镉致鸡血管氧化应激与金属硫蛋白含量的变化

为探讨镉(Cd)对血管抗氧化功能及金属硫蛋白(MT)的影响,将180只50日龄健康雌性海兰鸡随机分为3组(对照组、低剂量组和高剂量组),分别饲喂含0、140、210mg·kg-1(BW)CdCl2的基础日粮,在饲养20、40、60d后采集主动脉和前腔静脉,测定其MT含量,超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量.结果表明:1)Cd暴露后,与对照组相比,低剂量组血管MT含量显著升高(p<0.01),并随暴露时间的延长而逐渐增加;高剂量组血管MT含量显著降低(p<0.01),并随暴露时间的延长先升高后降低.2)随着Cd暴露剂量的加大,血管SOD、GSH-Px活性逐渐降低,而MDA含量逐渐升高,具有明显的剂量-效应关系.3)随着暴露时间的延长,血管SOD、GSH-Px活性逐渐降低,MDA含量逐渐升高,具有明显的时间-效应关系.4)Cd暴露下,主动脉与前腔静脉各指标具有相同的变化趋势.以上结果表明,Cd具有血管毒性,其毒作用机理可能与MT含量变化以及抗氧化功能失衡有关.

Effects of Cadmium on Oxidative Stress and Metallothionein of Blood Vessel in Hens

In order to study the effects of cadmium on anti-oxidation activity and metallothionein (MT) of blood vessel, 180 hens were fed with different doses of cadmium (0, 140, 210mg·kg-1 (BW)) for 20, 40 and 60d. The content of MT, the activities of antioxidases and the content of malondialdehyde (MDA) in blood vessel were detected. Results showed that MT content increased significantly in the low Cd dose groups (p<0.01) compared with the control groups, and it increased gradually as exposure time extended. On the contrary, the MT content decreased significantly in the high Cd dose groups (p<0.01) compared with the control groups, and it decreased as exposure time extended; Both the increase of the doses of Cd and the extending of exposure time could cause a significant reduction of the activities of SOD and GSH-Px and a significant increase of the content of MDA (p<0.01). Cd had toxicity on blood vessel, and it might be related to the content of MT and the unbalance of anti-oxidation system function on it.