![]() |
|
|






* Research Institute for the Biology of Farm Animals (FBN), Dummerstorf, Germany;
Nanjing Agricultural University, Nanjing, China;
** Free University, Berlin, Germany;
Research Institute of Animal Production, Nitra, Slovakia; and

University of Berne, Berne, Switzerland
3To whom correspondence should be addressed. E-mail: hans.hagemeister{at}gast.uni-rostock.de.
We tested the hypothesis that the dietary energydependent alterations of the rumen papillae size are accompanied by corresponding changes in systemic insulin-like growth factor (IGF)-1 concentration and in rumen papillary IGF type 1 receptors (IGF-1R). Young male goats (n = 24) were randomly allocated to two groups (n = 12) and fed a high level (HL) metabolizable energy [1200 kJ/(kg0.75 · d)] or a low level (LL) [500 kJ/(kg0.75 · d)] diet for 42 d. The concentration of ruminal total SCFA did not differ between the groups, but the molar proportion of butyric acid was enhanced by 70% in the HL group (P < 0.05). Both the length and width of the papillae were greater (P < 0.05) in the HL group, and the surface was 50100% larger (P < 0.05) in the tissue sampled from the artrium ruminis, the ventral ruminal sac and the ventral blind sac. Transport of Na+ across the rumen epithelium, which is amiloride sensitive, was higher (P < 0.05) in the HL than in the LL group. Furthermore, the plasma IGF-1 concentration was about twofold higher in the HL group (P < 0.05), and the maximal rumen epithelial IGF-1R binding was also higher in the HL (P < 0.05) than in the LL group. IGF-1R mRNA and IGF-1 mRNA were detected in rumen papillae; however, they were unaffected by dietary treatments. DNA synthesis and cell proliferation of cultured rumen epithelial cells were higher (P < 0.05) after IGF-1 treatment (25 or 50 µg/L) compared with those in the medium without IGF-1. Thus dietary energydependent alterations of rumen morphology and function are accompanied by corresponding changes in systemic IGF-1 and ruminal IGF-1R.
KEY WORDS: nutrition level rumen papillae Na+ transport IGF-1 IGF-1 receptor
This article has been cited by other articles:
![]() |
U. Lodemann and H. Martens Effects of diet and osmotic pressure on Na+ transport and tissue conductance of sheep isolated rumen epithelium Exp Physiol, May 1, 2006; 91(3): 539 - 550. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. E. Odongo, O. AlZahal, M. I. Lindinger, T. F. Duffield, E. V. Valdes, S. P. Terrell, and B. W. McBride Effects of mild heat stress and grain challenge on acid-base balance and rumen tissue histology in lambs J Anim Sci, February 1, 2006; 84(2): 447 - 455. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Graham and N. L. Simmons Functional organization of the bovine rumen epithelium Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2005; 288(1): R173 - R181. [Abstract] [Full Text] [PDF] |
||||