Effects of dietary fibre and protein on urea transport across the cecal mucosa of piglets
| Autor: | S. Klingspor, Jörg R. Aschenbach, Holger Martens, Ulrike Lodemann, A. G. Van Kessel, Robert Pieper, Katarina Wolf, Jürgen Zentek, Friederike Stumpff |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Dietary Fiber
medicine.medical_specialty Chromatography Gas Patch-Clamp Techniques Physiology Sus scrofa Biology Biochemistry Cecum Ammonia chemistry.chemical_compound Rumen Endocrinology Animal science Intestinal mucosa Internal medicine medicine Animals Urea Intestinal Mucosa Genetics and epigenetic pathways of disease Translational research [NCMLS 6] Ecology Evolution Behavior and Systematics Analysis of Variance Biological Transport Factorial experiment Hydrogen-Ion Concentration medicine.anatomical_structure Urea transport chemistry Animal Science and Zoology Dietary Proteins Flux (metabolism) |
| Zdroj: | Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology, 183, 1053-63 Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology, 183, 8, pp. 1053-63 |
| ISSN: | 0174-1578 |
| DOI: | 10.1007/s00360-013-0771-2 |
| Popis: | In ruminants, gastrointestinal recycling of urea is acutely enhanced by fibre-rich diets that lead to high ruminal concentration of short chain fatty acids (SCFA), while high ammonia has inhibitory effects. This study attempted to clarify if urea flux to the porcine cecum is similarly regulated. Thirty-two weaned piglets were fed diets containing protein (P) of poor prececal digestibility and fibre (F) at high (H) or low levels (L) in a 2 × 2 factorial design. After slaughter, cecal content was analyzed and the cecal mucosa incubated in Ussing chambers to measure the effect of pH, SCFA and NH4 + on the flux rates of urea, short-circuit current (I sc) and tissue conductance (G t). NH4 + significantly enhanced I sc (from 0.5 ± 0.2 to 1.2 ± 0.1 μEq cm−2 h−1). No acute effects of SCFA or ammonia on urea flux were observed. Tissue conductance was significantly lower in the high dietary fibre groups irrespective of the protein content. Only the HP-LF group emerged as different from all others in terms of urea flux (74 ± 6 versus 53 ± 3 nmol cm−2 h−1), associated with higher cecal ammonia concentration and reduced fecal consistency. The data suggest that as in the rumen, uptake of ammonia by the cecum may involve electrogenic transport of the ionic form (NH4 +). In contrast to findings in the rumen, neither a high fibre diet nor acute addition of SCFA enhanced urea transport across the pig cecum. Instead, a HP-LF diet had stimulatory effects. A potential role for urea recycling in stabilizing luminal pH is discussed. |
| Databáze: | OpenAIRE |
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