Change of urinary nitrogen excretion in response to low-protein diets in adults

1976 ◽  
Vol 29 (6) ◽  
pp. 639-644 ◽  
Author(s):  
W M Rand ◽  
V R Young ◽  
N S Scrimshaw
Keyword(s):  
Nitrogen Excretion ◽  
Low Protein ◽  
Protein Diets ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Partition of nitrogen in the urine of African sheep given a variety of low-protein diets

1967 ◽  
Vol 9 (2) ◽  
pp. 219-227 ◽  
Author(s):  
J. H. Topps ◽  
R.C. Elliott
Keyword(s):  
Crude Protein ◽  
The Body ◽  
Nitrogen Excretion ◽  
Crude Protein Content ◽  
Positive Correlation ◽  
Low Protein ◽  
Nitrogen Intake ◽  
Protein Diets ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

1. Sixteen foods, made up with differing proportions of roughage and concentrates and ranging in crude protein content from approximately 2·6% to 10·0%, were each offered ad libitum to Blackhead Persian wether sheep. The nitrogen balance of the sheep and the distribution of nitrogen in the urine were measured.2. Urinary nitrogen excretion decreased with the digestible nitrogen intake. There was a highly significant (P < 0·01) positive correlation between either excretion of urea or of allantoin and digestible nitrogen intake.3. The amount of creatinine excreted varied little with diet but was directly related to the body weight of the sheep.4. For 8 diets, hippurate excretion by the sheep was directly related (P<0·01) to intake of digestible nitrogen, while a significant (P<0·05) positive correlation between the same measures was found for the other 8 diets.5. It is suggested that with certain types of diets the excretion of either nitrogen, urea or allantoin in the urine may be useful indicators of digestible nitrogen intake of low-protein diets by sheep.

scholarly journals Potassium Bicarbonate Attenuates the Urinary Nitrogen Excretion That Accompanies an Increase in Dietary Protein and May Promote Calcium Absorption

2009 ◽  
Vol 94 (2) ◽  
pp. 645-653 ◽  
Author(s):  
Lisa Ceglia ◽  
Susan S. Harris ◽  
Steven A. Abrams ◽  
Helen M. Rasmussen ◽  
Gerard E. Dallal ◽  
...  
Keyword(s):  
Dietary Protein ◽  
Calcium Absorption ◽  
High Protein Diet ◽  
Protein Diet ◽  
Nitrogen Excretion ◽  
Low Protein ◽  
Igf I ◽  
Fractional Calcium Absorption ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Abstract Context: Protein is an essential component of muscle and bone. However, the acidic byproducts of protein metabolism may have a negative impact on the musculoskeletal system, particularly in older individuals with declining renal function. Objective: We sought to determine whether adding an alkaline salt, potassium bicarbonate (KHCO3), allows protein to have a more favorable net impact on intermediary indices of muscle and bone conservation than it does in the usual acidic environment. Design: We conducted a 41-d randomized, placebo-controlled, double-blind study of KHCO3 or placebo with a 16-d phase-in and two successive 10-d metabolic diets containing low (0.5 g/kg) or high (1.5 g/kg) protein in random order with a 5-d washout between diets. Setting: The study was conducted in a metabolic research unit. Participants: Nineteen healthy subjects ages 54–82 yr participated. Intervention: KHCO3 (up to 90 mmol/d) or placebo was administered for 41 d. Main Outcome Measures: We measured 24-h urinary nitrogen excretion, IGF-I, 24-h urinary calcium excretion, and fractional calcium absorption. Results: KHCO3 reduced the rise in urinary nitrogen excretion that accompanied an increase in protein intake (P = 0.015) and was associated with higher IGF-I levels on the low-protein diet (P = 0.027) with a similar trend on the high-protein diet (P = 0.050). KHCO3 was also associated with higher fractional calcium absorption on the low-protein diet (P = 0.041) with a similar trend on the high-protein diet (P = 0.064). Conclusions: In older adults, KHCO3 attenuates the protein-induced rise in urinary nitrogen excretion, and this may be mediated by IGF-I. KHCO3 may also promote calcium absorption independent of the dietary protein content.

EFFECTS OF VITAMIN B12 AND AUREOMYCIN ON NITROGEN RETENTION IN INFANTS

PEDIATRICS ◽  
1954 ◽  
Vol 13 (5) ◽  
pp. 462-475
Author(s):  
ROBERT KAYE ◽  
RONALD H. CAUGHEY ◽  
WALLACE W. MCCRORY
Keyword(s):  
Vitamin B12 ◽  
Nitrogen Retention ◽  
High Protein ◽  
Nitrogen Excretion ◽  
Minimum Requirement ◽  
Beneficial Effects ◽  
Low Protein ◽  
Low Nitrogen ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

The effects of vitamin B12 on weight, nitrogen and electrolyte balances were studied in six male infants. Three of the infants were offered nitrogen intakes of approximately 1.0 gm./kg./day, and the remaining three an intake of 0.1 gm./kg./ day. The effects of aureomycin were studied by the same criteria in two of the infants on low nitrogen intakes. The authors were unable to obtain unequivocal evidence that vitamin B12 exerts a nitrogen anabolic effect in infants maintained on constant intakes of high and low protein content. Vitamin B12 administration to the subjects on a high protein intake resulted in an increased urinary nitrogen excretion which may be a reflection of an enhanced rate of conversion of protein into carbohydrate or fat. Averages of the control and B12 period nitrogen retentions and weight gains in gm./kg./day were 0.235 and 11.8 for the high protein-fed subjects, and .011 and 2.4 for the low protein-fed subjects. Aureomycin did not produce beneficial effects on weight or nitrogen retention, but rather showed a tendency to augment fecal nitrogen losses. Appetite stimulation was noted in 2 of the 6 subjects given B12. A nitrogen intake of 0.1 gm./kg./day derived from cow's milk protein approximates the minimum requirement for equilibrium in male infants under the conditions of this study.

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.

214 Dietary Supplementation with a Combination of Valine and Isoleucine Annuls the Negative Effects of Very Low Protein Diets on Growth and Gut Development of Young Pigs

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 112-113
Author(s):  
Mohammad Habibi ◽  
Parniyan Goodarzi ◽  
Cedrick N N Shili ◽  
Julia Sutton ◽  
Caitlyn Wileman ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Growth Performance ◽  
Nitrogen Excretion ◽  
Gut Development ◽  
Negative Effects ◽  
Final Body Weight ◽  
Low Protein ◽  
Feed Cost ◽  
Young Pigs ◽  
Protein Diets

Abstract Increased feed cost, post-weaning diarrhea, and nitrogen excretion are challenging the modern swine industry. Very low-protein (LP) diets (&gt;4% units reduced protein) may reduce feed cost, diarrhea and nitrogen excretion; however, these diets impair growth performance of pigs despite supplementation of limiting amino acids (i.e., lysine, threonine, methionine and tryptophan). The objective of this study was to investigate the effect of valine, isoleucine and combination of both supplemented to VLP diet on growth, thermal radiation, and gut development in young pigs. Forty three-week-old weaned barrows were weighed (6.75 ± 0.14 kg) and randomly assigned to five groups (8 pigs/group) including: 1) standard diet or positive control (PC), 2) LP diet, 3) LP + valine (LPV), 4) LP + isoleucine (LPI) and 5) LP + both valine and isoleucine (LPVI) for five weeks. Daily feed intake and weekly growth characteristics were measured and weekly thermal images were captured. All pigs were euthanized at week 5 and tissue samples collected. All data were analyzed with univariate GLM followed by Tukey’s post-hoc test (SPSS®). Compared to PC, final body weight, average daily gain, average daily protein intake and gain:feed ratio were reduced in LP group, but feeding pigs with LPVI partially or completely recovered these parameters. Pigs fed with LPVI had higher thermal radiation than those fed with PC, LP, and LPI on days 28 and 35 of study and had a greater the area under the curve for thermal radiation than LP and LPI. Duodenal villus width and crypt depth, and ileal villus height were decreased in LP relative to PC, but LPVI either partially or fully recovered these measurements. In conclusion, supplementing a combination of valine and isoleucine recovered the negative effects of very low-protein diets on growth performance and gut development, but increased the thermal radiation in weaned pigs.

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