【作者】 王钟翊；

【导师】 李前勇；

【作者基本信息】 西南大学 ， 临床兽医学， 2009， 硕士

【摘要】 本试验选用1日龄四川麻鸭200只,随机分为5组,设对照组（常规日粮）、中毒组（AFB₁80ppb）、纳米硒Ⅰ组（AFB₁80ppb+0.4ppmf内米硒）、纳米硒Ⅱ组（AFB₁80ppb+0.8ppm纳米硒）、纳米硒Ⅲ（AFB₁80ppb+1.6ppm纳米硒）,试验期42d。对定期采样的肉鸭进行组织器官病理变化观察,血液、肝脏功能指标和黄曲霉毒素B₁残留量的检测,以及采用RT-PCR方法对不同组鸭肝组织CYP450基因mRNA表达量进行研究,以探讨纳米硒对于肉鸭黄曲霉毒素B₁中毒的解毒效果。结果表明,在肉鸭基础日粮中添加80ppb的AFB₁,中毒组出现典型的临床症状,且慢性中毒导致试验鸭频繁发生死亡现象,中毒组死亡率高达30%。AFB₁严重影响了试验鸭的生长性能利造血功能,严重损害了试验鸭的肝脏功能和肾脏功能。与对照组比较,中毒组肉鸭血液中RBC、WBC数量和Hb含量显著降低（P＜0.01）;血清中AKP、GPT、GOT、GR、GST、ADA的含量显著升高（P＜0.01）,肝脏中GR、GST、ADA的含量显著降低（P＜0.01）;对肝脏病理学观察发现肝细胞颗粒性变性,血清、肝脏和肌肉中AFB₁的残留量显著升高（P＜0.01）;肝脏CYP450酶活性显著降低（P＜0.01）;肝脏CYP450基因mRNA表达水平降低（P＜0.01）。在肉鸭基础日粮中添加3个不同剂量的纳米硒,纳米硒组较中毒组与对照组比较,血液和肝脏中各功能指标都有一定的优势,对AFB₁有一定的解毒趋势。其中,血液中RBC、WBC数量和Hb含量显著高于中毒组（P＜0.01）;血清中AKP、GPT、GOT、GR、GST、ADA的含量高于对照组但均低于中毒组;肝脏中GR、GST、ADA的含量低于对照组但均高于中毒组;肝脏病理学观察发现肝细胞浸润;血清、肝脏和肌肉中AFB₁的残留量较中毒组显著降低（P＜0.01）;肝脏CYP450活性较中毒组显著升高（P＜0.01）;肝脏CYP450基因mRNA表达水平显著升高（P＜0.01）。本试验通过对玉米粉接种AFB₁菌种,成功建立鸭AFB₁慢性中毒（AFB₁80ppb）模型,肝脏中AFB₁和血清中谷胱甘肽硫转移酶含量随着试验天数的增加而增加,可作为AFB₁中毒解毒效果的特异性指标。通过添加纳米硒,试验中肉鸭机体损害程度指标都趋于缓解,机体表现出对抗AFB₁毒性作用的增强,可能与鸭体肝脏解毒能力提高,促进体内抗氧化作用和清除自由基的蓄积,保护肝脏功能等作用机制有关。更多还原

【Abstract】 200 one-day-old Sichuan ducks were randomly divided into five groups,and fed with conventional diets in the control group,80 ug/Kg AFB₁ in the other four groups,and nano selenium of 0.4 mg/Kg in groupⅠ,nano selenium of 0.8 mg/Kg in groupⅡ,nano selenium of 1.6 mg/Kg in groupⅢ.By clinic and pathological observation,detection of blood,hepatic function index,and the residual of AFB₁,and the studying of expression of CYP450 gene mRNA in ducks liver of different groups using the method of RT-PCR at the end of test,To study the effect of Nano-Selenium on dietary AFB₁ detoxification in meat ducks for 42 days.The results showed that,ducks of toxic group with 80 ug/Kg AFB₁ presented typical clinical symptoms.Chronic poisoning leaded to death and the ducks’ mortality reached to 30%.The AFB₁ seriously affected growth performance and hematopoietic function,maded great damage on the liver and kidney function.Compared with the control group,the RBC,WBC quantity and content of Hb in blood decreased significantly.The contents of AKP,GPT,GOT,GR,GST,ADA enzyme in serum increased significantly,the contents of GR,GST,ADA in liver decreased significantly,Cells particles degenerated of duck liver by hepatic pathological observation.The residual of AFB₁ in serum,liver and muscle increased significantly.The activity of CY450 enzyme decreased significantly,the expression of CYP450 gene mRNA decreased significantly.Compared with toxic group,the toxic symptom of three nano-Selenium group obviously relieved, and showed a certain of detoxification.The RBC,WBC quantity and content of Hb in nano-Selenium group significantly higher than toxic group,The contents of AKP,GPT,GOT,GR, GST,ADA enzyme in serum higher than control group and lower than control group,The contents of GR,GST,ADA in liver lower than control group and higher than control group.Cells infiltrated of duck liver by hepatic pathological observation.The residual of AFB₁ in serum,liver and muscle decreased significantly.The activity of CY450 enzyme increased significantly,the expression of CYP450 gene mRNA increased significantly.Corn meal did fermentation test by inoculation of AFB₁ strain in 80 ug/Kg,and builded the model of chronic poisoning.The contents of GST enzyme in serum and liver increased with increasing test days,and were specific index of detoxifying effect in AFB₁ poisoning.In the experimentation,by the using of nanoselenium,the damage index of duck organism is well alleviated and organism’s ability of antitoxic effect on AFB₁ is enhanced.The exact reason may be because that the using of nanoselenium could induce the organism’s immunity,accelerate the antioxidation effect,and clear the accumulation of free radicals,protect the liver,etc.更多还原