900 MHz微波辐射对鸡胚心脏的影响

[目的]研究900MHz微波辐射对鸡胚心率、QRS间期、心脏超氧化物歧化酶(SOD)活性和HSP70mRNA水平的影响.[方法]海兰白鸡受精卵28枚,随机分为6组,对照组和辐射组各3小组,两个3小组都分别为4、5、5枚.辐射组在孵化的第5天至第20天每天接受4 h整体微波辐射.对照组不照射.利用壳膜外无损测量鸡胚心电图的方法,测定鸡胚心率和QRS间期;分别在鸡胚发育第13、20天采集心脏组织,以黄嘌呤氧化酶法测定SOD活性、RT-PCR法测.定HSPT0mRNA水平.[结果]辐射组鸡胚心率在孵化第20天与对照组相比,显著降低,而在第15天差异无统计学意义.辐射组鸡胚心脏组织匀浆的SOD活性在鸡胚孵化第13天与对照组相比,显著降低,而HSP70mRNA水平比对照组显著升高.到第20天时,辐射组鸡胚心脏SOD活性及HSPT0mRNA水平与对照组比较,差异未见统计学意义.[结论]900MHz微波辐射可以引起鸡胚心脏发生应激反应,并影响心率.     

Effects of polychlorinated biphenyls on thyroid hormones and liver type I monodeiodinase in the chick embryo.

Polychlorinated biphenyls (PCBs) are widespread environmental contaminants which can biomagnify to higher tropic level organisms including birds. Circulating thyroid hormones (TH) and growth are decreased by PCB exposure. The first set of studies investigated the effects of PCBs on an enzyme responsible for TH homeostasis, hepatic type I monodeiodinase (MDI) in chicken embryos. Fertile chicken eggs were injected with Aroclor 1242, Aroclor 1254, 2,2',6, 6'-tetrachlorobiphenyl (TCB), 3,3',4,4'-TCB, or 3,3',5,5'-TCB on Day 0 and studies were terminated on Incubation Day 21. Hepatic MDI activity was reduced in embryos treated with the Aroclor mixtures. No effects on MDI activities were observed after PCB isomer treatment. Liver weights from embryos treated with Aroclor 1242 were decreased. In the second study, chick embryos were exposed to these same PCBs in order to evaluate their effect on circulating THs and growth. Treatment with PCBs had no effect on body weight. Femur length were decreased with Arcolor 1242 treatment. A decrease in plasma concentration of thyroxine was observed after treatment with Aroclor 1242 and Aroclor 1254. Based on these findings, it is evident that PCBs alter the thyroid axis. Bird circulating TH levels, which are generally reported, may not be a good biomarker for low-dose exposure to PCBs. However, the reduction in MDI activity was more sensitive to PCB mixture exposure and may be a useful biomarker.     

In vivo imaging of activated estrogen receptors in utero by estrogens and bisphenol A

Environmental estrogens are of particular concern when exposure occurs during embryonic development. Although there are good models to study estrogenic activity of chemicals in adult animals, developmental exposure is much more difficult to test. The weak estrogenic activity of the environmental estrogen bisphenol A (BPA) in embryos is controversial. We have recently generated transgenic mice that carry a reporter construct with estrogen-responsive elements coupled to luciferase. We show that, using this in vivo model in combination with the IVIS imaging system, activation of estrogen receptors (ERs) by maternally applied BPA and other estrogens can be detected in living embryos in utero. Eight hours after exposure to 1 mg/kg BPA, ER transactivation could be significantly induced in the embryos. This was more potent than would be estimated from in vitro assays, although its intrinsic activity is still lower than that of diethylstilbestrol and 17beta-estradiol dipropionate. On the basis of these results, we conclude that the estrogenic potency of BPA estimated using in vitro assays might underestimate its estrogenic potential in embryos.     

Sister chromatid exchange induction by the herbicide 2,4-dichlorophenoxyacetic acid in chick embryos

As genetic damage may result from exposure to agricultural chemicals, it seemed appropriate to assess the genotoxic potential of 2,4-dichlorophenoxyacetic acid (2,4-D), a widely used broad-leaf herbicide, using a test system that may provide some indications on the genetic risk to animal species in the wild. In the present study, sister chromatid exchange (SCE) induction and cell cycle kinetics alterations by 2,4-D in 4-day old chick embryos were evaluated. Both a commercial herbicide formulation containing 37% 2,4-D isooctyl ester as active ingredient and pure 2,4-D were tested. Chick embryos were treated with 0, 0.5, 1, 2, or 4 mg 2,4-D. Test solutions were applied to the inner shell membrane on day 0 of incubation. Either commercial formulation or pure 2,4-D induced a dose-related increase in SCE frequency over the concentration range from 0 to 4 mg/embryo. Significantly higher SCE frequency was seen for the 4-mg group of embryos treated with the commercial product. A slightly higher SCE value was observed for the vehicle group (acetone-treated embryos) compared with the negative controls (untreated embryos). Significant inhibition of cell cycle progression was evident in both experimental groups and was generally dose related. The extent of changes in cell kinetics was similar in both groups, although somewhat more marked in the group treated with pure 2,4-D. The present findings corroborate the positive results from recent in vivo rodent studies.     

二硫化碳发育毒性的体外实验研究

本文应用大鼠全胚胎培养方法 检测了二硫化碳(CS_2)的发育毒性。孕鼠于妊娠7、8两天经呼吸道吸入浓度为100mg/m~3的CS_2,每天染毒4小时。取染毒孕鼠9.5天胚胎,于正常大鼠血清中培养44小时。结果表明,染毒组胚胎卵黄囊直径、颅臀长、头长、胚胎蛋白含量、体节数、鳃弓及前肢芽发生率明显低于对照组。表明CS_2能引起胚胎发育迟缓,具有发育毒性,与体内致畸实验结果一致。     

酒精对小鼠胚胎脑线粒体发育的影响

目的探讨孕期酒精染毒对后代脑线粒体发育的影响。方法ICR孕鼠随机分成3个酒精染毒组和一个空白对照组,染毒期为孕6～15天,孕18天剖腹取胎,提取胎鼠脑线粒体,测定线粒体膜电位、呼吸酶活性、ATP合成酶活性和线粒体内ATP含量。结果随着酒精染毒剂量的增高,胎鼠头体重比逐渐降低,中、高剂量组出现小头畸形;流式细胞检测显示胚胎脑线粒体幼稚群的比例逐渐增多,由对照组的18%上升到34%;在中、高剂量组呼吸酶复合体Ⅰ和Ⅳ的活性均较对照显著降低,30g(kg·d)染毒组分别相当于对照的917%和879%,60g(kg·d)染毒组分别相当于对照的724%and697%,呈剂量反应关系;60g(kg·d)染毒组胎鼠脑线粒体ATP合成酶的活性较对照显著降低,相当于对照的803%;30g(kg·d)和60g(kg·d)染毒组胎鼠脑线粒体内ATP的含量均较对照组显著降低。结论孕期酒精染毒能够影响胚胎脑线粒体的发育和功能成熟,可能与酒精所致神经管畸形有关。     

Participation of glucose in the synthesis of glycoproteins in preimplantation mouse embryos

Electrophoretic separation of solubilized embryos incubated for 24 h in the presence of [U-14C]glucose indicated incorporation of glucose carbon into a number of protein bands. Treatment of nitrocellulose blots of electrophoretograms with glucosidases had no effect on incorporated counts, confirming that the labelled bands were not due to protein bound glycogen. Furthermore, addition of 0.1 microgram mL-1 tunicamycin to the incubation medium virtually eliminated incorporation of glucose into the protein bands but had no effect on the pattern or rate of incorporation of labelled amino acids in parallel experiments. Also the pattern of labelling of protein by glucose was reflected in the pattern of binding of Con A to the nitrocellulose blots. There were quantitative and qualitative changes in labelling as development progressed. For embryos cultured from the 2-cell stage, a small amount of label was incorporated in two major bands at relative mobility (Mr) 69 and 97 K. With culture from the 8-cell stage, three additional major bands (33, 44 and 56 K) were labelled. Embryos cultured from the morula stage showed a different profile of incorporation; there was much more active labelling, and eight major and a number of minor radioactive bands were identified. Whilst tunicamycin suppressed glucose incorporation into glycoproteins and inhibited compaction of embryos, it had little effect on other parameters of metabolism during incubation in its presence for 24 h. No significant effects of the metabolite on protein synthesis, glycogen storage, lactate production or overall macromolecular synthesis were evident. By contrast, the anabolic metabolism of embryos decompacted by long periods of exposure to tunicamycin was severely reduced although glycolysis was still unaffected. Amphomycin at very high concentration (500 micrograms mL-1) was toxic to embryos but at concentrations up to 250 micrograms mL-1 had no effect on compaction and development of blastocysts. Addition of monensin to the incubation medium [16 micrograms mL-1] did not interfere with the development of either 2-cell or 8-cell embryos to blastocysts.     

Chronic ethanol alters CNS cholinergic and cerebellar development in chick embryos

Chick embryos were given daily injections of ethanol (approximately 30 mg/day) either chronically from embryonic days 4 to 15 (E4–E15) or E18, or acutely from E15 to E18. Untreated and saline-injected embryos served as controls. Although morphological indicators of developmental age were not different among groups, chronic ethanol reduced weights of several brain regions. Similar to rodent models of prenatal ethanol exposure, chronic ethanol treatment reduced cerebellar Purkinje cell numbers compared to controls. Chronic but not acute ethanol exposure resulted in a significant reduction in choline acetyltransferase activity in the optic tectum (OT) and forebrain (FB) compared with controls. This study demonstrates that the chick embryo is a viable model to investigate the effects of ethanol exposure on CNS development. Unlike the mammalian fetus, the avian embryo is isolated from maternal interactions and may prove more useful in investigating the mechanisms by which ethanol directly influences brain development.     

Oxidative stress in zebrafish embryos induced by short-term exposure to bisphenol A, nonylphenol, and their mixture

Bisphenol A (BPA) and nonylphenol (NP) are well-known endocrine-disrupting chemicals (EDCs) present in the aquatic environment, but little is known about their oxidative stress effects on fish embryos. In the present study, we examined the oxidative stress indices and antioxidant parameters of zebrafish embryos after a short-term exposure to various concentrations of BPA, NP, and their mixture (BPA-NP) for 4 h postfertilization (hpf) to 168 hpf. Exposure to the chemicals was found to enhance the production of hydroxyl radicals and lipid peroxidation in a concentration-dependent manner. The content of total glutathione (TG), reduced glutathione (GSH), and oxidized glutathione (GSSH), as well as the activity of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase were all significantly inhibited after exposure to BPA, NP, and BPA-NP, indicating the occurrence of oxidative stress. Coexposure to BPA-NP resulted in an additive effect on some antioxidant parameters. In addition, the alkaline phosphatase activity was also significantly inhibited after exposure to BPA, NP, and their mixtures. Our results demonstrated that BPA, NP, and BPA-NP in aquatic systems can affect antioxidant responses in zebrafish embryos.     

Effect of polybrominated biphenyls on the accumulation of DNA, RNA, and protein in cultured rat embryos following maternal administration

Using a system of whole-embryo culture, the effect of polybrominated biphenyls (PBB) was investigated on the rates of DNA, RNA, and protein accumulation in rat embryos. Embryos were isolated on the 10th gestational day (sperm day = Day 0) either 4 or 24 hr after maternal administration. The cultivation period was for 24 or 42 hr. DNA, RNA, and protein accumulation rates were not affected by a 4-hr previous maternal administration either at the beginning or following cultivation. At the beginning of cultivation for embryos exposed to PBB 24 hr before dissection, there was a significant reduction in DNA and total embryonic protein but RNA values were not affected. At 24 hr cultivation, protein values were no longer significantly different. DNA values remained significantly lower throughout culture. The significant anatomical differences noted at 24 hr cultivation were: (i) a failure of neuropore closure; (ii) a retention of a dorsiflexed position; (iii) a retardation in somite development; (iv) a reduced number with anterior limb buds present; (v) a reduction in the number establishing a visceral yolk sac circulation; and (vi) a decreased heart rate. After 42 hr in culture, the only significant anatomical differences were a reduction in the number of embryos developing anterior limb buds and a decrease in the number of somites added. It is concluded that the major embryonic effects of PBB for the first 24 hr after administration appear to be transitory if the embryo is removed from the exposure environment.     

Changes of procoagulant and fibrinolytic activities in the alveoli of rats exposed to ozone

The purpose of this study was to evaluate the role of ozone, a reactive product of environmental photochemical oxidation, in the development of pulmonary fibrosis. Male Wistar rats were exposed continuously to 0.5 ppm ozone for 1,4,7 and 14 days, and alveolar macrophages and lavage fluid obtained by bronchoalveolar lavage were examined. The results were as follows: 1) The total protein content in the lavage fluid was significantly increased compared to the control at 1 to 7 days by ozone exposure. Both alveolar macrophage and neutrophil counts increased in response to ozone exposure. However, approximately 90% of the free cells recovered were alveolar macrophages throughout the exposure period. 2) The plasminogen activator (PA) activity released from alveolar macrophages did not change in the group exposed for 1 day. But the activities were significantly high in the groups exposed for 4 to 14 days. 3) The PA activity of the lavage fluid showed a marked increase on the 1st day of ozone exposure, and subsequently decreased rapidly. However, the significantly increased activity was maintained throughout the exposure period. 4) In contrast, the procoagulant (PC) activity was unchanged on the 1st day of ozone exposure but the activity increased significantly on the 4th day, and was maintained at a high level until the 14th day. 5) The elastase inhibitory capacity (EIC) of the lavage fluid was significantly increased compared to the control by ozone exposure, but this difference was not seen throughout the exposure period when the EIC was corrected for the total protein content in the lavage fluid. These results revealed that both PA and PC activities increased in the alveolar fluid of rats exposed to 0.5 ppm ozone. The transition in the respective activities suggested that the fibrinolytic pathway in the alveoli was enhanced early in the exposure to ozone, while the coagulation pathway was enhanced later. This imbalance in coagulation homeostasis may be important in the regulation of fibrotic responses in the lungs of rats exposed to ozone. These findings are in agreement with morphological reports indicating that ozone exposure initially damaged the alveoli and later caused pulmonary fibrosis.     

Vitamin A effects on fetal mouse cephalic acetylcholinesterase and choline acetyltransferase

Pregnant C3H mice were exposed to vitamin A on the 7th to 10th day after copulation. Fetuses were examined at 18 or 19 days gestation for gross abnormalities, and assayed for total brain acetylcholinesterase (EC 3.1.1.7., AChE) activity and choline acetyltransferase (EC 2.3.1.6., ChAT) activity. A dose-related increase in embryolethality was found after treatment with vitamin A on day 9. Earlier administration of vitamin A on day 7 or 8 was associated with a higher fetal mortality. A marked increase in the incidence of gross abnormalities was found with an increase in dose of the teratogen. Administration of 5,000 IU vitamin A on day 9 was not associated with an alteration in fetal weight, brain weight or brain AChE activity. Similarly, there was no change in brain weight or AChE activity after 10,000 IU on day 9, although fetal weight was reduced. The administration of 10,000 IU on day 10, however, was associated with an elevated brain AChE activity, but no alteration in fetal weight, brain total protein content, or brain ChAT activity. The increased brain AChE activity was due predominantly to an increase in one of the isoenzymes. The results indicate that an alteration in brain AChE activity depends on the dose and timing of administration of vitamin A, and does not necessarily correlate with morphological abnormalities, ChAT activity, or brain protein content.Since x-irradiation and environmental contaminants such as carbamates and organophosphates may be teratogenic and affect adversely brain AChE activity following exposure to toxic amounts, these findings may also have a bearing on the toxicity to the fetus of agents other than vitamin A. Furthermore, the findings confirm the teratogenic potential of megadoses of vitamin A in the mouse fetus, a warning that also applies to humans, particularly with the increasing use of vitamin A and the retinoids.     

胚胎卵裂速度异常对囊胚形成的影响

目的:探讨卵裂速度异常对胚胎发育能力的影响。方法:回顾分析78个第2天未卵裂的胚胎及1 298个发育迟缓的胚胎继续培养至第6天的囊胚形成情况。结果:卵裂迟缓的胚胎囊胚形成率、优质囊胚率、胚胎利用率(24.7%、25.6%、6.3%)均显著低于卵裂速度正常的优质胚胎(50.3%、62.3%、31.3%),且细胞数越少囊胚形成率越低。第2～3天发育停滞的胚胎,其囊胚形成率、胚胎利用率(21.9%、4.7%)均显著低于继续卵裂的胚胎(27.7%、8.1%)。第2天未卵裂胚胎培养后无囊胚形成。结论:卵裂速度是影响胚胎发育能力的重要因素,第2天不卵裂的胚胎及第3天细胞数≤3的胚胎几乎无发育活性,第2～3天继续卵裂的胚胎具有较高的临床利用价值。     

The red tide toxin, brevetoxin, induces embryo toxicity and developmental abnormalities

Brevetoxins are lipophilic polyether toxins produced by the red tide dinoflagellate Gymnodinium breve, and their neurotoxic effects on adult animals have been documented. In this study, we characterized adverse developmental effects of brevetoxin-1 (PbTx-1) using an exposure paradigm that parallels the maternal oocyte transfer of toxin. Medaka fish (Oryzias latipes) embryos were exposed to PbTx-1 via microinjection of toxin reconstituted in a triolein oil droplet. Embryos microinjected with doses of 0.1-8.0 ng/egg (ppm) of brevetoxin-1 exhibited pronounced muscular activity (hyperkinesis) after embryonic day 4. Upon hatching, morphologic abnormalities were commonly found in embryos at the following lowest adverse effect levels: 1.0-3.0 ppm, lateral curvature of the spinal column; 3.1-3.4 ppm, herniation of brain meninges through defects in the skull; and 3.4-4.0 ppm, malpositioned eye. Hatching abnormalities were also commonly observed at brevetoxin doses of 2.0 ppm and higher with head-first, as opposed to the normal tail-first, hatching, and doses > 4.1 ng/egg produced embryos that developed but failed to hatch. Given the similarity of developmental processes found between higher and lower vertebrates, teratogenic effects of brevetoxins have the potential to occur among different phylogenetic classes. The observation of developmental abnormalities after PbTx-1 exposure identifies a new spectrum of adverse effects that may be expected to occur following exposure to G. breve red tide events.     

Effects of Phos-Chek G75-F and Silv-Ex on developing northern bobwhite quail (Colinus virginianus)

Eggs of nesting birds situated in peripheral areas serving as fire breaks are at risk of being sprayed with fire control chemicals. Acute toxicity tests were conducted by immersing northern bobwhite quail eggs for 10 s in different water-based concentrations of Silv-Ex(R) (SE), a foam-suppressant chemical, and Phos-Chek(R) G75-F (PC), a fire retardant chemical, on day 4 or day 11 of incubation. An attempt was made to relate the treatment concentrations to the actual field application levels. Mortality appeared higher in most groups exposed on day 11 than on day 4, suggesting that on day 11 the extensive chorioallantoic vascular network permitted greater uptake of chemical. Only 24-60% of the embryos survived to hatch at exposure concentrations of 202, 269, and 454 g/L PC when treated on incubation day 11. At higher concentrations including 681956, and 1211 g/L PC, the compound did not completely dissolve in water and clumped on eggshells, resulting in greater hatching success. Exposures to SE at 100 g/L on incubation day 11 did not significantly affect hatching success of embryos but did significantly reduce the percent hematocrit in blood compared with controls. Incubation day 11 exposure to 202 and 1211 g/L PC led to a significant increase in plasma aspartate aminotransferase, and day 4 exposure to 1211 g/L PC resulted in a significant increase in alanine aminotransferase. In addition to elevated liver enzymes, these treatments resulted in a decrease in the number of hepatocyte profiles (1211 g/L PC at day 4 and day 11) and an increase in hepatocyte size (202 and 1211 g/L PC at day 11) in hatchlings. A combination of SE and PC was synergistic (202 g/L PC and 50 g/L SE) at day 11 of incubation with respect to decreased hatching success and reduced bone lengths. However, lower concentrations of SE (10 g/L or 30 g/L) combined with 202 g/L of PC appeared antagonistic. This may be due to SE, as a surfactant, altering the ability of PC to penetrate the egg. Our results show fewer adverse effects following exposure to SE than to PC; therefore application of SE may be less harmful to breeding bird populations.     

Effects of Phos-Chek G75-F and Silv-Ex on Developing Northern Bobwhite Quail (Colinus virginianus)

Eggs of nesting birds situated in peripheral areas serving as fire breaks are at risk of being sprayed with fire control chemicals. Acute toxicity tests were conducted by immersing northern bobwhite quail eggs for 10 s in different water-based concentrations of Silv-Ex® (SE), a foam-suppressant chemical, and Phos-Chek® G75-F (PC), a fire retardant chemical, on day 4 or day 11 of incubation. An attempt was made to relate the treatment concentrations to the actual field application levels. Mortality appeared higher in most groups exposed on day 11 than on day 4, suggesting that on day 11 the extensive chorioallantoic vascular network permitted greater uptake of chemical. Only 24–60% of the embryos survived to hatch at exposure concentrations of 202, 269, and 454 g/L PC when treated on incubation day 11. At higher concentrations including 681, 956, and 1,211 g/L PC, the compound did not completely dissolve in water and clumped on eggshells, resulting in greater hatching success. Exposures to SE at 100 g/L on incubation day 11 did not significantly affect hatching success of embryos but did significantly reduce the percent hematocrit in blood compared with controls. Incubation day 11 exposure to 202 and 1,211 g/L PC led to a significant increase in plasma aspartate aminotransferase, and day 4 exposure to 1,211 g/L PC resulted in a significant increase in alanine aminotransferase. In addition to elevated liver enzymes, these treatments resulted in a decrease in the number of hepatocyte profiles (1,211 g/L PC at day 4 and day 11) and an increase in hepatocyte size (202 and 1,211 g/L PC at day 11) in hatchlings. A combination of SE and PC was synergistic (202 g/L PC and 50 g/L SE) at day 11 of incubation with respect to decreased hatching success and reduced bone lengths. However, lower concentrations of SE (10 g/L or 30 g/L) combined with 202 g/L of PC appeared antagonistic. This may be due to SE, as a surfactant, altering the ability of PC to penetrate the egg. Our results show fewer adverse effects following exposure to SE than to PC; therefore application of SE may be less harmful to breeding bird populations.     

Pulmonary effects due to subchronic exposure to oil fog

Male and in some cases female rats were exposed to an oil fog generated by flash vaporization and subsequent condensation of light-weight lubricating oil. Exposures were for 3.5 h/d, 4d/wk for 13 wk. Males were exposed at concentrations of 1.5, 0.5, 0.2 or 0.0 mg/l (1500, 500, 200, and 0 mg/m3) and a particle size of approximately 1 micron (mass median aerodynamic diameter). A number of biologic endpoints were assessed the day after the last exposure and, in some cases, after a 4 wk recovery period. Effects of 1.5 mg/l on male and female rats were compared. Diffuse accumulation of macrophages in the alveoli was observed in all oil fog exposed groups. The degree of severity was concentration dependent. Histopathologic changes were more prominent in males than in females and represented the most notable gender-related differences. Histologic effects observed one day and 4 wk post exposure were similar. Minimal histopathologic changes and minimal increase in lavage fluid protein were the only effects observed at the 0.2 mg/l exposure level. There was a significant increase in lavage fluid protein, percent lavagable polymorphonuclear leukocytes and lung wet and dry weight following exposure to both 0.5 and 1.5 mg/l. At the highest exposure concentration effects on lung weights were still evident 4 wk post exposure. Pulmonary function endpoints including total lung capacity, vital capacity, residual volume, diffusing capacity to CO, compliance, and end expiratory volume (EEV) were unaffected by oil fog exposure with the exception of EEV in males exposed at the 1.5 mg/l level. All of the changes observed following oil fog exposure were consistent with a mild inflammatory edema.     

亚致死性浓度的二噁英在斑马鱼胚胎中所致的毒性反应

[目的]观察亚致死性浓度的二噁英（TCDD）对斑马鱼胚胎发育的毒性作用。[方法]将72hpf（受精后小时）斑马鱼胚胎暴露于渐升的TCDD亚致死性浓度下,观察累积死亡率、心功能及颌软骨发育的变化,与对照组比较。[结果]10pg／ml及25pg／ml的TCDD浓度所导致的两周内的累积死亡率与对照组类似。然而在胚胎内这两种浓度的TCDD均能导致急性及亚急性心脏毒性。暴露在这两种浓度TCDD下与对照组相比,在毒物处理后的12h、1d、2d及1周后胚胎均表现出心每搏输出量及心输出量的显著降低。最显著的发现是72hpf胚胎在10pg／ml的TCDD处理后1周表现出显著的每搏输出量及心输出量降低,伴轻微的心包积液。[结果]该研究表明较低浓度的二噁英污染对野生鱼类能造成威胁,而亚致死性浓度的TCDD对胚胎的颌骨发育无影响。