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1.
This study was aimed to evaluate the toxic effects of fluoride (F) and/or sulfur dioxide (SO 2) on morphology and DNA integrity in liver of male rats. For this, 96 Wistar rats (12-week-old) were randomly divided into four groups after 1-week adaptive breeding: the control group, treated with deionized water; the NaF group, administered high F (100 mg NaF/L in the drinking water); the SO 2 group, with sulfur dioxide in ambient air (15 ppm SO 2, 4 h/day); and NaF + SO 2 group, treated with high F and sulfur dioxide together for 8 consecutive weeks. The body weight, liver organ coefficient, morphology, and DNA damage in the liver of rats were examined. The results showed that the body weight and liver organ coefficient were not significantly changed; however, significant pathological changes of liver tissues were observed in the NaF + SO 2 group compared with the individual treated groups and control group. Furthermore, comet assay indicated that DNA damage in liver was significantly increased in the F and/or SO 2 treatment groups at 2, 4, 6, and 8 weeks, especially at 4 weeks. These results indicate that the liver morphology and DNA integrity of rats are adversely affected by F and/or SO 2 exposure. 相似文献
2.
Both NaCl and NaF promoted PGE 2 binding to epididymal adipocyte membranes by apparent increase in the binding affinity. In order to distinguish between the effect of fluoride and the ‘salt effect’ of sodium on PGE 2 binding, the effects of Mg 2+ and guanyl nucleotides on PGE 2 binding in the presence of NaCl or NaF were compared. Mg 2+ decreased PGE 2 binding; high NaF concentration abolished this inhibition, while increased NaCl concentratipns did not affect the Mg 2+ inhibition. In the presence of Mg 2+ the effects of NaCl and NaF were additive. The enhancement of PGE 2 binding by fluoride, unlike sodium, was dependent on the presence of Mg 2+. Induction of the membranes with GDPβS, Gpp(NH)p, GTP or GTPγS increased PGE, binding. Gradual increase in NaF concentrations in the presence of guanyl nucleotides resulted in stimulation of PGE 2 binding at low NaF concentrations and inhibition of PGE 2 binding at higjh NaF concentrations. No changes in the stimulatory action of NaCl on PGE 2 binding were observed in the simulatenous presence of NaCl and guanyl nucleotides. A biphasic effect on PGE 2 binding was observed with a wide concentration range of guanyl nucleotides. Treatment of the isolated membranes with cholera or pertussis toxins stimulated the adenylyl cyclase activity of the membranes, but failed to influence PGE 2 binding. The implications of these findings are discussed. 相似文献
3.
The light- and sulfide-dependent induction process leading to photosystem I-mediated sulfide utilization by Oscillatoria limnetica, for either H 2 evolution or CO 2 photoassimilation, was studied. The identical dependence on pH of the lag length, the inhibition of leucine incorporation and final H 2S concentration imply that the latter exerts a deleterious effect on nonadapted cells. Na-dithionite (Na2S2O4), Na-sulfite (Na2SO3), or ethanol cannot serve as photosynthetic electron donors. However, when these compounds were added to the sulfide-containing system, the need for induction was eliminated. At pH 6.9, in the presence of 3.5 millimolar sulfide, these substances (at concentrations of 10 millimolar, 5 millimolar, or 0.4 molar, respectively) completely abolished the delay preceding sulfide-dependent H2 evolution. It is suggested that all three compounds expose a site capable of directly accepting sulfide electrons. Only dithionite could adapt the cells to sulfide utilization on its own. Sulfite or ethanol acted only in the presence of sulfide. It is implied that this specific activity of dithionite is related to its characteristic low redox potential. Sulfide-dependent H2 evolution was insensitive to 3-(3,4-dichlorophenyl)-1,1-dimethylurea, but was inhibited by the plastoquinone antagonist 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone, in the presence as well as in the absence of dithionite. In both cases, therefore, the plastoquinone was implied in the electron transport from sulfide. 相似文献
4.
Summary Spruce cuttings were potted in quartz sand. One half was watered with tap water, the other with deionized water containing 100 ppm F - as NaF, during winter till bud break. After flushing the plants were exposed continuously for five weeks (June/July) either to normal air or to air with 0.025 and 0.075 ppm SO 2, respectively. CO 2-uptake was measured in the laboratory (40,000 lux) with an IRGA.Even in the absence of visible symptoms of injury to last year's needles, root-applied fluoride did suppress CO 2-uptake significantly. Also the fumigation with 0.075 ppm SO 2 caused a depression of CO 2-uptake, whereas 0.025 ppm SO 2 remained without significant reaction within five weeks. Fluorides infiltrating through roots and airborne SO 2 acting together may depress CO 2-uptake synergistically.Soil applied fluoride accumulated particularly in roots and twigs, whereas very little was found in the stem. The F --accumulation even increased with increasing SO 2-concentrations but was without effect on S-accumulation. 相似文献
5.
Effects of SO 2, aqueous fluoride (NaF) and a solution of nitrogen compounds (NH 4NO 3) on the visible symptoms, pollutant accumulation and ultrastructure of Scots pine ( Pinus sylvestris L.) and Norway spruce [ Picea abies (L.) Karst.] seedlings were studied in an open-air experiment lasting for 3 consecutive years. Visible injury symptoms were
most pronounced in combination exposures and whenever F was applied. Visible symptoms correlated well with needle pollutant
concentrations. Exposure to NaF increased needle F contents particularly when F was applied with SO 2 or NH 4NO 3. This suggests that a reduction in N or SO 2 emissions, in F polluted areas, could improve the condition of conifers via decreased accumulation of phytotoxic F in the
needles. Norway spruce needles accumulated 2 – 10 times as much S and F as those of Scots pine. Microscopic observations showed
various changes in the needle mesophyll cell ultrastructure. In both species, exposure to SO 2 increased significantly the amount of cytoplasmic vacuoles, suggesting detoxification of excess sulphate or low pH. F treatments
resulted in a significant enlargement of plastoglobuli in Scots pine and a darkening of plastoglobuli in Norway spruce. All
exposures enhanced the accumulation of lipid bodies. An increased portion of translucent plastoglobuli was most pronounced
in N treatments. Many of the ultrastructural changes and visible symptoms appeared only as number of years exposed increased,
indicating that long-term experiments are needed. Both visible symptoms and ultrastructural changes pointed to the more pronounced
sensitivity of Norway spruce compared to Scots pine. Ultrastructural results mostly supported earlier qualitative observations
of F, N and SO 2 effects on needle mesophyll cell ultrastructure. However, no reduction of thylakoids in SO 2 containing exposure or curling of thylakoids in F exposure could be detected in the present study.
Received: 5 December 1994 / Accepted: 28 April 1995 相似文献
6.
The aim of this study is to investigate to what extend the addition of an electrolyte (NaCl or Na 2SO 4) can improve the selectivity of the sodium lactate/glucose separation by nanofiltration. Experimental results were used to get the variation of the observed retentions versus the permeation flux and to evaluate the separation efficiency from the separation factor. In presence of NaCl, both glucose and lactate retentions slightly decrease and remain very close except at low permeation fluxes where the addition of NaCl has more effect on lactate retention than on glucose one. On the contrary, whilst the addition of Na 2SO 4 has no influence on glucose retention, a strong effect was pointed out on the lactate one, especially for high electrolyte concentrations for which negative retentions were obtained at low permeation fluxes. Then, the separation was much more improved by the addition of Na 2SO 4 compared to NaCl. A maximum separation factor of 1.9 was obtained with Na 2SO 4 at 0.25 M added to the glucose (0.1 M)/sodium lactate (0.1 M) solution whereas the separation was impossible without the addition of salt. 相似文献
7.
Sulfur dioxide (SO 2) is a well-known and widespread air pollutant but it also acts as signaling molecule in various processes in animals. However, there is limited information on the role of SO 2 in plants except of its toxicity. Here we studied the role of SO 2 on stomatal movements in sweet potato ( Ipomoea batatas) leaves. SO 2, generated by Na 2SO 3/NaHSO 3 solutions, was applied on epidermal strips. We found that the SO 2 donor induced stomatal closure in a dose-dependent manner. Rapid increases in endogenous hydrogen sulfide and nitric oxide content levels were observed in leaves after the treatment with the SO 2 donor. The SO 2-induced stomatal closure was reversed by the H 2S scavenger hypotaurine and the NO-specific scavenger cPTIO. Our results indicate that the SO 2-induced stomatal closure was likely mediated by the H 2S and NO signaling pathways. 相似文献
8.
The effect of sulfated polysaccharides on the AMP-dependent activity of rabbit muscle phosphorylase b as compared with that of Na 2SO 4 has been studied. It has been shown that sulfated polysaccharides and Na 2SO 4 greatly stimulated AMP-activation of the enzyme at low AMP concentrations. Dextran sulfate and Na 2SO 4 desensitized the allosteric interactions of the enzyme towards the nucleotide activator and reversed the enzyme inhibition caused by glucose-6-phosphate and glucose. Furthermore, it was found that while dextran sulfate decreased the K m value for both substrates, glucose-1-phosphate and glycogen, sulfate anions decreased only the K m value for glycogen. 相似文献
9.
Summary Development of spruce shoot aphid ( Cinara pilicornis Hartig) populations was monitored in natural and artificial infestations of Norway spruce ( Picea abies Karst.) seedlings, exposed to air pollutants in an experimental field. The pollutants, applied both singly and in mixtures, were gaseous sulphur dioxide, NaF (30 mg l -1 F) and Ca(NO 3) 2 or (NH 4) 2SO 4 in aqueous solutions (200 mg l -1 N). Aphid numbers on 10 seedlings in each treatment and two control plots were counted at 2-week intervals. At the beginning of the experiment aphid numbers did not differ between treatments. Aphid populations peaked in late June and early July. All the pollutants and their combinations significantly increased the numbers of aphids per seedling. Four apterous females were transferred to spruce seedlings which were growing in containers in the same plots. After 4–5 weeks aphid numbers were significantly higher in the fluoride treatment and in the combined treatment of fluoride, nitrogen and SO 2. The pollution treatments did not have a significant effect on shoot growth. Concentrations of F and S in needles were higher in treatments involving these pollutants. There were no significant differences in the concentrations of free amino acids in shoot stems between control and fluoride treatment. However, the relatively low concentration of arginine in the F treatment at the end of the growing season might indicate disturbances in the nitrogen metabolism of spruce seedlings. 相似文献
10.
In the present study, Na 3(SO 4) X ( X = F or Cl) halosulphate phosphors have been synthesized by the solid‐state diffusion method. The phase formation of the compounds Na 3(SO 4)F and Na 3(SO 4)Cl were confirmed by X‐ray powder diffraction (XRD) measurement. Photoluminescence (PL) excitation spectrum measurement of Na 3(SO 4)F:Ce 3+ and Na 3(SO 4)Cl:Ce 3+ shows this phosphor can be efficiently excited by near‐ultraviolet (UV) light and presents a dominant luminescence band centred at 341 nm for Ce 3+, which is responsible for energy transfer to Dy 3+and Mn 2+ ions. The efficient Ce 3+ → Dy 3+ energy transfer in Na 3(SO 4)F and Na 3(SO 4)Cl under UV wavelength was observed due to 4 F 9/2 to 6H 15/2 and 6H 13/2 level, while Ce 3+ → Mn 2+ was observed due to 4 T 1 state to 6A 1. The purpose of the present study is to develop and understanding the photoluminescence properties of Ce 3+‐, Dy 3+‐ and Mn 2+‐doped fluoride and chloride Na 3(SO 4) X ( X = F or Cl) luminescent material, which can be the efficient phosphors in many applications, such as scintillation applications, TL dosimetry and the lamp industry, etc. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
11.
Shoots of Thellungiella derived by micropropagation were used to estimate the plants'' salt tolerance and ability to regulate Na + uptake. Two species with differing salt tolerances were studied: Thellungiella salsuginea ( halophilla), which is less tolerant, and Thellungiella botschantzevii, which is more tolerant. Although the shoots of neither ecotype survived at 700 mM NaCl or 200 mM Na 2SO 4, micropropagated shoots of T. botschantzevii were more tolerant to Na 2SO 4 (10–100 mM) and NaCl (100–300 mM). In the absence of roots, Na 2SO 4 salinity reduced shoot growth more dramatically than NaCl salinity. Plantlets of both species were able to adapt to salt stress even when they did not form roots. First, there was no significant correlation between Na + accumulation in shoots and Na + concentration in the growth media. Second, K + concentrations in the shoots exposed to different salt concentrations were maintained at equivalent levels to control plants grown in medium without NaCl or Na 2SO 4. These results suggest that isolated shoots of Thellungiella possess their own mechanisms for enabling salt tolerance, which contribute to salt tolerance in intact plants.Key words: Thellungiella salsuginea, Thellungiella botschantzevii, salt tolerance, isolated shoots, growth, rhizogenesis, ion accumulation 相似文献
12.
Osmotic and ion-specific effects of NaCl and Na 2SO 4 on Phragmites australis (Cav.) Trin ex. Steud. were investigated in a laboratory experiment by examining effects of iso-osmotic solutions of NaCl and Na 2SO 4 on growth, osmolality of cell sap, proline content, elemental composition and gas exchange. Plants were supplied with a control standard nutrient solution ( Ψ = −0.09 MPa) or solutions of NaCl or Na 2SO 4 at water potentials of −0.50, −1.09 or −1.74 MPa. Salt treatments increased root concentrations of Na and S or Cl, whereas P. australis had efficient mechanisms for exclusion of Na and S and partly Cl ions from the leaves. Incomplete exclusion of Cl from the leaves may affect aboveground biomass production, which was significantly more reduced by NaCl than Na 2SO 4. Stomatal conductance was negatively influenced by decreasing water potentials caused by NaCl or Na 2SO 4, implying that a non-significant photosynthetic depression observed in plants grown at −1.74 MPa was mainly due to osmotically induced stomatal closure. This was supported by decreasing internal CO 2 concentrations. Saline conditions increased the intrinsic water use efficiency and did not alter photosynthetic parameters derived from light response curves, supporting the assumption of a well-functioning CO 2 utilization in salt stressed plants. The leaf proline concentration increased equally in NaCl and Na 2SO 4-treated plants, and may play an important role as a compatible organic solute. P. australis possesses a range of mechanisms conferring tolerance to both NaCl and Na 2SO 4 stress and except in terms of growth the phytotoxicity of NaCl and Na 2SO 4 are comparable. 相似文献
13.
互花米草(Spartina alterniflora)的入侵给海岸带盐沼生态系统的结构和功能带来了显著影响。互花米草盐沼中的硫含量高于附近的土著芦苇(Phragmites australis)盐沼。为探讨硫元素对互花米草和芦苇竞争过程的可能影响及其作用机制,以50mmol·L–1的Na2SO4和Na2S对互花米草和芦苇进行处理,分析处理前后5天内两种植物光合气体交换和叶绿素荧光指标变化的差异,实验另设等Na+浓度的Na Cl处理作为比较。研究发现:Na2S对互花米草和芦苇光合作用影响的差异最大,Na Cl次之,Na2SO4最小。Na2S处理后,互花米草净光合速率(Pn)出现显著上升,芦苇Pn值大幅度下降。互花米草的光饱和点(Isat)上升而芦苇的Isat值无变化。表明Na2S处理对互花米草的光合能力有促进作用,但对芦苇的光合能力有抑制作用。Na Cl处理后互花米草Pn值也出现小幅上升,而芦苇Pn值略有下降。Na2SO4处理对互花米草和芦苇的Pn值均无显著影响。除Na2SO4处理的互花米草外,不同盐处理后的互花米草和芦苇非光化学淬灭(NPQ)均出现上升趋势。研究结果表明互花米草对环境硫胁迫的适应能力显著高于芦苇,暗示盐沼高硫环境尤其是硫化物有助于互花米草相对于芦苇的竞争,也很可能是其形成单一植被的重要原因之一。 相似文献
14.
Growth characteristics of Deleya halophila (CCM 3662 T), were determined using a defined medium. Deleya halophila presented its optimal growth at 7.5% (wt/vol) total salts when it was grwon at incubation temperatures of 32° and 42°C; when the temperature was lowered to 22°C, it had optimal growth at 5% (wt/vol) total salts. This bacterium had an absolute requirement for the Na + cation; it could not be replaced by other cations. NaBr, Na 2SO 4, or Na 2S 2O 3 could be substituted for NaCl in the growth medium, but, when MgCl 2, KCl, LiCl, NaI, NaF, or NaNO 3 was substituted for NaCl, the medium did not support growth. Growth rates of the strain were diverse when NaCl was partially replaced by other sodium salts. Finally, D. halophila suffered loss of viability when the culture was diluted into different low NaCl concentrations (0, 0.5%, and 1%, wt/vol) at various incubation temperatures. 相似文献
15.
Abstract The regenerated shoots from sodium sulphate (Na 2SO 4) grown callus of tobacco ( Nicotiana tabacum L. cv. Wisconsin 38) were evaluated for Na 2SO 4 tolerance based on shoot proliferation and rooting in vitro, and seed germination in vivo in response to Na 2SO 4. An increase in Na 2SO 4 concentration resulted in significantly decreasing shoot fresh weight, number of shoots, shoot length and leaf size, and increasing per cent shoot dry weight of both control and Na 2SO 4-grown cultures. In rooting, shoots of Na 2SO 4-grown cultures exhibited the highest per cent rooting (85%) in the presence of 1% w/v Na 2SO 4. However, per cent rooting, root number per rooted cutting and root fresh weight decreased significantly with increasing Na 2SO 4 concentration when shoots were transferred to the medium in the absence of Na 2SO 4 for 4-monthly passages. Following acclimatization of the rooted shoots of Na 2SO 4-grown cultures, phenotypic variation was observed during growth and development. There were 13.2% sterile plants. Fertile plants were sorted into normal (N), tolerant (T), and sensitive (S) categories and the respective percentages of plants were 31.6, 44.7 and 10.5, based on per cent germination, germination velocity index and seedling survival to Na 2SO 4. The response of N, T and S types to Na 2SO 4 in subsequent shoot proliferation was similar to that of seed germination. 相似文献
16.
Fluoride (F) and sulfur dioxide (SO 2) are the two common environmental contaminants that are associated with neurotoxicity. The present study was conducted to explore individual and combined exposure effects of F and SO 2 on histological alteration and DNA damage in rat brain. For this, male Wistar albino rats were exposed to sodium fluoride (100 mg/L NaF) and sulfur dioxide (39.3 mg/m 3) individually and in combination for 8 weeks. Histological alteration in brain is evaluated by hematoxylin–eosin staining, showed shrunken neurons, darkly stained small nucleus and decreased cell numbers in F and SO 2 exposed groups. The effect of F and SO 2 on DNA damage was assessed by comet assay. The results showed an increase in ratio of tailing and tail length in F or/and SO 2 administered rats. In addition, the proportion of grade II and III were also increased in individual and combined exposed groups. Compared with the individual exposure, the proportion the grade III was significantly high in combined exposure, suggesting a synergistic effect of F and SO 2. These results indicate that the brain was more susceptible to the toxic effects of F and SO 2. And combined exposure to these pollutants can lead more pronounced toxic effects on brain. 相似文献
17.
Sinorhizobium meliloti CE52G strain produces a periplasmic laccase that has been purified by a two-step procedure involving heat treatment and immobilized metal affinity chromatography (IMAC). The fraction with laccase activity retained its original activity after 24 h of incubation at pH between 4.0 and 8.0 and after 3 h of incubation at 70 °C, pH 7.2 and supplemented with 1.3 M (NH 4) 2SO 4. It proved to be a homodimeric protein with an apparent molecular mass of 45 kDa each subunit and an isoelectric point of 6.2. CE52G laccase was inhibited by halides (NaF and NaCl), ions (Fe 3+, Mn 2+, and Cu 2+), sulfhydryl organic compounds (β-mercaptoethanol and reduced glutathione), and electron flow inhibitors (NaCN and NaF). Laccase activity was strongly enhanced by (NH 4) 2SO 4, Na 2SO 4, and K 2SO 4. The effects of all these agents, as well as the probability of a partially unfolding polypeptide chain to enhance the interaction between the substrate and the active site, are discussed. CE52G laccase is a pH- and thermo-stable protein with promising biotechnological applications. 相似文献
18.
Concentrations of various sulfur compounds (SO 42−, H 2S, S 0, acid-volatile sulfide, and total sulfur) were determined in the profundal sediments and overlying water column of a shallow eutrophic lake. Low concentrations of sulfate relative to those of acid-volatile sulfide and total sulfur and a decrease in total sulfur with sediment depth implied that the contribution of dissimilatory sulfur reduction to H 2S production was relatively minor. Addition of 1.0 mM Na 235SO 4 to upper sediments in laboratory experiments resulted in the production of H 235S with no apparent lag. Kinetic experiments with 35S demonstrated an apparent Km of 0.068 mmol of SO 42− reduced per liter of sediment per day, whereas tracer experiments with 35S indicated an average turnover time of the sediment sulfate pool of 1.5 h. Total sulfate reduction in a sediment depth profile to 15 cm was 15.3 mmol of sulfate reduced per m 2 per day, which corresponds to a mineralization of 30% of the particulate organic matter entering the sediment. Reduction of 35S 0 occurred at a slower rate. These results demonstrated that high rates of sulfate reduction occur in these sediments despite low concentrations of oxidized inorganic compounds and that this reduction can be important in the anaerobic mineralization of organic carbon. 相似文献
19.
Trace elements can influence dental health, possibly by altering tooth resistance during preeruptive development. Therefore, it was investigated whether lead and fluoride would be incorporated into the calcifying matrices or the cellular parts of tooth germs in vitro. Using laser microprobe mass analysis, the localization of lead and fluoride was studied in the different layers or tooth germs that had been cultured in a medium to which PbCl 2 of NaF had been added in different concentrations. Both elements could only be detected in the dentine layer. Hence, the enamel organ in the secretory stage of tooth development excludes lead and fluoride from the enamel, even when enamel formation by the ameloblasts is visibly disturbed. Furthermore, there seemed to be a process of saturation in the accumulation of lead and fluoride in the dentine. 相似文献
20.
The ectomycorrhizal fungus Pisolithus tinctorius was grown in vitro with different concentrations and combinations of three different sodium salts viz., sodium chloride, sodium sulphate and trisodium citrate (NaCl, Na 2SO4 and Na 3C 6H 5O 7) for 30 days. At the end of the experiment the mycelial biomass and protein content of the fungus was evaluated. Based on the salts tested the combination of NaCl and Na 2SO 4 in optimum concentrations actually promoted the growth of P. tinctorius. Box-Behnken design with three variables like NaCl, Na 2SO 4 and Na 3C 6H 5O 7 was used to identify a significant correlation between the effect of these variables on mycelial biomass production. The experimental values are in good agreement with predicted values, the correlation coefficient being 0.9880. 相似文献
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