Benzo[a]pyrene(B[a]P)is a food contaminant toxic for cardiovascular diseases.The nuclear translocation of Arylhydrocarbon receptor(AhR)plays an important role in B[a]P-induced oxidative stress and vascular diseases.We...Benzo[a]pyrene(B[a]P)is a food contaminant toxic for cardiovascular diseases.The nuclear translocation of Arylhydrocarbon receptor(AhR)plays an important role in B[a]P-induced oxidative stress and vascular diseases.We confi rmed that B[a]P promoted ROS production in vascular smooth muscle cells(VSMCs)in vitro and in vivo,associated with the nuclear translocation of AhR.It is known that phosphorylation inhibits while dephosphorylation of AhR promotes nuclear translocation of AhR.However,from the posttranslational modifi cation level,the mechanism by which B[a]P activates and regulates the nuclear translocation of AhR is unclear.Co-immunoprecipitation results showed that cytoplasmic AhR was phosphorylated before B[a]P stimulation,and switched to O-GlcNAcylation upon B[a]P 1-h stimulation in VSMCs,suggesting there may be a competitively inhibitory relationship between O-GlcNAcylation and phosphorylation of AhR.Next,siRNAs of O-linked N-acetylglucosamine transferase(OGT),O-GlcNAcase(OGA)and OGA inhibitor PUGNAc were used.SiOGT blocks but siOGA and PUGNAc promote B[a]P-dependent AhR nuclear translocation and oxidative stress.Ser11 may be the competitive binding site for phosphorylation and O-GlcNAcylation of AhR.Phosphorylation-mimic variant inhibits but O-GlcNAcylation of AhR promotes AhR nuclear translocation and oxidative stress.Our fi ndings highlight a new perspective for AhR nuclear translocation regulated by the competitive modifi cation between phosphorylation and O-GlcNAcylation.展开更多
A bacterial strain BAP5 with a relatively high degradation ability of benzo[a]pyrene (BaP) was isolated from marine sediments of Xiamen Western Sea, China and identified as Ochrobactrum sp. according to 16S rRNA gene ...A bacterial strain BAP5 with a relatively high degradation ability of benzo[a]pyrene (BaP) was isolated from marine sediments of Xiamen Western Sea, China and identified as Ochrobactrum sp. according to 16S rRNA gene sequence as well as Biolog microbial identification system. Strain BAP5 could grow in mineral salt medium with 50 mg/L of BaP and degrade about 20% BaP after 30 d of incubation. Ochrobactrum sp. BAP5 was able to utilize other polycyclic aromatic hydrocarbons (PAHs) (such as phenanthrene, pyrene and fluoranthene) as the sole carbon source and energy source, suggesting its potential application in PAHs bioremediation. The profile of total soluble protein from Ochrobactrum sp. BAP5 was also investigated. Some over- and special-expressed proteins of strain BAP5 when incubated with the presence of BaP were detected by two-dimensional polyacrylamide gel electrophoresis, and found to be related with PAHs metabolism, DNA translation, and energy production based on peptide fingerprint analysis through matrix-assisted laser desorption/ionization-time of flight mass spectrometry.展开更多
AIM To study the inhibitory effects of VES( RRR-α-tocopheryl Succinate, VES ), aderivative of natural Vitamin E, on benzo (a)pyrene (B (a) P)-induced forestomach tumor infemale mice.METHODS The model of B (a)P-induce...AIM To study the inhibitory effects of VES( RRR-α-tocopheryl Succinate, VES ), aderivative of natural Vitamin E, on benzo (a)pyrene (B (a) P)-induced forestomach tumor infemale mice.METHODS The model of B (a)P-inducedforestomach tumor was established according tothe methods of Wattenberg with slightmodifications. One hundred and eighty femalemice (6 weeks old) were divided into six groupsequally; negative control (Succinic acid),vehicle control ( Succinate + B (a) P), positivecontrol(B(a) P), high VES(2.5g/kg. b. w + B(a)P), Iow VES(1 .25 g/kg. b. w + B(a) P) ig as wellas VES by ip (20 mg/kg, b. w + B(a) P). Exceptthe negative control group, the mice wereadministrated with B(a)P ig. and correspondingtreatments for 4 weeks to study the anti-carcinogenetic effect of VES during the initiationperiod. The experiment lasted 29 weeks, inwhich the inhibitory effects of VES both ontumor incidence and tumor size were tested.RESULTS The models of B (a)P-inducedforestomach tumor in female mice wereestablished successfully. Some werecauliflower-like, others looked like papilla, evena few were formed into the ulcer cavities. VES at1.25 g/kg. b. w, 2.5 g/kg. b.w. by ig and 20 mg/kg. b. w. via ip could decrease the number oftumors per mouse (1.7 ± 0. 41, 1.6 ± 0.34 and 1.1±0.43), being lower than that of B(a)P group(5.4 ± 0.32, P＜0.05). The tumor incidence wasinhibited by 18.2%, 23.1% and 50.0%. VES at1.25g/kg.b.w., 2.5 g/ kg.b.w. by ig and20 mg/kg. b.w. via ip reduced the total volumeof tumors per mouse (54.8 ± 8.84, 28.4 ± 8.32and 23.9± 16.05), being significantly lower thanthat of B(a)P group (150.2±20.93, P＜0.01).The inhibitory rates were 63.5%, 81.1% and84.1%, respectively.CONCLUSION VES has inhibitory effects on B(a) P-induced forestomach carcinogenesis infemale mice, especially by ip and it may be apotential anti-cancer agent in vivo.展开更多
The rates of photodegradation and photocatalysis of benzo[a]pyrene (BaP) on soil surfaces under UV light have been stu- died. Different parameters such as temperature, soil particle sizes, and soil depth responsible f...The rates of photodegradation and photocatalysis of benzo[a]pyrene (BaP) on soil surfaces under UV light have been stu- died. Different parameters such as temperature, soil particle sizes, and soil depth responsible for photodegradation, catalyst loads and wavelength of UV irradiation blamed for photocatalysis have been monitored. The results obtained indicated that BaP photodegradation follows pseudo-first-order kinetics. BaP photodegradation was the fastest at 30℃. The rates of BaP photo- degradation at different soil particle size followed the order: less than 1 mm>less than 0.45 mm>less than 0.25 mm. When the soil depth increased from 1 mm to 4 mm, the half-life increased from 13.23 d to 17.73 d. The additions of TiO2 or Fe2O3 accelerated the photodegradation of BaP, and the photocatalysis of BaP follows pseudo-first-order kinetics. Changes in catalyst loads of TiO2 (0.5%, 1%, 2%, and 3% (wt)) or Fe2O3 (2%, 5%, 7%, and 10% (wt)) did not significantly affect the degradation rates. Both BaP photocatalysis in the presence of TiO2 and Fe2O3 were the fastest at 254 nm UV irradiation.展开更多
Objective Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, is a potent procarcinogen and mutagen that can elicit tumors, leading to malignancy. Heat shock proteins (Hsp) have been shown to protect cells a...Objective Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, is a potent procarcinogen and mutagen that can elicit tumors, leading to malignancy. Heat shock proteins (Hsp) have been shown to protect cells against damages caused by various stresses including exposure to numerous chemicals. Whether Hsps, or more specifically Hsp70, are involved in repair of B[a]P-induced DNA damage is currently unknown. Methods We assessed the potential role of the inducible form of Hsp70 in B[a]P-induced DNA damage of human embryonic lung (HEL) cells using immunoblot and the comet assay (i.e., the single cell gel electrophoresis assay). Results Exposure to B[a]P induced a dose-dependent decrease in the level of Hsp70, but a dose-dependent increase in DNA damage both in untreated (control) HEL cells and in cells preconditioned by a heat treatment. Heat preconditioning prior to B[a]P exposure potentiated the effect of B[a]P at a low dose (10 (mol/L), but appeared to be protective at higher doses. There was a negative correlation between Hsp70 level and DNA damage in the non-preheated as well as in the preconditioned cells. Conclusion These data suggest that exposure of HEL cells to B[a]P may induce a dose-dependent reduction in the levels of the inducible Hsp70. The detailed mechanisms for the reduction of Hsp70 levels by B[a]P and the role of Hsp70 in DNA damage under different concentrations of B[a]P remains to be determined.展开更多
Two indigenous microorganisms, Bacillus sp. SB02 and Mucor sp. SF06, capable of degrading polycyclic aromatic hydrocarbons (PAHs) were co-immobilized on vermiculite by physical adsorption and used to degrade benzo[a] ...Two indigenous microorganisms, Bacillus sp. SB02 and Mucor sp. SF06, capable of degrading polycyclic aromatic hydrocarbons (PAHs) were co-immobilized on vermiculite by physical adsorption and used to degrade benzo[a] pyrene (BaP). The characteristics of BaP degradation by both free and co-immobilized microorganism were then investigated and compared. The removal rate using the immobilized bacterial-fungal mixed consortium was higher than that of the freely mobile mixed consortium. 95.3% of BaP was degraded using the co-immobilized system within 42 d, which was remarkably higher than the removal rate of that by the free strains. The optimal amount of inoculated co-immobilized system for BaP degradation was 2%. The immobilized bacterial-fungal mixed consortium also showed better water stability than the free strains. Kinetics of BaP biodegradation by co-immobilized SF06 and SB02 were also studied. The results demonstrated that BaP degradation could be well described by a zero-order reaction rate equation when the initial BaP concentration was in the range of 10—200 mg/kg. The scanning electronic microscope (SEM) analysis showed that the co-immobilized microstructure was suitable for the growth of SF06 and SB02. The mass transmission process of co-immobilized system in soil is discussed. The results demonstrate the potential for employing the bacterial-fungal mixed consortium, co-immobilized on vermiculite, for in situ bioremediation of BaP.展开更多
Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was...Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment.展开更多
The objective of this study was to examine the effect of benzo[a]pyrene(Ba P) on the detoxification and antioxidant systems of two microalgae,Isochrysis zhanjiangensis and Platymonas subcordiformis.In our study,these ...The objective of this study was to examine the effect of benzo[a]pyrene(Ba P) on the detoxification and antioxidant systems of two microalgae,Isochrysis zhanjiangensis and Platymonas subcordiformis.In our study,these two algae were exposed to Ba P for 4 days at three different concentrations including 0.5 μg^(L-1)(low),3 μg^(L-1)(mid) and 18 μg^(L-1)(high).The activity of detoxification enzymes,ethoxyresorufin O-deethylase(EROD) and glutathione S-transferase(GST) increased in P.subcordiformis in all Ba P-treated groups.In I.zhanjiangensis,the activity of these two enzymes increased at the beginning of exposure,and then decreased in the groups treated with mid-and high Ba P.The activity of antioxidant enzyme superoxide dismutase(SOD) increased in I.zhanjiangensis in all Ba P-treated groups,and then decreased in high Ba P-treated group,while no significant change was observed in P.subcordiformis.The activity of antioxidant enzyme catalase(CAT) increased in I.zhanjiangensis and P.subcordiformis in all Ba Ptreated groups.The content of malondialdehyde(MDA) in Isochrysis zhanjiangensis increased first,and then decreased in high Ba P-treated group,while no change occurred in P.subcordiformis.These results demonstrated that Ba P significantly influenced the activity of detoxifying and antioxidant enzymes in microalgae.The metabolic related enzymes(EROD,GST and CAT) may serve as sensitive biomarkers of measuring the contamination level of Ba P in marine water.展开更多
The effects on hepatic EROD (7-ethoxyresorufin O-deethylase) in Mugil so-iuy exposed to benzo(a)pyrene (BaP), pyrene and their mixtures of equal concentration were investigated, at concentrations of 0.1, 1.0, 5.0, 10....The effects on hepatic EROD (7-ethoxyresorufin O-deethylase) in Mugil so-iuy exposed to benzo(a)pyrene (BaP), pyrene and their mixtures of equal concentration were investigated, at concentrations of 0.1, 1.0, 5.0, 10.0, 50.0 μg/dm3, in experimental condition. Time-effects and doseresponse of the biochemical indexs were observed. The results showed that the hepatic EROD activities were induced by the exposure of BaP, pyrene and their mixtures at high concentration. Dose-response connections were that the hepatic EROD activities were elevated with increasing concentration of the pollutants. The combined effect of BaP and pyrene at 1:1 concentration ratio on hepatic EROD activity was antagonism.展开更多
Tributyltin(TBT), an organometal used as an antifouling biocide, has b een reported to induce masculinization of fish. Benzo[a]pyrene(BaP), a widesprea d carcinogenic polycyclic aromatic hydrocarbon, has been reported...Tributyltin(TBT), an organometal used as an antifouling biocide, has b een reported to induce masculinization of fish. Benzo[a]pyrene(BaP), a widesprea d carcinogenic polycyclic aromatic hydrocarbon, has been reported that its micro somal 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 analyz ed for sex hormone levels and alkali labile protein phosphorus(ALPP), which is r elated to the yolk precursor protein vitellogenin. The pollutants at all doses s ignificantly reduced serum testosterone, estradiol and ALPP content after 2 inje ctions compared with the corresponding controls. The reduction of the estradiol levels should be response for the decrease of the vitellogenin levels. The resul ts in the present study suggested that aromatase seems not the major target acte d by TBT and BaP in fish. This study demonstrated that TBT or BaP exposure both inhibit the reproductive potential in female Sebastiscus marmoratus. Combined ef fect of TBT and BaP on the serum testosterone, estradiol and ALPP was not antago nism from the anticipation.展开更多
Objective The present study aimed to test whether exposure to benzo(a)pyrene [B(a)P] affects spatial learning and short-term memory by modulating the expression of the Gria1 and Grin2a glutamate receptor subunit genes...Objective The present study aimed to test whether exposure to benzo(a)pyrene [B(a)P] affects spatial learning and short-term memory by modulating the expression of the Gria1 and Grin2a glutamate receptor subunit genes in the hippocampus.Methods Thirty-six 21-24-day-old,male rats were randomly assigned into high-,medium-,and low-dose toxin exposure groups (6.25,2.5,and 1 mg/kg,respectively) and a control group,each containing nine rats.The behavioral performance of adult rats exposed to sub-chronic administration of B(a)P was monitored by learning and memory tests (Morris water maze).Real-time PCR assays were used to quantify Gria1 and Grin2a gene expression in the hippocampus.Results At medium and high doses,B(a)P impaired spatial learning performance.The crossing-platform-location frequency and the time spent swimming in the platform area,which both relate to short-term memory,were significantly decreased in B(a)P-treated rats compared with controls.The level of Gria1 mRNA increased 2.6-5.9-fold,and the level of Grin2a mRNA increased 10-14.5-fold,with a greater fold increase associated with higher doses of B(a)P.Conclusion We demonstrated that sub-chronic administration of B(a)P inhibits spatial learning and short-term memory,and increases Gria1 and Grin2a expression in the hippocampus.This suggests a relationship of B(a)P exposure levels with Gria1 and Grin2a expression and impairment of short-term and spatial memory.展开更多
In order to investigate the mechanism of benzo[a]pyrene uptake by a filamentous fungus Fusarium solani, a biochemical characterization of its concentrated culture filtrate has been conducted. The preparation contained...In order to investigate the mechanism of benzo[a]pyrene uptake by a filamentous fungus Fusarium solani, a biochemical characterization of its concentrated culture filtrate has been conducted. The preparation contained approximately (w/w): 50% of total carbohydrate, 6.5% of uronic acid and 6% protein, as determined by colorimetric tests. Gel filtration and anion-exchange chromatographic profiles indicated that the main product of the culture filtrate was a glycoprotein, which contained mannose, glucose and galactose in an approximate molar ratio of 1.5: 0.8: 1. The polysaccharide fraction of the culture filtrate was prepared by treatment with proteinase K, followed by gel-filtration chromatography. Its chemical structure was studied by methylation analysis, gas-liquid chromatography-mass spectrometry (GC-MS) and Nuclear Magnetic Resonance spectroscopy (NMR). The major carbohydrate was a polymer of β-(1 → 6)-linked galactofuranose units fully branched at positions O-2 by single residues of α-glucopyranose. The Fusarium concentrated culture filtrate increased 4-fold the BaP solubilization in comparison with its aqueous solubility and suggested that the carbohydrate present in this filtrate should probably be involved in this enhancement. Our findings point out the potential role of fungal glycoproteins in PAH microbial bioavaibility, an important step for PAH biodegradation.展开更多
Objective To investigate the roles of the cyclin D1/CDK4 and E2F-1/4 pathways and compare their work patterns in cell cycle changes induced by different doses of B[a]P. Methods Human embryo lung fibroblasts (HELFs) we...Objective To investigate the roles of the cyclin D1/CDK4 and E2F-1/4 pathways and compare their work patterns in cell cycle changes induced by different doses of B[a]P. Methods Human embryo lung fibroblasts (HELFs) were treated with 2 μmol/L or 100 μmol/L B[a]P which were provided with some characteristics of transformed cells (T-HELFs). Cyclin D1, CDK4 and E2F-1/4 expressions were determined by Western blotting. Flow cytometry was used to detect the distribution of cell cycle. Results After B[a]P treatment, the proportion of the first gap (G1) phase cells decreased. CDK4 and E2F-4 expression did not change significantly. In 2 μmol/L treated cells, a marked overexpression of cyclin D1 and E2F-1 was observed. However, in T-HELFs overexpression was limited to cyclin D1 only, and no overexpression of E2F-1 was observed. The decreases of G1 phase in response to B[a]P treatment were blocked in antisense cyclin D1 and antisense CDK4 transfected HELFs (A-D1 and A-K4) and T-HELFs (T-A-D1 and T-A-K4). After 2 μmol/L B[a]P treatment, overexpression of E2F-1 was attenuated in A-D1, and E2F-4 expression was decreased significantly in A-K4. In T-A-D1 and T-A-K4, E2F-4 expression was increased significantly, compared with T-HELFs. The E2F-1 expression remained unchanged in T-A-D1 and T-A-K4. Conclusions Cyclin D1/CDK4-E2F-1/4 pathways work in different patterns in response to low dose and high dose B[a]P treatment. In HELFs treated with 2 μmol/L B[a]P, cyclin D1 positively regulates the E2F-1 expression while CDK4 negatively regulates the E2F-4 expression; however, in HELFs treated with 100 μmol/L B[a]P, both cyclin D1 and CDK4 negatively regulate the E2F-4 expression.展开更多
The toxic effects of benzo[α]pyrene (B[α]P) at different concentrations (0.1, 0.5, 1, 2.5 and 7.5 μgL-1) on scallop (Chlamys farreri) immune system were studied. The results showed that B[α]P had significant toxic...The toxic effects of benzo[α]pyrene (B[α]P) at different concentrations (0.1, 0.5, 1, 2.5 and 7.5 μgL-1) on scallop (Chlamys farreri) immune system were studied. The results showed that B[α]P had significant toxic effects on the haemocyte counts, neutral red uptake, phagocytosis, bacteriolytic and antibacterial activity (P<0.05), while the seawater control and acetone control had no significant differences. The haemocyte counts, neutral red uptake, phagocytosis and bacteriolytic activity in all B[α]P treatment groups as well as antibacterial activity in groups of 0.5, 1, 2.5 and 7.5 μgL-1 B[α]P decreased significantly (P<0.05). Some of these indices tended to be stable on the sixth day and others on the ninth day, and the indices showed clear time-and concentra- tion-response to B[α]P. Bacteriolytic activity in 0.1μgL-1 B[α]P treatment group and antibacterial activity in 0.1 μgL-1 and 0.5 μgL-1 B[α]P treatment groups increased at the beginning of exposure and reached their peaks on day 1 and day 6, respectively. Following that, both activities decreased gradually and became stable after day 9. When all the indices reached stability, they were significantly lower than those in control group (P<0.05), except for antibacterial activity in 0.1 μgL-1 B[α]P treatment group (P>0.05). Thus, B[α]P has evident toxic effects on scallop immune system, which supports the view that a relationship exists between pollution and immunomodulation in aquatic organisms.展开更多
In this study, the RNA sequencing was used to describe the response of Nannochloropsis oceanica, a marine microalga, to benzo[a]pyrene(BaP), a polycyclic aromatic hydrocarbon, in order to elucidate the metabolic pathw...In this study, the RNA sequencing was used to describe the response of Nannochloropsis oceanica, a marine microalga, to benzo[a]pyrene(BaP), a polycyclic aromatic hydrocarbon, in order to elucidate the metabolic pathways(or processes) involved in microalgal response to this stubborn pollutant. N. oceanica was exposed to BaP at a concentration of 90 μg L^-1 for 72 h, and its transcriptome was sequenced through the Illumina HiSeq^TM 2500 platform. This concentration of BaP was selected as it is the lowest for modeling the most appropriate growth inhibition of N. oceanica for transcriptomic analysis. We found that N. oceanica responds to BaP through degrading proteins and repairing DNA damaged by BaP. In addition, superoxide dismutase(SOD) strengthened its performance by increasing its transcript abundance. The physiological mechanism underlining the response of N. oceanica to BaP as revealed by transcriptomic analysis was consistent with the biochemical insights documented previously.展开更多
Rapid amplification of cDNA ends (RACE) and real-time polymerase chain reaction (RT-PCR) were carried out to analyze the CYP4 gene expression in polychaete Marphysa sanguinea exposed to benzo[a]pyrene (BaP) in this st...Rapid amplification of cDNA ends (RACE) and real-time polymerase chain reaction (RT-PCR) were carried out to analyze the CYP4 gene expression in polychaete Marphysa sanguinea exposed to benzo[a]pyrene (BaP) in this study. The full length of MsCYP4 cDNA was 2 470 bp, and it encoded 512 amino acids. The deduced amino acid sequence showed 47% identity with CYP4F from frog Xenopus tropicalis and shared high homology with other known CYP4 sequences. To analyse the role of CYP4 in protecting M. sanguinea from BaP exposure, three BaP groups were established: 0.5, 5 and 50 μg/L. Polychaetes were sampled after 3, 7 and 12 d. At 0.5 μg/L, the effect of BaP on MsCYP4 gene expression increased with time prolonged. MsCYP4 gene expression curve showed Ushaped trend with time in 5 and 50 μg/L BaP groups. Therefore, MsCYP4 gene may play an important role in maintaining the balance of cellular metabolism and protecting M. sanguinea from BaP toxicity.展开更多
The ability of Stenotrophomonas maltophilia was demonstrated to selectively remove Cu2+from Cu(NO3)2 solution under the circumstance that 1 mg/L benzo[a]pyrene(BaP) was either present or not. The removal ratios of 2 a...The ability of Stenotrophomonas maltophilia was demonstrated to selectively remove Cu2+from Cu(NO3)2 solution under the circumstance that 1 mg/L benzo[a]pyrene(BaP) was either present or not. The removal ratios of 2 and 10 mg/L Cu2+by 0.25 g/L biosorbent are up to 80% and 49% at 10 min, respectively. The biosorption includes ion exchange, NO3 reduction, ion release, and cell oxidation by Cu2+. BaP does not significantly affect Cu2+removal and ion release. Although 2 mg/L Cu2+increases the release of PO4 3, K+, NH4 +and Ca2+, 10 mg/L Cu2+has strong oxidation on cell, and then decreases NO3 reduction and hinders the release of K+, NH4 +and Ca2+. Exogenous cations inhibit the Cu2+biosorption, while additional anions increase the removal ratios of 10 mg/L Cu2+from 52% to 88%.展开更多
The concentrations of reduced glutathione(GSH) in liver and ovary of Boleophthalmus pectinirostris are quantified. The concentrations of GSH in the ovary are much higher than that of GSH in the liver(nearly 3 times of...The concentrations of reduced glutathione(GSH) in liver and ovary of Boleophthalmus pectinirostris are quantified. The concentrations of GSH in the ovary are much higher than that of GSH in the liver(nearly 3 times of the liver). The study also investigates the changes of GSH contents in the two organs while the fishes were exposed to benzo(a)pyrene(BaP) at concentrations of 0, 0.05, 0.2 and 0.5 mg/L respectively for up to a week. The concentrations of GSH in the liver of BaP exposed fish increased significantly with dose, whereas the concentrations of GSH in the ovary decreased significantly compared to controls. The results suggested that both the liver and the ovary are the primary organ in BaP metabolism, and that the changes of GSH levels may represent an adaptive response or toxic effect to BaP exposure.展开更多
基金supported by the National Key Research Project of China(2022YFF1100300)National Natural Science Foundation of China(32272328)+5 种基金Natural Science Foundation of Hebei Province(B2022321001)Major Public Welfare Projects in Henan Province(201300110200)National Key Research Project of Hebei Province(20375502D)National Key Research Project of Hebei Province(H2021206427)University Science and Technology Research Project of Hebei Province(QN2017107)Postdoctoral Research Funds of Hebei Medical University(307050100163759).
文摘Benzo[a]pyrene(B[a]P)is a food contaminant toxic for cardiovascular diseases.The nuclear translocation of Arylhydrocarbon receptor(AhR)plays an important role in B[a]P-induced oxidative stress and vascular diseases.We confi rmed that B[a]P promoted ROS production in vascular smooth muscle cells(VSMCs)in vitro and in vivo,associated with the nuclear translocation of AhR.It is known that phosphorylation inhibits while dephosphorylation of AhR promotes nuclear translocation of AhR.However,from the posttranslational modifi cation level,the mechanism by which B[a]P activates and regulates the nuclear translocation of AhR is unclear.Co-immunoprecipitation results showed that cytoplasmic AhR was phosphorylated before B[a]P stimulation,and switched to O-GlcNAcylation upon B[a]P 1-h stimulation in VSMCs,suggesting there may be a competitively inhibitory relationship between O-GlcNAcylation and phosphorylation of AhR.Next,siRNAs of O-linked N-acetylglucosamine transferase(OGT),O-GlcNAcase(OGA)and OGA inhibitor PUGNAc were used.SiOGT blocks but siOGA and PUGNAc promote B[a]P-dependent AhR nuclear translocation and oxidative stress.Ser11 may be the competitive binding site for phosphorylation and O-GlcNAcylation of AhR.Phosphorylation-mimic variant inhibits but O-GlcNAcylation of AhR promotes AhR nuclear translocation and oxidative stress.Our fi ndings highlight a new perspective for AhR nuclear translocation regulated by the competitive modifi cation between phosphorylation and O-GlcNAcylation.
基金supported by the National Natural Sci-ence Foundation of China (No 40206015, 30970106)the Fork Ying Tong Education Foundation (No 94002) the Science and Technology Project of Guangdong Province,China (No 2006A36502001, 2007A032600003)
文摘A bacterial strain BAP5 with a relatively high degradation ability of benzo[a]pyrene (BaP) was isolated from marine sediments of Xiamen Western Sea, China and identified as Ochrobactrum sp. according to 16S rRNA gene sequence as well as Biolog microbial identification system. Strain BAP5 could grow in mineral salt medium with 50 mg/L of BaP and degrade about 20% BaP after 30 d of incubation. Ochrobactrum sp. BAP5 was able to utilize other polycyclic aromatic hydrocarbons (PAHs) (such as phenanthrene, pyrene and fluoranthene) as the sole carbon source and energy source, suggesting its potential application in PAHs bioremediation. The profile of total soluble protein from Ochrobactrum sp. BAP5 was also investigated. Some over- and special-expressed proteins of strain BAP5 when incubated with the presence of BaP were detected by two-dimensional polyacrylamide gel electrophoresis, and found to be related with PAHs metabolism, DNA translation, and energy production based on peptide fingerprint analysis through matrix-assisted laser desorption/ionization-time of flight mass spectrometry.
基金Project Supported by National Natural Science Foundation of China, No. 39870662
文摘AIM To study the inhibitory effects of VES( RRR-α-tocopheryl Succinate, VES ), aderivative of natural Vitamin E, on benzo (a)pyrene (B (a) P)-induced forestomach tumor infemale mice.METHODS The model of B (a)P-inducedforestomach tumor was established according tothe methods of Wattenberg with slightmodifications. One hundred and eighty femalemice (6 weeks old) were divided into six groupsequally; negative control (Succinic acid),vehicle control ( Succinate + B (a) P), positivecontrol(B(a) P), high VES(2.5g/kg. b. w + B(a)P), Iow VES(1 .25 g/kg. b. w + B(a) P) ig as wellas VES by ip (20 mg/kg, b. w + B(a) P). Exceptthe negative control group, the mice wereadministrated with B(a)P ig. and correspondingtreatments for 4 weeks to study the anti-carcinogenetic effect of VES during the initiationperiod. The experiment lasted 29 weeks, inwhich the inhibitory effects of VES both ontumor incidence and tumor size were tested.RESULTS The models of B (a)P-inducedforestomach tumor in female mice wereestablished successfully. Some werecauliflower-like, others looked like papilla, evena few were formed into the ulcer cavities. VES at1.25 g/kg. b. w, 2.5 g/kg. b.w. by ig and 20 mg/kg. b. w. via ip could decrease the number oftumors per mouse (1.7 ± 0. 41, 1.6 ± 0.34 and 1.1±0.43), being lower than that of B(a)P group(5.4 ± 0.32, P＜0.05). The tumor incidence wasinhibited by 18.2%, 23.1% and 50.0%. VES at1.25g/kg.b.w., 2.5 g/ kg.b.w. by ig and20 mg/kg. b.w. via ip reduced the total volumeof tumors per mouse (54.8 ± 8.84, 28.4 ± 8.32and 23.9± 16.05), being significantly lower thanthat of B(a)P group (150.2±20.93, P＜0.01).The inhibitory rates were 63.5%, 81.1% and84.1%, respectively.CONCLUSION VES has inhibitory effects on B(a) P-induced forestomach carcinogenesis infemale mice, especially by ip and it may be apotential anti-cancer agent in vivo.
基金The National Basic Research Program (973) of China (No. 2004CB418506)the National Natural Science Foundation of China (No.20337010) the Hi-Tech Research and Development Program (863) of China (No. 2004AA649060)
文摘The rates of photodegradation and photocatalysis of benzo[a]pyrene (BaP) on soil surfaces under UV light have been stu- died. Different parameters such as temperature, soil particle sizes, and soil depth responsible for photodegradation, catalyst loads and wavelength of UV irradiation blamed for photocatalysis have been monitored. The results obtained indicated that BaP photodegradation follows pseudo-first-order kinetics. BaP photodegradation was the fastest at 30℃. The rates of BaP photo- degradation at different soil particle size followed the order: less than 1 mm>less than 0.45 mm>less than 0.25 mm. When the soil depth increased from 1 mm to 4 mm, the half-life increased from 13.23 d to 17.73 d. The additions of TiO2 or Fe2O3 accelerated the photodegradation of BaP, and the photocatalysis of BaP follows pseudo-first-order kinetics. Changes in catalyst loads of TiO2 (0.5%, 1%, 2%, and 3% (wt)) or Fe2O3 (2%, 5%, 7%, and 10% (wt)) did not significantly affect the degradation rates. Both BaP photocatalysis in the presence of TiO2 and Fe2O3 were the fastest at 254 nm UV irradiation.
基金This work was supported by grants from the National Natural Science Foundation of China (NNSFC) and the National Key Basic Research and Development Program to WT (2002 CB512905) by a collaborative exchange grant between the NNSFC and the CIHR of Canad
文摘Objective Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, is a potent procarcinogen and mutagen that can elicit tumors, leading to malignancy. Heat shock proteins (Hsp) have been shown to protect cells against damages caused by various stresses including exposure to numerous chemicals. Whether Hsps, or more specifically Hsp70, are involved in repair of B[a]P-induced DNA damage is currently unknown. Methods We assessed the potential role of the inducible form of Hsp70 in B[a]P-induced DNA damage of human embryonic lung (HEL) cells using immunoblot and the comet assay (i.e., the single cell gel electrophoresis assay). Results Exposure to B[a]P induced a dose-dependent decrease in the level of Hsp70, but a dose-dependent increase in DNA damage both in untreated (control) HEL cells and in cells preconditioned by a heat treatment. Heat preconditioning prior to B[a]P exposure potentiated the effect of B[a]P at a low dose (10 (mol/L), but appeared to be protective at higher doses. There was a negative correlation between Hsp70 level and DNA damage in the non-preheated as well as in the preconditioned cells. Conclusion These data suggest that exposure of HEL cells to B[a]P may induce a dose-dependent reduction in the levels of the inducible Hsp70. The detailed mechanisms for the reduction of Hsp70 levels by B[a]P and the role of Hsp70 in DNA damage under different concentrations of B[a]P remains to be determined.
基金The National Basic Research Program (973) of China (No. 2004CB418506)the National Natural Science Foundation of China (No.20337010) the Hi-Tech Research and Development Program (863) of China (No. 2004AA649060)
文摘Two indigenous microorganisms, Bacillus sp. SB02 and Mucor sp. SF06, capable of degrading polycyclic aromatic hydrocarbons (PAHs) were co-immobilized on vermiculite by physical adsorption and used to degrade benzo[a] pyrene (BaP). The characteristics of BaP degradation by both free and co-immobilized microorganism were then investigated and compared. The removal rate using the immobilized bacterial-fungal mixed consortium was higher than that of the freely mobile mixed consortium. 95.3% of BaP was degraded using the co-immobilized system within 42 d, which was remarkably higher than the removal rate of that by the free strains. The optimal amount of inoculated co-immobilized system for BaP degradation was 2%. The immobilized bacterial-fungal mixed consortium also showed better water stability than the free strains. Kinetics of BaP biodegradation by co-immobilized SF06 and SB02 were also studied. The results demonstrated that BaP degradation could be well described by a zero-order reaction rate equation when the initial BaP concentration was in the range of 10—200 mg/kg. The scanning electronic microscope (SEM) analysis showed that the co-immobilized microstructure was suitable for the growth of SF06 and SB02. The mass transmission process of co-immobilized system in soil is discussed. The results demonstrate the potential for employing the bacterial-fungal mixed consortium, co-immobilized on vermiculite, for in situ bioremediation of BaP.
基金Project supported by the National Natural Science Foundation of China(No.20447001, 40476049)the Natural Science Foundation of Fujian Province of China(No. D0410007).
基金Supported by the Technology Development Program of Shandong (No. 2008GG1005010)the Program of Introducing Talents of Discipline of Universities (111 Project, No. B08049)
文摘Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment.
基金supported by the State Oceanic Administration Specific Public Project of China (201105013)
文摘The objective of this study was to examine the effect of benzo[a]pyrene(Ba P) on the detoxification and antioxidant systems of two microalgae,Isochrysis zhanjiangensis and Platymonas subcordiformis.In our study,these two algae were exposed to Ba P for 4 days at three different concentrations including 0.5 μg^(L-1)(low),3 μg^(L-1)(mid) and 18 μg^(L-1)(high).The activity of detoxification enzymes,ethoxyresorufin O-deethylase(EROD) and glutathione S-transferase(GST) increased in P.subcordiformis in all Ba P-treated groups.In I.zhanjiangensis,the activity of these two enzymes increased at the beginning of exposure,and then decreased in the groups treated with mid-and high Ba P.The activity of antioxidant enzyme superoxide dismutase(SOD) increased in I.zhanjiangensis in all Ba P-treated groups,and then decreased in high Ba P-treated group,while no significant change was observed in P.subcordiformis.The activity of antioxidant enzyme catalase(CAT) increased in I.zhanjiangensis and P.subcordiformis in all Ba Ptreated groups.The content of malondialdehyde(MDA) in Isochrysis zhanjiangensis increased first,and then decreased in high Ba P-treated group,while no change occurred in P.subcordiformis.These results demonstrated that Ba P significantly influenced the activity of detoxifying and antioxidant enzymes in microalgae.The metabolic related enzymes(EROD,GST and CAT) may serve as sensitive biomarkers of measuring the contamination level of Ba P in marine water.
基金This project was supported by the National Natural Science Fundation of China under contract No. 49876029.
文摘The effects on hepatic EROD (7-ethoxyresorufin O-deethylase) in Mugil so-iuy exposed to benzo(a)pyrene (BaP), pyrene and their mixtures of equal concentration were investigated, at concentrations of 0.1, 1.0, 5.0, 10.0, 50.0 μg/dm3, in experimental condition. Time-effects and doseresponse of the biochemical indexs were observed. The results showed that the hepatic EROD activities were induced by the exposure of BaP, pyrene and their mixtures at high concentration. Dose-response connections were that the hepatic EROD activities were elevated with increasing concentration of the pollutants. The combined effect of BaP and pyrene at 1:1 concentration ratio on hepatic EROD activity was antagonism.
基金TheN ationalNaturalScienceFoundationofChina (No.40476049)andtheStateKeyLaboratoryofM arineEnvironm entalScience(X iam enU niversity),China(No.M EL201)
文摘Tributyltin(TBT), an organometal used as an antifouling biocide, has b een reported to induce masculinization of fish. Benzo[a]pyrene(BaP), a widesprea d carcinogenic polycyclic aromatic hydrocarbon, has been reported that its micro somal 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 analyz ed for sex hormone levels and alkali labile protein phosphorus(ALPP), which is r elated to the yolk precursor protein vitellogenin. The pollutants at all doses s ignificantly reduced serum testosterone, estradiol and ALPP content after 2 inje ctions compared with the corresponding controls. The reduction of the estradiol levels should be response for the decrease of the vitellogenin levels. The resul ts in the present study suggested that aromatase seems not the major target acte d by TBT and BaP in fish. This study demonstrated that TBT or BaP exposure both inhibit the reproductive potential in female Sebastiscus marmoratus. Combined ef fect of TBT and BaP on the serum testosterone, estradiol and ALPP was not antago nism from the anticipation.
基金support by the National Science Foundation of China (NO.30671744)
文摘Objective The present study aimed to test whether exposure to benzo(a)pyrene [B(a)P] affects spatial learning and short-term memory by modulating the expression of the Gria1 and Grin2a glutamate receptor subunit genes in the hippocampus.Methods Thirty-six 21-24-day-old,male rats were randomly assigned into high-,medium-,and low-dose toxin exposure groups (6.25,2.5,and 1 mg/kg,respectively) and a control group,each containing nine rats.The behavioral performance of adult rats exposed to sub-chronic administration of B(a)P was monitored by learning and memory tests (Morris water maze).Real-time PCR assays were used to quantify Gria1 and Grin2a gene expression in the hippocampus.Results At medium and high doses,B(a)P impaired spatial learning performance.The crossing-platform-location frequency and the time spent swimming in the platform area,which both relate to short-term memory,were significantly decreased in B(a)P-treated rats compared with controls.The level of Gria1 mRNA increased 2.6-5.9-fold,and the level of Grin2a mRNA increased 10-14.5-fold,with a greater fold increase associated with higher doses of B(a)P.Conclusion We demonstrated that sub-chronic administration of B(a)P inhibits spatial learning and short-term memory,and increases Gria1 and Grin2a expression in the hippocampus.This suggests a relationship of B(a)P exposure levels with Gria1 and Grin2a expression and impairment of short-term and spatial memory.
文摘In order to investigate the mechanism of benzo[a]pyrene uptake by a filamentous fungus Fusarium solani, a biochemical characterization of its concentrated culture filtrate has been conducted. The preparation contained approximately (w/w): 50% of total carbohydrate, 6.5% of uronic acid and 6% protein, as determined by colorimetric tests. Gel filtration and anion-exchange chromatographic profiles indicated that the main product of the culture filtrate was a glycoprotein, which contained mannose, glucose and galactose in an approximate molar ratio of 1.5: 0.8: 1. The polysaccharide fraction of the culture filtrate was prepared by treatment with proteinase K, followed by gel-filtration chromatography. Its chemical structure was studied by methylation analysis, gas-liquid chromatography-mass spectrometry (GC-MS) and Nuclear Magnetic Resonance spectroscopy (NMR). The major carbohydrate was a polymer of β-(1 → 6)-linked galactofuranose units fully branched at positions O-2 by single residues of α-glucopyranose. The Fusarium concentrated culture filtrate increased 4-fold the BaP solubilization in comparison with its aqueous solubility and suggested that the carbohydrate present in this filtrate should probably be involved in this enhancement. Our findings point out the potential role of fungal glycoproteins in PAH microbial bioavaibility, an important step for PAH biodegradation.
基金Grants of National Natural Science Foundation of China (30371206, 30028019)973 National Key Basic Research and Development Program (2002 CB 512905)
文摘Objective To investigate the roles of the cyclin D1/CDK4 and E2F-1/4 pathways and compare their work patterns in cell cycle changes induced by different doses of B[a]P. Methods Human embryo lung fibroblasts (HELFs) were treated with 2 μmol/L or 100 μmol/L B[a]P which were provided with some characteristics of transformed cells (T-HELFs). Cyclin D1, CDK4 and E2F-1/4 expressions were determined by Western blotting. Flow cytometry was used to detect the distribution of cell cycle. Results After B[a]P treatment, the proportion of the first gap (G1) phase cells decreased. CDK4 and E2F-4 expression did not change significantly. In 2 μmol/L treated cells, a marked overexpression of cyclin D1 and E2F-1 was observed. However, in T-HELFs overexpression was limited to cyclin D1 only, and no overexpression of E2F-1 was observed. The decreases of G1 phase in response to B[a]P treatment were blocked in antisense cyclin D1 and antisense CDK4 transfected HELFs (A-D1 and A-K4) and T-HELFs (T-A-D1 and T-A-K4). After 2 μmol/L B[a]P treatment, overexpression of E2F-1 was attenuated in A-D1, and E2F-4 expression was decreased significantly in A-K4. In T-A-D1 and T-A-K4, E2F-4 expression was increased significantly, compared with T-HELFs. The E2F-1 expression remained unchanged in T-A-D1 and T-A-K4. Conclusions Cyclin D1/CDK4-E2F-1/4 pathways work in different patterns in response to low dose and high dose B[a]P treatment. In HELFs treated with 2 μmol/L B[a]P, cyclin D1 positively regulates the E2F-1 expression while CDK4 negatively regulates the E2F-4 expression; however, in HELFs treated with 100 μmol/L B[a]P, both cyclin D1 and CDK4 negatively regulate the E2F-4 expression.
基金supported by Science and Technology Development Project of Qingdao,China (06-2-2-21-jch)
文摘The toxic effects of benzo[α]pyrene (B[α]P) at different concentrations (0.1, 0.5, 1, 2.5 and 7.5 μgL-1) on scallop (Chlamys farreri) immune system were studied. The results showed that B[α]P had significant toxic effects on the haemocyte counts, neutral red uptake, phagocytosis, bacteriolytic and antibacterial activity (P<0.05), while the seawater control and acetone control had no significant differences. The haemocyte counts, neutral red uptake, phagocytosis and bacteriolytic activity in all B[α]P treatment groups as well as antibacterial activity in groups of 0.5, 1, 2.5 and 7.5 μgL-1 B[α]P decreased significantly (P<0.05). Some of these indices tended to be stable on the sixth day and others on the ninth day, and the indices showed clear time-and concentra- tion-response to B[α]P. Bacteriolytic activity in 0.1μgL-1 B[α]P treatment group and antibacterial activity in 0.1 μgL-1 and 0.5 μgL-1 B[α]P treatment groups increased at the beginning of exposure and reached their peaks on day 1 and day 6, respectively. Following that, both activities decreased gradually and became stable after day 9. When all the indices reached stability, they were significantly lower than those in control group (P<0.05), except for antibacterial activity in 0.1 μgL-1 B[α]P treatment group (P>0.05). Thus, B[α]P has evident toxic effects on scallop immune system, which supports the view that a relationship exists between pollution and immunomodulation in aquatic organisms.
基金financially supported by the Fundamental Research Funds for the Central Universities (No. 201762017)
文摘In this study, the RNA sequencing was used to describe the response of Nannochloropsis oceanica, a marine microalga, to benzo[a]pyrene(BaP), a polycyclic aromatic hydrocarbon, in order to elucidate the metabolic pathways(or processes) involved in microalgal response to this stubborn pollutant. N. oceanica was exposed to BaP at a concentration of 90 μg L^-1 for 72 h, and its transcriptome was sequenced through the Illumina HiSeq^TM 2500 platform. This concentration of BaP was selected as it is the lowest for modeling the most appropriate growth inhibition of N. oceanica for transcriptomic analysis. We found that N. oceanica responds to BaP through degrading proteins and repairing DNA damaged by BaP. In addition, superoxide dismutase(SOD) strengthened its performance by increasing its transcript abundance. The physiological mechanism underlining the response of N. oceanica to BaP as revealed by transcriptomic analysis was consistent with the biochemical insights documented previously.
基金The Dalian Science Fund for Distinguished Young Scholars under contract No.2016RJ06the Natural Science Foundation of Liaoning Province under contract No.201602107+1 种基金the Superior College Science Technology Research Project of Liaoning Province under contract No.ZL201701the National Natural Science Foundation of China under contract No.41306138
文摘Rapid amplification of cDNA ends (RACE) and real-time polymerase chain reaction (RT-PCR) were carried out to analyze the CYP4 gene expression in polychaete Marphysa sanguinea exposed to benzo[a]pyrene (BaP) in this study. The full length of MsCYP4 cDNA was 2 470 bp, and it encoded 512 amino acids. The deduced amino acid sequence showed 47% identity with CYP4F from frog Xenopus tropicalis and shared high homology with other known CYP4 sequences. To analyse the role of CYP4 in protecting M. sanguinea from BaP exposure, three BaP groups were established: 0.5, 5 and 50 μg/L. Polychaetes were sampled after 3, 7 and 12 d. At 0.5 μg/L, the effect of BaP on MsCYP4 gene expression increased with time prolonged. MsCYP4 gene expression curve showed Ushaped trend with time in 5 and 50 μg/L BaP groups. Therefore, MsCYP4 gene may play an important role in maintaining the balance of cellular metabolism and protecting M. sanguinea from BaP toxicity.
基金Projects(21007020,U0933002,U0833002) supported by the National Natural Science Foundation of ChinaProject(2009B030500002) supported by the Science and Technology Projects of Guangdong Province,China
文摘The ability of Stenotrophomonas maltophilia was demonstrated to selectively remove Cu2+from Cu(NO3)2 solution under the circumstance that 1 mg/L benzo[a]pyrene(BaP) was either present or not. The removal ratios of 2 and 10 mg/L Cu2+by 0.25 g/L biosorbent are up to 80% and 49% at 10 min, respectively. The biosorption includes ion exchange, NO3 reduction, ion release, and cell oxidation by Cu2+. BaP does not significantly affect Cu2+removal and ion release. Although 2 mg/L Cu2+increases the release of PO4 3, K+, NH4 +and Ca2+, 10 mg/L Cu2+has strong oxidation on cell, and then decreases NO3 reduction and hinders the release of K+, NH4 +and Ca2+. Exogenous cations inhibit the Cu2+biosorption, while additional anions increase the removal ratios of 10 mg/L Cu2+from 52% to 88%.
文摘The concentrations of reduced glutathione(GSH) in liver and ovary of Boleophthalmus pectinirostris are quantified. The concentrations of GSH in the ovary are much higher than that of GSH in the liver(nearly 3 times of the liver). The study also investigates the changes of GSH contents in the two organs while the fishes were exposed to benzo(a)pyrene(BaP) at concentrations of 0, 0.05, 0.2 and 0.5 mg/L respectively for up to a week. The concentrations of GSH in the liver of BaP exposed fish increased significantly with dose, whereas the concentrations of GSH in the ovary decreased significantly compared to controls. The results suggested that both the liver and the ovary are the primary organ in BaP metabolism, and that the changes of GSH levels may represent an adaptive response or toxic effect to BaP exposure.
