CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, S/N, 4450-208, Matosinhos, Portugal; ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
DTU, Technical University of Denmark, National Institute of Aquatic Resources, Section for Aquaculture, Niels Juelsvej 30, 9850, Hirtshals, Denmark.
Food Chem Toxicol. 2020 Jun;140:111332. doi: 10.1016/j.fct.2020.111332. Epub 2020 Apr 17.
This study aimed to evaluate the impact of diets including increasing amounts (1, 2 and 4%) of an iodine-rich macroalgae, Saccharina latissima, on gene expression and fillet composition of commercial-sized rainbow trout. Liver and muscle expression of genes related to growth, iodine, oxidative stress, and lipid metabolism, and the fillet content of fatty acids, cholesterol, and vitamin D were assessed. The highest kelp inclusion led to lower final body weight and HSI, without significant differences in mRNA transcription of genes involved in growth (ghr1, ghr2 and igf1) or iodine metabolism (dio1, thra, and thrb). A significant downregulation of an oxidative stress marker, gpx1b2, was observed in fish fed 2% S. latissima, which might suggest the need for less endogenous antioxidants. Dietary inclusion of kelp impacted lipid metabolism, with a downregulation of fatty acid synthase, accompanied by a general decrease of fatty acids in fillet. The present study demonstrated that supplementation of diets with 1 or 2% S. latissima can be achieved without detrimental effects on rainbow trout final weight. Evidence suggest a lipid-lowering effect of diets that did not compromise fillet EPA and DHA concentrations, being 3.7 times above the recommended levels for human consumption.
本研究旨在评估在商业规格虹鳟鱼的饮食中添加不同剂量（1%、2%和 4%）富碘大型海藻裙带菜对基因表达和鱼片成分的影响。检测了与生长、碘、氧化应激和脂质代谢相关的基因在肝脏和肌肉中的表达，以及鱼片的脂肪酸、胆固醇和维生素 D 含量。最高的裙带菜添加量导致最终体重和 HSI 降低，但与生长（ghr1、ghr2 和 igf1）或碘代谢（dio1、thra 和 thrb）相关基因的 mRNA 转录没有显著差异。在摄食 2%裙带菜的鱼中观察到一种氧化应激标志物 gpx1b2 的显著下调，这可能表明需要更少的内源性抗氧化剂。裙带菜的饮食添加影响了脂质代谢，脂肪酸合酶下调，伴随着鱼片内脂肪酸的普遍减少。本研究表明，在不影响虹鳟鱼最终体重的情况下，在饮食中添加 1%或 2%的裙带菜是可行的。有证据表明，这种饮食具有降低脂质的效果，不会影响鱼片 EPA 和 DHA 的浓度，其浓度是人类推荐摄入量的 3.7 倍以上。
