奶牛脂肪肝综合诊断指标的筛选及氧化应激对犊牛肝脏线粒体OCT活性的影响
发布时间：2018-07-17 20:38
【摘要】：奶牛脂肪肝是营养代谢性疾病之一,是由于奶牛肝脂代谢发生障碍,导致过量的脂类以甘油三脂(TG)的形式在肝脏蓄积,同时伴有严重的肝脏功能紊乱。奶牛脂肪肝发病率高达50%以上,患牛表现出明显的产奶量下降以及繁殖力和免疫力的降低,严重阻碍奶牛业的发展。因此,及时对奶牛脂肪肝进行确诊显得尤为重要。目前,确诊脂肪肝只能依据肝组织活检,但因该方法对操作者技能要求较高,影响受检奶牛的生产性能,使得在生产实践中的可操作性和可行性差。为了方便、准确的诊断奶牛脂肪肝,本研究探讨奶牛脂肪肝的临床综合诊断手段以及发现可能的诊断指标。另有报道,高脂会引发奶牛肝脏线粒体氧化应激,而肝脏线粒体特异性酶鸟氨酸氨基甲酰转移酶(OCT)在脂肪肝患牛血清中升高,但线粒体氧化应激与线粒体OCT活性变化的关系尚不清楚。本研究以体外分离的犊牛肝脏线粒体氧化损伤为模型,探讨线粒体氧化损伤对OCT活性的影响。结果如下:1.采用主成分分析和聚类分析两种数学统计分析方法,结合临床生产实际,对112头奶牛血浆中与肝脏疾病相关的生化指标天门冬氨酸氨基转移酶(AST)、总胆红素(TBIL)、TG、钙(Ca)、钾(K+)、非酯化脂肪酸(NEFA)、OCT和脂多糖(LPS)进行分析,并以超声波检查和体况评分作为辅助手段,共同研究奶牛脂肪肝可能的临床综合诊断指标。结果显示:112头受检奶牛可分为三个组,疑似脂肪肝组奶牛13头,其中产后奶牛占84%;健康组奶牛7头;潜在发病组奶牛92头。围产期奶牛中疑似脂肪肝奶牛发病率占围产期奶牛的44%。血浆NEFA、OCT、TBIL、K+、AST以及LPS水平升高,TG和Ca水平降低。疑似脂肪肝组B超检查有10头奶牛其肝脏可见液性暗区和疑似钙化灶的亮点,疑似脂肪肝。疑似脂肪肝组奶牛的体况评分均值为4.25,分值偏高。2.利用Fenton反应的Fe2+/H2O2体系,体外构建犊牛肝脏线粒体氧化损伤模型,检测线粒体内OCT的活性,研究犊牛肝脏线粒体氧化损伤对OCT活性的影响。结果显示:随着H2O2浓度的增加,线粒体丙二醛(MDA)含量以及线粒体肿胀程度增加,线粒体内琥珀酸脱氢酶(SDH)和OCT活性降低,且在一定范围内呈浓度依赖性关系。自由基清除剂甘露醇可以显著抑制Fenton反应条件下诱导的线粒体MDA含量和线粒体肿胀程度的增加以及线粒体内SDH活性的降低。在Fenton反应条件下,体外成功构建犊牛肝脏线粒体氧化损伤模型,在高浓度的Fe2+/H2O2反应体系中,线粒体内OCT活性呈极显著降低。从以上结果可得出以下结论:1.血浆生化指标NEFA、OCT以及TBIL同时升高可作为奶牛脂肪肝临床诊断指标,LPS升高也可以作为奶牛发生脂肪肝的参考指标。血浆生化指标,超声检查和体况评分可综合诊断奶牛脂肪肝。2.成功构建体外分离的犊牛肝脏线粒体氧化损伤模型,证实氧化损伤可导致线粒体内OCT的活性下降。脂肪肝奶牛血清中OCT活性的上升其中一个可能机制是线粒体氧化应激。
[Abstract]:Fatty liver of dairy cows is one of the nutritional and metabolic diseases, which is due to the disorder of liver lipid metabolism in dairy cows, resulting in the accumulation of excess lipids in the form of glycerol three fat (TG) in the form of liver, accompanied by severe liver dysfunction. The incidence of fatty liver in cows is over 50%, and cattle show significant decline in milk production, fecundity and immunity. As a result, the development of dairy cattle is seriously hindered. Therefore, it is very important to confirm the diagnosis of fatty liver in dairy cows in time. At present, the diagnosis of fatty liver can only be based on the liver biopsy, but the method has a high requirement on the operator's skills, which affects the production performance of the dairy cows, and makes the operation and feasibility of the production poor. In this study, the diagnosis of fatty liver in dairy cows was accurately diagnosed. This study explored the comprehensive diagnostic methods of fatty liver in cows and the possible diagnostic indicators. Furthermore, high fat could cause oxidative stress in the liver mitochondria of the cows, and the liver mitochondrial specific enzyme ornithine aminoformyl transferase (OCT) increased in the serum of fatty liver and mitochondria. The relationship between oxidative stress and the changes of mitochondrial OCT activity was not clear. In this study, the effects of mitochondrial oxidative damage on mitochondrial oxidative damage were studied in vitro. The effects of mitochondrial oxidative damage on the activity of OCT were investigated. The results are as follows: 1. using two mathematical statistical analysis methods using principal component analysis and cluster analysis, combined with clinical practice, 112 milk was used. AST, TBIL, TG, Ca, K+, K+, K+, NEFA, OCT and lipopolysaccharide (LPS) were analyzed in bovine plasma related to liver disease, and the clinical comprehensive diagnostic index of fatty liver in dairy cows was studied by ultrasonic examination and body condition score. The results showed that 112 dairy cows could be divided into three groups, 13 cows suspected of fatty liver, 84% of the postpartum cows, 7 in the healthy group and 92 in the latent group, and the incidence of 44%. plasma NEFA, OCT, TBIL, K+, AST and LPS in perinatal cows was lower. In the liver group, 10 cows showed bright spots in the liver and suspected calcified foci in the liver of 10 cows and suspected fatty liver. The mean value of the body condition score of the suspected fatty liver group was 4.25. The score was higher than the Fe2+/H2O2 system of Fenton reaction. The mitochondrial oxidative damage model of calf liver was constructed in vitro, and the activity of OCT in the mitochondria was detected. The effects of mitochondrial oxidative damage on the liver of calves showed that the content of mitochondrial malondialdehyde (MDA) and the swelling of mitochondria increased with the increase of H2O2 concentration, and the activity of mitochondrial succinic dehydrogenase (SDH) and OCT decreased in the mitochondria, and the concentration dependent relationship was found in a certain range. The free radical scavenger mannitol could significantly inhibit the OCT activity. Under the condition of Fenton reaction, the content of mitochondrial MDA and the degree of mitochondria swelling and the decrease of SDH activity in mitochondria. Under the condition of Fenton reaction, the mitochondrial oxidative damage model of calf liver was successfully constructed in vitro. In the high concentration Fe2+/H2O2 reaction system, the activity of OCT in the mitochondria was greatly reduced. We can draw the following conclusions: 1. the plasma biochemical indexes NEFA, OCT and TBIL can be used as the clinical diagnostic index of fatty liver in dairy cows. The elevation of LPS can also be used as a reference index of fatty liver in dairy cows. The plasma biochemical indexes, ultrasound examination and body condition score can be used to synthetically diagnose the calf liver.2. of milk fat fatty liver in vitro, and the calf liver line separated in vitro is successfully constructed. The oxidative damage model shows that oxidative damage can lead to the decrease of OCT activity in mitochondria. One of the possible mechanisms for the increase of OCT activity in the serum of fatty liver cows is mitochondrial oxidative stress.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.23
本文编号：2130865
[Abstract]:Fatty liver of dairy cows is one of the nutritional and metabolic diseases, which is due to the disorder of liver lipid metabolism in dairy cows, resulting in the accumulation of excess lipids in the form of glycerol three fat (TG) in the form of liver, accompanied by severe liver dysfunction. The incidence of fatty liver in cows is over 50%, and cattle show significant decline in milk production, fecundity and immunity. As a result, the development of dairy cattle is seriously hindered. Therefore, it is very important to confirm the diagnosis of fatty liver in dairy cows in time. At present, the diagnosis of fatty liver can only be based on the liver biopsy, but the method has a high requirement on the operator's skills, which affects the production performance of the dairy cows, and makes the operation and feasibility of the production poor. In this study, the diagnosis of fatty liver in dairy cows was accurately diagnosed. This study explored the comprehensive diagnostic methods of fatty liver in cows and the possible diagnostic indicators. Furthermore, high fat could cause oxidative stress in the liver mitochondria of the cows, and the liver mitochondrial specific enzyme ornithine aminoformyl transferase (OCT) increased in the serum of fatty liver and mitochondria. The relationship between oxidative stress and the changes of mitochondrial OCT activity was not clear. In this study, the effects of mitochondrial oxidative damage on mitochondrial oxidative damage were studied in vitro. The effects of mitochondrial oxidative damage on the activity of OCT were investigated. The results are as follows: 1. using two mathematical statistical analysis methods using principal component analysis and cluster analysis, combined with clinical practice, 112 milk was used. AST, TBIL, TG, Ca, K+, K+, K+, NEFA, OCT and lipopolysaccharide (LPS) were analyzed in bovine plasma related to liver disease, and the clinical comprehensive diagnostic index of fatty liver in dairy cows was studied by ultrasonic examination and body condition score. The results showed that 112 dairy cows could be divided into three groups, 13 cows suspected of fatty liver, 84% of the postpartum cows, 7 in the healthy group and 92 in the latent group, and the incidence of 44%. plasma NEFA, OCT, TBIL, K+, AST and LPS in perinatal cows was lower. In the liver group, 10 cows showed bright spots in the liver and suspected calcified foci in the liver of 10 cows and suspected fatty liver. The mean value of the body condition score of the suspected fatty liver group was 4.25. The score was higher than the Fe2+/H2O2 system of Fenton reaction. The mitochondrial oxidative damage model of calf liver was constructed in vitro, and the activity of OCT in the mitochondria was detected. The effects of mitochondrial oxidative damage on the liver of calves showed that the content of mitochondrial malondialdehyde (MDA) and the swelling of mitochondria increased with the increase of H2O2 concentration, and the activity of mitochondrial succinic dehydrogenase (SDH) and OCT decreased in the mitochondria, and the concentration dependent relationship was found in a certain range. The free radical scavenger mannitol could significantly inhibit the OCT activity. Under the condition of Fenton reaction, the content of mitochondrial MDA and the degree of mitochondria swelling and the decrease of SDH activity in mitochondria. Under the condition of Fenton reaction, the mitochondrial oxidative damage model of calf liver was successfully constructed in vitro. In the high concentration Fe2+/H2O2 reaction system, the activity of OCT in the mitochondria was greatly reduced. We can draw the following conclusions: 1. the plasma biochemical indexes NEFA, OCT and TBIL can be used as the clinical diagnostic index of fatty liver in dairy cows. The elevation of LPS can also be used as a reference index of fatty liver in dairy cows. The plasma biochemical indexes, ultrasound examination and body condition score can be used to synthetically diagnose the calf liver.2. of milk fat fatty liver in vitro, and the calf liver line separated in vitro is successfully constructed. The oxidative damage model shows that oxidative damage can lead to the decrease of OCT activity in mitochondria. One of the possible mechanisms for the increase of OCT activity in the serum of fatty liver cows is mitochondrial oxidative stress.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.23
【参考文献】
相关期刊论文 前1条
1 周作荣,彭向欣;线粒体反应氧体系与脂肪肝[J];中华肝脏病杂志;2003年02期
，本文编号：2130865
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