饲料鱼溶浆影响黄颡鱼的胆汁酸代谢及脂肪沉积

为探讨鱼溶浆(SW)对黄颡鱼(Pelteobagrus fulvidraco)胆汁酸代谢的影响, 以30%鱼粉日粮为对照(FM), 在无鱼粉日粮中分别添加约8% (SW8)、17% (SW17)和25% (SW25)的鱼溶浆(干物质), 设计4组等氮等能日粮, 在池塘网箱中养殖黄颡鱼初始体重(15.67±0.11) g] 60d。结果显示: 与FM组相比, SW25组黄颡鱼全鱼脂肪含量显著降低(P<0.05), SW17、SW25组肝胰脏脂肪含量显著降低; 同时, SW17、SW25组血清胆固醇降低11.9%—16.6%, 甘油三酯降低32.5%—47.9% (P<0.05)。SW25组肝胰脏胆汁酸水平比FM组降低了76.3% (P<0.05), 而在血清、肠道中胆汁酸水平升高了125.7%和123.3% (P<0.05)。黄颡鱼肝胰脏CYP7A1基因的mRNA表达量没有显著变化(P>0.05), BSEP、ABCC4、NTCP 基因的表达量随鱼溶浆添加量增加而呈现上升趋势, SW25组的表达量比FM组高16.9%、68.2%和222.8%, ABCC4、NTCP表达量变化显著(P<0.05)。结果表明: 在无鱼粉日粮中添加25%的鱼溶浆(干物质), 不影响黄颡鱼肝胰脏胆汁酸的合成作用, 但促使胆汁酸向血液、肠道中转移, 增强了脂肪的能量代谢作用, 减少鱼体脂肪沉积。

EFFECTS OF STICKWATER ON BILE ACID AND LIPID METABOLISM OF YELLOW CATFISH (PELTEOBAGRUS FULVIDRACO)

To explore effects of stickwater (SW) on bile acid metabolism, 4 isonitrogenous and isoenergetic diets including the control diet containing 30% fish meal (FM) and three experimental diets without fish meal but with 8% (SW8), 17% (SW17), 25% (SW25) stickwater (dry matter) were fromulated to feed the yellow catfish with the initial body weight of (15.67±0.11) g for 60 days in pond cage farming. Compared with FM group, fat content of whole fish of SW25 group decreased observably (P<0.05), and liver fat content of SW17 and SW25 group reduced significantly (P<0.05); Cholesterol in serum of SW17 and SW25 groups decreased from 11.9% to 16.6%, and triglyceride decreased from 32.5% to 47.9% (P<0.05). Liver bile acid of SW25 group decreased by 76.3% (P<0.05) compared with FM group, but serum and intestine bile acid increased by 125.7% and 123.3% (P<0.05). The liver CYP7A1 at mRNA level had no significant difference among five groups, but the expression of BSEP, ABCC4, and NTCP increased by stickwater with 16.9%, 68.2% and 222.8%, respectively, in SW25 group. The mRNA level of ABCC4 and NTCP varied significantly (P<0.05). The results indicated that addition of 25% stickwater (dry matter) in diets without fish meal had no effect in liver bile acid synthesis, but it promoted transferring bile acid to serum and intestine to improve fat metabolism and reduce fat deposition in yellow catfish.