Effects of dietary carbohydrate on hepatic de novo lipogenesis in European seabass (Dicentrarchus labrax L.)
Effects of dietary carbohydrate on hepatic de novo lipogenesis in European seabass (Dicentrarchus labrax L.)
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DOI：
10.1194/jlr.m067850
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发表时间：
2016-05
影响因子：
6.5
通讯作者：
I. Viegas;I. Jarak;J. Rito;R. Carvalho;I. Metón;M. Pardal;I. Baanante;John G. Jones
中科院分区：
文献类型：
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作者：
I. Viegas;I. Jarak;J. Rito;R. Carvalho;I. Metón;M. Pardal;I. Baanante;John G. Jones
养殖的鲈鱼比它们的野生同类有更高的肥胖率，这通常被归因于碳水化合物(CHO)的喂养。这是否反映了脂肪氧化的减少，新生脂肪生成(DNL)的增加，或者两者兼而有之，尚不清楚。为了研究高CHO饲料对肝脏甘油三酯生物合成的影响，在富含2H的池塘水中，分别饲喂无CHO对照饲料(CTRL)和添加可消化淀粉(DS)和生淀粉(RS)的鱼，测定了6天后肝脏TG的生物合成。通过2H核磁共振分析计算肝脏甘油三酯和脂肪酸的合成分数(FSRs，−1)。甘油FSR在所有情况下都超过FA FSR，表明循环活跃。与CTRL相比，DS FISH没有表现出更高的成脂能力。与其他饲料相比，RS鱼的甘油FSR水平较低，FA FSR水平可以忽略不计，尽管肝脏TG水平与CTRL相似。在葡萄糖-6-磷酸脱氢酶(G6PDH)和葡萄糖-6-磷酸脱氢酶(G6PDH)的情况下，DS-FISH对提供NADPH的酶的活性高于CTRL，对G6PDH和6-磷酸葡萄糖酸脱氢酶的活性相对于RS。这一方法表明，DS喂养引起的肝脏肥胖症的增加并不归因于DNL的增加。
Farmed seabass have higher adiposity than their wild counterparts and this is often attributed to carbohydrate (CHO) feeding. Whether this reflects a reduction in fat oxidation, increased de novo lipogenesis (DNL), or both, is not known. To study the effects of high CHO diets on hepatic TG biosynthesis, hepatic TG deuterium (2H) enrichment was determined following 6 days in 2H-enriched tank water for fish fed with a no-CHO control diet (CTRL), and diets with digestible starch (DS) and raw starch (RS). Hepatic fractional synthetic rates (FSRs, percent per day−1) were calculated for hepatic TG-glyceryl and FA moieties through 2H NMR analysis. Glyceryl FSRs exceeded FA FSRs in all cases, indicating active cycling. DS fish did not show increased lipogenic potential compared to CTRL. RS fish had lower glyceryl FSRs compared with the other diets and negligible levels of FA FSRs despite similar hepatic TG levels to CTRL. DS-fed fish showed higher activity for enzymes that can provide NADPH for lipogenesis, relative to CTRL in the case of glucose-6-phosphate dehydrogenase (G6PDH) and relative to RS for both G6PDH and 6-phosphogluconate dehydrogenase. This approach indicated that elevated hepatic adiposity from DS feeding was not attributable to increased DNL.