类的麻痹性贝毒素进行了调查和分析,结果表明,舟山海域近岸的贝类毒素检出率为14％,染毒的贝类毒素含量不高,低于小白鼠生物检测法的测定范围;深圳近岸贝类毒素检出率为30％以上,华贵栉孔扇贝是主要的染毒贝类,有1个样品毒素含量达5．1Mu·g-1,超出安全食用标准．从深圳大亚湾华贵栉孔扇贝检测出10种麻痹性贝毒素成分,消化腺的主要毒素成分为GTXl+2和GTX5,Cl+2和GTX2+3,而剔除消化腺后其余贝组织的主要成分为neoSTX和GTX5．贝毒素主要积累在扇贝的消化腺内,消化腺含有的毒素是贝肉组织的8倍．     

栉孔扇贝消化系统γ-氨基丁酸的免疫组织化学定位

采用抗生物素-生物素-过氧化物酶法(ABC法)的免疫组织化学技术,对γ-氨基丁酸(GABA)在栉孔扇贝(Chlamys farreri)消化系统各组织器官中的分布进行了定位研究。结果表明,栉孔扇贝的唇瓣、口唇、肠道的上皮细胞均呈GABA阳性反应,阳性反应物质呈颗粒状分布且多集中于上皮细胞游离端;胃上皮中未见GABA阳性反应;肝胰腺的上皮细胞及部分结缔组织中呈现GABA阳性反应,其中部分上皮细胞中的阳性反应物质呈团块状分布。GABA在栉孔扇贝消化系统除胃以外的各器官均有分布,推测其可能参与消化功能的调节作用。     

褪黑素对邻苯二甲酸(2-乙基己基)酯致雄性小鼠生殖细胞DNA损伤的拮抗作用

目的探讨邻苯二甲酸(2-乙基己基)酯(DEHP)致小鼠睾丸细胞DNA损伤及褪黑素(MT)对此损伤的拮抗作用。方法将40只CL57BL/6J雄性小鼠随机分为4组,包括对照组、MT组、DEHP组和MT+DEHP联合组。MT采用腹腔注射(剂量为15 mg·kg-1),DEHP灌胃染毒(染毒剂量为1000 mg·kg-1),每天染毒1次,连续30 d。检测睾丸组织中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活力和丙二醛(MDA)、8-羟基脱氧鸟嘌呤(8-OHd G)含量。单细胞凝胶电泳(彗星实验)检测睾丸细胞DNA损伤,慧星图像软件测定慧星尾长、慧尾DNA百分含量、尾矩及Olive尾矩。结果与对照组比较,DEHP组小鼠睾丸组织GSH-Px和SOD活力降低,MDA和8-OHd G含量增加,睾丸细胞彗星尾长、彗尾DNA百分含量、尾矩、Olive尾矩均显著增加,差异均有统计学意义(P<0.05);与DEHP组比较,MT+DEHP联合组小鼠睾丸组织GSH-Px和SOD活力升高,MDA和8-OHd G含量降低,睾丸细胞DNA损伤程度减轻,差异均有统计学意义(P<0.05)。结论 DEHP造成小鼠睾丸明显的氧化应激,并引起睾丸细胞DNA的损伤;MT可拮抗因DEHP染毒导致的睾丸氧化损伤。     

一株形态特殊的细菌对栉孔扇贝致病性的初步研究

为研究分离到的一株形态特殊的细菌对栉孔扇贝(Chlamys farreri)致病性,采用测定病原液蛋白含量的方法,对病原相对定量。用含200～300μg／ml蛋白的病原液进行了不同浓度梯度、同一温度和相同浓度梯度、不同温度对栉孔扇贝的致病作用的测试,结果表明：扇贝人工感染后潜伏期3～7d,死亡高峰期为5～10d,符合一般病原感染的规律。病死贝的一般病理变化与养殖海区自然发病扇贝的病理变化一致。23、26℃下该病原体对栉孔扇贝具有强致病作用。可以确定该细菌为造成栉孔扇贝大规模发病死亡的主要病原之一。     

不同水深养殖栉孔扇贝的形态测量学研究和比较

为了探究远岸深水海区和近岸浅水海区养殖的栉孔扇贝(Chlamys farreri)形态上的差异, 运用传统形态测量学和几何形态测量学的方法, 对来自近岸浅水海区(15 m水深)和远岸深水海区(30 m水深)底栖养殖的2龄栉孔扇贝进行形态测量学研究和比较分析。结果表明: 深水养殖的栉孔扇贝的壳高(SH)、壳长(SL)和壳宽(SW)都极显著大于浅水养殖的栉孔扇贝(P<0.01); 通过界标点(Landmarks)和半界标点(Semi-landmarks)的方法, 及广义普鲁克分析(GPA)、主成分分析(PCA)和典型变量分析(CVA), 结果表明深水养殖的栉孔扇贝的整体壳形尺寸大于浅水养殖的栉孔扇贝, 除去尺寸大小因素后两者的壳耳和壳体扇形边缘存在显著差异。文章为栉孔扇贝深水养殖的选育和增养殖工作提供基于形态学研究的理论依据, 同时比较分析了传统形态测量学和几何形态测量学的原理和分析方法, 为研究生物体形态差异时选择合适的研究方法提供新参考。     

莠去津慢性染毒对河蟹血淋巴细胞DNA的影响

利用不同浓度(0.01、0.1、1mg·L-1)的莠去津对河蟹进行慢性染毒处理90d,采用单细胞凝胶电泳技术检测其对河蟹血淋巴细胞DNA损伤的影响。结果表明,不同浓度的莠去津能引起河蟹血淋巴细胞的DNA损伤,且随着浓度的增加,TM值、TailDNA逐渐变大,尤以1mg·L-1浓度组最为显著。证明一定浓度的莠去津可以造成河蟹血淋巴细胞DNA链的断裂,破坏其DNA结构。     

Formation and repair of DNA-protein crosslinks in newly replicated DNA

The production and removal of gamma-radiation-induced DNA-protein crosslinks (DPC) in nuclear matrix-associated newly replicated DNA were examined, as well as the relationship of DPC to DNA replication. In unirradiated, exponentially growing Chinese hamster V79 cells, DNA pulse labeled with [3H]thymidine was observed to be bound preferentially to protein. The pulse-labeled DNA subsequently became dissociated from protein. After a 30- to 60-min chase period, the level of labeled DNA in DPC was reduced to the same level as for bulk DNA. The radiation dose response for the formation of DPC was similar in newly replicated DNA that had been chased for various times and in mature chromatin DNA. Labeled DNA, in the DPC formed after 60 Gy, was rapidly removed from protein during the postirradiation incubation period. However, no recovery of DNA synthesis was observed, even after the majority of DPC were released. Thus either DPC are not the sole cause of the inhibition of DNA synthesis or their removal is not sufficient for DNA synthesis to resume.     

Induction of aryl hydrocarbon hydroxylase and DNA adduct formation in parental and carcinogen transformed C3H/10T1/2 clone 8 cells by benzo[a]pyrene

C3H/10T1/2 clone 8 (10T1/2) cells possess aryl hydrocarbon hydroxylase (AHH) activity capable of metabolizing polycyclic aromatic hydrocarbons to ultimate carcinogenic forms. AHH activity in 10T1/2 cells was measured before and after culturing in the presence of benzo[a]pyrene (B[a]P), and compared to the AHH activity found in carcinogen-transformed 10T1/2 cell lines treated similarly. The cell lines were also examined for B[a]P-DNA adduct formation, using the 32P-postlabelling technique. Treatment of parental 10T1/2 cells with B[a]P was found to significantly increase AHH activity and produce substantial numbers of DNA adducts. In addition to a major B[a]P-DNA adduct, 5-6 minor DNA adducts were also detected. Relative to parental 10T1/2 cells, an aflatoxin B1-transformed 10T1/2 cell line (7SA) was found to have significantly depressed AHH activity. In addition, after treatment with B[a]P, 7SA cells had only 8% of the B[a]P-DNA adduct levels found in 10T1/2 cells. This system may provide an in vitro model for investigating mechanisms responsible for the depression of cytochrome P-450 activities by chemical carcinogens.     

Biomarkers in Ruditapes decussatus: a potential bioindicator species.

The clam Ruditapes decussatus is distributed worldwide and due to its ecological and economical interest has been proposed as a bioindicator in areas where mussels are not available. The accumulation of several anthropogenic compounds in their tissues suggests that they possess mechanisms that allow them to cope with the toxic effects of these contaminants. Besides pollutant uptake, the use of biomarkers is pointed out in this paper since it is a promising approach to monitor the effect of these contaminants in the marine environment. Biomarkers complement the information of the direct chemical characterization of different types of contaminants. Therefore, the aim of this paper is to review the role of several biomarkers: (metallothioneins (MT), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and selenium-dependent), lipid peroxidation (measured as MDA, one of the final products of lipid peroxidation), glutathione S-transferase (GST) and acetylcholinesterase (AChE), measured in different tissues of the clam R. decussatus, in laboratory conditions and under various environmental stresses, in two ecosystems (Ria Formosa lagoon- Portugal) and Bizerta lagoon (Tunisia) in a perspective of a multibiomarker approach to assess environmental changes. Experiment and field studies are in good agreement since MT levels, especially in the gills, the first target tissue of these contaminants, can be used as biomarker of exposure to Cd. GPx and MDA may also be determined in this respect. AChE activity is inhibited by pesticide and, to a less extent, by metal exposure in the gills and whole soft body of clams. However, the induction of GST isoforms experimentally demonstrated is not observed in the field because only global GST activity was determined. The whole set of results opens new research perspectives for the use of this species to assess the effect of mixtures of pollutants in the aquatic environment.     

Potential health effects of exposure to carcinogenic compounds in incense smoke in temple workers

Incense smoke is a potential hazard to human health due to various airborne carcinogens emitted from incense burning. This study aimed to evaluate the potential health effects of exposure to benzene, 1,3-butadiene, and polycyclic aromatic hydrocarbons (PAHs) emitted from incense smoke in temple workers. Exposure and health risks were assessed through the measurement of ambient exposure as well as through the use of biomarkers of exposure and early biological effects. Ambient air measurement showed that incense burning generates significantly higher levels of airborne benzene (P<0.01), 1,3-butadiene (P<0.001) and total PAHs (P<0.01) inside the temples, compared to those of the control workplace. Temple workers were exposed to relatively high levels of benzene (45.90 microg/m(3)) 1,3-butadiene (11.29 microg/m(3)) and PAHs (19.56 ng/m(3)), which were significantly higher than those of control workers (P<0.001). The most abundant PAHs were chrysene, B[ghi]P, B[a]P, B[a]F and fluoranthene. Concentrations of B[a]P and B[a]P equivalents in air samples to which temple workers were exposed were 63- and 16-fold, higher, respectively, than those to which control subjects were exposed (P<0.001). Biomarkers of exposure to benzene (blood benzene and the urinary metabolites trans,trans-muconic acid and S-phenylmercapturic acid), 1,3-butadiene (urinary monohydroxy-butenyl mercapturic acid) and PAHs (1-hydroxypyrene) were all significantly higher in temple workers than those in control workers. DNA damage and DNA repair capacity were measured as biomarkers of early biological effects. Temple workers had a significant increase in DNA damage observed as a 2-fold increase in the levels of leukocyte 8-hydroxy-2'-deoxguanosine (8-OHdG) and DNA strand breaks (P<0.001). A significant reduction of DNA repair capacity in temple workers determined by the radiation challenge assay was also observed. These results indicate that exposure to carcinogens emitted from incense burning may increase health risk for the development of cancer in temple workers.     

Modulation of Masheri- and benzo[a]pyrene-inducible carcinogen-metabolizing enzymes by dietary vitamin A

The modulatory role of dietary vitamin A on the carcinogen metabolizing enzymes was studied in masheri extract and benzo[a]pyrene-treated rats. Weanling male Sprague-Dawley rats were fed vitamin A deficient (SR-) and vitamin A sufficient (SR+) semisynthetic diets for 12 weeks. ME/B[a]P treatment significantly increased the phase I activating enzymes in both SR- and SR+ groups. However, a higher percentage increase in enzyme activities was observed in both liver and lung of the SR- animals compared to the SR+ groups. Glutathione content and activity of glutathione S-transferase were decreased in both liver and lung of SR- animals on treatment with either ME or B[a]P. In the SR+ group, an increase in GSH content and GST activity was observed following the ME/B[a]P treatment. The hepatic pool of vitamin A was depleted while that of vitamin C was increased after ME or B[a]P treatment in both SR- and SR+ groups.     

Growth inhibition and DNA damage induced by benzo[a]pyrene and formaldehyde in primary cultures of rat tracheal epithelial cells

The effects of benzo[a]pyrene (BAP) and formaldehyde (HCHO), alone and combined, on cell growth and DNA damage were determined in primary cultures of rat tracheal epithelial cells dissociated from rat tracheas. Cell cultures treated with 25 microM BAP for 24 h or 200 microM HCHO for 90 min did not have a marked reduction in cell growth. However, their combined treatment reduced cell growth by 60% of control when cultures were exposed to BAP followed by HCHO as well as the reverse order. None of these treatments significantly decreased cell viability as judged by dye exclusion, nor did they enhance cell terminal differentiation as measured by cornified envelope formation. Alkaline elution analysis of DNA damage detected both DNA-protein crosslinks (DPC) and DNA single-strand breaks (SSB) as a result of HCHO treatment, whereas BAP treatment caused only SSB. While HCHO-induced SSB were repaired within 2 h, BAP-induced SSB were detected 3 days after treatment. Combined treatment of cell cultures with BAP followed by HCHO resulted in more SSB than was obtained from either agent alone, but less DPC than was detected from HCHO alone. The increased number of SSB obtained from this combined treatment may be related to the marked enhancement of carcinogenesis observed in earlier in vivo-in vitro studies.     

Investigation of EROD, CYP1A immunopositive proteins and SOD in haemocytes of Chamelea gallina and their role in response to B[a]P

CYP1A sub-family represents the main form of cytochrome P450 involved in benzo[a]pyrene (B[a]P) detoxification, but there are no clear evidences about its presence in invertebrates. 7-Ethoxy resorufin O-deethylase (EROD) activity is strictly related to CYP1A presence, at the same time P450-dependent oxidative metabolism leads to reactive oxygen species (ROS) production, thought to be an important mechanism of pollutant-mediated toxicity in aquatic organisms. Superoxide dismutases (SODs), EROD and CYP1A activities and/or expressions were detected in haemocytes of pooled clams (Chamelea gallina) and cell-free haemolymph after 24 h, 7 and 12 days of exposure to 0.5 mg/L of B[a]P. After 24 h, B[a]P content was maximum in whole tissues. A 61 kDa band was recognized in haemocytes and cell-free haemolymph by polyclonal anti-fish CYP1A, while 53.5 and 63.8 kDa CYP1A immunopositive proteins were discriminate without differences of expression. Differently, EROD, MnSOD activity/expression and ECSOD expression decreased in haemocytes and haemolymph. C. gallina immune system presents an interesting response dose/time exposure of B[a]P and the 7 days condition highlights the major effects of xenobiotic action. The identification of basal EROD levels supports the possible presence of the CYP1A, never identified in C. gallina and more specifically never isolated in immune cells, as confirmed by CYP1A-immunopositive proteins identification.     

Benzoapyrene-induced DNA damage in Mytilus galloprovincialis: measurement of bulky DNA adducts and DNA oxidative damage in terms of 8-oxo-7,8-dihydro-2´-deoxyguanosine formation

Bulky DNA adducts and 8-oxo-7,8-dihydro-2´-deoxyguanosine (8-oxodGuo) were measured in gill DNA of benzo[a]pyrene (B[a]P)-exposed mussels (50 mg kg^-1 dw day^-1), respectively by the ³²P-post-labelling technique and high performance liquid chromatography coupled to electrochemical detection assay. A time-course study was performed for both biomarkers and their potential use for marine biomonitoring discussed for the sentinel species studied. In gills, B[a]P-related DNA adducts were positively correlated with B[a