College of Fisheries and Life Sciences, Center for Research on Environmental Ecology and Fish Nutrition of Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China.
College of Fisheries and Life Sciences, Center for Research on Environmental Ecology and Fish Nutrition of Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquaculture, Shanghai 201306, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China.
Comp Biochem Physiol C Toxicol Pharmacol. 2019 Sep;223:15-25. doi: 10.1016/j.cbpc.2019.05.002. Epub 2019 May 3.
This study evaluated the efficacy of replacing dietary fish oil (FO) with vegetable oils (virgin coconut and corn oil) on enzyme activities (glycolytic, oxidative and lipid metabolites), mRNA expression of lipid metabolic genes and histomorphology of liver and intestine in O. niloticus. O. niloticus (6.07 ± 0.07 g) was fed six experimental diets where fish oil (FO) served as the control diet, and then was supplemented by dietary oils; virgin coconut oil (VCO) {3%FO + 3%VCO; 3FVCO}, and corn oil (CO) {3%FO + 3%CO; 3FCO}, 6%VCO (VCO), 6%CO (CO) and 6%VO {3%VCO + 3%CO; VO}. Growth performances measured indicated fish fed diet 3FCO had higher weight gain (WG) and specific growth rate (SGR). Fish fed diet 3FCO recorded the highest activities in lactate dehydrogenase (LDH), pyruvate kinase (PK), citrate synthase (CS), cytochrome coxidase (COX), malic enzymes (ME) and lipoprotein lipase (LPL) respectively. Stearoyl-CoA desaturase (SCD1) was upregulated in groups fed diets 3FVCO and 3FCO. Also, groups fed diet VCO and CO expressed highly in LPL, whereas, elongase of very long-chain fatty acids (ELOVL-5) was not influenced by the lipid sources. Histological representations in the liver were highly impacted in vegetable diets where lipid accumulation was higher except those fed VCO. However, in the digestive tract from distal to middle and posterior, the same group (VCO) exhibited altered morphological structure as those fed diet 3FCO were similar to FO. The study shows that, corn oil in diets relates positively to growth and enzymatic activities which becomes evident in their depositions in liver and functional intestinal tracts. This study indicates dietary alternatives may cause alterations in lipid metabolic pathways (LPL and SCD1) involved in fatty acid transport. As such, polyunsaturated fatty acid (PUFA) rich diets (CO) based on this study results increases metabolic activities involving especially the production, distribution and consumption of adenosine triphosphate (ATP) in O. niloticus.
本研究评估了用植物油（初榨椰子油和玉米油）替代饮食中的鱼油（FO）对尼罗罗非鱼（Oreochromis niloticus）的酶活性（糖酵解、氧化和脂质代谢物）、脂质代谢基因的 mRNA 表达和肝肠组织形态的影响。尼罗罗非鱼（6.07±0.07g）被喂食六种实验饲料，其中鱼油（FO）作为对照饲料，然后用饲料油补充；初榨椰子油（VCO）{3%FO+3%VCO；3FVCO}和玉米油（CO）{3%FO+3%CO；3FCO}、6%VCO（VCO）、6%CO（CO）和 6%VO{3%VCO+3%CO；VO}。测量的生长性能表明，喂食 3FCO 饲料的鱼的体重增加（WG）和特定生长率（SGR）更高。喂食 3FCO 饲料的鱼的乳酸脱氢酶（LDH）、丙酮酸激酶（PK）、柠檬酸合酶（CS）、细胞色素 coxidase（COX）、苹果酸酶（ME）和脂蛋白脂肪酶（LPL）活性最高。在喂食 3FVCO 和 3FCO 饲料的组中，硬脂酰辅酶 A 去饱和酶（SCD1）上调。此外，喂食 VCO 和 CO 饲料的组中 LPL 表达较高，而长链脂肪酸延长酶（ELOVL-5）不受脂质来源的影响。在植物性饲料中，肝脏的组织学表现受到高度影响，除了喂食 VCO 的组外，脂质积累更高。然而，在从远端到中间和后端的消化道中，同一组（VCO）表现出形态结构改变，而喂食 3FCO 饲料的组与 FO 相似。研究表明，玉米油在饮食中与生长和酶活性呈正相关，这在它们在肝脏和功能性肠道中的沉积中表现得很明显。本研究表明，饮食替代品可能会改变参与脂肪酸转运的脂质代谢途径（LPL 和 SCD1）。因此，根据本研究结果，富含多不饱和脂肪酸（PUFA）的饲料（CO）会增加涉及特别是三磷酸腺苷（ATP）生产、分配和消耗的代谢活动。
