Ducasse-Cabanot S, Zambonino-Infante J, Richard N, Medale F, Corraze G, Mambrini M, Robin J, Cahu C, Kaushik S, Panserat S
1INRA, UMR1067 Nutrition Aquaculture & Génomique, Pôle d'hydrobiologie, CD918, F-64310 St-Pée-sur-Nivelle, France.
Animal. 2007 Oct;1(9):1272-82. doi: 10.1017/S1751731107000596.
For sustainable aquaculture, the removal of marine resource ingredients in fish diets is an important objective. While most studies focus on the replacement of fish oil by vegetable oil, little is known on the nutritional effects of presence (which corresponds to the control diet) or absence of dietary fish oil. We studied fatty acid composition of brush-border membranes and digestive enzyme activities of the intestine and measured the expression and activities of several enzymes involved in the hepatic intermediary metabolism of rainbow trout (Oncorhynchus mykiss) fed for 7 weeks with or without fish oil. The diets were pair-fed to ensure that fish fed either diet had comparable carbohydrate and protein intakes. Absence of fish oil significantly reduced growth rate, protein efficiency and plasma lipid components. Activities of intestinal digestive enzymes were significantly decreased in the anterior intestine in fish fed without fish oil. In liver, dietary fish oil removal did not affect the transcript levels or activities of the main enzymes involved in lipogenesis (fatty acid synthase) and fatty acid β-oxidation (3-hydroxyacyl-CoA dehydrogenase), glycolysis or amino acid oxidation. It lowered the expression of the genes coding for gluconeogenic enzymes (glucose-6-phosphatase and phosphoenolpyruvate carboxykinase), but their enzyme activities were not affected. The activities, but not gene expression of lipogenic enzymes, involved in NADPH and malonyl-CoA formation were also modified after fish oil removal as reflected by higher activities of isocitrate dehydrogenase/glucose-6-phosphate dehydrogenase and acetyl-CoA carboxylase enzymes. Overall, our results indicate that the intestinal digestive capacity was strongly modified by dietary fish oil removal, while hepatic intermediary metabolism was only marginally affected, in fed rainbow trout.
对于可持续水产养殖而言，去除鱼类饲料中的海洋资源成分是一个重要目标。虽然大多数研究集中在植物油替代鱼油方面，但对于日粮中存在（对应于对照日粮）或不存在鱼油的营养影响却知之甚少。我们研究了虹鳟（Oncorhynchus mykiss）肠道刷状缘膜的脂肪酸组成和消化酶活性，并测量了喂食含或不含鱼油7周的虹鳟肝脏中间代谢中几种酶的表达和活性。日粮进行配对投喂以确保喂食任何一种日粮的鱼具有相当的碳水化合物和蛋白质摄入量。缺乏鱼油显著降低了生长速率、蛋白质效率和血浆脂质成分。在无鱼油喂养的鱼中，前肠肠道消化酶的活性显著降低。在肝脏中，日粮中去除鱼油并未影响参与脂肪生成（脂肪酸合酶）和脂肪酸β-氧化（3-羟基酰基辅酶A脱氢酶）、糖酵解或氨基酸氧化的主要酶的转录水平或活性。它降低了编码糖异生酶（葡萄糖-6-磷酸酶和磷酸烯醇丙酮酸羧激酶）的基因的表达，但它们的酶活性未受影响。去除鱼油后，参与NADPH和丙二酰辅酶A形成的脂肪生成酶的活性（而非基因表达）也发生了改变，这表现为异柠檬酸脱氢酶/葡萄糖-6-磷酸脱氢酶和乙酰辅酶A羧化酶的活性升高。总体而言，我们的结果表明，在喂食的虹鳟中，日粮中去除鱼油会强烈改变肠道消化能力，而肝脏中间代谢仅受到轻微影响。
