title: Increased anaplerosis, TCA cycling, and oxidative phosphorylation in the liver of dairy cows with intensive body fat mobilization during early lactation.
abstract: 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 β-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.
authors.affiliation: Research Unit Nutritional Physiology Oskar Kellner, Leibniz Institute for Farm Animal Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Schäff
authors.forename: Sabina
authors.initials: S
authors.lastname: Börner
authors.forename: Sandra
authors.initials: S
authors.lastname: Hacke
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kautzsch
authors.forename: Dirk
authors.initials: D
authors.lastname: Albrecht
authors.forename: Harald M
authors.initials: HM
authors.lastname: Hammon
authors.forename: Monika
authors.initials: M
authors.lastname: Röntgen
authors.forename: Björn
authors.initials: B
authors.lastname: Kuhla
mesh_terms: D000273:Adipose Tissue; D000818:Animals; D002417:Cattle; D002952:Citric Acid Cycle; D003612:Dairying; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007774:Lactation; D008099:Liver / Q000378:metabolism*; D008112:Liver Glycogen / Q000378:metabolism; D013058:Mass Spectrometry; D010085:Oxidative Phosphorylation; D036801:Parturition; D011506:Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D008112:Liver Glycogen; D011506:Proteins