Hormetic response of cholinesterase from Daphnia magna in chronic exposure
to triazophos and chlorpyrifos |
| |
Authors: | Shaonan Li and Yajun Tan |
| |
Institution: | 1. Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology,Zhejiang University, Hangzhou 310029, China 2. Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology,Zhejiang University, Hangzhou 310029, China;Research Institute of Tianjin Product Quality Inspection Technology, Tianjin 300384, China |
| |
Abstract: | In vivo activity of cholinesterase (ChE) in Daphnia magna was measured at di erent time points during 21-day exposure to triazophos
and chlorpyrifos ranging from 0.05 to 2.50 g/L and 0.01 to 2.00 g/L, respectively. For exposure to triazophos, ChE was induced up
to 176.5% at 1.5 g/L and day 10 when measured by acetylthiocholine (ATCh), whereas it was induced up to 174.2% at 0.5 g/L
and day 10 when measured by butyrylthiocholine (BTCh). For exposure to chlorpyrifos, ChE was induced up to 134.0% and 160.5%
when measured by ATCh and BTCh, respectively, with both maximal inductions detected at 0.1 g/L and day 8. Obvious induction
in terms of ChE activity was also detected in daphnia removed from exposures 24 hr after their birth and kept in a recovery culture
for 21 days. Results indicated that the enzyme displayed symptoms of hormesis, a characteristic featured by conversion from low-dose
stimulation to high-dose inhibition. In spite of that, no promotion in terms of reproduction rate and body size was detected at any tested
concentrations regardless of whether the daphnia were collected at end of the 21-day exposure or at end of a 21-day recovery culture.
This suggested that induction of ChE caused by anticholinesterases had nothing to do with the prosperity of the daphnia population. |
| |
Keywords: | Daphnia magna anticholinesterase ChE enzyme promotion exposure recovery culture population prosperity |
本文献已被 维普 万方数据 PubMed 等数据库收录! |
| 点击此处可从《环境科学学报(英文版)》浏览原始摘要信息 |
| 点击此处可从《环境科学学报(英文版)》下载免费的PDF全文 |
|