Coutinho F, Castro C, Rufino-Palomares E, Ordóñez-Grande B, Gallardo M A, Oliva-Teles A, Peres H
Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, Edifício FC4, 4169-007 Porto, Portugal; CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, Edifício FC4, 4169-007 Porto, Portugal; CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
Comp Biochem Physiol A Mol Integr Physiol. 2016 Jan;191:9-17. doi: 10.1016/j.cbpa.2015.09.012. Epub 2015 Sep 28.
A study was undertaken to evaluate dietary glutamine supplementation effects on gilthead sea bream performance, intestinal nutrient absorption capacity, hepatic and intestinal glutamine metabolism and oxidative status. For that purpose gilthead sea bream juveniles (mean weight 13.0g) were fed four isolipidic (18% lipid) and isonitrogenous (43% protein) diets supplemented with 0, 0.5, 1 and 2% glutamine for 6weeks. Fish performance, body composition and intestinal nutrient absorption capacity were not affected by dietary glutamine levels. Hepatic and intestinal glutaminase (GlNase), glutamine synthetase (GSase), alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase activities were also unaffected by dietary glutamine supplementation. In the intestine GlNase activity was higher and GSase/GlNase ratio was two-fold lower than in the liver, suggesting a higher use of glutamine for energy production by the intestine than by the liver. The liver showed higher catalase and glucose-6-phosphate dehydrogenase activities, while the intestine presented higher glutathione peroxidase and glutathione reductase activities and oxidised glutathione content, which seems to reveal a higher glutathione dependency of the intestinal antioxidant response. Total and reduced glutathione contents in liver and intestine and superoxide dismutase activity in the intestine were enhanced by dietary glutamine, though lipid peroxidation values were not affected. Overall, differences between liver and intestine glutamine metabolism and antioxidant response were identified and the potential of dietary glutamine supplementation to gilthead sea bream's antioxidant response was elucidated.
开展了一项研究，以评估日粮添加谷氨酰胺对金头鲷生长性能、肠道营养物质吸收能力、肝脏和肠道谷氨酰胺代谢及氧化状态的影响。为此，将金头鲷幼鱼（平均体重13.0克）投喂四种等脂（18%脂肪）和等氮（43%蛋白质）日粮，分别添加0%、0.5%、1%和2%的谷氨酰胺，为期6周。日粮谷氨酰胺水平对鱼类生长性能、身体组成和肠道营养物质吸收能力没有影响。日粮添加谷氨酰胺对肝脏和肠道谷氨酰胺酶（GlNase）、谷氨酰胺合成酶（GSase）、丙氨酸转氨酶、天冬氨酸转氨酶和谷氨酸脱氢酶的活性也没有影响。肠道中的GlNase活性较高，GSase/GlNase比值比肝脏低两倍，这表明肠道比肝脏更多地利用谷氨酰胺来产生能量。肝脏表现出较高的过氧化氢酶和葡萄糖-6-磷酸脱氢酶活性，而肠道则表现出较高的谷胱甘肽过氧化物酶和谷胱甘肽还原酶活性以及氧化型谷胱甘肽含量，这似乎表明肠道抗氧化反应对谷胱甘肽的依赖性更高。日粮谷氨酰胺可提高肝脏和肠道中总谷胱甘肽和还原型谷胱甘肽的含量以及肠道中超氧化物歧化酶的活性，不过脂质过氧化值未受影响。总体而言，确定了肝脏和肠道谷氨酰胺代谢及抗氧化反应之间的差异，并阐明了日粮添加谷氨酰胺对金头鲷抗氧化反应的潜在作用。
