Castro Carolina, Peréz-Jiménez Amalia, Coutinho Filipe, Corraze Geneviève, Panserat Stéphane, Peres Helena, Teles Aires Oliva, Enes Paula
CIMAR/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.
Departamento de Zoología, Facultad de Ciencias, Universidad de Granada, Campus Fuentenueva s/n, 18071, Granada, Spain.
Fish Physiol Biochem. 2018 Jun;44(3):911-918. doi: 10.1007/s10695-018-0480-6. Epub 2018 Feb 19.
The aim of the present study was to assess the impact of an acute handling stress on hepatic oxidative status of European sea bass (Dicentrarchus labrax) juveniles fed diets differing in lipid so urce and carbohydrate content. For that purpose, four diets were formulated with fish oil (FO) and vegetable oils (VO) as lipid source and with 20 or 0% gelatinized starch as carbohydrate source. Triplicate groups of fish with 74 g were fed each diet during 13 weeks and then subjected to an acute handling stress. Stress exposure decreased hematocrit (Ht) and hemoglobin (Hb) levels. Independent of dietary treatment, stress exposure increased hepatic lipid peroxidation (LPO). Stressed fish exhibited lower glucose 6-phosphate dehydrogenase (G6PD), catalase (CAT), and superoxide dismutase (SOD) activities, independent of previous nutritional history. In the VO groups, stress exposure increased glutathione peroxidase (GPX) activity. Diet composition had no effect on Ht and Hb levels. In contrast, dietary carbohydrate decreased hepatic LPO and CAT activity and increased glutathione reductase (GR) and G6PD activities. Dietary lipids had no effect on LPO. Fish fed the VO diets exhibited higher G6PD activity than fish fed the FO diets. In conclusion, dietary carbohydrates contributed to the reduction of oxidative stress in fish. However, under the imposed handling stress conditions, liver enzymatic antioxidant mechanisms were not enhanced, which may explain the overall increased oxidative stress.
本研究的目的是评估急性处理应激对摄食不同脂质来源和碳水化合物含量饲料的欧洲海鲈（Dicentrarchus labrax）幼鱼肝脏氧化状态的影响。为此，以鱼油（FO）和植物油（VO）作为脂质来源，并分别以20%或0%糊化淀粉作为碳水化合物来源，配制了四种饲料。将每组74克的三组重复实验鱼投喂每种饲料13周，然后对其施加急性处理应激。应激暴露降低了血细胞比容（Ht）和血红蛋白（Hb）水平。无论饮食处理如何，应激暴露都会增加肝脏脂质过氧化（LPO）。无论之前的营养史如何，应激鱼的葡萄糖6-磷酸脱氢酶（G6PD）、过氧化氢酶（CAT）和超氧化物歧化酶（SOD）活性均较低。在VO组中，应激暴露增加了谷胱甘肽过氧化物酶（GPX）活性。饮食组成对Ht和Hb水平没有影响。相反，饮食中的碳水化合物降低了肝脏LPO和CAT活性，并增加了谷胱甘肽还原酶（GR）和G6PD活性。饮食中的脂质对LPO没有影响。投喂VO饲料的鱼比投喂FO饲料的鱼表现出更高的G6PD活性。总之，饮食中的碳水化合物有助于降低鱼类的氧化应激。然而，在施加的处理应激条件下，肝脏酶抗氧化机制并未增强，这可能解释了整体氧化应激的增加。
