Department of Biology, University of Padova, Via U. Bassi 58/b, 35131 Padova, Italy.
Comp Biochem Physiol C Toxicol Pharmacol. 2012 May;155(4):580-6. doi: 10.1016/j.cbpc.2012.01.008. Epub 2012 Jan 31.
The main characteristic of Antarctic seawater is its low constant temperature and its high concentration of O(2), which can increase the formation rate of reactive oxygen species (ROS), together with a natural occurrence of elevated cadmium and copper levels. In the present paper, we studied the presence of cadmium, copper and zinc, metallothioneins (MTs) and glutathione (GSH), and antioxidant enzyme activities in the Antarctic teleosts Trematomus bernacchii and Trematomus newnesi, in order to determine the influence of the peculiar physico-chemical features of the Antarctic marine environment on these physiological defence systems in two species of teleosts. In both of them, cadmium and copper accumulation occurs mostly in the liver. T. bernacchii accumulates zinc mostly in the hepatic tissue, whereas T. newnesi does not show a preferential accumulation site. In addition to the intra-specific analysis, we decided to compare the two species of the Trematomus genus in order to verify if the different feeding habits and motility of these fish affects metal accumulation. Our results show that the liver of T. bernacchii accumulates cadmium and zinc at a higher extent with respect to T. newnesi. Glutathione (GSH) and metallothioneins (MTs) are present in great quantity in the liver of both species. Moreover liver is the tissue which generally showed the highest antioxidant enzyme levels. The results provide further insights in the physiological mechanisms evolved by animals living in this extreme environment.
南极海水的主要特征是其恒定的低温和高浓度的 O(2)，这可以增加活性氧物质 (ROS) 的形成速率，再加上镉和铜含量自然升高。在本研究中，我们研究了南极鱼类 Trematomus bernacchii 和 Trematomus newnesi 中镉、铜和锌、金属硫蛋白 (MTs) 和谷胱甘肽 (GSH) 的存在以及抗氧化酶活性，以确定南极海洋环境的特殊理化特征对这两种鱼类生理防御系统的影响。在这两种鱼类中，镉和铜主要积聚在肝脏中。T. bernacchii 主要在肝组织中积累锌，而 T. newnesi 则没有优先的积聚部位。除了种内分析外，我们还决定比较 Trematomus 属的两个物种，以验证这些鱼类不同的摄食习性和运动方式是否会影响金属的积累。我们的研究结果表明，T. bernacchii 的肝脏比 T. newnesi 积累更多的镉和锌。谷胱甘肽 (GSH) 和金属硫蛋白 (MTs) 在两种物种的肝脏中大量存在。此外，肝脏通常表现出最高的抗氧化酶水平。这些结果为生活在这种极端环境中的动物的生理机制提供了进一步的见解。
