title: Plasma ghrelin is positively associated with body fat, liver fat and milk fat content but not with feed intake of dairy cows after parturition.
abstract: Ghrelin is a gastrointestinal peptide hormone that is present in blood mostly in a non-posttranslationally modified form, with a minor proportion acylated at Ser(3). Both ghrelin forms were initially assigned a role in the control of food intake but there is accumulating evidence for their involvement in fat allocation and utilization. We investigated changes in the ghrelin system in dairy cows, exhibiting differences in body fat mobilization and fatty liver, from late pregnancy to early lactation. Sixteen dairy cows underwent liver biopsy and were retrospectively grouped based on high (H) or low (L) liver fat content post-partum. Both groups had a comparable feed intake in week -6 (before parturition) and week 2 (after parturition). Only before parturition was preprandial total ghrelin concentration higher in L than in H cows and only after parturition was the basal plasma concentration of non-esterified fatty acids higher in H than in L cows. Both before and after parturition, H cows had higher preprandial plasma concentrations of acyl ghrelin, a higher acyl:total ghrelin ratio, lower plasma triacylglyceride concentrations and a lower respiratory quotient compared with L cows. These group differences could not be attributed to an allelic variant of the acyl ghrelin receptor. Rather, the ratio of acyl:total ghrelin correlated with several aspects of fat metabolism and with respiratory quotient but not with feed intake. These results show that endogenous ghrelin forms are associated with fat allocation, fatty liver, and utilization of fat during the periparturient period.
authors.affiliation: Research Unit Nutritional Physiology 'Oskar Kellner', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
authors.forename: Sabina
authors.initials: S
authors.lastname: Börner
authors.forename: Michael
authors.initials: M
authors.lastname: Derno
authors.forename: Sandra
authors.initials: S
authors.lastname: Hacke
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kautzsch
authors.forename: Christine
authors.initials: C
authors.lastname: Schäff
authors.forename: Sint
authors.initials: S
authors.lastname: Thanthan
authors.forename: Hideto
authors.initials: H
authors.lastname: Kuwayama
authors.forename: Harald M
authors.initials: HM
authors.lastname: Hammon
authors.forename: Monika
authors.initials: M
authors.lastname: Röntgen
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Weikard
authors.forename: Christa
authors.initials: C
authors.lastname: Kühn
authors.forename: Armin
authors.initials: A
authors.lastname: Tuchscherer
authors.forename: Björn
authors.initials: B
authors.lastname: Kuhla
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D004435:Eating / Q000502:physiology*; D005260:Female; D054439:Ghrelin / Q000097:blood*; D008099:Liver / Q000378:metabolism*; D008892:Milk / Q000737:chemistry; D036801:Parturition / Q000097:blood*; D011247:Pregnancy
chemical_list: D054439:Ghrelin