Blewett Tamzin A, Ransberry Victoria E, McClelland Grant B, Wood Chris M
Department of Biology, McMaster University, Hamilton, ON, L8S 4K1, Canada.
Department of Biology, McMaster University, Hamilton, ON, L8S 4K1, Canada.
Environ Pollut. 2016 Apr;211:370-81. doi: 10.1016/j.envpol.2016.01.002. Epub 2016 Jan 19.
The Atlantic killifish (Fundulus heteroclitus) is a resilient estuarine species that may be subjected to anthropogenic contamination of its natural habitat, by toxicants such as nickel (Ni). We investigated Ni accumulation and potential modes of Ni toxicity, in killifish, as a function of environmental salinity. Killifish were acclimated to 4 different salinities [0 freshwater (FW), 10, 30 and 100% seawater (SW)] and exposed to 5 mg/L of Ni for 96 h. Tissue Ni accumulation, whole body ions, critical swim speed and oxidative stress parameters were examined. SW was protective against Ni accumulation in the gills and kidney. Addition of Mg and Ca to FW protected against gill Ni accumulation, suggesting competition with Ni for uptake. Concentration-dependent Ni accumulation in the gill exhibited saturable relationships in both FW- and SW-acclimated fish. However SW fish displayed a lower Bmax (i.e. lower number of Ni binding sites) and a lower Km (i.e. higher affinity for Ni binding). No effect of Ni exposure was observed on critical swim speed (Ucrit) or maximum rate of oxygen consumption (MO2max). Markers of oxidative stress showed either no effect (e.g. protein carbonyl formation), or variable effects that appeared to depend more on salinity than on Ni exposure. These data indicate that the killifish is very tolerant to Ni toxicity, a characteristic that may facilitate the use of this species as a site-specific biomonitor of contaminated estuaries.
大西洋鳉鱼(Fundulus heteroclitus)是一种适应能力强的河口物种,其天然栖息地可能会受到镍(Ni)等有毒物质的人为污染。我们研究了鳉鱼体内镍的积累情况以及镍毒性的潜在作用模式,将其作为环境盐度的函数。鳉鱼被驯化适应4种不同的盐度[0淡水(FW)、10、30和100%海水(SW)],并暴露于5 mg/L的镍中96小时。检测了组织镍积累、全身离子、临界游泳速度和氧化应激参数。海水对鳃和肾脏中的镍积累具有保护作用。向淡水中添加镁和钙可防止鳃中镍的积累,表明它们与镍在摄取过程中存在竞争。在淡水和海水驯化的鱼中,鳃中镍的浓度依赖性积累均呈现出饱和关系。然而,海水环境中的鱼表现出较低的Bmax(即较低的镍结合位点数)和较低的Km(即对镍结合的亲和力较高)。未观察到镍暴露对临界游泳速度(Ucrit)或最大耗氧率(MO2max)有影响。氧化应激标志物要么没有影响(如蛋白质羰基形成),要么表现出不同的影响,这些影响似乎更多地取决于盐度而非镍暴露。这些数据表明,鳉鱼对镍毒性具有很强的耐受性,这一特性可能有助于将该物种用作受污染河口的特定地点生物监测器。