Lavradas Raquel Teixeira, Hauser-Davis Rachel Ann, Lavandier Ricardo Cavalcanti, Rocha Rafael Christian Chávez, Saint' Pierre Tatiana D, Seixas Tércia, Kehrig Helena Amaral, Moreira Isabel
Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Departamento de Química, Laboratório de Bioanalítica, Rua Marquês de São Vicente, 225, Gávea, CEP: 22453-900 Rio de Janeiro, RJ, Brazil.
Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Departamento de Química, Laboratório de Bioanalítica, Rua Marquês de São Vicente, 225, Gávea, CEP: 22453-900 Rio de Janeiro, RJ, Brazil.
Ecotoxicol Environ Saf. 2014 Sep;107:55-60. doi: 10.1016/j.ecoenv.2014.04.013. Epub 2014 Jun 4.
Metal concentrations (Cu, Pb, Zn and Cd) were determined in muscle, gills, soft tissues and eggs in male, non-ovigerous and ovigerous female Callinectes sp. specimens from a reference site in Southeastern Brazil. Metallothionein (MT) and reduced glutathione (GSH) levels were also determined. Results demonstrate that sex has a significant influence on metal, MT and GSH concentrations. Significant maternal transfer of Pb and Zn from ovigerous females to eggs was verified, while female crabs, both ovigerous and non-ovigerous, showed elevated GSH and MT in viscera when compared to males, indicating possible MT role in excreting metals to eggs in ovigerous females of this species. Several strong statistical correlations between metals and MT indicate MTs role in detoxification of both toxic and essential elements in different organs. Pb and Zn were significantly correlated to GSH, indicating oxidative stress caused by the former and a direct link between Zn and GSH in maintaining homeostasis. Regarding human consumption, metal concentrations were lower than the maximum permissible levels established by international and Brazilian regulatory agencies, indicating that this species is safe for human consumption concerning this parameter. The presence of metals in Callinectes sp., however, is still of importance considering that this is a key species within the studied ecosystem and, therefore, plays a major role in the transference of pollutants to higher trophic levels. In addition, the presence of significant metal concentrations found in eggs must be considered in this context, since crab eggs are eaten by several other species, such as shorebirds, seabirds, and fish. Also, to the best of our knowledge, this is the first study regarding both MT and GSH levels in Callinectes sp. eggs and is of interest in the investigation of molecular mechanisms regarding metal exposure in these crustaceans. Data reported in this study support the conclusions from previous reports, provide mechanistic insights regarding metal exposure, metallothionein and oxidative stress induction in this species and also present novel data regarding eggs.
在巴西东南部一个参考地点采集的雄性、未抱卵雌性和抱卵雌性的美青蟹样本中，测定了肌肉、鳃、软组织和卵中的金属浓度（铜、铅、锌和镉）。还测定了金属硫蛋白（MT）和还原型谷胱甘肽（GSH）的水平。结果表明，性别对金属、MT和GSH浓度有显著影响。证实了抱卵雌蟹向卵中大量母体转移铅和锌，而抱卵和未抱卵的雌蟹与雄蟹相比，内脏中的GSH和MT含量升高，表明MT可能在该物种抱卵雌蟹向卵中排泄金属方面发挥作用。金属与MT之间存在若干强统计相关性，表明MT在不同器官中对有毒和必需元素的解毒作用。铅和锌与GSH显著相关，表明前者引起氧化应激，以及锌与GSH在维持体内平衡方面的直接联系。就人类消费而言，金属浓度低于国际和巴西监管机构规定的最大允许水平，表明就该参数而言，该物种对人类消费是安全的。然而，美青蟹中金属的存在仍然很重要，因为这是所研究生态系统中的关键物种，因此在污染物向更高营养级的转移中起主要作用。此外，在这种情况下，必须考虑卵中发现的显著金属浓度，因为蟹卵被其他几种物种食用，如滨鸟、海鸟和鱼类。此外，据我们所知，这是第一项关于美青蟹卵中MT和GSH水平的研究，对于研究这些甲壳类动物中金属暴露的分子机制具有重要意义。本研究报告的数据支持了先前报告的结论，提供了关于该物种金属暴露、金属硫蛋白和氧化应激诱导的机制见解，还提供了关于卵的新数据。
