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Alisa Wangsongsak Suwimol Utarnpongs Maleeya Kruatrachue MathurosePonglikitmongko Prayad Pokethitiyook Thitinun Sumranwanich 《环境科学学报(英文版)》2007,19(11):1341-1348
Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue. 相似文献
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为研究四溴双酚A(TBBPA)亚慢性呼吸暴露对大鼠的毒性效应,将36只健康的无特定病原菌级别(SPF级)Wistar雄性大鼠分为6组,分别为空白对照组、控制对照组和129、546、1 216、4 550μg·m-3TBBPA气溶胶染毒组,采用经口鼻呼吸暴露方式连续染毒90 d。暴露实验期间每天观察大鼠状态,每10天记录1次大鼠体重,于第91天解剖受试大鼠,分离主要脏器,并对肺组织进行病理检查。结果显示,与对照组比较,各暴露组大鼠肾脏及脾脏的脏器系数均有显著降低(P0.05);TBBPA工业品气溶胶暴露组大鼠肺部病变程度和病变发生率高于空白对照组及控制对照组。研究结果表明Wistar大鼠经亚慢性呼吸暴露TBBPA颗粒后,可能造成一定程度的肾、脾脏毒性效应和肺部炎症。 相似文献
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3,3′,4,4′-Tetrachlorobiphenyl (PCB 77), one of the environmentally persistent polychlorinated biphenyls that have been used for industrial purposes, was repeatedly administered to pregnant rats by gavage at a dose of minimal, non-lethal toxicity in order to study its effects on routine blood variables, parameters of oxidative stress and hematopoietic organs in pregnant female rats. Of the routine blood parameters, PCB 77 reduced the mean corpuscular hemoglobin concentration and platelet counts; the levels of malondialdehyde and glutathione peroxidase in the blood were higher during the first days of gestation (1–7), as compared to the respective controls. In the subsequent period between days 8 and 18, these parameters did not show any significant change after PCB 77 treatment. Routine blood parameters and oxidative stress parameters indicated a moderate degree of oxidative stress which alone could not bring about the serious weight reduction of the thymus, pituitary, and kidneys. The extent of oxidative stress did not correlate with the weight reduction of some of the blood-forming organs. 相似文献
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环境行政公益诉讼——以美、印经验为借鉴 总被引:6,自引:0,他引:6
环境行政公益诉讼的建立在我国具有理论上的依据,但是具体的构建尚需要借鉴成熟经验.本文介绍了世界公益诉讼的典范--美国环境的公民诉讼和具有巨大创造性的印度环境行政公益诉讼,这两个国家在环境公益诉讼上的经验,给我国建构环境行政公益诉讼提供了借鉴. 相似文献
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Pollimyrus adspersus discriminates the individually variable waveforms of Electric Organ Discharges (EODs) of conspecifics of only 150–250 s duration. We examined: (1) the discrimination threshold for artificially generated EODs of similar waveform, (2) the mechanism of signal analysis (spectral vs temporal) present, by determining the discrimination between different waveforms of identical amplitude spectra, and (3) the threshold field intensity and reach of discrimination. The triphasic P. adspersus EOD waveform was artificially generated by superimposing two Gaussians, one wide, the second narrow, inverted, and of threefold amplitude. The natural variability among individual EOD waveforms was simulated by phase-shifting one Gaussian relative to the other. The symmetrical waveform where the peaks of the two Gaussians coincided was used as a reference (phase shift=0, rewarded stimulus S+). Results were: (1) in food-rewarded conditioning experiments, trained fish (N=7) detected a phase-shift in artificial EOD stimuli as low as 2 s (N=2 fish), 6 s (N=1) and 10 s (N=1). (2) All fish tested (N=3) discriminated between artificial EODs of identical amplitude spectra but different waveforms (hence, different phase spectra), demonstrating a temporal mechanism of signal analysis. (3) The maximum reach of waveform discrimination was 130 cm at 4.9 Vp-p/cm and 100 S/cm water conductivity (test signal generated at natural amplitude), that is, similar to the reach of EOD detection. Therefore, among the three kinds of electroreceptor organ present in mormyrids, we consider Knollenorgane the relevant sensory organs for EOD waveform discrimination.Communicated by J. Krause 相似文献
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研究吡草醚原药对大鼠一般生长情况的影响,寻找慢性毒性靶器官以及确定最大无作用剂量(NOAEL)。将初重为40~50 g的SPF级SD大鼠随机分成对照、低、中和高剂量组,160只/组,雌雄各半。各组动物分别给予含有不同浓度吡草醚原药的饲料(0,80,400,2 000 mg·kg-1的饲料),染毒期间不限制摄食饮水,期限为104周。结果显示雌、雄鼠中、高剂量组1~104周的体重、增重、食物利用率与对照组比较,于不同阶段均有不同程度降低,差异有显著性(P0.05或P0.01或P0.001);中、高剂量受试物可导致大鼠血液中尿素氮(BUN)水平升高及胆碱酯酶(Ch E)水平下降,肾脏器系数升高,与对照组比较差异有显著性(P0.05或P0.01或P0.001);病理学检查显示中、高剂量组可引起肾小管上皮细胞变性、肾脏间质炎、慢性进行性肾病等。实验结果表明在本试验条件下,中、高剂量的吡草醚原药可明显影响大鼠的体重增长及食物利用率,对SD大鼠的慢性毒性靶器官是肾脏。 相似文献
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During their seasonal runs in the Okavango and other freshwater bodies in southern Africa, the sharptooth catfish, Clarias gariepinus, specialises on the bulldog, Marcusenius macrolepidotus, as its main prey. We examined whether the catfish can locate bulldogs by detecting their pulse-type electric organ discharges
(EODs). The electrosensory threshold for single-cycle, monopolar square-wave pulses was exceedingly low (down to 13 μVp–p/cm for 4-ms pulses) in trained, food-rewarded sharptooth catfish (n=4), confirming the results of Lissmann and Machin who were, however, unable to identify a biological function. Other stimulus
pulse waveforms (single-cycle, monopolar as well as bipolar sine-wave pulses) were also effective stimuli according to their
spectral low-frequency energy contents (0– 30 Hz). Male bulldogs display an EOD pulse approximately 10× the duration of female
EODs (≈0.5 ms). The C. gariepinus threshold for field-recorded playbacks of a male bulldog EOD (of long duration) was 103 μVp–p/cm, whereas the brief female and juvenile EODs were not detected (using intensities of natural EODs). EODs of other mormyrids
were detected when either monopolar or of long duration. Signal source amplitude increased linearly with standard length (SL)
in bulldogs. Signal reach, as calculated from signal source amplitude and receiver sensitivity, is up to 150 cm for a large
male bulldog (SL 27.5 cm), and 83 cm for a male that has just turned sexually mature (SL 12.6 cm). Therefore, most bulldogs
eaten by catfish are probably male, in agreement with the size distribution of bulldogs found in catfish stomachs. These results
suggest that sharptooth catfish rely heavily on their acute electrical sense during hunting, and an important function for
electroreception in an African catfish has been identified.
Received: 13 December 1999 / Revised: 20 April 2000 / Accepted: 20 May 2000 相似文献
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野生与养殖长吻血液及不同器官同工酶的比较 总被引:10,自引:0,他引:10
采用聚丙烯酰胺凝胶电泳(PAGE-Electrophorsis),对野生及养殖长吻Uai心脏、肾脏、肌肉、肝脏四个器官及血液的LDH(EC.1.1.1.27)、POD(EC.1.1.1.1)、EST(EC.3.1.1.1)、MDH(EC.1.1.1.37)同工酶所获电泳图谱进行对比分析,发现以上各酶在不同组织器官中均表现出组织特异性;野生Uai和养殖Uai四种同工酶也存在差异;LDH同工酶电泳带分 相似文献