title: Intraruminal infusion of n-butyric acid induces an increase of ruminal papillae size independent of IGF-1 system in castrated bulls.
abstract: The objective of this study was to explore morphological alterations of rumen papillae induced by n-butyric acid in relation to the insulin-like growth factor (IGF) system in adult castrated bulls. Three animals fitted with rumen cannula were fed twice daily at a low and high nutritional level (LL and HL), i.e., at 1.1 x maintenance (M) and 1.6 x M, respectively. Diets contained artificial dried grass and concentrate (74:26 and 52:48). Bulls received no (B0) or daily intraruminal infusions of 500 g n-butyric acid (B500) over 14 d. The infusion started 1 h after the morning feeding (9:00) and lasted for 3.5 h. Thus, four treatments (BOLL, B500LL, BOHL, and B500HL) were compared. Blood and rumen mucosa samples from the atrium ruminis were taken at the last day of each period. Length, width and surface of rumen papillae were greater (p < 0.001) in BOHL than in BOLL. Treatment with n-butyric acid resulted in an increase of the papillae surface of 20-40% (p = 0.047) for both nutritional levels as compared to periods without n-butyric acid treatments. The higher nutritional level and intraruminal n-butyric acid infusion induced epithelial cell death. The percentage of proliferative cells was doubled by n-butyric acid treatment. The mRNA of IGF-1 and IGF type 1 receptor (IGF-1R), as well as IGF-1R binding capacity were unaffected by butyric acid treatments. The abundance of IGF-1 mRNA tended to be lower (p = 0.1) and IGF-1R abundance was lower (p = 0.03) in response to the HL. The plasma IGF-1 concentration was lower with butyric acid treatment (p < 0.01), but was unaffected by the nutritional level. In conclusion, under described experimental preconditions of daily short-time intraruminal n-butyric acid infusion alterations of rumen papillae morphology is not mediated by ruminal IGF type 1 receptor and by local IGF-1 expression in papillae in castrated bulls.
authors.affiliation: Research Institute for the Biology of Farm Animals (FBN), Dummerstorf, Germany.
authors.forename: Zanming
authors.initials: Z
authors.lastname: Shen
authors.forename: Siegfried
authors.initials: S
authors.lastname: Kuhla
authors.forename: Rudolf
authors.initials: R
authors.lastname: Zitnan
authors.forename: Hans-M
authors.initials: HM
authors.lastname: Seyfert
authors.forename: Falk
authors.initials: F
authors.lastname: Schneider
authors.forename: Hans
authors.initials: H
authors.lastname: Hagemeister
authors.forename: Arthur
authors.initials: A
authors.lastname: Chudy
authors.forename: Berthold
authors.initials: B
authors.lastname: Löhrke
authors.forename: Jörg W
authors.initials: JW
authors.lastname: Blum
authors.forename: Harald M
authors.initials: HM
authors.lastname: Hammon
authors.forename: Jürgen
authors.initials: J
authors.lastname: Voigt
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D020148:Butyric Acid / Q000008:administration & dosage / Q000494:pharmacology*; D002417:Cattle / Q000502:physiology*; D002455:Cell Division / Q000187:drug effects; D006633:Histamine Antagonists; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009919:Orchiectomy / Q000662:veterinary; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism*; D012417:Rumen / Q000187:drug effects* / Q000254:growth & development
chemical_list: D006633:Histamine Antagonists; D012333:RNA, Messenger; D020148:Butyric Acid; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1