饲料磷脂水平对巴丁鱼肝脏脂肪沉积及脂肪代谢酶活性的影响

Effect of dietary phospholipids level on lipid metabolism in liver of catfish(Pangasius sutchi)

研究旨在探讨饲料磷脂对巴丁鱼肝脏脂肪代谢的影响。将巴丁鱼(Pangasius sutchi)900尾[初始体重(1.45±0.08)g/尾]随机分成5组,分别投喂5组饲料,各组磷脂水平分别为0%(PL0组)、1%(PL1组)、2%(PL2组)、3%(PL3组)和4%(PL4组)。结果表明:1PL0组的肝脏脂肪含量最高,显著高于PL2组(P<0.05);2巴丁鱼肝细胞内含有程度不同的脂肪油滴,严重程度依次排序为PL0组>PL1组>PL4组>PL2组≈PL3组;3PL0组肝脏中的NADP-MDH和G-6-PDH活性最高,随着磷脂添加水平升高,酶的活性下降;PL3组的NADP-MDH活性和G-6-PDH活性最低,随后酶活缓慢升高。试验结果表明,在巴丁鱼幼鱼饲料中添加适宜的磷脂(3%),能有效降低鱼体肝脏中的脂肪沉积;而当饲料缺乏磷脂或磷脂过量时,肝脏脂肪沉积增多,脂肪合成相关酶的活性补偿性升高。

The aim of this study was to investigate mechanism of lipid metabolism of catfish （Pangasius sutehl） fed with increasing level of dietary phospholipids. 900 healthy catfish [（1.4±0.08） g of average weight] were randomly divided into five groups. Dietary phospholipid level of group PL0 was 0%, and 1%, 2%, 3%, 4% for group PL1, group PL2, group PL3, group PL4, respectively. The experiment last- ed for 56 days. The results showed that The liver lipid content of group PL0 was the highest,signifi- cantly higher than group PL2（P〈0.05）. The hepatic cell of catfish （Pangasius sutehl） contained vary- ing degree fat droplets, the severity of which was group PL0, PL1, PL4, PL2 and PL3 in sequence. （~） The activities of NADP-MDH and G-6-PDH in liver of group PL0 were the highest, decreased with adding phospholipids in diet; NADP-MDH activities and G-6-PDH activities of group 3 were the low- est, then the two lipogenie enzyme activities increased with further increment of dietary phospholipids level. The results indicated that adding optimal level of phospholipids （3%） in the diets for catfish （Pangasius sutehl） can reduce lipid deposit in liver, and if dietary phopholipids is deficient or excess, liver lipid content and lipogenic enzyme activity increase.