首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Freshwater fish, topmouth gudgeon (Pseudorasobora parva), were pretreated with piperronyl butoxide (PBO) or triphenyl phosphate (TPP) and then exposed to different concentrations of fenitrothion (FNT) in a static system. Evaluation of brain acetylcholinesterase (AchE) activity after 24, 48 and 96 h pesticide exposure indicated that AchE activity decreased as the concentration increased. Fish pretreated with TPP exhibited significantly decreased AchE activity whilst in the PBO pretreated group, increased activity was observed as compared with those exposed to FNT alone. The pattern of AchE recovery was also assessed in fish previously exposed for 96h and then transferred to clean (chemical free) water. Following 8 days of recovery period, the AchE activity of those exposed to FNT alone and pretreated with TPP was still lower than that of the control. This study showed that FNT may cause hazard to fish after field application.  相似文献   

2.
INTRODUCTIONFenitrothion(0,0dimethyl0(3methyl4nitrophenol)phosphorothioate),theactiveingredientintheformulatedproductsumithion,isanorganophosphate(O-P)insecticideandusedinagricultureforcropprotectionandcontrolofvectorborndiseasesinvariouscountries(Selfetal.,19…  相似文献   

3.
Two common fish species, mosquitofish (Gambusia affinis) and topmouth gudgeon (Pseudorasobora para) were exposed to different concentrations of fenitrothion in static system for 96 h. Hepatic glutathione S-transferase activity was evaluated after 48 and 96 h pesticide exposure, and was also examined in fish pretreated with pepironyl butoxide and triphenyl phosphate and then exposed to fenitrothion. Results indicated presence of intense glutathione S-transferase activity in both species, mosquitofish exhibiting the higher activity. In both species the activity decreased as the concentration of fenitrothion increased, topmouth gudgeon being more susceptible than mosquitofish. In mosquitofish pretreated with pepironyl butoxide, glutathione S-transferase activity was increased (11.8%) compared with the control but in topmouth gudgeon it was decreased (21.6%) at the end of 96 h. Glutathione S-transferase activity was significantly reduced in both species pretreated with triphenyl phosphate at the end of 96 h exposure, topmouth gudgeon being highly susceptible. Ph. D. student, from Southern Ethiopia Health Bureau, Center for Health Research, P. O. Box 317, Awassa, F. R. Ethiopia.  相似文献   

4.
为研究硒镉联合作用对番茄根尖细胞遗传学效应,用不同硒浓度和100μmol/L镉联合处理番茄根尖24 h、48 h、72 h、96 h,统计有丝分裂指数、染色体畸变率和微核率.结果表明:单一镉处理时番茄根尖细胞有丝分裂指数下降,染色体畸变率和微核率增加,且随时间的延长而毒害加深.硒镉处理时,硒浓度低于1.0μmol/L时番茄根尖细胞有丝分裂指数增加,染色体畸变率和微核率下降,高于1.0μmol/L时番茄根尖细胞有丝分裂下降,染色体畸变率和微核率升高,但浓度过高时,微核率随着镉处理时间的延长反而有所降低,表现出低浓度硒对镉的毒害有缓解作用,高浓度硒与镉协同毒害作用.  相似文献   

5.
The aim was to investigate how the PI3K/Akt pathway is involved in the protection of dexmedetomidine against propofol. The hippocampal neurons from fetal rats were separated and cultured in a neurobasal medium. Cell viability was assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Then neurons were pretreated with different concentrations of dexmedetomidine before 100 μmol/L propofol was added. Akt, phospho-Akt (p-Akt), Bad, phospho-Bad (p-Bad), and Bcl-xL were detected by Western blot. Also, neurons were pretreated with dexmedetomidine alone or given the inhibitor LY294002 before dexmedetomidine pretreatment, and then propofol was added for 3 h. The results demonstrated that propofol decreased the cell viability and the expression of p-Akt and p-Bad proteins, increased the level of Bad, and reduced the ratio of Bcl-xL/Bad. Dexmedetomidine pretreatment could reverse these effects. The enhancement of p-Akt and p-Bad induced by dexmedetomidine was prevented by LY294002. These results showed that dexmedetomidine potently protected the developing neuron and this protection may be partly mediated by the PI3K/Akt pathway.  相似文献   

6.
目的:研究肢体缺血预处理(LIP)对大鼠缺血再灌后心脏损伤的影响。方法:采用反复捆绑后肢造成缺血预适应的方法,观察其对心肌缺血再灌后梗死面积和形态学改变的影响,对心肌CK-MB和cTn-I的影响,以及对抗氧化物酶的影响。结果:与缺血再灌组比较,预处理能明显降低心肌梗死面积,减轻心肌细胞的损害,减少心肌酶的漏出并能提高SOD的活性。结论:LIP对心肌损伤具有保护作用。  相似文献   

7.
The attenuating effect of daidzein (DAD on oxidative toxicity induced by Aroclor 1254 (A 1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A 1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with DAI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary DAI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.  相似文献   

8.
The effects of different fatty acid (FA) contents in diet on serum parameters, FA compositions of eggs and meat, and liver morphological changes were studied in Shaoxing laying ducks. A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil (FO), 25 g/kg sunflower oil (SO), or 30 g/kg palm oil with 20 g/kg beef tallow (PBO). Malondialdehyde (MDA) content in the liver and the serum of ducks fed the PBO diet was significantly (P<0.05) higher than that of ducks fed the other diets. Triglyceride (TG) and total cholesterol (TC) levels were significantly lower (P<0.05) in ducks fed the FO diet. Serum TC also was lower in ducks fed the SO diet. Superoxide dismutase (SOD) activity was also affected by diets. The contents of polyunsaturated FAs (PUFAs) in eggs and meat were significantly higher (P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet. The level of C22:6 (n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets. However, the conversion efficiency of the longer-chain C20:5 (n-3) FA was higher than that of C22:6 (n-3). Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver. These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids.  相似文献   

9.
A relationship between status epilepticus (SE) and oxidative stress has recently begun to be recognized. To explore whether the flavonoids extracted from licorice (LFs) have any protective effect on kainate (KA)-induced seizure in mice, we treated mice with LFs before and after KA injection. In KA-treated mice, we found that superoxide dismutase (SOD) activity decreased immediately after the onset of seizure at 1 h and then increased at 6 h. It returned to baseline 1 d after seizure and then increased again at 3, 7, and 28 d, while malondialdehyde (MDA) content remained at a high level at 1 h, 6 h, 3 d, 7 d, and 28 d, indicating a more oxidized status related to the presence of more reactive oxygen species (ROS). Treatment with LFs before KA injection reversed the seizure-induced change in SOD activity and MDA content at 1 h, 6 h, 3 d, 7 d, and 28 d. Treatment with LFs after seizure decreased KA-induced SOD activity and MDA content at 7 and 28 d. Also, LF pre- and post-KA treatments decreased seizure-induced neuronal cell death. Subsequently, Morris water maze tests revealed that the escape latency was significantly decreased and the number of target quadrant crossings was markedly increased in the LF-treated groups. Thus, our data indicate that LFs have protective effects on seizure-induced neuronal cell death and cognitive impairment through their anti-oxidative effects.  相似文献   

10.
We studied the responses of the activities of adenosine-triphosphate (ATP) sulfurylase (ATPS) and serine acetyl-transferase (SAT) to cadmium (Cd) levels and treatment time in hyperaccumulating ecotype (HE) Sedum alfredii Hance, as compared with its non-hyperaccumulating ecotype (NHE). The results show that plant growth was inhibited in NHE but promoted in HE when exposed to high Cd level. Cd concentrations in leaves and shoots rapidly increased in HE rather than in NHE, and they became much higher in HE than in NHE along with increasing treatment time and Cd supply levels. ATPS activity was higher in HE than in NHE in all Cd treatments, and increased with increasing Cd supply levels in both HE and NHE when exposed to Cd treatment within 8 h. However, a marked difference of ATPS activity between HE and NHE was found with Cd treatment for 168 h, where ATPS activity increased in HE but decreased in NHE. Similarly, SAT activity was higher in HE than in NHE at all Cd treatments, but was more sensitive in NHE than in HE. Both ATPS and SAT activities in NHE leaves tended to decrease with increasing treatment time after 8 h at all Cd levels. The results reveal the different responses in sulfur assimilation enzymes and Cd accumulation between HE and NHE. With increasing Cd stress, the activities of sulfur assimilation enzymes (ATPS and SAT) were induced in HE, which may contribute to Cd accumulation in the hyperaccumulator Sedum alfredii Hance.  相似文献   

11.
The effect of total dissolved gas (TDG) supersaturation on fish living downstream of dams is one of the main ecological risks of high dam construction. A strategy for mitigating the negative effects is needed urgently since many high dams are under construction in the upper reaches of the Yangtze River in China. Experiments on the hatching process of David’s schizothoracin were carried out and the results show that the hatching rate decreased with increasing TDG levels, and that most eggs hatched within a very short time in the higher TDG saturation groups. By using a stereomicroscope, damages to the head, yolk sac, body, anus, etc. were found in larvae which hatched in TDG supersaturated water. Results show that the lesion rate increased with increasing TDG levels. Furthermore, 7-d-old David’s schizothoracin were exposed to TDG supersaturated water levels of 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, and 140% for testing their tolerance to TDG supersaturation. We found that the median lethal concentrations (LC50 ) for 13, 14, 20, 35, 52, 73, and 96 h exposure were 138%, 138%, 134%, 130%, 129%, 128%, and 126%, respectively. The median lethal times (LT50 ) were 7.49, 11.04, 19.25, and 35.38 h for exposure to water with TDG levels of 145%, 140%, 135%, and 130%, respectively.  相似文献   

12.
To investigate the effect of glycitein, a synthetic soybean isoflavone (ISF), on the intestinal antioxidant capacity, morphology, and cytokine content in young piglets fed oxidized fish oil, 72 4-d-old male piglets were assigned to three treatments. The control group was fed a basal diet containing fresh fish oil, and the other two groups received the same diet except for the substitution with the same dosage of oxidized fish oil alone or with ISF (oxidized fish oil plus ISF). After 21 d of feeding, supplementation of oxidized fish oil increased the levels of malondialdehyde (MDA), oxidized glutathione (GSSG), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), nuclear factor κ B (NF-κB), inducible nitric oxide synthase (iNOS), NO, and Caspase-3 in jejunal mucosa, and decreased the villous height in duodenum and the levels of secretory immunoglobulin A (sIgA) and IL-4 in the jejunal mucosa compared with supplementation with fresh oil. The addition of oxidized fish oil plus ISF partially alleviated this negative effect. The addition of oxidized fish oil plus ISF increased the villous height and levels of sIgA and IL-4 in jejunal mucosa, but decreased the levels of IL-1β and IL-2 in jejunal mucosa (P<0.05) compared with oxidized fish oil. Collectively, these results show that dietary supplementation of ISF could partly alleviate the negative effect of oxidized fish oil by improving the intestinal morphology as well as the antioxidant capacity and immune function in young piglets.  相似文献   

13.
We studied the responses of the activities of adenosine-triphosphate (ATP) sulfurylase (ATPS) and serine acetyltransferase (SAT) to cadmium (Cd) levels and treatment time in hyperaccumulating ecotype (HE) Sedum alfredii Hance, as compared with its non-hyperaccumulating ecotype (NHE). The results show that plant growth was inhibited in NHE but promoted in HE when exposed to high Cd level. Cd concentrations in leaves and shoots rapidly increased in HE rather than in NHE, and they became much higher in HE than in NHE along with increasing treatment time and Cd supply levels. ATPS activity was higher in HE than in NHE in all Cd treatments, and increased with increasing Cd supply levels in both HE and NHE when exposed to Cd treatment within 8 h. However, a marked difference of ATPS activity between HE and NHE was found with Cd treatment for 168 h, where ATPS activity increased in HE but decreased in NHE. Similarly, SAT activity was higher in HE than in NHE at all Cd treatments, but was more sensitive in NHE than in HE. Both ATPS and SAT activities in NHE leaves tended to decrease with increasing treatment time after 8 h at all Cd levels. The results reveal the different responses in sulfur assimilation enzymes and Cd accumulation between HE and NHE. With increasing Cd stress, the activities of sulfur assimilation enzymes (ATPS and SAT) were induced in HE, which may contribute to Cd accumulation in the hyperaccumulator Sedum alfredii Hance. Project supported by the National Natural Science Foundation of China (No. 30630046) and the Hi-Tech Research and Development Program (863) of China (No. 2006AA06Z386), and the Program for Changjiang Scholars and Innovative Research Team in University, China (No. IRT0536)  相似文献   

14.
烟草感染马铃薯Y病毒脉坏死株系后,过氧化物酶活性升高,但非转基因敏感烟草升高的幅度大于转基因抗病烟草;同时,非转基固敏感烟草的苯丙氨酸解氨酶和多酚氧化酶活性均增高,并且都出现两个活性高峰,但转基因抗病烟草的苯丙氨酸解氨酶活性仅出现第一个活性高峰,随后其活性值降低并逐渐恢复至未接种时的水平,而多酚氧化酶活性则降低;在未感染PVYN的情况下,转基因抗病烟草的过氧化物酶、苯丙氨酸解氨酶和多酚氧化酶活性均比非转基因敏感烟草高.  相似文献   

15.
Forty-eight maleBetta splendens were assigned to three groups of 16 (eight pairs) each. In two of the groups, pairs of fish were first allowed to fight until a dominance-subordinance relationship was established. Then each subject was tested on measures of time spent in approach and threat display toward either (1) its own pair member, with which it was experienced and familiar (Group EF), or toward (2) another combat-experienced fish, with which it was unfamiliar (Group EU). A third group of inexperienced and unfamiliar individuals (Group IU) were first exposed to their own mirror images and then tested for approach and threat-display duration. Pairs of these fish were then allowed to fight until dominance was determined. The three major findings were: (a) Dominant subjects approached and displayed significantly more than subordinates in all three groups; (2) Dominant subjects of Group IU did not differ significantly from dominants in the other two groups with respect to time spent in approach and display; and (3) Fish exposed to mirrors prior to combat required significantly fewer sessions to establish dominance than fish not receiving mirror exposure. Results suggest that dominant fish can be distinguished on the basis of their approach tendency and threat-display scores prior to actual physical combat. An habituation model of dominance determination was proposed.  相似文献   

16.
Children within institutional care settings experience significant global growth suppression, which is more profound in children with a higher baseline risk of growth impairment (e.g., low birth weight [LBW] infants and children exposed to alcohol in utero). Nutritional insufficiencies as well as suppression of the growth hormone–insulin‐like growth factor axis (GH‐IGF‐1) caused by social deprivation likely both contribute to the etiology of psychosocial growth failure within these settings. Their relative importance and the consequent clinical presentations probably relate to the age of the child. While catch‐up growth in height and weight are rapid when children are placed in a more nurturing environment, many factors, particularly early progression through puberty, compromise final height. Potential for growth recovery is greatest in younger children and within more nurturing environments where catch‐up in height and weight is positively correlated with caregiver sensitivity and positive regard. Growth recovery has wider implications for child well‐being than size alone, because catch‐up in height is a positive predictor of cognitive recovery as well. Even with growth recovery, persistent abnormalities of the hypothalamic‐pituitary‐adrenal system or the exacerbation of micronutrient deficiencies associated with robust catch‐up growth during critical periods of development could potentially influence or be responsible for the cognitive, behavioral, and emotional sequelae of early childhood deprivation. Findings in growth‐restricted infants and those children with psychosocial growth are similar, suggesting that children experiencing growth restriction within institutional settings may also share the risk of developing the metabolic syndrome in adulthood (obesity, Type 2 diabetes mellitus, hypertension, heart disease). Psychosocial deprivation within any caregiving environment during early life must be viewed with as much concern as any severely debilitating childhood disease.  相似文献   

17.
In three experiments in which rats were used as subjects, we developed an extinction procedure using a Morris pool. The animals were trained to find a hidden platform located at a fixed position and were then given extinction trials in which the platform was removed from the pool. When training and extinction were carried out in the same context and time was allowed to elapse between extinction and test, spontaneous recovery of learning was observed. On the other hand, those rats that received extinction in a context different from the one used for training failed to show spontaneous recovery of learning when tested in the extinction context after an interval of 96 h. However, they did show renewal of spatial learning when tested in the training context. These results show that extinction in the spatial domain behaves like extinction in standard conditioning preparations.  相似文献   

18.
肉鸡肺动脉高压肝脏和心脏线粒体氧自由基变化研究   总被引:6,自引:0,他引:6  
400只艾维茵肉鸡按常规方法育雏在21日龄时随机分为两组,A组200只在24℃下饲养,B组200只在低温12℃下饲养。在28、35、42、49日龄测定腹水心脏指数和红细胞压积,分离鉴定腹水肉鸡心、肝线粒体,测定其所含的MnSOD活性以及线粒体膜结构的MDA含量变化经。结果表明:(1)低温处理后一周和二周,在肝脏和心脏线粒体中,SOD含量升高或显著升高(p<0.05)。MDA含量降低或显著降低(p<0.05)。(2)低温处理三周后,SOD的含量降低或显著降低。MDA的含量升高或显著升高(p<0.05)。本实验结果显示肝脏和心脏的线粒体SOD和MDA的变化与肉鸡腹水综合征的发生发展关系密切,氧自由基在亚细胞水平上参与了疾病的病理过程。  相似文献   

19.
INTRODUCTION Fish behavior under culture conditions holds important information for aquaculturist (McFarlane et al., 2004; Kristiansen et al., 2004). Most physiological,environmental changes and handling process can in-duce variations in fish behavior (Israeli and Kimmel, 1996; Israeli-Weinstein and Kimmel, 1998; Petrell and Ang, 2001; Almazán-Rueda et al., 2004). Meth-ods of monitoring and quantifying the behavioral re-sponse have become potential alternatives for assess-ing stress…  相似文献   

20.
目的:通过观察预热处理前后大鼠急性运动股四头肌热休克蛋白70(HSP70)、超氧化物歧化酶(SOD)、丙二醛(MDA)的变化,探讨预热处理诱导HSP70表达对运动机体的保护作用.方法:三月龄雄性SD大鼠随机分为室温安静组、室温运动后即刻组、室温运动后3 h组、预热处理安静组、预热处理运动后即刻组、预热处理运动后3 h组.预热处理组进行热暴露处理后,室温恢复24 h后,运动组大鼠进行一次急性运动,运动后即刻和3h进行取样,对股四头肌HSP70的含量、SOD活性、MDA含量进行测试.结果:(1)预热处理安静组HSP70含量明显高于室温安静组(P<0.05)(2)室温组运动后即刻股四头肌HSP70有上升的趋势,但与安静组比较没有显著性的差异,预热处理组运动后即刻HSP70的含量与预热处理安静组比较有显著性的差异,运动后3 h,两组HSP70的表达都明显增加.(3)运动后即刻股四头肌SOD的活性明显升高,3 h后其活性降低,但与安静组比较仍具有显著性差异.在变化过程中预热处理组SOD活性高于室温组.(4)运动后即刻股四头肌MDA的含量明显升高,3 h后减少,在运动后前3 h,预热处理组MDA的清除比室温组迅速,有显著性差异.以上结果表明预热处理诱导HSP70的大量表达可提高运动时SOD活性,降低MDA的含量.提示HSP70可能会提高机体的抗氧化能力,减少自由基对机体的损害,对运动机体具有一定的保护作用.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号