摘要
为探讨农药的"手性"特征对非靶生物的毒性,采用急性毒性试验和生化测定方法,研究了手性农药rac-甲霜灵及R-甲霜灵对模式生物斑马鱼的致死和亚致死(ATP酶活性)效应。rac-甲霜灵对斑马鱼的24h和96h的LC50分别为258.47、241.98mg·L-1,R-甲霜灵对斑马鱼的24h和96h的LC50分别为237.67、227.38mg·L-1,都属于低毒农药。rac-甲霜灵和R-甲霜灵对斑马鱼Ca2+-ATP酶的活性,在96h的测定时间范围内都只表现出诱导效应,但R-甲霜灵对其的诱导效应更为显著,诱导时间也较长;相同浓度下R-甲霜灵比rac-甲霜灵对Na+,K+-ATP酶的活性诱导时间长,并且在高浓度诱导效应开始的早。结果表明R-甲霜灵比rac-甲霜灵对斑马鱼的急性毒性稍大,但两者在亚致死效应上存在较为明显的差异,表明斑马鱼体内可能存在对映选择性。
Many studies indicated that enantiomers of chiral pesticides differed in biological activity,which meant single enantiomer pesticides might had different effects on non-target organisms relative to racemate. So far, few studies whether R-metalaxyl brings about the same environmental effects on aquatic organisms as rac-metalaxyl has been reported. In order to provide more information for aquatic risk about metalaxyl, 24 h and 96 h acute toxicity of rae-metalaxyl and R-metalaxyl to adult zebrafish （Danio rerio）were tested, and the variance of ATPase activity in zebrafish under sublethal concentrations was investigated. The results showed both of them belonged to low-toxic pesticides based on LC50 values （24 h and 96 LC50） for rac-metalaxyl were 258.47 mg·L^-1 and 241.98 mg·L^-1; for R-metalaxyl were 227.38 mg·L^-1 and 237.67 mg·L^-1 ）,and had a little difference in actue toxicity to zebrafish between the two compounds. In the case of ATPase test,the induction of AT- Pase activity was observed during the 96 h-test, and no inhibition effects observed. Moreover, induction effect on Ca^2＋-ATPase for R-metalaxyl was more significant than rae-metalaxyl. For Na^＋, K^＋-ATPase,R-metalaxyl began a induction earlier in the highest concentration exposed（ 70 mg·L^-1 ）,and had a longer time in induction than rac-metalaxyl. In general, the results showed a little difference in acute toxicity to zebrafish and a pronounced difference in effects on ATPase activity in zebrafish between rac-metalaxyl and R-metalaxyl. It is a possible explanation that enantioselective action occurred in zebrafish.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2008年第6期2456-2460,共5页
Journal of Agro-Environment Science
