饲料丙二醛对草鱼生长、肝胰脏及肠道结构和功能的影响

为了探讨丙二醛(MDA)对草鱼Ctenopharyngodon idellus(74.821.49) g生长、肝胰脏及肠道结构和功能的影响并初步对比MDA与其他油脂氧化产物的毒副作用, 本试验以新鲜豆油、低氧化程度的鱼油为饲料脂肪源, 制成豆油组(S组)、鱼油组(F组), 并在豆油组中喷涂不同浓度的MDA, 制成MDA水平为61.59 (M1组)、123.92 (M2组)、185.04 (M3组) mg/kg的5种等氮等能的试验饲料。经72d池塘网箱养殖后, 试验结果显示:(1)饲料中MDA及油脂其他氧化产物均可显著增加草鱼饲料系数(FCR) (P0.05), 显著降低特定生长率(SGR)、蛋白质沉积率(PRR)(P0.05), MDA还可显著降低草鱼脂肪沉积率(LRR) (P0.05); (2)饲料中MDA及油脂其他氧化产物均可显著降低血清总胆汁酸(TBA)含量(P0.05), 并使血清总胆固醇(TC)、甘油三酯(TG)、MDA含量及超氧化物歧化酶(SOD)酶活性显著上升(P0.05), 饲料中MDA还可显著增加血清丙氨酸氨基转移酶(ALT)含量(P0.05), 显著降低血清高密度脂蛋白与低密度脂蛋白之比(HDL/LDL)、白蛋白与球蛋白之比(A/G)比值(P0.05); (3)饲料中MDA及油脂及其他氧化产物会显著增加肝胰脏脂肪(P0.05), 且MDA还会显著增加肝胰脏SOD含量(P0.05), 导致草鱼肝胰脏氧化应激; (4)饲料中MDA会损伤肝胰脏细胞线粒体, 降低细胞核数量, 使肝胰脏细胞有明显纤维化趋势; (5)饲料MDA及鱼油其他氧化产物均会引起草鱼肠道黏膜杯状细胞数量增加, 损伤肠道微绒毛, 并会损伤肠道紧密连接结构, 增加肠道通透性, 导致血清内毒素及D-乳酸含量显著增加(P0.05)。上述结果表明: (1)饲料MDA会引起草鱼鱼体应激, 并通过干扰正常胆汁酸循环来干扰草鱼对脂肪的消化吸收, 最终导致草鱼生长性能下降; (2)MDA会引起肝胰脏氧化应激, 并可通过损伤肝胰脏细胞线粒体内部结构来损伤草鱼肝胰脏, 增加其发生脂肪性肝炎机率, 而鱼油其他氧化产物则是通过影响线粒体膜结构改变线粒体形态来损伤肝胰脏; (3)饲料MDA及鱼油其他氧化产物均会损伤草鱼肠道绒毛和微绒毛来降低其消化吸收能力, 还可损伤肠道紧密连接结构, 增加肠道通透性。

EFFECTS OF MDA ON THE GROWTH PERFORMANCE,STRUCTURE AND FUNCTION OF HEPATOPANCREAS AND INTESTINE OF GRASS CARP (CTENOPHARYNGODON IDELLUS)

The study investigated effects of MDA on the growth performance, structure and function of hepatopancreas and intestine of grass carp (Ctenopharyngodon idellus) and evaluated effects between MDA and other products of oxi-dized fish oil. Five isonitrogenous and isoenergetic diets were prepared with soybean oil, fish oil and different level of MDA for a 72-day experiment. The results indicated that MDA and other products of oxidized fish oil both signifi-cantly increased the FCR of grass carp and decreased the SGR and PRR of grass carp (P<0.05). Only MDA signifi-cantly decreased the LRR (P<0.05). Moreover, MDA and other products of oxidized fish oil both significantly de-creased the TBA content in serum (P<0.05), and increased the content of TC, TG and MDA and the activity of SOD in serum (P<0.05). Only MDA significantly increased ALT content and decreased the radio between HDL and LDL in serum (P<0.05). MDA and other products of oxidized fish oil both significantly increased the lipid content of hepato-pancreas (P<0.05) and stimulated the oxidative stress of hepatopancreas. MDA damaged the morphology in hepatopan-creas cell and significantly decreased the number of nucleus of hepatopancreas cell (P<0.05), which lead to the obvi-ously trend of fibrosis of the hepatopancreas cell. MDA and other products of oxidized fish oil both significantly in-creased the number of goblet cells in the microvilli (P<0.05). To the permeability, serum D-lactic acid and endotoxin significantly increased because of the defect of the tight junction, the hyperplasia and edema of villi. In conclusion, MDA decrease the growth performance of grass carp by regulating the oxidative stress and lipid metabolism. MDA and other products of oxidized fish oil affect the hepatopancreas with different mechanism. Both MDA and other products of oxidized fish oil can mediate the function of intestine.