Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, 101 Rua do Matão, SP 05508-090, Brazil..
Sci Total Environ. 2020 May 15;717:137182. doi: 10.1016/j.scitotenv.2020.137182. Epub 2020 Feb 10.
The eutrophication increases the quantity of algae that are deficient in highly unsaturated fatty acids (HUFA) n3, as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), altering the bottom-up transfer of the entire food chain. Due to the importance of the fatty acids (FA) in physiological processes related to the main role of the membrane phospholipids (PL) and precursors of eicosanoids, and also the little knowledge about the influence of eutrophication in tropical ecosystems, it is important to understand how anthropogenic changes in the aquatic ecosystem affect the lipid quality, specifically n3 HUFAs. This study aimed to investigate the influence of eutrophication on the FA profile of the hepatic PL, as well as prostaglandin (PG) levels in Astyanax altiparanae females. Fish were collected in reservoirs with different eutrophication degrees: Jundiaí (Ju) reservoir and Embu-Guaçu (EG) branch, considered as mesotrophic points, and Barragem (Ba) and Aracati (Ar), branches from Guarapiranga reservoir, considered as supereutrophic and hypereutrophic points, respectively. The FA profile of the liver PL was analyzed by gas chromatography, and the concentration of liver PGE2 was analyzed using ELISA immunoassay kits. The degree of eutrophication did not alter the PG concentration and produced few modifications in the FA profile of hepatic PL. Fish collected at Ba and EG presented similar FA profiles, both with high percentages of n3 HUFA, especially DHA, in comparison to fish from Ju. However, no change was observed in the n3 HUFA profile of the fish from Ar. These data demonstrated that the FA profile in A. altiparanae seems to be more related to different physiological requirements of n3 HUFA of the species than eutrophication. So, this study contributed to findings on the trophic transfer dynamics in tropical freshwater reservoirs, where a direct effect of eutrophication on the availability of HUFA n3 to animals is not suggested.
富营养化会增加缺乏高度不饱和脂肪酸 (HUFA) n3 的藻类数量，如 EPA（二十碳五烯酸）和 DHA（二十二碳六烯酸），从而改变整个食物链的自上而下的转移。由于脂肪酸 (FA) 在与膜磷脂 (PL) 和前列腺素 (PG) 前体相关的生理过程中具有重要作用，而且对富营养化对热带生态系统的影响知之甚少，因此了解人为改变水生生态系统如何影响脂质质量，特别是 n3 HUFAs，是很重要的。本研究旨在调查富营养化对肝脏 PL 中 FA 谱以及 Astyanax altiparanae 雌性鱼类 PG 水平的影响。在富营养化程度不同的水库中采集鱼类：Jundiaí（Ju）水库和 Embu-Guaçu（EG）支流，被认为是中营养点，以及 Barragem（Ba）和 Aracati（Ar），分别是 Guarapiranga 水库的支流水库，被认为是超营养和过营养点。通过气相色谱法分析肝脏 PL 的 FA 谱，并使用 ELISA 免疫测定试剂盒分析肝脏 PGE2 的浓度。富营养化程度并未改变 PG 浓度，对肝脏 PL 的 FA 谱产生的影响也很小。从 Ba 和 EG 采集的鱼类具有相似的 FA 谱，与从 Ju 采集的鱼类相比，它们的 n3 HUFA，特别是 DHA 的比例都很高。然而，从 Ar 采集的鱼类的 n3 HUFA 谱没有变化。这些数据表明，A. altiparanae 的 FA 谱似乎与其物种对 n3 HUFA 的不同生理需求有关，而与富营养化无关。因此，本研究有助于了解热带淡水水库中的营养转移动态，在这些水库中，富营养化对动物获得 n3 HUFA 的直接影响并不明显。
