School of Biological Sciences, University of Canterbury , Christchurch, 8014, New Zealand.
Environ Sci Technol. 2015 Feb 3;49(3):1896-902. doi: 10.1021/es5052815. Epub 2015 Jan 20.
Utilizing an in vitro technique, the skin of Pacific hagfish (Eptatretus stouti) was shown to take up nickel from the water via a high affinity, low capacity transport pathway. Uptake was biphasic, with saturation occurring at low nickel exposure concentrations, superseded by linear, diffusive uptake at levels greater than 50 μM. In vivo exposures showed that nickel accumulated mainly in the gill, heart, and brain, representing a tissue distribution distinct from that found in teleosts. Slime on the epidermal surface was shown to significantly reduce the uptake of low concentrations (10 μM) of the metals zinc and nickel, but slime had no effect on organic nutrient (the amino acid l-alanine) absorption. At a higher metal exposure concentration (1 mM), slime was no longer protective, indicating saturation of metal-binding sites. This is the first study to show that metals can be taken up by the integument of hagfish. The ability of the skin to act as a transport epithelium may be of particular importance for a burrowing, benthic scavenger, such as hagfish, which are likely to be exposed to relatively enriched levels of metal toxicants through their habitat and lifestyle, and this may have consequences for human health through hagfish consumption.
利用体外技术，研究表明太平洋八目鳗（Eptatretus stouti）的皮肤可以通过高亲和力、低容量的运输途径从水中摄取镍。摄取呈双相性，在低镍暴露浓度下达到饱和，然后在大于 50 μM 的水平上呈线性扩散摄取。体内暴露表明，镍主要积累在鳃、心脏和大脑中，这与硬骨鱼中的分布不同。表皮表面的黏液被证明可以显著减少低浓度（10 μM）锌和镍等金属的吸收，但黏液对有机营养物质（氨基酸 l-丙氨酸）的吸收没有影响。在更高的金属暴露浓度（1 mM）下，黏液不再具有保护作用，表明金属结合位点已饱和。这是第一项表明金属可以被八目鳗的表皮吸收的研究。皮肤作为运输上皮的能力对于穴居、底栖食腐动物（如八目鳗）可能尤为重要，因为它们通过栖息地和生活方式可能会接触到相对富集的金属毒物，这可能会对人类健康产生影响，因为人们会食用八目鳗。
