Matsuo A Y O, Val A L
Laboratório de Ecofisiologia e Evolução Molecular, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, 69083-000, Brazil.
Braz J Biol. 2007 Nov;67(4):657-61. doi: 10.1590/s1519-69842007000400010.
Understanding the effects of metal contamination in the Amazon basin is important because of the potential impact on this region of high biodiversity. In addition, the significance of fish as the primary source of protein for the local human population (living either alongside the Amazon River or in the city of Manaus) highlights the need for information on the metal transfer through the food chain. Bioaccumulation of metals in fish can occur at significant rates through the dietary route, without necessarily resulting in death of the organism. The goal of this work was to expose an economic relevant species from the Amazon basin (tambaqui, Colossoma macropomum) to dietary cadmium (Cd) at concentrations of 0, 50, 100, 200, and 400 microg.g-1 dry food. Fish were sampled on days 15, 30, and 45 of the feeding trials. Tissues were collected for analysis of Cd concentration using graphite furnace atomic absorption spectrophotometry. Cd accumulation in the tissues occurred in the following order: kidney > liver > gills > muscle. Relative to other freshwater fish (e.g., rainbow trout, tilapia), tambaqui accumulated remarkably high levels of Cd in their tissues. Although Cd is known to affect Ca2+ homeostasis, no mortality or growth impairment occurred during feeding trials.
了解亚马逊河流域金属污染的影响至关重要，因为这可能对该生物多样性丰富的地区产生潜在影响。此外，鱼类作为当地人口（居住在亚马逊河沿岸或玛瑙斯市）主要蛋白质来源的重要性，凸显了获取有关金属在食物链中转移信息的必要性。金属可通过饮食途径在鱼类中以显著速率发生生物累积，而不一定导致生物体死亡。这项工作的目标是让亚马逊河流域一种具有经济价值的物种（巨脂鲤，Colossoma macropomum）摄入浓度为0、50、100、200和400微克·克⁻¹干饲料的膳食镉（Cd）。在喂养试验的第15天、30天和45天对鱼进行采样。收集组织，使用石墨炉原子吸收分光光度法分析镉浓度。组织中镉的积累顺序如下：肾脏＞肝脏＞鳃＞肌肉。相对于其他淡水鱼（如虹鳟鱼、罗非鱼），巨脂鲤组织中积累的镉水平极高。尽管已知镉会影响Ca²⁺稳态，但在喂养试验期间未发生死亡或生长受损情况。
