Phillips T A, Summerfelt R C, Atchison G J
Department of Animal Ecology, Iowa State University, 124 Science II, Ames, Iowa 50011-3221, USA.
Arch Environ Contam Toxicol. 2002 Jul;43(1):75-80. doi: 10.1007/s00244-002-1134-2.
Organophosphorus (OP) insecticides have high acute toxicity toward many nontarget vertebrate and invertebrate organisms, but direct measurement of OPs in environmental samples is difficult because their concentrations may fall below detection limits within hours to days after entering aquatic ecosystems. Because OPs exert toxicity through cholinesterase (ChE) inhibition, which may persist for up to several weeks, ChE inhibition has been widely used in aquatic ecosystems as a biomarker for OP exposure in aquatic organisms. However, the biological, environmental, and methodological factors affecting ChE activity have not been well documented and must be considered and understood before ChE activity can be used as a dependable indicator of OP exposure to aquatic organisms. This study examined the influence of water temperature, size of larval and juvenile walleye (Stizostedion vitreum), stress, long-term storage, postmortem changes, and methods of euthanasia on ChE activity. Water temperature (17.2, 20.9, and 24.6 degrees C), stress, long-term storage (up to 180 days), postmortem changes, and method of euthanasia had no effect on ChE activity of walleye. There was a strong positive correlation (r = 0.87) between whole body ChE activity and total length (7.2-17.9 mm) for larval walleye, but a negative correlation between brain ChE activity and total length (59-164 mm) for juvenile walleye (r = 0.75). Because size, age, and development may affect ChE activity, fish of similar size should be used when evaluating the effects of ChE inhibitors. If fish of similar size are not available, it is recommended that relations between size, age, and development be understood so estimates of variation in ChE activity can be made.
有机磷（OP）杀虫剂对许多非靶标脊椎动物和无脊椎动物具有高急性毒性，但在环境样品中直接测量有机磷却很困难，因为它们进入水生生态系统后的数小时至数天内，其浓度可能会降至检测限以下。由于有机磷通过抑制胆碱酯酶（ChE）发挥毒性作用，这种抑制作用可能会持续长达数周，因此ChE抑制作用已在水生生态系统中广泛用作水生生物接触有机磷的生物标志物。然而，影响ChE活性的生物学、环境和方法学因素尚未得到充分记录，在ChE活性能够用作水生生物接触有机磷的可靠指标之前，必须对这些因素加以考虑和理解。本研究考察了水温、幼体及幼龄大眼狮鲈（Stizostedion vitreum）的大小、应激、长期保存、死后变化以及安乐死方法对ChE活性的影响。水温（17.2、20.9和24.6摄氏度）、应激、长期保存（长达180天）、死后变化以及安乐死方法对大眼狮鲈的ChE活性均无影响。幼体大眼狮鲈的全身ChE活性与全长（7.2 - 17.9毫米）之间存在强正相关（r = 0.87），但幼龄大眼狮鲈的脑ChE活性与全长（59 - 164毫米）之间存在负相关（r = 0.75）。由于大小、年龄和发育可能会影响ChE活性，因此在评估ChE抑制剂的作用时，应使用大小相似的鱼类。如果无法获得大小相似的鱼类，建议了解大小、年龄和发育之间的关系，以便能够对ChE活性的变化进行估计。
