不同剂量钼对绵羊肝脏细胞的损伤作用

选用18只2月龄小尾寒羊,体质量约为（20±1.34）kg,随机分为3组,分别在基础日粮（Mo 5.61mg/kg）中添加不同剂量的钼（mg/kg）构成加钼日粮（Ⅰ组Mo 0、Ⅱ组Mo 30、Ⅲ组Mo 60）,试验周期120d,定期采血,剖杀取样,以化学比色法、流式细胞术和透射电镜的方法观察钼对绵羊肝脏细胞损伤的影响。与Ⅰ组相比：Ⅱ、Ⅲ组肝脏超氧化物歧化酶（SOD）和黄嘌呤氧化酶（XOD）活性显著下降（P〈0.01）,丙二醛（MDA）和NO含量显著升高（P〈0.01）,血清NO含量和相应抗氧化酶活性变化与肝脏中的一致;Ⅱ、Ⅲ组肝脏细胞G0/G1期和凋亡细胞百分数显著升高（P〈0.01）,S期、G2＋M期和增殖指数（PI）显著降低（P〈0.01）。与Ⅲ组相比：Ⅱ组需要更长的作用时间引起机体抗氧化酶活性、NO含量和细胞周期发生相应变化。电镜观察,Ⅱ组肝细胞出现空泡变性及线粒体肿胀,Ⅲ组细胞线粒体数目减少,严重空泡化。结论：日粮钼含量30mg/kg及其以上可引起绵羊肝脏抗氧化功能降低和NO含量升高,导致细胞增殖分化受阻,细胞受损程度与机体钼暴露剂量和时间有关。

Effect of various doses of molybdenum on the cellular damage of liver in sheep

The experiment aimed to explore the effect of molybdenum on NO metabolism and hepatocellular injury in sheep by the methods of chemical colorimetry,flow cytometry and ultrastructural pathology.Three different doses of molybdenum（Mo 0 mg/kg,groupⅠ;Mo 30 mg/kg,molybdenum groupⅡ;Mo 60 mg/kg,molybdenum groupⅢ）were added to the basal diets（Mo 5.61 mg/kg）to feed 18 sixty-days-old small tailed Han sheep（20±1.34）kg divided into three groups randomly for 120 days.Autopsies were made periodically to get the blood and tissue specimens.The result showed that in the liver tissue,the malondialdehyde（MDA）contents and the levels of NO were increased（P0.01）in groupⅡandⅢ,the superoxide dismutase（SOD）and xanthine oxide（XOD）activities in groupⅡandⅢ were lower（P0.01）when compared with groupⅠ.Changes of the above mentioned enzymes activities and the level of NO in serum were consistent with those of liver.The G0 /G1 phase of cell cycle of hepatocyte and the percentage of cellular apoptosis were higher（P0.01）,S and G2 ＋M phases lower in groupⅡandⅢthan in groupⅠ（P 0.01）by FCM.Changes above in groupⅡretarded relatively when compared with group Ⅲ.Morphological changes of vacuolar degeneration and swelled mitochondria in groupⅡand the decrease of mitochondria and severe vacuolar degeneration in group Ⅲ were ultrastructurally observed.It is conclude that dietary molybdenum over 30 mg/kg can impaire antioxidant function and increased the level of NO,cause differentiation and proliferation retardation of hepatocyte and increased hepatocyte apoptotsis,which related to the dose and time.