Fermentable carbohydrate exerts a urea-lowering effect in normal and nephrectomized rats

1997 ◽  
Vol 272 (3) ◽  
pp. G515-G521 ◽  
Author(s):  
H. Younes ◽  
C. Remesy ◽  
S. Behr ◽  
C. Demigne
Keyword(s):  
Potato Starch ◽  
Short Chain Fatty Acids ◽  
Nitrogen Excretion ◽  
Nitrogen Transfer ◽  
Plasma Urea ◽  
Fecal Nitrogen ◽  
Cecal Wall ◽  
Fermentable Carbohydrates ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

The influence of nondigestible carbohydrate on intestinal fermentations and on the route of nitrogen excretion has been investigated in normal rats and in unilaterally nephrectomized rats. Rats were adapted to 10% casein diets, either fiber free or containing different levels of two fermentable carbohydrates, inulin or crude potato starch. Ingestion of fermentable carbohydrate led to a considerable enlargement of the cecum because of hypertrophy of the cecal wall and an increase in cecal contents. Cecal digesta contained elevated concentrations of short-chain fatty acids, resulting in acidic pH. Diets containing fermentable carbohydrate enhanced fecal nitrogen excretion, which was more than doubled at the highest level of inulin or potato starch. In parallel, urinary nitrogen excretion was significantly decreased by fermentable carbohydrate. Although these changes were similar in all animals, there were quantitative differences in the response of nephrectomized animals to fermentable carbohydrate. In nephrectomized rats, plasma urea concentrations were more than 2.5 times higher than in normal rats (5.8 mM compared with 2.2 mM). Plasma urea concentrations were reduced by approximately 50% when normal rats were fed diets containing 7.5-15% inulin or 10-20% resistant starch. In nephrectomized animals fed the highest level of fermentable carbohydrate, plasma urea concentrations were also significantly decreased, but only by 30%. In nephrectomized rats, the concentration of nitrogen cycling in the cecum was greater (urea nitrogen transfer into the cecum was 50-60% greater and ammonia flux from the cecal lumen to the blood was two times higher than in normal rats), but fecal nitrogen excretion was equivalent in normal and nephrectomized animals. When expressed as a percentage of total nitrogen excretion, fecal nitrogen excretion was <20% in animals fed fiber-free diets, compared with 45-50% in normal animals and 40% in nephrectomized animals fed fermentable carbohydrate.

scholarly journals Evaluation of Urinary Nitrogen Excretion from Plasma Urea Nitrogen in Dry and Lactating Cows

2008 ◽  
Vol 21 (8) ◽  
pp. 1159-1163 ◽  
Author(s):  
S. Kume ◽  
K. Numata ◽  
Y. Takeya ◽  
Y. Miyagawa ◽  
S. Ikeda ◽  
...  
Keyword(s):  
Nitrogen Excretion ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Lactating Cows ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

THE ENDOGENOUS URINARY AND METABOLIC FECAL NITROGEN EXCRETIONS OF NEWBORN DAIRY CALVES

1957 ◽  
Vol 37 (2) ◽  
pp. 152-156 ◽  
Author(s):  
H. M. Cunningham ◽  
G. J. Brisson
Keyword(s):  
Body Weight ◽  
Dry Matter ◽  
Nitrogen Excretion ◽  
Dairy Calves ◽  
Dry Matter Intake ◽  
Fecal Nitrogen ◽  
Endogenous Urinary Nitrogen ◽  
Metabolic Fecal Nitrogen ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Daily observations were made on the fecal and urinary nitrogen excretions of four calves fed nitrogen-free diets during the second and fifth weeks after birth. The endogenous urinary nitrogen excretion was equivalent to 65.3 mg. per kg. of body weight (W) per day or 186 mg. per kg. W0.72. The metabolic fecal nitrogen excretion averaged 44.0 mg. per kg. of body weight per day or 0.334 per cent of the dry matter intake.

The effect of diethylstilbestrol on nitrogen excretion in sheep

1970 ◽  
Vol 48 (8) ◽  
pp. 573-574 ◽  
Author(s):  
T. L. Huber
Keyword(s):  
Nitrogen Metabolism ◽  
Direct Effect ◽  
Tubular Reabsorption ◽  
Arginase Activity ◽  
Nitrogen Excretion ◽  
Plasma Urea ◽  
Urea Excretion ◽  
Nitrogen Conservation ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Administration of 2 mg of diethylstilbestrol (DES) daily to lambs reduced total urinary nitrogen excretion, urea excretion, plasma urea concentrations, and liver arginase activity. The percent of filtered urea reabsorbed was greater in untreated lambs, thus suggesting that the increased nitrogen conservation observed following DES administration to ruminants is not the result of a direct effect of DES on tubular reabsorption of urea but on nitrogen metabolism.

scholarly journals Feasibility of achieving different protein targets using a hypocaloric high-protein enteral formula in critically ill patients

Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Pierre Singer ◽  
Itai Bendavid ◽  
Ilana BenArie ◽  
Liran Stadlander ◽  
Ilya Kagan
Keyword(s):  
Critically Ill ◽  
Nitrogen Balance ◽  
High Protein ◽  
Nitrogen Excretion ◽  
Protein Targets ◽  
Protein Target ◽  
Group A ◽  
Group B ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Abstract Background and aims Combining energy and protein targets during the acute phase of critical illness is challenging. Energy should be provided progressively to reach targets while avoiding overfeeding and ensuring sufficient protein provision. This prospective observational study evaluated the feasibility of achieving protein targets guided by 24-h urinary nitrogen excretion while avoiding overfeeding when administering a high protein-to-energy ratio enteral nutrition (EN) formula. Methods Critically ill adult mechanically ventilated patients with an APACHE II score > 15, SOFA > 4 and without gastrointestinal dysfunction received EN with hypocaloric content for 7 days. Protein need was determined by 24-h urinary nitrogen excretion, up to 1.2 g/kg (Group A, N = 10) or up to 1.5 g/kg (Group B, N = 22). Variables assessed included nitrogen intake, excretion, balance; resting energy expenditure (REE); phase angle (PhA); gastrointestinal tolerance of EN. Results Demographic characteristics of groups were similar. Protein target was achieved using urinary nitrogen excretion measurements. Nitrogen balance worsened in Group A but improved in Group B. Daily protein and calorie intake and balance were significantly increased in Group B compared to Group A. REE was correlated to PhA measurements. Gastric tolerance of EN was good. Conclusions Achieving the protein target using urinary nitrogen loss up to 1.5 g/kg/day was feasible in this hypercatabolic population. Reaching a higher protein and calorie target did not induce higher nitrogen excretion and was associated with improved nitrogen balance and a better energy intake without overfeeding. PhA appears to be related to REE and may reflect metabolism level, suggestive of a new phenotype for nutritional status. Trial registration 0795-18-RMC.

Effect of starch on the utilization by sheep of a straw diet supplemented with urea and minerals

1976 ◽  
Vol 27 (1) ◽  
pp. 139 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe ◽  
WR McManus
Keyword(s):  
Organic Matter ◽  
Nitrogen Retention ◽  
Nitrogen Excretion ◽  
Digestible Organic Matter ◽  
Cellulose Digestibility ◽  
Oat Straw ◽  
Total Body ◽  
Body Energy ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Individually penned Border Leicester x Merino wethers, aged 11 months, were fed ad lib. for 16 weeks on a basal ration of ground, pelleted oat straw, urea and minerals, supplemented with 0, 5, 10, 15, 20, 30 or 40% starch. The diets contained equal percentages of nitrogen and minerals. Dry matter intake reached a maximum of 2000 g/day with 30% starch; above this starch level, digestive disturbances were observed. Organic matter digestibility was increased by the addition of starch, but cellulose digestibility was depressed by as much as 18 units with the addition of 30% starch. Up to 10% the starch level had little effect on cellulose digestibility. Liveweight change was significantly correlated with digestible organic matter intake, mean daily weight gains varying from 22 g with no starch to 104 g with 30% starch. However, a large percentage of the liveweight gain was as total body water, and body energy storage increased appreciably only when the diet contained at least 20% starch. The inclusion of 5% starch slightly depressed both intake and liveweight gain. Daily clean wool production was significantly increased at starch levels higher than 20% and ranged from 5.3 to 7.5 g/day with 0 and 40% starch respectively. Increasing levels of starch had little effect on apparent nitrogen digestibility, but resulted in a substantial increase in nitrogen retention through a reduction in urinary nitrogen excretion. Serum urea levels fell from a mean of 42 mg/100 ml during the first week to 31 mg/100 ml during subsequent periods, with no significant differences between diets. With the general exception of potassium, mineral balances were positive or close to zero throughout the experiment.

Branched-Chain Amino Acids, Nitrogen Excretion and Injury in Man

1976 ◽  
Vol 50 (5) ◽  
pp. 393-399 ◽  
Author(s):  
J. H. Wedge ◽  
R. De Campos ◽  
A. Kerr ◽  
R. Smith ◽  
Rose Farrell ◽  
...  
Keyword(s):  
Amino Acids ◽  
Venous Blood ◽  
Branched Chain Amino Acids ◽  
Nitrogen Excretion ◽  
Adult Males ◽  
Blood Concentrations ◽  
Branched Chain ◽  
Injured Patients ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

1. Venous blood concentrations of the branched-chain amino acids, valine, leucine and isoleucine, and urinary nitrogen excretion have been measured in sixteen adult males, from 2 h to 7 days after injury, and in four adults after elective skin grafts. 2. In the injured group the concentrations of these amino acids rose significantly 24 h after injury and had doubled at 4 days and remained high; in contrast the skin-graft patients showed no significant change. 3. In those injured patients with initial hyperketonaemia, defined as more than 0·2 mmol/l, the increase in concentrations of branched-chain amino acids at the fourth and seventh days after injury was significantly less than in those with normoketonaemia, and was accompanied by lower urinary nitrogen excretion throughout the whole period. 4. It is suggested that the changes in the concentration of branched-chain amino acids after injury indicate decreased uptake by muscle or excessive release due to an imbalance between protein synthesis and protein catabolism in this tissue.

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