摘要
本文旨在研究人工饲料中蛋氨酸对瓦氏黄颡鱼幼鱼肝脏及血浆中谷草转氨酶和谷丙转氨酶活力的影响。在基础饲料中分别添加0.0、0.3、0.6、0.9、1.2和1.5g/100g的晶体DL-Met,以L-Glu作为等氮替代物,配制6组等氮等脂饲料(Met的实测值为0.40、0.73、1.04、1.33、1.70和1.98g/100g饲料),在室内循环水系统中进行为期70d的生长实验。实验表明,随着饲料中蛋氨酸含量的增加,肝脏谷丙转氨酶(GPT)活力显著升高,并在蛋氨酸含量为1.70g/100g饲料时,活力达最大值(P<0.05);肝脏谷草转氨酶(GOT)活力与GPT活力有相似的变化趋势,但各处理组间无显著性差异(P>0.05)。随着饲料中蛋氨酸含量的增加,血浆中的GPT活力呈现先升高后平稳的变化趋势,且拐点出现在蛋氨酸含量为1.04g/100g(P<0.05)饲料组,而血浆中GOT活力呈现先升高后降低的变化趋势,且最大值出现在蛋氨酸含量为0.73g/100g(P<0.05)饲料组。研究表明,当饲料中蛋氨酸含量不足或过量时,都会影响瓦氏黄颡鱼幼鱼转氨酶的活力,从而在一定程度上影响鱼体的氨基酸代谢。
A 10-week feeding trialina recirculation rearing system was tried in order to determine the influence of dietary methionine on the activity of glutamic-pyruvic and glutamic oxalacetic transaminasesin the liver and plasma of juvenile darkbarbel catfish(Pelteobagrus vachelli).Six nitrogen and lipid contents identicaldiets were formulated by supplementing 0.0%,0.3%,0.6%,0.9%,1.2%and 1.5%of methionine,making the final dietary methionine content to be 0.40%,0.73%,1.04%,1.33%,1.70% and1.98%,respectively.The results showed that when dietary methionine increased,the activity of glutamic-pyruvic transaminase(GPT)in liver increased significantly(P<0.05),reaching the highest when the content of diet methionine was 1.70%,while the activity of glutamicoxalacetictransaminase(GOT)in liver increased in the same trend as that of GPT although no significantdifferencewas found among diets.As dietary methionine increased,the activities of plasma GPTincreased first and then turned to be stable when the content of methionine was 1.04%(P<0.05).Similarly,the activity of plasma GOTfirst increased,reaching the highest when the content of methionine was 0.73%and then decreased(P<0.05).In conclusion,the activity of two transaminases wassignificantly influenced by dietary methionine.
引文
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