Tashjian Diran H, Teh Swee J, Sogomonyan Arutyun, Hung Silas S O
Department of Animal Science, University of California, One Shields Avenue, Davis, 95616-8521, USA.
Aquat Toxicol. 2006 Oct 12;79(4):401-9. doi: 10.1016/j.aquatox.2006.07.008. Epub 2006 Jul 18.
An 8-week growth trial was conducted to determine the sensitivity of white sturgeon (Acipenser transmontanus) to the toxicological effects of elevated dietary selenium (Se). Juvenile white sturgeon were fed diets supplemented with Se in the form of L-selenomethionine (SeMet), resulting in dietary concentrations of 0.4, 9.6, 20.5, 41.7, 89.8, and 191.1 microg Se/g diet on a dry weight basis. Effects of dietary SeMet on survival, swimming activity, growth, whole-body proximate composition, tissue Se concentrations, and histopathology were determined. Sturgeon survival among treatment groups did not differ significantly with a mean survival rate of 99+/-0.43% across all groups. A significant decrease (p<0.05) in swimming activity and growth rate was observed in sturgeon fed at or above 41.7 microg Se/g diet. Dietary SeMet concentrations were negatively correlated with whole-body protein and lipid content, but positively correlated with ash and moisture content. Selenium accumulated in the kidney, muscle, liver, gill, and plasma tissues in a dose-dependent manner. Histopathological alterations in the liver and kidney were observed in sturgeon fed above 20.5 microg Se/g diet. The threshold dietary Se toxicity concentration for white sturgeon was estimated to lie between 10 and 20 microg Se/g diet based on the histopathological alterations in the kidney. Research examining the consequences of elevated dietary Se concentrations on more sensitive life stages and the interactive effects of Se with other chemical or physical stressors are needed in order to determine if dietary threshold should be lowered to minimize the potential impacts of Se on white sturgeon in the San Francisco Bay-Delta.
进行了一项为期8周的生长试验，以确定白鲟（Acipenser transmontanus）对膳食中硒（Se）含量升高的毒理学影响的敏感性。给幼年白鲟喂食添加了L-硒代蛋氨酸（SeMet）形式的硒的饲料，干重基础上饲料中的硒浓度分别为0.4、9.6、20.5、41.7、89.8和191.1微克硒/克饲料。测定了膳食SeMet对存活率、游泳活动、生长、鱼体常规成分、组织硒浓度和组织病理学的影响。各处理组之间的鲟鱼存活率没有显著差异，所有组的平均存活率为99±0.43%。在喂食硒含量为41.7微克/克及以上饲料的鲟鱼中，观察到游泳活动和生长速率显著下降（p<0.05）。膳食SeMet浓度与鱼体蛋白质和脂质含量呈负相关，但与灰分和水分含量呈正相关。硒以剂量依赖的方式在肾脏、肌肉、肝脏、鳃和血浆组织中积累。在喂食硒含量高于20.5微克/克饲料的鲟鱼中，观察到肝脏和肾脏的组织病理学改变。根据肾脏的组织病理学改变，估计白鲟的膳食硒毒性阈值浓度在10至20微克硒/克饲料之间。为了确定是否应降低膳食阈值以尽量减少硒对旧金山湾-三角洲白鲟的潜在影响，需要研究膳食硒浓度升高对更敏感生命阶段的影响以及硒与其他化学或物理应激源的相互作用。
