Biomaterial Database

Digestible fiber (gum arabic), nitrogen excretion and urea recycling in rats. 1994

S A Assimon, and T P Stein

Department of Surgery, University of Medicine and Dentistry of New Jersey, School of Osteopathic Medicine, Stratford 08084.

The effect of dietary fiber and level of amino acid (AA) intake on 1) partitioning of N excretion between urine and feces, 2) level of dietary AA on urea N kinetics, and 3) reutilization of urea-originated N into essential AAs was determined. In the first experiment, rats were adapted to one of two isocaloric (928-mJ.kg-1.day-1) and isonitrogenous (1.33-g N.kg-1.day-1) liquid diets containing 0 or 9% of nonprotein energy as gum arabic (GA) for 7 days. The rats were further subdivided, with half from each group continuing their diet and the AA intake of the remainder reduced by half (0.67 g N.kg-1.day-1). Daily N balance was determined over the next 5 days. For experiment 2, a catheter was inserted into the rats used for experiment 1, and 5-6 days later, urea production and urea N recycling were determined with [15N2]urea. In experiment 3, as in experiment 1, rats were adapted to the reduced AA diet with and without GA and then given [15N2]urea. Plasma lysine was then analyzed for 15N to determine whether AA synthesis by intestinal bacteria was a contributing source of AAs to the body and whether this process was increased with dietary fiber. Dietary fiber decreased urinary N excretion and increased fecal N excretion but had no net effect on N balance. On the adequate-AA diet, GA decreased urea production (523 +/- 36 vs. 374 +/- 47 mg N.rat-1.day-1, p < 0.01), and urea N recycling (47 +/- 4 vs. 30 +/- 6 mg N.rat-1.day-1, p < 0.01) was found.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008239	Lysine	An essential amino acid. It is often added to animal feed.	Enisyl,L-Lysine,Lysine Acetate,Lysine Hydrochloride,Acetate, Lysine,L Lysine
D009584	Nitrogen	An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
D009587	Nitrogen Isotopes	Stable nitrogen atoms that have the same atomic number as the element nitrogen but differ in atomic weight. N-15 is a stable nitrogen isotope.	Nitrogen Isotope,Isotope, Nitrogen,Isotopes, Nitrogen
D004043	Dietary Fiber	The remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.	Fiber, Dietary,Roughage,Wheat Bran,Bran, Wheat,Brans, Wheat,Dietary Fibers,Fibers, Dietary,Roughages,Wheat Brans
D005243	Feces	Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
D005260	Female		Females
D005526	Food, Formulated	Food and dietary formulations including elemental (chemically defined formula) diets, synthetic and semisynthetic diets, space diets, weight-reduction formulas, tube-feeding diets, complete liquid diets, and supplemental liquid and solid diets.	Diet, Chemically Defined,Diet, Elemental,Diet, Formula,Diet, Synthetic,Dietary Formulations,Chemically Defined Diet,Synthetic Diet,Chemically Defined Diets,Dietary Formulation,Diets, Chemically Defined,Diets, Elemental,Diets, Formula,Diets, Synthetic,Elemental Diet,Elemental Diets,Foods, Formulated,Formulated Food,Formulated Foods,Formulation, Dietary,Formulations, Dietary
D006170	Gum Arabic	Powdered exudate from various Acacia species, especially A. senegal (Leguminosae). It forms mucilage or syrup in water. Gum arabic is used as a suspending agent, excipient, and emulsifier in foods and pharmaceuticals.	Acacia Gum,Gum Acacia,Acacia, Gum,Arabic, Gum,Gum, Acacia
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia