小花棘豆中毒对和田羊脑组织α-甘露糖苷酶的影响

摘要

The aim of this study was to investigate the effects of Oxytropis glabra DC on the content and transcriptional expression of α-mannosidase( AMA) of brain in Hetian sheep,and reveal the toxic mechanism of O.glabra DC.12 Hetian sheep were randomly and equally divided into 3 groups( the control group and exper-imental groupⅠ,Ⅱ) ,the dried plant of O.glabra DC was comminnuted,and the two experimental groups were fed with O.glabra DC at 10 g and 20 g per kg weight everyday respectively during the test period.The sheep consumed the forages freely until typical symptoms were observed.Brain were collected and the contents of AMA and its mRNA expression in different encephalic regions were measured on the 35th day.It was found that AMA in golgi and lysosomal was expressed in brain of all groups, O.glabra DC inhibited the expression of brain AMA1 and AMA2 mRNA,and the difference was obvious.The expression of AMA2 mRNA was not obvious in the brain of experimental groupⅠand the control group( P>0.05) ,the expression of AMA2 mRNA of cerebel-lum in experimental groupⅡwas significantly lower than that in the normal control group(P0.05) .The expression of AMA1 mRNA decreased in experimental groupⅡ,very significant lower than in the control group in cerebellum and thalamus(P0.05) .The results showed that O.glabra DC has remarkable effects on the contents of AMA of brain in Hetian sheep.It is indicated that three regions were the effect target sites of O.glabra DC in the brain tissue.It can be concluded that O.glabra DC produces poisoning effect on the contents of AMA and its mRNA expression by promoting cerebellum,cerebrum and thalamus.%探讨小花棘豆中毒对和田羊脑组织α－甘露糖苷酶（ AMA）的影响，进一步揭示小花棘豆的毒性作用机理。将12只和田羊随机分为3组，即对照组、试验Ⅰ组和试验Ⅱ组。试验组每日分别按每千克体质量10 g和20 g的剂量饲喂小花棘豆，饲喂至典型中毒症状出现为止。试验第35天屠宰后每组采集试验羊的全脑，检测和田羊不同脑区AMA活性及表达的变化。结果显示和田羊脑组织中高尔基体α－甘露糖苷酶Ⅱ（ AMA1）和溶酶体α－甘露糖苷酶（ AMA2）均有表达，但各试验组表达转录水平与对照组差异显著，试验Ⅰ组和田羊各脑区的AMA2的表达均与对照组差异不显著（P＞0．05），试验Ⅱ组和田羊小脑AMA2的表达显著低于对照（P＜0．05），其余脑区AMA2的表达均与对照组差异不显著（ P＞0．05）；试验Ⅱ组和田羊小脑和丘脑AMA1的表达极显著低于对照（ P＜0．01），大脑AMA1的表达显著低于对照（ P﹤0．05）；试验Ⅰ组和田羊小脑AMA1的表达显著低于对照（ P＜0．05），其余脑区AMA1的表达均与对照组差异不显著（ P＞0．05）。结果表明不同剂量小花棘豆均可降低和田羊脑组织AMA活性及其mRNA表达量，小脑、大脑和丘脑是其主要作用的靶区，小花棘豆毒性成分可通过影响AMA活性导致和田羊发生中毒反应。