Inhibition of protein synthesis by zinc: comparison between protein synthesis and RNA synthesis

被引:10
|
作者
Walther, UI [1 ]
Schulze, J [1 ]
Forth, W [1 ]
机构
[1] Univ Munich, Walther Straub Inst Pharmakol & Toxikol, D-80336 Munich, Germany
关键词
zinc toxicity; protein synthesis inhibition; RNA synthesis inhibition;
D O I
10.1191/096032798678908116
中图分类号
R99 [毒物学(毒理学)];
学科分类号
100405 ;
摘要
Inhalation of zinc fumes may lead to the acute respiratory distress syndrome. The mechanisms of pulmonary zinc toxicity are not yet understood. Therefore we investigated zinc-dependent depression of protein and RNA synthesis in rat and human lung cell lines. 1 After exposure to 120 or 150 mu mol/l zinc, RNA synthesis as assessed by uridine incorporation decreased by 60 - 70% between 0 and 2 h exposition in rat alveolar type II cells (L2 cells) and human fibroblastlike cells (11Lu and 16Lu cells), and by 90% between 0 and 4 h in carcinoma-derived cells (A549 cells). 2 After 2 h exposure, L2, 11Lu, and 16Lu cells were half-maximally inhibited by 50 mu mol/l zinc, whereas A549 cells were more resistant with half-maximal inhibition at 100 mu mol/zinc. 3 Protein and RNA synthesis was inhibited in parallel in L2, 11Lu, and A549 cells as indicated by simultaneous determination of uridine and amino acid incorporation. In 16Lu cells, the decline in protein synthesis preceded RNA synthesis inhibition. Pretreatment with RNA synthesis inhibitors (amanitin or actinomycin D) had no effect on time curve and intensity of RNA synthesis inhibition. Taken together, our results indicate that the suppression of RNA and protein synthesis likely are independent phenomena, due to direct zinc effects on these biosynthetic pathways.
引用
收藏
页码:661 / 667
页数:7
相关论文
共 50 条