碲化镉量子点对小鼠肝脏超微结构及重要生物酶活性的影响

Influences of CdTe Quantum Dots on Ultrastructure and Enzymatic Activities of Mice Liver

探讨了碲化镉量子点(cadmium telluride quantum dots,CdTeQDs)对小鼠肝组织超微结构及琥珀酸脱氢酶(succinate dehydrogenase,SDH)和三磷酸腺苷酶(adenosine triphosphatase,ATPase)活性的影响。将20只雄性ICR小鼠随机分成QDs染毒组和对照组,采用尾静脉注射方式进行一次性染毒,染毒组每只小鼠注射2μmol·kg-1体重的CdTeQDs(以Cd^(2+)的摩尔浓度计算)。每5只为一组分别在染毒后的1 d、3 d和7 d处死小鼠,另外5只注射生理盐水作为对照组。取部分肝组织在透射电镜下观察其超微结构变化并使用试剂盒测定肝脏中SDH、Na^+/K^+-ATP酶、Ca~(^(2+))/Mg^(2+)-ATP酶的活性。结果显示CdTeQDs暴露后染毒组小鼠肝细胞胞浆疏松,线粒体出现肿胀、空泡、嵴减少等结构变化,表明肝细胞受到损伤且染毒1 d后损伤最严重;肝脏中染毒组SDH活性与对照组相比显著降低(P<0.05);染毒1 d后,Na^+/K^+-ATP酶和Ca^(2+)/Mg^(2+)-ATP酶活性与对照组相比显著升高,随着染毒后时间的延长,其活性呈现下降的变化趋势。单次量注射CdTeQDs能够引起小鼠肝脏损伤,抑制SDH活性,引起ATP酶活性改变,这些症状在暴露时间内呈现恢复趋势。

In the present study,influences of cadmium telluride quantum dots（ CdTeQDs） on the ultrastructure and the activities of succinate dehydrogenase and adenosine triphosphatase in liver of mice were examined. Twenty ICR mice were randomly divided into exposed groups and control group,and injected with 2 μmol·kg^-1 weight of CdTeQDs（ as Cd） by tail intravenous injection（ IOCV）. Mice injected with normal saline were used as the control. Each of 5 mice was sacrificed at 1 d,3 d and 7 d,respectively. Liver tissue was sampled to observe the ultrastructural changes by transmission electron microscopy（ TEM） and homogenized to measure enzymatic activities of SDH,Na^＋/ K^＋-ATPase,Ca^2＋/ Mg^2＋-ATPase using assay kits. The TEM results showed that mitochondria swelling,vacuole,crest reduction occurred after CdTeQDs exposure,indicating the hepatocytes damage,especially for1 d exposure. The activities of SDH in the treated groups were significantly lower than that in the control group（ P〈0. 05）. The activities of Na^＋/ K^＋-ATPase and Ca^2＋/ Mg^2＋-ATPase in the liver tissue were significantly higher than those in the control group at 1 d exposure. As the exposure time increasing,the activities of ATPase showed a downward trend. We concluded that single dose of CdTeQDs exposure could induce mice liver damage,affect activities of both SDH and ATP enzyme,which could gradually recovered.