Increased Anaplerosis, TCA Cycling, and Oxidative Phosphorylation in the Liver of Dairy Cows with Intensive Body Fat Mobilization during Early Lactation
Increased Anaplerosis, TCA Cycling, and Oxidative Phosphorylation in the Liver of Dairy Cows with Intensive Body Fat Mobilization during Early Lactation
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DOI：
10.1021/pr300732n
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发表时间：
2012-11-01
影响因子：
4.4
通讯作者：
Kuhla, Bjoern
中科院分区：
文献类型：
--
作者：
Schaeff, Christine;Boerner, Sabina;Kuhla, Bjoern
产奶的开始让哺乳动物经历了巨大的能量和营养需求。为了满足这些要求，高产奶牛会调动体内脂肪，导致肝脏氧化代谢增强，这被认为是抑制产犊后饥饿的信号。为了研究脂肪动员的程度如何影响肝脏氧化代谢，进而影响采食量，我们在整个围产期采集了 19 头荷斯坦奶牛的血液和肝脏样本。根据高（H）和低（L）肝脏脂肪含量进行回顾性分组，H牛的脂肪酸含量高于L牛，但血浆氨基酸浓度较低，采食量也较低。肝脏磷酸化AMPK/总AMP比率在各组之间没有差异，但在分娩后下降。 2-DE 耦合 MALDI-TOF-TOF 分析和 qRT-PCR 研究显示，H 奶牛参与线粒体 β-氧化、尿素循环和戊糖磷酸途径的主要酶表达较低，但参与过氧化物酶体和内质脂肪酸降解、丙酮酸和 TCA 循环、氨基酸分解代谢、氧化磷酸化和氧化应激防御的酶表达较高。这些数据表明，增加脂肪分解会导致回补和线粒体呼吸的营养分解代谢增强，从而在肝脏氧化过程和采食量之间提供分子联系。
The onset of milk production lets mammals experience an enormous energy and nutrient demand. To meet these requirements, high-yielding dairy cows mobilize body fat resulting in an augmented hepatic oxidative metabolism, which has been suggested to signal for depressing hunger after calving. To examine how the extent of fat mobilization influences hepatic oxidative metabolism and thus potentially feed intake, blood and liver samples of 19 Holstein cows were taken throughout the periparturient period. Retrospectively grouped according to high (H) and low (L) liver fat content, H cows showed higher fatty acid but lower amino acid plasma concentrations and lower feed intake than L cows. The hepatic phospho-AMPK/total AMP ratio was not different between groups but decreased after parturition. A 2-DE coupled MALDI-TOF-TOF analysis and qRT-PCR studies revealed H cows having lower expressions of major enzymes involved in mitochondrial beta-oxidation, urea cycling, and the pentose phosphate pathway but higher expressions of enzymes participating in peroxisomal and endoplasmic fatty acid degradation, pyruvate and TCA cycling, amino acid catabolism, oxidative phosphorylation, and oxidative stress defense. These data indicate that increasing lipolysis leads to augmenting nutrient catabolism for anaplerosis and mitochondrial respiration, providing a molecular link between hepatic oxidative processes and feed intake.