饲料氧化鱼油对草鱼(Ctenopharyngodon idellus)肠道谷胱甘肽/谷胱甘肽转移酶通路基因表达活性的影响

The Effect of Glutathione/Glutathione Transferase Gene Pathway in Intestinal of Grass Carp(Ctenopharyngodon idellus)by Feeding Oxidized Fish Oil

为了研究饲料氧化鱼油对草鱼肠道抗氧化防御能力的影响,以谷胱甘肽/谷胱甘肽转移酶(GSH/GSTs)通路为研究对象,以豆油、鱼油、氧化鱼油为饲料脂肪源分别设计豆油组(6S)、鱼油组(6F)、2%氧化鱼油(2OF)、4%氧化鱼油(4OF)及6%氧化鱼油(6OF)5组等氮、等能半纯化饲料,在池塘网箱养殖草鱼[平均体重(74.8±1)g]72 d。采用荧光定量PCR(RT-QPCR)的方法,测定了草鱼肠道组织中谷氨酸-半胱氨酸连接酶催化亚(GCLC)、谷胱甘肽合成酶(GSS)和谷胱甘肽还原酶(GSR)以及谷胱甘肽S-转移酶的ω1(GSTω1)、PI-谷胱甘肽S-转移酶(GSTPI)和微粒体谷胱甘肽S-转移酶1(MGSt1)的表达活性,并测定了肠道中谷胱甘肽GSH的含量。结果显示,2OF、4OF和6OF组草鱼肠道中GSH/GSTs通路基因表达均上调,其中6F组中MSGT1在肠道中表达显著上调(P<0.05),4OF组中GSR和MGST1在肠道中表达显著上调(P<0.05),6OF中GCLC和MGST1在草鱼肠道中表达显著上调(P<0.05);GCLC表达活性与饲料中MDA含量呈多项式的关系,MGST1表达活性与饲料中AV和(EPA+DHA)呈多项式关系。结果表明,氧化鱼油使草鱼肠道GSH/GSTs通路基因表达活性上调,且GSH/GSTs通路基因表达活性对不同浓度氧化鱼油所引起的肠道氧化损伤具有不同的应对方式。

The effect of dietary oxidized fish oil on oxidative stress pathway was studied by measuring the intesti- nal of grass carp GSH/GSTs pathway gene expression. The fish, with an initial weight of （74.8 ± 1 ） g, was fed 72 d with a basal diet and 5 diets added with soybean oil （6S）, fish oil （6F）, 2%oxidized fish oil （2OF）, 4% oxidized fish oil （4OF） and 6 % oxidized fish oil （6OF）. Using RT - QPCR method, determinethe GSH/GSTs pathway gene expression and the GSH content in grass carp intestinal. The results showed that, 2OF, 4OF and 6OF grass carp in- testinal GSH/GSTs gene pathway genes were increased, which 6F group MSGT1 expression was significantly in- creased （ P 〈 0.05 ） in the intestinal, 4OF group GSR and MGST1 expression significantly increased （ P 〈 0.05 ） in the intestinal, 6OF group GCLC and MGST1 expression was significantly increased （ P 〈 0.05 ） in the intestinal; MDA content in dietary with the relative expression of GCLC was polynomial relations, AV and （ EPA ＋ DHA） con- tent in dietary with the relative expression of GCLC was polynomial relations. In conclusion, oxidized fish oil had an influence on GSH/GSTs gene pathway had the intestinal and when oxidized fish oil different concentrations, GSH/ GSTs gene pathway in different ways to deal with.