三硝基甲苯对斑马鱼组织ATP酶·乳酸脱氢酶和谷胱甘肽活性的影响

[目的]探讨三硝基甲苯(TNT)对斑马鱼(Danio rerio)组织中酶活性的影响,为评价TNT的毒性效应提供参考。[方法]采用毒性试验方法研究了不同浓度(0.5、1.0、2.0、4.0 mg/L)的TNT对斑马鱼肝和鳃中ATP酶、头中乳酸脱氢酶(LDH)和肝中谷胱甘肽(GSH)活性的影响。[结果]肝和腮组织中的ATP酶活性随浓度的升高而降低;肝中GSH的活性随浓度的升高而升高;头中LDH活性随浓度的升高而降低。酶活随时间的变化规律和随不同浓度的变化规律相同,但变化缓慢。[结论]用斑马鱼肝和腮组织中酶活性作为毒理学指标能较好地评价TNT的毒性效应。     

Behavioural endpoints in earthworm ecotoxicology

Background, Aims and Scope  Endpoints in earthworm ecotoxicology scheduled in guidelines are mortality and reproduction rates. However, not only the direct influence of pollutants on population parameters but also changes in behaviour such as substrate avoidance can have an important impact on soil ecosystems. In practice two different avoidance response tests are applied in earthworm ecotoxicology: (i) a six-chamber test system and (ii) a two-chamber test system. Both avoidance response-test systems were compared to establish their respective advantages and disadvantages in order to advance the standardisation of behavioural tests. The earthworm avoidance-response tests were applied in addition to the standard acute and chronic earthworm toxicity tests (ISO 11268) in order to compare the sensitivity of the test endpoints. Methods  Test substrates were contaminated with crude oil and 2,4,6-Trinitrotoluene (TNT), respectively. The test species wasEisenia fetida. The earthworms were exposed to the contaminated substrates and their mortality (14 d), reproduction rates (number of cocoons after 28 d, juvenile hatching after 56 d), and substrate preference (48 h) determined. Results and Discussion  Whereas 1000 mg/kg TPH (Total Petroleum Hydrocarbons) did not show any lethal effects, 100% mortality occurred in soil with comparable TNT concentration. The acute tests consistently produced the highest effect concentrations whereas reproduction and substrate avoidance were the more sensitive test parameters. Both behavioural test systems, when compared, showed similar substrate avoidance after an incubation time of 48 h. The six-chamber test system provides the potential to test six different substrates/concentrations at one time. It was observed, however, that earthworms did not migrate among all test chambers within a test unit in order to select the most appropriate substrate. Orientation was observed only between directly neighbouring test compartments, which complicates the interpretation of the test results. Conclusion  Substrate avoidance and reproduction variables were clearly more sensitive test endpoints than mortality. Therefore avoidance-response tests proved to be useful test methods in detecting effects of sublethal concentrations of pollutants on earthworms. The test duration of the avoidance tests is much shorter compared to the standard acute and chronic earthworm toxicity tests, which makes them a quick screening tool for identifying potential soil toxicity. Both avoidance-response test systems showed comparable results regarding the test sensitivity. Nonetheless, the incomplete substrate use in the six-chamber avoidance test due to the reduced migration possibilities (orientation only to neighbouring chambers) might reduce the distinctness of test results as it allows only reliable information on the most avoided and therefore most toxic substrate but not on 1 a clear dose-response pattern. Thus, to gain valid results, the number of replicates and the arrangement of the different substrates must be adopted. The two-chamber test system is less time-consuming due to easy handling and test results can be quantified more easily. Recommendations and Outlook  In consequence of the better validity of test results, lower expenses for test containers and less time for handling, the use of the two-chamber system is preferred over the six-chamber test system to assess the toxicity of polluted soil. Because of the ecosystem consequences of behavioural effects and the fact that avoidance response tests can reveal the toxic potential of pollutants in low concentrations, such tests should be included into ecotoxicological test protocols.     

A study on the genetic noxiousness of trinitrotoluen

In this paper, the mutagencity of TNT was studied for mice and fruit flies. It was indicated that TNT had a great deal of mutagenic effect on the somatic cells and sexual cells of the animals used as the subjects of the experiment, and calculated that TNT would have a genetic harmfulness to human beings. Responsible editor: Chai Ruihai     

A study on the genetic noxiousness of trinitrotoluene

lntroductionTrinitrotoIuene(TNT),animportantmaterialtosyn-thesizegunpower,isoneofthecommonandancientindustrypoisonsandhasaharmfuInesstomanyorgansandsystemsuchastheliver,bloodsystem,andcrystaIIinelenscontactedwithit(A1thouse1983).Butthereportsstudyingonthechronicgeneticnox-ionsnessofTNTarereIativeIyraresofar.Therefore,itisverynecessarytostudydeeplyonthemutageniceffectsofTNTandtocalcuIatethegeneticharrnfuI-nessofTNTtovariousanimals(Draggan1978).lnthispaper,wehavestudiedthatthemutagencity…