College of Life Science, Shandong Normal University, Ji'nan 250014, China.
College of Life Science, Shandong Normal University, Ji'nan 250014, China.
Chemosphere. 2015 Feb;120:252-7. doi: 10.1016/j.chemosphere.2014.06.081. Epub 2014 Aug 9.
As a key enzyme that hydrolyzes the neurotransmitter acetylcholine in cholinergic synapses of both vertebrates and invertebrates, acetylcholinesterase (AChE) is strongly inhibited by organophosphates. AChE inhibition may induce the decrease of swimming ability. According to previous research, swimming behavior of different aquatic organisms could be affected by different chemicals, and there is a shortage of research on direct correlation analysis between swimming behavior and biochemical indicators. Therefore, swimming behavior and whole-body AChE activity of Daphnia magna under dichlorvos (DDVP) exposure were identified in order to clarify the relationship between behavioral responses and AChE inhibition in this study. In the beginning, AChE activity was similar in all treatments with the control. During all exposures, the tendency of AChE activity inhibition was the same as the behavioral responses of D. magna. The AChE activity of individuals without movement would decrease to about zero in several minutes. The correlation analysis between swimming behavior of D. magna and AChE activity showed that the stepwise behavioral response was mainly decided by AChE activity. All of these results suggested that the toxicity characteristics of DDVP as an inhibitor of AChE on the swimming behavior of organisms were the same, and the AChE activity inhibition could induce loss of the nerve conduction ability, causing hyperactivity, loss of coordination, convulsions, paralysis and other kinds of behavioral changes, which was illustrated by the stepwise behavioral responses under different environmental stresses.
作为脊椎动物和无脊椎动物胆碱能突触中水解神经递质乙酰胆碱的关键酶，乙酰胆碱酯酶（AChE）被有机磷强烈抑制。AChE 抑制可能会导致游泳能力下降。根据以往的研究，不同水生生物的游泳行为可能会受到不同化学物质的影响，而且关于游泳行为和生化指标之间的直接相关分析的研究还很少。因此，本研究旨在明确行为反应与 AChE 抑制之间的关系，检测了二氯氧磷（DDVP）暴露下大型溞的游泳行为和全身 AChE 活性。在开始时，所有处理组的 AChE 活性与对照组相似。在所有暴露期间，AChE 活性抑制的趋势与大型溞的行为反应相同。没有运动的个体的 AChE 活性在几分钟内会降至接近零。大型溞游泳行为与 AChE 活性的相关分析表明，逐步行为反应主要由 AChE 活性决定。所有这些结果表明，DDVP 作为 AChE 抑制剂对生物游泳行为的毒性特征是相同的，AChE 活性抑制会导致神经传导能力丧失，从而引起过度活跃、协调丧失、抽搐、瘫痪等行为变化，这在不同环境胁迫下的逐步行为反应中得到了说明。
