Rodrigo Ana P, Costa Pedro M
Environmental Toxicology Lab, MARE - Marine and Environmental Sciences Centre, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia da Universidade Nova de LisboaCaparica, Portugal.
Front Physiol. 2017 Apr 20;8:232. doi: 10.3389/fphys.2017.00232. eCollection 2017.
The relevance of cephalopods for fisheries and even aquaculture, is raising concerns on the relationship between these molluscs and environmental stressors, from climate change to pollution. However, how these organisms cope with environmental toxicants is far less understood than for other molluscs, especially bivalves, which are frontline models in aquatic toxicology. Although, sharing the same basic body plan, cephalopods hold distinct adaptations, often unique, as they are active predators with high growth and metabolic rates. Most studies on the digestive gland, the analog to the vertebrate liver, focused on metal bioaccumulation and its relation to environmental concentrations, with indication for the involvement of special cellular structures (like ) and proteins. Although the functioning of phase I and II enzymes of detoxification in molluscs is controversial, there is evidence for CYP-mediated bioactivation, albeit with lower activity than vertebrates, but this issue needs yet much research. Through novel molecular tools, toxicology-relevant genes and proteins are being unraveled, from metallothioneins to heat-shock proteins and phase II conjugation enzymes, which highlights the importance of increasing genomic annotation as paramount to understand toxicant-specific pathways. However, little is known on how organic toxicants are stored, metabolized and eliminated, albeit some evidence from biomarker approaches, particularly those related to oxidative stress, suggesting that these molluscs' digestive gland is indeed responsive to chemical aggression. Additionally, cause-effect relationships between pollutants and toxicopathic effects are little understood, thus compromising, if not the deployment of these organisms for biomonitoring, at least understanding how they are affected by anthropogenically-induced global change.
头足类动物在渔业乃至水产养殖中的重要性，引发了人们对这些软体动物与从气候变化到污染等环境压力源之间关系的关注。然而，与其他软体动物相比，尤其是作为水生毒理学前沿模型的双壳类动物，人们对这些生物如何应对环境毒物的了解要少得多。尽管头足类动物与其他软体动物有着相同的基本身体结构，但它们具有独特的适应性，而且往往是独一无二的，因为它们是具有高生长和代谢率的活跃捕食者。大多数关于消化腺（相当于脊椎动物的肝脏）的研究都集中在金属生物积累及其与环境浓度的关系上，研究表明特殊的细胞结构（如 ）和蛋白质参与其中。尽管软体动物中 I 期和 II 期解毒酶的功能存在争议，但有证据表明 CYP 介导的生物活化作用，尽管其活性低于脊椎动物，但这个问题仍需要大量研究。通过新的分子工具，与毒理学相关的基因和蛋白质正在被揭示，从金属硫蛋白到热休克蛋白和 II 期结合酶，这凸显了增加基因组注释对于理解毒物特异性途径的重要性。然而，对于有机毒物如何储存、代谢和消除知之甚少，尽管生物标志物方法提供了一些证据，特别是那些与氧化应激相关的证据，表明这些软体动物的消化腺确实对化学侵害有反应。此外，污染物与毒性病理效应之间的因果关系鲜为人知，这不仅影响了将这些生物用于生物监测的应用，至少也影响了我们对它们如何受到人为引起的全球变化影响的理解。
