摘要
目的 了解NiCl2 在体内对大鼠细胞的DNA产生何种损伤以及与聚腺苷二磷酸核糖聚合酶(PARP)活性的关系。方法 以 10 ,2 0 ,30mg·kg- 1NiCl2 ip给大鼠进行染毒 ,2 4h后处死动物 ,分离外周血淋巴细胞和肺细胞 ,应用单细胞凝胶电泳 (彗星试验 ) ,检测DNA单链、双链断裂和DNA 蛋白质交联 ,同时用 [3H]NAD渗透法检测PARP活性的变化。结果 外周血淋巴细胞和肺细胞均没有出现明显的DNA单链和双链断裂。所有剂量组的外周血淋巴细胞都出现了不同程度的DNA 蛋白质交联 ,交联率为 14 %～ 36 %,但没有剂量反应关系。 2 0mg·kg- 1NiCl2 也能诱导肺细胞DNA 蛋白质交联 ,交联率达 30 %。所有剂量组的NiCl2 均能明显抑制大鼠外周血淋巴细胞PARP酶的活性 ,酶活性下降至对照组的 38%～ 5 7%,但没有表现出剂量反应关系。大鼠肺细胞中该酶活性不受NiCl2 染毒的影响。结论 NiCl2 在体内环境下能诱导大鼠外周血淋巴细胞和肺细胞的DNA损伤 ,主要是引起DNA 蛋白质交联 ,而不直接造成DNA链的断裂 ;NiCl2 还能明显抑制外周血淋巴细胞的PARP酶活性 ,进而可能影响DNA修复。
AIM To investigate which damage will be induced by nickel chloride in vivo in rat cells and its relation to the activity of poly ADP ribose polymerase(PARP). METHODS Peripheral blood lymphocytes and lung cells of rats were isolated 24 hours after acute treatment with nickel chloride (10, 20, 30 mg·kg -1 , respectively) injected intraperitoneally. Three types of DNA damage: single strand breaks (SSB), double strand breaks (DSB) and DNA protein crosslinks(DPC) were evaluated using single cell gel electrophoresis (comet assay). The activity of PARP was determined by means of NAD permeabilization. RESULTS In peripheral blood lymphocytes and lung cells, no SSB and DSB were evident with all these doses, but DPC was observed in peripheral blood lymphocytes of all the three groups with crosslinks rates ranged from 14% to 36%, but showed no dose response relationship; and NiCl 2 in 20 mg·kg -1 induced the lung cells DPC with a crosslink rate of 30%. The drop of PARP activity of peripheral blood lymphocytes was significant but with no dose dependence, and the enzyme activity was reduced from (1.53±0.59)×10 3 dpm to (0.82±0.13)×10 3 dpm, (0.58±0.69)×10 3 dpm, (0.87± 0.11) ×10 3 dpm, respectively, with droping rates from 38% to 57% (P<0.01, compared with control) in three Ni treated groups, whereas the lung cells in all treated groups didn′t show any detectable alteration of PARP activity. CONCLUSION NiCl 2 at relative low concentration can induce DNA damage of PBLs in rats in vivo, of which main form is DNA protein crosslinks, not direct DNA strand breaks. NiCl 2 also exhibits remarkable inhibition of PARP activity in peripheral blood lymphocytes in vivo, probably therefore influencing DNA repair.
出处
《中国药理学与毒理学杂志》
CAS
CSCD
北大核心
2002年第5期387-390,共4页
Chinese Journal of Pharmacology and Toxicology
基金
国家自然科学基金资助项目 (39970 6 3)
