α-硫辛酸对摄食高脂饲料的大口黑鲈生长性能和肝脏脂质代谢的影响

Effects of dietary alpha-lipoic acid on growth performance and hepatic lipid metabolism of largemouth bass(Micropterus salmoides)fed diet with high lipid supplementation

实验旨在探究高脂饲料中添加α-硫辛酸(α-LA)对大口黑鲈生长性能和肝脏脂质代谢的影响,配制3组等氮实验饲料,分别为粗脂肪14%的基础饲料组(D1),粗脂肪14%添加α-LA组(D2),粗脂肪16%添加α-LA组(D3),投喂大口黑鲈幼鱼[初体质量(5.01±0.02)g],养殖实验持续8周。结果显示,D3组与D1组之间的鱼体增重率和特定生长率差异不显著,显著高于D2组;D3组的蛋白质效率和蛋白沉积率显著高于D1和D2组;D2和D3组血清甘油三酯、谷草转氨酶和谷丙转氨酶活性比D1组显著降低,各组间总胆固醇含量差异不显著。D2和D3组的肝脏空泡化面积和脂肪含量显著低于D1组;D2和D3组肝脏的脂肪甘油三酯脂肪酶和肉碱棕榈酰转移酶Ⅰ活性显著提高,脂肪酸合成酶和乙酰辅酶A羧化酶的活性显著降低;肝脏代谢组学结果显示,D3组不饱和脂肪酸的生物合成代谢通路相比D1组显著上调。D3组肌肉十五烷酸、十七烷酸和二十一碳酸含量显著升高,D2和D3组花生四烯酸(ARA)、二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)的含量显著升高。研究表明,高脂饲料中添加α-LA,通过不饱和脂肪酸的生物合成代谢通路增强脂质分解并抑制脂质合成,减少肝脂积累,促进肝脏健康,增加肌肉ARA、DHA和EPA的沉积。

The experiment aims to investigate the effect of adding alpha-lipoic acid(α-LA)to high-fat diets on the growth performance and liver lipid metabolism of largemouth bass(Micropterus salmoides).Three isonitrogenous experimental diets were prepared:a basal diet with 14% crude lipid(D1),the second diet with 14%crude lipid added toα-LA(D2)and the third diet with 16% crude lipid added toα-LA(D3).M.salmoides[(5.01±0.02)g initial weight]juveniles ingested the three diets for 8 weeks.The results showed that the weight gain rate and specific growth rate of M.salmoides in groups D3 and D1 were not significantly different(P>0.05),but significantly higher than in group D2(P<0.05);the protein efficiency and protein deposition rate of M.salmoides in group D3 were significantly higher than those in groups D1 and D2(P<0.05).Serum triglycerides levels,glutamic oxaloacetic transaminase,and glutamic alanine transaminase activity were significantly lower in groups D2 and D3 compared to group D1(P<0.05),while the difference in total cholesterol levels was not significant between the groups(P>0.05).Liver vacuolation and fat deposition were significantly lower in groups D2 and D3 than in group D1(P<0.05).The hepatic metabolome results showed that the biosynthetic metabolic pathway of unsaturated fatty acids was significantly upregulated in group D3 compared to group D1(P<0.05).Muscle fatty acids were significantly elevated in group D3 for pentadecanoic acid,heptadecanoic acid,and 21 carbonic acids(P<0.05).The contents of arachidonic acid(ARA),eicosapentaenoic acid(EPA),and docosahexaenoic acid(DHA)in muscle were significantly higher in groups D2 and D3(P<0.05).High-lipid diet withα-LA enhanced lipolysis,inhibited lipid synthesis through the biosynthetic metabolic pathway of unsaturated fatty acids,and reduced hepatic lipid accumulation,as well as increased ARA,DHA,and EPA deposition in muscle.