School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat St, Box 355020, Seattle, WA 19195-5020, United States.
College of Pharmacy, University of Minnesota, Life Science 232, 1110 Kirby Drive, Duluth, MN 55812-3003, United States.
Comp Biochem Physiol C Toxicol Pharmacol. 2018 Feb;205:34-42. doi: 10.1016/j.cbpc.2018.01.002. Epub 2018 Feb 3.
Studies were conducted to determine the distribution and elimination of imidacloprid (IMI) in rainbow trout. Animals were injected with a low (47.6 μg/kg), medium (117.5 μg/kg) or high (232.7 μg/kg) dose directly into the bloodstream and allowed to depurate. The fish were then sampled to characterize the loss of IMI from plasma and its appearance in expired water (all dose groups) and urine (medium dose only). In vitro biotransformation of IMI was evaluated using trout liver S9 fractions. Mean total clearance (CL) values determined by non-compartmental analysis of plasma time-course data were 21.8, 27.0 and 19.5 mL/h/kg for the low, medium and high dose groups, respectively. Estimated half-lives for the same groups were 67.0, 68.4 and 68.1 h, while fitted values for the steady-state volume of distribution (V) were 1.72, 2.23 and 1.81 L/kg. Branchial elimination rates were much lower than expected, suggesting that IMI is highly bound in blood. Renal clearance rates were greater than measured rates of branchial clearance (60% of CL in the medium dose group), possibly indicating a role for renal membrane transporters. There was no evidence for hepatic biotransformation of IMI. Collectively, these findings suggest that IMI would accumulate in trout in continuous waterborne exposures.
本研究旨在确定吡虫啉（IMI）在虹鳟鱼体内的分布和消除情况。动物被直接注入低（47.6μg/kg）、中（117.5μg/kg）或高（232.7μg/kg）剂量的药物，并允许其净化。然后对鱼进行采样，以确定 IMI 从血浆中的损失及其在呼出水中（所有剂量组）和尿液（仅中剂量组）中的出现情况。使用虹鳟鱼肝 S9 级分评估 IMI 的体外生物转化。通过非房室分析血浆时间过程数据确定的平均总清除率（CL）值分别为低、中、高剂量组的 21.8、27.0 和 19.5 mL/h/kg。同一组的估计半衰期分别为 67.0、68.4 和 68.1 h，而拟合的稳态分布容积（V）值分别为 1.72、2.23 和 1.81 L/kg。鳃消除率远低于预期，表明 IMI 在血液中高度结合。肾清除率高于鳃清除率（中剂量组为 CL 的 60%），可能表明存在肾膜转运体的作用。没有证据表明 IMI 发生肝生物转化。综上所述，这些发现表明，在连续的水暴露中，IMI 会在虹鳟鱼体内积累。
