Antioxidant responses to benzo[a]pyrene,tributyltin and their mixture in the spleen of Sebasticus marmoratus

It has been reported that there is an interaction between Benzo[a]pyrene （BaP）, a widespread carcinogenic polycyclic aromatic hydrocarbon, and tributyltin （TBT）, an organometal used as an antifouling biocide. This study was therefore designed to examine the potential in vivo influence of BaP, TBT and their mixture on splenic antioxidant defense systems of Sebastiscus marmoratus. The fish were exposed to water containing environmentally relevant concentrations of BaP, TBT and their mixture. Spleens were collected for biochemical analysis after exposure for 7, 25, 50 d and after recovery for 7, 20 d. Cotreatment with BaP and TBT for 7 d potentiated the induction of glutathione peroxidase （GPx） activity by BaP or TBT alone. The cotreatment for 25 and 50 d resulted in inhibition of GPx activity, which was similar to the effect of TBT. Splenic glutathione S-transferase （GST） activities were significantly elevated in S. marmoratus exposed to BaP starting from 7 d and remained high up to 25 d. However, no further activity change was found with prolonged exposure. Cotreatment of BaP and TBT primarily inhibited the GST activity, which was similar to the effect of TBT. Cotreatment with BaP and TBT for 25 or 50 d potentiated the depletion of GSH （glutathione） by BaP or TBT alone. MDA （malondialdehyde） contents in spleen of S. marmoratus were not significantly altered compared with the control during the test period. Spleen, as an immune organ, is sensitive to exposure of BaP or TBT. It should have an effective mechanism to counteract oxidative damage. Antioxidative defense systems in spleen of S. marmoratus should be considered as potential biomarkers. Short-term exposure of BaP or TBT could result in induction of antioxidant defense system. A significant decrease of these indices, such as GSH, GST, GPx might indicate more severe contamination.

Combined effect of tributyltin and benzo[a] pyrene on the levels of sex hormone and vitellogenin in female Sebastiscus marmoratu

Tributyltin（TBT）, an organometal used as an antifouling biocide, has been reported to induce masculinization of fish. Benzo [a]pyrene （BaP）, a widespread carcinogenic polycyclic aromatic hydrocarbon, has been reported that its microsomal metabolites can produce an estrogenic response when tested in vitro. This study was therefore designed to examine the potential in vivo influence of TBT, BaP and their mixture on sex hormone levels in serum of Sebastiscus marmoratus, which were given 2 separate intraperitoneally （ip） injections（a single injection every 7 d） of TBT（0.5, 1, 5 and 10 mg/kg）, BaP（0.5, 1, 5 and 10 mg/kg）, or both in combination（0.5, 1, 5 and 10 mg/kg）; control fish received olive oil vehicle only. Six days after the 2nd injection, serum samples were collected and analyzed for sex hormone levels and alkali labile protein phosphorus （ALPP）, which is related to the yolk precursor protein vitellogenin. The pollutants at all doses significantly reduced serum testosterone, estradiol and ALPP content after 2 injections compared with the corresponding controls. The reduction of the estradiol levels should be response for the decrease of the vitellogenin levels. The results in the present study suggested that aromatase seems not the major target acted by TBT and BaP in fish. This study demonstrated that TBT or BaP exposure both inhibit the reproductive potential in female Sebastiscus marmoratus. Combined effect of TBT and BaP on the serum testosterone, estradiol and ALPP was not antagonism from the anticipation.

Effect of Tributyltin on Escherichia coli:Role of Modifying Factors

The effects of inorganic and organic tin compounds and various factors affecting the toxicity of the latter to Escherichia coli were studied.In comparison to stannous chloride,tributyltin chloride(TBTC)was more inhibitory to the growth of the test organism;this may be due to its greater liposolubility and ready absorption through the bacterial membrane.The toxicity of TBTC to E.coli was modulated by various factors,such as pH,sulfate and chloride ions,and the presence of glucose,succinate,and reducing agents like cysteine and dithiothreitol(DTT). TBTC was more toxic to cells in minimal than in complex media.Similarly,this compound was more inhibitory to the growth of E.coli at acid pH than at basic pH.Succinate in contrast to glucose,when used as a carbon source,made the bacterium more sensitive to TBTC.Cysteine and DTT(both at a final concentration of 0.5 mM)partially protected the cells against the inhibitory effect of this agent.1989 Academic Press,Inc.

Effects of tributyltin at environmental levels on monooxygenase system of digestive gland in hard clam Meretrix meretrix

The effects on ethoxyresorufin O-deethylase （EROD）, NADPH-cytochrome c reductase and NADH cytochrorne b5 reductase activities of digestive gland in Meretrix meretrix exposed to tributyltin （TBT） at environmental levels （0.1,1.0,10.0 ng/dm as stannum concentration）,in experimental condition, were evaluated. The EROD, NADH cytochrorne b5 reductase activities were significantly inhibited after exposure to 10.0 ng/dm^3 TBT for 8 and 20 d, the NADPH cytochrorne c reductase activities were significantly inhibited after exposure to 0.1,1.0 and 10.0 ng/dm TBT for 8 d and to 1.0 and 10.0 ng/dm for 20 d, as compared with the matched control, while NADH cytochrorne b5 reductases and NADPH cytochrome c reductase activities were induced after exposure to 10.0 ng/dm^3 TBT for 2 d. The EROD activity in the 10 ng/dm^3 group,and the NADH cytochrome b5 reductases activities in 1.0 and 10.0 ng/dm groups, were significantly induced when transferred to clean recovery tanks for 7 d. The three enzymic activities in the clams exposed to TBT were recovered to the level corresponding to that of the control group after transfer to clean recovery tanks for 20 d. NADPH cytochrome c reductase activity in Meretrix meretrix seems to be more sensitive to exposure of TBT than that of the EROD and NADH cytochrome b5 reductases. The results suggest that induction and inhibition by TBT to the monooxygenase system enzymic activity in Meretrix meretrix would simultaneously exist. The enzymic activities were inhibited by exposure for a long time. The results suggest that inhibition of the monooxygenase system should be an indication of the exposure to environmentally relevant concentrations of TBT for a long time.

Isolation and Biological Characterization of Tributyltin Degrading Bacterial from Onne Port Sediment

Marine sediments collected from Onne Port, Rivers State Nigeria were manually polluted with tributyltin chloride (TBTCl) to evaluate the abilities of bacterial isolates to degrade the pollutant. Bacterial isolates were screened with at varying concentrations of 3 mM, 5 mM, 7 mM, and 10 mM. Bacterial strains with outstanding capabilities of utilizing TBTCl were biochemically and molecularly characterized. The total bacterial counts varied from 42 × 102 to 64.4 × 102 cfu/g when plated on MSA only and the viable counts on MSA to 3 mM TBTCl and MSA + 5 mM TBTCl ranged from 22 × 101 to 38.5 × 102 cfu/g and 18 × 101 from 21.9 × 101 cfu/g respectively;however, the total viable count in MSA + 10 mM TBTCl ranged from 1.1 × 101 - 3.8 × 101 cfu/g. Statistically, total bacterial count varied significantly across the sample sites p < 0.05 (one-way ANOVA). The 2 isolates that showed distinctive growth in the presence of high concentration of TBTCl (10 mM) were molecularly identified as Pseudomonas aeruginosa, and Pseudomonas fluorescens. The 16 SrRNA sequence phylogenetic analysis using BLAST program showed that the isolates were proteobacteria. Since there are scanty works on the mechanisms of the degradation of organotin, it is then important that isolates that can tolerate organotin to a large extent can be used in the cleanup of organotin-contaminated site. Pseudomonas aeuroginosa and Pseudomonas fluorescens are candidates for the bioremediation of the contaminated site.

Effect of bis(tributyltin)oxide on reproduction and population growth rate of calanoid copepod Schmackeria poplesia

A full life-cycle toxicity test,combined with histology,on calanoid copepod Schmackeria poplesia was used to study the effect of bis(tributyltin)oxide(TBTO).The results indicate no sex-specific differences in TBTO toxicity.Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L-1were significantly elevated compared with that of control,and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L-1.The percentages of ovigerous females were reduced compared with the control(P<0.01)after 24 days exposure to concentrations higher than 10 ng TBTO L-1.Histological examinations suggest that exposure to TBTO might block the posterior end of the diverticula and inhibits the production of egg sacs.A modified Euler-Lotka equation was used to calculate a population-level endpoint,the intrinsic rate of natural increase(rm),from individual life-table endpoints,i.e.mortality rate,time of release of first brood,sex ratio,the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female.Apart from the highest TBTO concentration(60 ng L-1),where all females aborted their egg sacs,20 ng TBTO L-1was the only concentration that significantly decreased rm compared with that of control(an effect associated with decreased sex ratio).The results show that the S.poplesia is affected by prolonged exposure to low concentrations of TBTO.The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters.

Effects of tributyltin (TBT) on enzyme activity and oxidative stress in hepatopancreas and hemolymph of small abalone,Haliotis diversicolor supertexta

We investigated the effect of tributyltin (TBT) exposure on the concentration of malondialdehyde (MDA) and the activity levels of the superoxide dismutase (SOD),catalase (CAT),and acid and alkaline phosphatase (ACP and AKP) enzymes in the small abalone,Haliotis diversicolor supertexta.We collected samples of the hepatopancreas and hemolymph 2,6,24,48,96,and 192 h after exposure to 0.35 μg (Sn)/L TBT.In the hepatopancreas,ACP activity was significantly higher in animals exposed to TBT 2,24,and 96 h post-exposure compared with the control animals.AKP activity was also higher after 2 h,but SOD and CAT activity was unchanged.The concentration of MDA in the hemolymph was significantly higher than the control animals 2 and 6 h post-exposure.In the hemolymph of animals exposed to TBT,ACP activity was significantly lower than in the control animals 192 h post-exposure,whereas AKP activity was significantly lower 2 and 192 h post-exposure.Hemolymph SOD activity and levels of MDA were significantly lower than in the control animals 24 h after exposure but significantly higher after 96 h.Our results demonstrate that exposure to TBT cause rapid changes in ACP and AKP activity as well as altering the concentration of MDA in the hepatopancreas and hemolymph.SOD and CAT do not appear to be involved in the detoxification of TBT in the hepatopancreas of small abalone.

Tributyltin causes generational neurodevelopmental toxicity and the protective effect of folic acid in zebrafish

Tributyltin(TBT),a common organotin environmental pollutant,may pose a threat to human development during critical early-life periods.We aimed to assess the neurodevelopmental intergenerational toxicity of early-life exposure to TBT and the protective effect of DNA methyl donor folic acid(FA).Specifically,after early-life exposure(1–21 days postfertilization,dpf)to TBT(0,1,10 and 100 ng/L),zebrafish(Danio rerio)were cultured in clean medium until sexual maturity.The exposed females were mated with unexposed males to produce embryos(F1).The F1 generation were cultured(4–120 hours post-fertilization,hpf)with and without 1 mmol/L FA.The neurotoxic effects of early-life TBT exposure for zebrafish and their offspring(F1)were significantly enhanced anxiety and reduced aggression,decreased gene expression of DNA methyltransferase in the brain and increased serotonin levels in the body.Moreover,the intergenerational neurodevelopmental toxicity,as manifested in the F1 generation,was attenuated by FA supplementation.In summary,early-life TBT exposure led to intergenerational neurodevelopmental deficits in zebrafish,and DNA methyl donors had a protective effect on F1 neurodevelopment,which can inform the prevention and treatment of intergenerational neurotoxicity due to organotin pollutants.

Acute and chronic effects of tributyltin on the Chinese rare minnow(Gobiocypris rarus)

The acute (12 h) and chronic (7 or 14 d) effects of tributyltin chloride (TBT) on a new type of test fish, the Chinese rare minnow (Gobiocypris rarus), have been studied. High accumula-tion of the pollutant in the fish muscle and obvious changes in hepatosomatic index and gonad somatic index were observed after exposure. The ultrastructural findings show a series of patho-logical changes existing in the exposed gill cells and hepatocytes, which demonstrates the toxicity effects of tributyltin compounds on aquatic organisms. The results clearly show that the Chinese rare minnow is a new sensitive test fish material, whose exposure system is suitable for the exten-sive organometallic toxicity studies.

Histological observation on unique phenotypes of malformation induced in Xenopus tropicalis larvae by tributyltin

Tributyltin（TBT）,a biocide used in antifouling paints,has shown strong teratogenic effects on Xenopus tropicalis embryos at environmentally relevant concentrations.X.tropicalis embryos were exposed to 50,100 and 200 ng/L tributyltin chloride for 72 hr.The histological changes were further observed on abnormal eyes,enlarged trunks,enlarged proctodaeums and absence of fins induced by TBT.The lens and the retinal layers of abnormal eyes were slightly or barely differentiated,and that the pigment epithelium was neither continuous nor smooth.The abdomens were full of undifferentiated gut tissue with yolk-rich inclusions in the tadpoles with enlarged trunks.The proctodaeums formed a bump-like or columnar structure.The mass of yolk-rich cells occupied the lumen,blocked the opening and even turned inside out of the proctodaeum.Both the ventral and dorsal fins in trunks and tails became narrow or even disappeared totally.Our results suggest that great changes of histology took place corresponding to the unique phenotypes.The gut tissue was poorly differentiated,which led to the failed elongation of the guts and subsequently the enlarged trunks.The enlarged proctodaeums were due to the undifferentiation of inner layer,the expansion of outer epidermal part and the absence of fins around them.In brief,the histological observations provided insights into the reason of the unique external malformations in some degree.

液相色谱-串联三重四极杆质谱法测定船舶防腐涂料中三丁基氧化锡的含量

取混合均匀的样品1.00 g于比色管中,加入15 mL提取剂(水基型涂料采用甲醇;溶剂型涂料采用乙酸乙酯),于35℃超声提取15 min,将提取液离心5 min,取10 mL上层清液,氮吹至近干,用甲醇复溶并定容至2 mL,过0.45μm滤膜(水基型涂料采用尼龙滤膜;溶剂型涂料采用有机滤膜),采用液相色谱-串联三重四极杆质谱法测定滤液中三丁基氧化锡的含量。以EC-C_(18)色谱柱为固定相,以不同体积比的0.1%(体积分数)甲酸溶液和甲醇的混合液为流动相进行梯度洗脱。质谱分析中采用电喷雾正离子源和多反应监测模式,外标法定量。结果表明,三丁基氧化锡的质量浓度在0.1~2.0 mg·L^(-1)内与对应的峰面积呈线性关系,检出限为0.031 mg·kg^(-1)。按标准加入法进行回收试验,回收率为86.9%~92.9%,测定值的相对标准偏差(n=6)均小于4.0%。方法用于分析溶剂型涂料和水基型涂料各10个样品,其中溶剂型涂料中有2个样品检出三丁基氧化锡,检出量为1.18,0.82 mg·kg^(-1);水基型涂料中有1个样品检出三丁基氧化锡,检出量为0.48 mg·kg^(-1)。

Modulation of the DNA repair system and ATR-p53 mediated apoptosis is relevant for tributyltin-induced genotoxic effects in human hepatoma G2 cells

The toxic effects of tributyltin（TBT） have been extensively documented in several types of cells, but the molecular mechanisms related to the genotoxic effects of TBT have still not been fully elucidated. Our study showed that exposure of human hepatoma G2 cells to 1–4 μmol/L TBT for 3 hr caused severe DNA damage in a concentration-dependent manner. Moreover, the expression levels of key DNA damage sensor genes such as the replication factor C, proliferating cell nuclear antigen and poly（ADP-ribose）polymerase-1 were inhabited in a concentration-dependent manner. We further demonstrated that TBT induced cell apoptosis via the p53-mediated pathway, which was most likely activated by the ataxia telangiectasia mutated and rad-3 related（ATR）protein kinase. The results also showed that cytochrome c, caspase-3, caspase-8,caspase-9, and the B-cell lymphoma 2 were involved in this process. Taken together, we demonstrated for the first time that the inhibition of the DNA repair system might be more responsible for TBT-induced genotoxic effects in cells. Then the generated DNA damage induced by TBT initiated ATR-p53-mediated apoptosis.

Iodine Catalyzed Three-component Strecker-type Synthesis of α-Aminonitriles from Aldehydes, Amines and Tributyltin Cyanide

一个简单、有效的一个壶方法与高收益面对碘的催化数量从醛，胺和 tributyltin 氰化物为 -aminonitriles 的合成被开发了。反应经由很简单的过程在房间温度顺利继续了。

三丁基锡对文蛤鳃酸性磷酸酶、碱性磷酸酶和Na^+,K^+-ATP酶活性的影响

在实验生态条件下,观察浓度分别为0.1、1.0和10ng/L的三丁基锡(TBT)暴露2、8、20d以及恢复7d和20d后对文蛤鳃酸性磷酸酶(aaciphosphatase,ACP)、碱性磷酸酶(alkalinephosphatase,AKP)以及Na+,K+-ATPase活性的影响。结果显示在暴露早期TBT不影响ACP、AKP活性,暴露时间延长则主要表现出诱导作用。TBT具有抑制Na+、K+-ATPase活性作用,可观察效应浓度为0.1ng/L。Na+、K+-ATPase可作为一种潜在的有机锡污染监测的生物标志物。

三丁基锡暴露对褐菖鲉碱性磷酸酶活性的影响

研究了在实验室条件下,腹腔注射不同浓度(1.9、9.6、19.3、193μg/kg)的三丁基锡(tributyltin,TBT)对褐菖鲉肝脏、肾脏和脾脏碱性磷酸酶[alkalinephosphatase(AKP)]活性的影响.研究结果表明,在7d的曝污实验中,低剂量的TBT对碱性磷酸酶活性主要产生诱导作用,碱性磷酸酶活性随着TBT浓度的增大呈现先增大后减小的钟形曲线.这提示TBT暴露会影响褐菖鲉正常的代谢及其免疫功能.

三丁基锡对文蛤消化腺脂质过氧化及抗氧化酶活性的影响

在实验生态条件下,观察浓度分别为0.1、11、0 ng/L的三丁基锡(TBT)分别对文蛤暴露2、8、20 d以及恢复7 d和20 d后对文蛤消化腺过氧化氢酶(CAT)、超氧化物歧化酶(SOD)以及丙二醛(MDA)含量的影响.结果显示:TBT对CAT的作用为早期抑制而后没有影响,TBT对超氧化物歧化酶(SOD)以及脂质过氧化的产物丙二醛(MDA)的影响,在暴露后均为显著诱导作用.在恢复实验20 d后,各指标均恢复到对照组相当的水平.该研究结果为文蛤消化腺的SOD活性与MDA含量作为海洋环境有机锡污染监测的潜在生物标志物提供了依据.

三苯基锡和三丁基锡对大型蚤(Daphnia magna)的毒性作用研究

本研究测定了三苯基锡(TPT)和三丁基锡(TBT)对大型蚤(Daphnia magna)的急性毒性及慢性毒性,同时研究了环境因素(腐殖酸、硬度、酸度)对TPT和TBT的24h-EC_(50)的影响 结果表明,TPT和TBT对大型蚤的24h-EC_(50)分别为13.33μgSn·1^(-1)和3.91μgSn·1^(-1).慢性实验结果表明,TPT对大型蚤的生长繁殖有一定的抑制作用,各种环境因素对TPT和TBT的24h-EC_(50)有很大影响.

TBT对大鼠肝脏ROS、抗氧化酶和解毒系统酶的影响

研究了三丁基锡(TBT)对大鼠肝脏ROS、抗氧化酶和解毒系统酶的影响.SD大鼠随机分为6组,TBT染毒剂量各组分别为,0,0.1,0.3,1.0,3.0,10.0mg/kg(B?W),连续灌胃7d,第8d处死,取肝脏检测活性氧(ROS)水平、谷胱甘肽转硫酶(GST)活性、过氧化氢酶(CAT)活性、谷胱甘肽还原酶(GR)活性和谷胱甘肽(GSH)含量.结果表明,ROS随TBT浓度增加而升高,各浓度组均有显著性差异.在0.3,1.0mg/kg时,GST活性升高且具有显著性差异,在3.0,10.0mg/kg有下降趋势;GR活性也升高且具有显著性差异.CAT活性及GSH含量在各浓度组均无明显变化.研究结果提示,染毒各组ROS水平明显升高,而与ROS去除有直接关系的GSH水平和CAT活性没有发生相关的变化,因此TBT在代谢转化过程中产生的自由基不能及时被清除可能是导致ROS水平明显升高的重要原因.

河口水及藻类对三丁基锡的降解作用

研究了海河河口水在不同条件下对三丁基锡（ＴＢＴ）的降解作用。不同条件下ＴＢＴ的降解半衰期为５．７天～８４．５天。提高温度、光照和加入营养盐和腐殖酸均加快ＴＢＴ的降解，说明ＴＢＴ的降解与生物作用有关。为此，进一步研究了两种藻——淡水斜生栅藻（Ｓｃｅｎｅｄｅｓｍｕｓｏｂｌｉｑｕｕｓ）和生于河口地区的扁藻（Ｐｌａｔｙｍｏｎａｓｓｐ．）及藻液中细菌群落对ＴＢＴ的降解作用。结果表明，光降解是微乎其微的。细菌群落对ＴＢＴ有一定的降解作用，栅藻、扁藻中的细菌群落对ＴＢＴ降解半衰期分别为５４．３天和２０．２天。藻类对ＴＢＴ的降解速度比细菌快很多，是ＴＢＴ降解的主要因素，栅藻、扁藻对ＴＢＴ降解半衰期分别为５．２天和１．７天。