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综合论述了稀土元素在机体肝脏的蓄积性及其毒性效应,分析了稀土农业应用对生态环境和人群健康的危害。稀土元素被长期低剂量摄入,可在肝脏中蓄积,导致肝脏形态和病理组织变化、肝细胞损伤、肝代谢紊乱引起脂肪肝;高于2 mg.kg-1剂量的农用稀土(常乐)仍能通过胎盘屏障引起肝细胞和发育中的红细胞DNA损伤。 相似文献
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氧化应激的产生及其对畜禽肝脏功能的影响与机制 总被引：1，自引：0，他引：1
现代畜牧业规模化生产中,养殖环境、饲粮构成、饲养方式等诸多因素变化可诱发畜禽产生氧化应激。氧化应激对畜禽的肝脏功能有负面作用,危害畜禽健康和生产。机体发生氧化应激时,大量的氧自由基在肝细胞内蓄积,通过损伤生物大分子物质、破坏肝细胞结构、影响细胞器功能、诱发肝细胞凋亡等,对肝脏造成严重损伤,并引发多种肝脏疾病。本文从机体氧化应激产生、氧化应激对肝脏功能的影响以及氧化应激影响肝脏功能的可能分子机制等方面进行综述,以期为缓解氧化应激危害提供理论依据。 相似文献
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1病因分析急性实质性肝炎是在致病因素的作用下,肝脏发生以肝细胞变性、坏死为主要特征的炎症。本病各种家畜、家禽都有发生。急性实质性肝炎主要是由传染性因素与中毒性因素引起。常见的传染性因素有细菌性因素、病毒性因素和寄生虫性因素。细菌性因素,如链球菌、葡萄球菌、坏死杆菌、结核杆菌、牛沙门氏菌及钩端螺旋体等都可引起肝炎。病毒性因素,犬病毒性肝炎病毒、鸭病毒性肝炎病毒等都可引起肝炎。寄生虫性因素,弓形虫、球虫、肝片吸虫、血吸虫等感染,可发生肝炎。进入肝脏的病原体,不仅可以破坏肝组织而产生毒性物质,同时其自身在代谢过程中也释放大量毒素,并且还以机械损伤作用使肝脏受到损伤,导致肝细胞变性、坏死。 相似文献
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霉菌毒素中毒引起母猪繁殖障碍的主要原因是由于猪只采食了发霉腐烂的饲料后引起的一种中毒性疾病,并且在各种年龄、品种的猪都可引起发生。妊娠母猪和小乳仔猪更为敏感。妊娠母猪和商品猪均从肝脏受到侵害。表现为肝脏充血和出血,在肝脏、肾脏实质变性、坏死导致肝细胞变性、胆管和肝细胞增生、怀孕母猪流产、公猪产生包皮炎和阴茎肿胀。 相似文献
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稀土元素是化学元素周期表中镧系元素及其化学性质相似的钪和钇共17种元素的总称.其化学组成一般为铈48%、镧25%、钕16 %、钐2%、镨5%,其他12种元素如铕、铒、钇等仅占4%.稀土添加剂分有机稀土和无机稀土两种.无机稀土主要有碳酸稀土、氯化稀土和硝酸稀土,目前应用较多的是硝酸稀土;有机稀土包括氨基酸稀土螯合物(稀土氨基酸、稀土甲壳素、稀土壳聚糖、稀土酵母)、有机稀土添加剂(如柠檬酸稀土、维生素C稀土、富马酸稀土)等;根据添加剂中所含稀土元素的种类还可以分为单一稀土添加剂和复合稀土添加剂. 相似文献
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稀土元素在家兔饲料中的应用 总被引：2，自引：0，他引：2
稀土元素是元素周期表中镧系元素和化学性质相似的钪,钇等17种元素的总称，由于它具有特殊的结构和较强的活性，近年来，在家兔饲料中的应用日渐广泛，并取得了良好的效果。1稀土元素的种类稀土元素分轻稀土元素和重稀土元素两类。目前常用的多为轻稀土元素，其原子序数小，离子半径大，呈弱碱性，通常以三价离子状态存在，其产品主要有：硝酸稀土，盐酸稀土，碳酸稀土和维生素C—稀土。在家兔饲养中应用最多的为硝酸稀土。2稀土元素在体内的分布与代谢2.1分布：稀土元素广泛存在于肺、肾、肝、脾、心、血、毛等组织器官中，但并非均匀分布… 相似文献
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《中国畜牧兽医文摘》2012,(6)
<正>1病因犬肝脏对高脂肪、病毒、寄生虫、毒物等造成损伤的应答反应,当犬的血清中胆红素浓度超过34umol/L时,组织发生黄染,可确诊为黄疸。黄瘟以良种犬或杂交犬多发,地方土种犬发病较少。肝细胞是胆红素代谢的主要器官,肝细胞的损伤会影响胆红素的摄取、结合、分泌和排泄,导致血清胆红素增高出现肝细胞性黄疸。肝细胞内和胆小管及肝内小胆管胆汁郁积。也可引起血 相似文献
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Tomoya Yamada 《Journal of toxicologic pathology》2021,34(4):283
The constitutive androstane receptor (CAR)-mediated mode of action (MOA) for phenobarbital (PB)-induced rodent liver tumor formation has been established, with increased hepatocyte proliferation, which is a key event in tumor formation. Previous studies have demonstrated that PB and other CAR-activators stimulate proliferation in cultured rodent hepatocytes, but not in cultured human hepatocytes. However, in the genetically humanized CAR and pregnane X receptor (PXR) mouse (hCAR/hPXR mouse, downstream genes are still mouse), PB increased hepatocyte proliferation and tumor production in vivo. In contrast to the hCAR/hPXR mouse, studies with chimeric mice with human hepatocytes (PXB-mouse, both receptor and downstream genes are human) demonstrated that PB did not increase human hepatocyte proliferation in vivo. PB increased hepatocyte proliferation in a chimeric mouse model with rat hepatocytes, indicating that the lack of human hepatocyte proliferation is not due to any functional defect in the chimeric mouse liver environment. Gene expression analysis demonstrated that the downstream genes of CAR/PXR activation were similar in hCAR/hPXR and CD-1 mice, but differed from those observed in chimeric mice with human hepatocytes. These findings strongly support the conclusion that the MOA for CAR-mediated rodent liver tumor formation is qualitatively implausible for humans. Indeed, epidemiological studies have found no causal link between PB and human liver tumors. There are many similarities with respect to hepatic effects and species differences between rodent CAR and peroxisome proliferator-activated receptor α activators. Based on our research, the chimeric mouse with human hepatocytes (PXB-mouse) is reliable for human cancer risk assessment of test chemicals. 相似文献
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Bexfield NH Andres-Abdo C Scase TJ Constantino-Casas F Watson PJ 《The Veterinary record》2011,169(16):415
Medical records and liver histology of 68 English springer spaniels (ESS) with a histological diagnosis of CH were reviewed retrospectively. PCR was performed on liver tissue for canine adenovirus-1 (CAV-1), canine parvovirus, canine herpesvirus and pathogenic Leptospira species. Follow-up information was obtained to calculate survival times. Median age at presentation was three years seven months (range, seven months to eight years five months) and there were 48 female and 20 male dogs. Clinical signs were non-specific and five dogs were asymptomatic. All dogs had an increase in serum activity of one or more hepatobiliary enzymes. Histopathology demonstrated hepatocyte necrosis and apoptosis with varying amounts of fibrosis. A predominantly lymphoplasmacytic infiltrate throughout the hepatic parenchyma was found in all 68 dogs, but 45 of these dogs also had a neutrophilic component to the inflammatory infiltrate. There was no significant copper accumulation and no aetiological agent was identified by PCR. The median survival time was 189 days (range, 1 to 1211 days), 38 dogs died within three months and 12 dogs survived more than a year following diagnosis. 相似文献
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Anne Bahr DVM Gregory B. Daniel DVM MS Robert DeNovo DVM MS Karen Young BS Joyce L. Merryman DVM PhD 《Veterinary radiology & ultrasound》1996,37(3):214-220
A nuclear medicine procedure that has been used for quantification of hepatocyte function in man is applied and validated in the dog. This procedure employs deconvolutional analysis of liver and heart time activity curves obtained following peripheral intravenous injection of hepatobiliary radiopharmaceutical. The deconvolutional analysis simulates a bolus injection of the radiopharmaceutical into the afferent blood supple of the liver which permits the calculation of the hepatic extraction fraction. Hepatic extraction fraction is a measure of hepatocyte function. In this report, the deconvolutional analysis via fast Fourier transformations and subsequent calculation of hepatic extraction fraction is validated by direct afferent intravascular ijection of 99m Tc-mebrofenin. The hepatic extraction fraction determined via deconvolutional analysis was found to be the same as the first pass hepatic extraction fraction determined via deconvolutional analysis was found to be the same as the first pass hepatic extraction fraction determined by direct mesenteric (portal) vein injection. The same results can be obtained in a sedated animal, making the technique clinically applicable. Thus hepatic extraction fraction, obtained from a perlpheral intravenous injection of 99m Tc-mebrofenin, can provide a quatitative measure of hepatocyte function from a non-invasive procedure. The quantitative ability to measure hepatocyte function has potential in many clinical and research situations. 相似文献
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Van Saun RJ Callihan BR Tornquist SJ 《Journal of the American Veterinary Medical Association》2000,217(10):1531-1535
A 3-year-old female llama that was 3 months into her first lactation and 10 weeks pregnant was evaluated for anorexia of 24 hours' duration. On physical examination, the llama was in lateral recumbency, bradycardic, tachypneic, and hyperthermic. Palpation per rectum confirmed the presence of a possible dry fecal mass in the spiral colon. A tissue biopsy specimen of the liver was obtained, and histologic examination revealed moderate diffuse lipid accumulation within the hepatocytes. Lactated Ringer's solution was administered for rehydration, and partial parenteral nutrition was then initiated. Hepatic lipidosis is a disease characterized by abnormal accumulation of lipid in the liver and is associated with high mortality in camelids. Anorexia associated with hepatic lipidosis promotes further lipid mobilization and fatty infiltration of the liver. Partial parenteral nutrition with enteral supplementation may be used to maintain adequate energy intake and minimize further lipid mobilization. The distinctive metabolism of camelids may require higher amino acid supplementation relative to nonprotein calories in parenteral solutions than those traditionally provided to other species. Treatment with insulin may be effective 相似文献
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Study on the performance enhancing effect of rare earth elements in growing and fattening pigs 总被引：5，自引：0，他引：5
M. L. He D. Ranz & W. A. Rambeck 《Journal of animal physiology and animal nutrition》2001,85(7-8):263-270
A feeding study was performed to investigate possible performance enhancing effects of rare earth elements (REE) in growing and fattening pigs, as well as their influence on the blood serum biochemical changes and the accumulation of REE in the organs of pigs treated with a REE diet for a longer time period. Fourteen crossbred piglets (Deutsche Landrasse × Piétrain) were allotted to two dietary treatments: a control group and the REE-treated group which was supplemented with 300 mg of an REE mixture per kg feed. The REE mixture contained mainly chlorides of lanthanum (La), cerium (Ce) and praseodymium (Pr). The whole feeding period consisted of a 2 months ad libitum feeding period M-I and a 1 month restricted feeding period M-II. It was found that in comparison with the control group, the REE group had a better daily body weight gain of 19% (p < 0.05) in the period M-I and 12% in the period M-II; the REE group also had a better feed conversion ratio of 11% in period M-I and 3% (p > 0.05) in the period M-II. The REE had no significant (p > 0.05) influence on blood serum thyroxine (T4 ), aspartate-amino-transferase (AST), alanine-amino-transferase (ALT), alkaline-phosphatase (AP), total cholesterol, triglyceride, total protein, albumin, glucose, Ca, P, Na, K and Cl. However, serum triiodothyronine (T3 ) in the REE group was significantly (p < 0.01) lower than that in the control group. The accumulation rate of La and Ce in the muscle, liver and kidneys was very low after feeding the REE diet for 3 months. The study indicates the possibility of using rare earth elements as safe and inexpensive alternative performance enhancers for pig production. 相似文献