Plasma urea nitrogen as an indicator of protein quality. I. Factors affecting the concentration of urea in the blood of the preruminant lamb

1976 ◽  
Vol 27 (1) ◽  
pp. 109 ◽  
Author(s):  
RD Kirk ◽  
DM Walker
Keyword(s):  
Protein Content ◽  
Protein Concentration ◽  
Protein Quality ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Dry Matter Content ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Low Protein ◽  
Gross Energy

Preruminant male crossbred lambs, aged between 2 days and 5 weeks, were given milk replacers of low (0.10 of total energy as protein) or medium (0.28) protein content. Plasma urea nitrogen (PUN) values were unaffected by: the time of blood sampling within 9 hr after feeding; the age of the lamb, between 3 and 33 days; the lamb's intake of the medium protein diet (range, 500–1180 kJ gross energy/day per kg0.73 storage of plasma samples at –15°C for 5 months before analysis; fasting of lambs for 4 days; feeding of lambs on a nitrogen-free diet for 7 days. PUN values were significantly increased by: an increase in the dietary protein concentration; a reduction in the lamb's intake of the low protein diet below 840 kJ gross energy/day per kg0.73 (negative nitrogen balance); an increase in the dry matter content of the medium protein diet from 0.10 to 0.25; the addition of urea to the low protein diet (peak values 4–6 hr after feeding). PUN values estimated on successive days reflected a change in the protein content of the diet within 3–4 days, regardless of whether the change in protein concentration was from low to medium, or medium to low. It is concluded that PUN values can be used to evaluate protein quality only when experimental conditions are strictly controlled. Blood samples taken without regard to the above factors may give misleading results.

scholarly journals RECIPROCAL CHANGES IN PLASMA PROTEIN AND PLASMA ACACIA AS RESULT OF HIGH AND LOW PROTEIN DIETS

1950 ◽  
Vol 91 (4) ◽  
pp. 425-431 ◽  
Author(s):  
R. E. Knutti ◽  
J. B. Goetsch ◽  
R. A. Warrick
Keyword(s):  
Protein Content ◽  
Plasma Protein ◽  
Protein Concentration ◽  
High Protein Diet ◽  
The Body ◽  
Protein Diet ◽  
Plasma Protein Concentration ◽  
Gum Acacia ◽  
Normal Limits ◽  
Low Protein

Dogs were made hypoproteinemic by repeated injections of gum acacia, and the acacia injections were discontinued. Diets of varying protein content were then given. When a high protein diet is provided the plasma protein concentration increases; with a low protein diet, or under conditions of fasting, the plasma protein concentration diminishes. Similarly, plasma acacia concentration shows increases and decreases which are reciprocal to the protein variations. Total circulating plasma protein and total circulating plasma acacia show similar changes. In all instances total circulating colloid (acacia plus protein) concentration adds up to an amount within normal limits for protein alone. The results indicate that under these conditions, acacia stored in the body (principally in the liver) can be removed from its site of deposit and returned to the blood. The data also show that dogs in which acacia is deposited in large quantities, require a larger amount of protein in the diet to maintain a constant plasma protein content than do normal dogs. It appears that the mechanism for maintenance of peripheral colloidal material may be dependent on differences in intracellular and extracellular colloidal osmotic pressure. The experiments also support the idea that plasma protein molecules, as well as gum acacia, may pass in and out of cells through the cell membranes.

MO613EFFECT OF 12 WEEK TRAINIG  ON PHYSICAL ACTIVITY ON PATIENT ON A LOW PROTEIN DIET

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Durdona Saipova
Keyword(s):  
Physical Activity ◽  
Oxygen Consumption ◽  
Protein Content ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Maximum Oxygen Consumption ◽  
Upper Arm ◽  
Low Protein ◽  
Arm Circumference ◽  
Limited Protein

Abstract Background and Aims Symptoms such as fatigue, muscle weakness and impaired nutritional status are common in CKD and lead to decreased exercise tolerance. The aim of the study was to study the effect of 12-week training on physical activity in patients with pre-dialysis stages of CKD on a low-protein diet. Method The study included 119 patients with CKD C3 and C4 stages. Clinical data included anthropometric data: body mass index (BMI), mid-thigh circumference and mid-shoulder circumference, laboratory data: urea, creatinine, electrolytes, albumin, total protein, hemoglobin. All patients underwent instrumental research methods: ECG, EchoCG, cardiopulmonary stress test. The patients included in the study were offered three dietary options - with a low protein content (0.6 g / kg / day;) and a limited protein content (0.6-0.8 g / kg / day;), and low protein diet with keto analogs (1 tab / 5 kg body weight / day). The physical exercise program was designed for independent home use and included cardiovascular exercises (primarily walking, morning exercises) and strength training exercises with dumbbells 1 and 3 kg. The training frequency was at least 3 times a week and had a duration of at least 20–30 minutes. The patients kept exercise diaries, which were reviewed by the doctor at each subsequent visit. The training exercise was adjusted depending on the self-perception of the patients; if necessary, the training time was increased to 60 minutes. Results The 1 group 24% of patients received a diet with a low protein content, the second group consisted of 40% of patients, the third group consisted of 37% of patients receiving a diet with a limited protein content. The male to female ratio, mean glomerular filtration rate, daily proteinuria and BMI did not differ significantly between groups. In the dynamics of 12 weeks of training, an increase in the mid-thigh and upper arm circumference was recorded. The study of physical activity of patients with different types of diet showed that in patients of the 1st group, even with a low nutritional status in the dynamics of 12 weeks of training, there was an improvement in such physical indicators as the circumference of the mid-thigh and upper arm, and also a slight improvement in the BMD. When comparing the groups of patients who received and did not receive ketoanologs (groups 2 and 3, respectively), physical training for 12 weeks instilled a significant improvement in indicators such as mid-arm circumference and maximum oxygen consumption(peak VO2). However, in the group receiving keto analogs, there was a significantly greater improvement in maximum oxygen consumption (peak VO2). Conclusion Regular dosed exercise has a positive effect on physical fitness in CKD patients on a low-protein diet. Correction of nutrition with keto analogs improves the cardiorespiratory status of patients.

Adaptation to a diet low in protein: effect of complex carbohydrate upon urea kinetics in normal man

1992 ◽  
Vol 82 (2) ◽  
pp. 191-198 ◽  
Author(s):  
M. Langran ◽  
B. J. Moran ◽  
J. L. Murphy ◽  
A. A. Jackson
Keyword(s):  
The Body ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Urea Nitrogen ◽  
Low Protein ◽  
Urea Production ◽  
Urea Kinetics ◽  
Normal Man ◽  
Faecal Weight ◽  
Formula Diets

1. Urea kinetics were measured by using prime/intermittent oral doses of [15N15N]urea in five healthy men taking formula diets adequate in energy and containing either 70 or 35 g of protein/day. In some studies the low-protein diet was supplemented with non-starch polysaccharides in the form of ispaghula husk or ripe bananas. 2. On the 70 g of protein/day diet urea production was 132% of intake. Only 54% of the urea produced was excreted in the urine with 46% being salvaged in the colon; 90% of the salvaged nitrogen was retained in the metabolic nitrogen pool. 3. On the 35 g of protein/day diet the small decrease in urea production rate compared with that on the 70 g of protein/day diet was not significant, but only 36% of the urea produced was excreted in urine, with the majority, 64%, being salvaged. 4. The extent of urea-nitrogen salvaging on the 35 g of protein/day diet was similar in magnitude to the decrease in nitrogen intake, with the effect that the sum of intake and salvaged nitrogen did not differ between the 35 and the 70 g of protein/day diets. This implies that quantitative control is exerted over the rate at which urea nitrogen is salvaged. 5. The addition of non-starch polysaccharides to the 35 g of protein/day diet had a demonstrable effect upon faecal weight and composition, but did not exert any significant influence upon urea kinetics. 6. It is concluded that large changes in the rate of urea production are not necessary for adaptation to a low-protein diet, rather the salvaging of urea nitrogen in the lower bowel appears to be an important mechanism through which the body adapts to a low-protein diet. The salvaging of urea nitrogen by the colon makes an important contribution to the conservation of body nitrogen.

scholarly journals THE EFFECT OF RESTRICTION OF PROTEIN INTAKE ON THE SERUM PROTEIN CONCENTRATION OF THE RAT

1933 ◽  
Vol 57 (5) ◽  
pp. 705-720 ◽  
Author(s):  
Arthur L. Bloomfield
Keyword(s):  
Body Weight ◽  
Serum Protein ◽  
Protein Intake ◽  
Protein Concentration ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Low Protein ◽  
Serum Protein Concentration

Rats placed on a low protein diet for 21 weeks, in spite of marked loss of body weight, showed no significant decrease of serum protein concentration aside from an initial (physiological ?) drop.

scholarly journals Specific adaptation of gastric emptying to diets with differing protein content in the rat: is endogenous cholecystokinin implicated?

Gut ◽  
1997 ◽  
Vol 41 (5) ◽  
pp. 612-618 ◽  
Author(s):  
G Shi ◽  
V Leray ◽  
C Scarpignato ◽  
N Bentouimou ◽  
S Bruley des Varannes ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Protein Content ◽  
Dietary Protein ◽  
Time Course ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Dietary Adaptation ◽  
Low Protein

Background—Recent studies indicate that gastric emptying may be influenced by patterns of previous nutrient intake. Endogenous cholecystokinin (CCK), whose synthesis and release can be affected by dietary intake, has a major role in the regulation of gastric emptying.Aims—To evaluate the influence of diets with differing protein content on gastric emptying of differing liquid test meals and plasma CCK levels in the rat and to check whether the inhibitory effect of exogenous CCK on gastric emptying is modified after long term intake of diets with differing protein content. Methods—Rats were fed for three weeks with high protein, medium protein (regular), or low protein diet. On day 22 gastric emptying of a peptone meal was studied. In addition, basal and postprandial CCK levels after the different dietary regimens were measured by bioassay. The time course of dietary adaptation was studied and its specificity assessed through the use of different (peptone, glucose, and methylcellulose) test meals. The effect of exogenous CCK-8 on gastric emptying was studied at the end of the adaptation period (three weeks).Results—Feeding the animals with a high protein diet for three weeks resulted in a significant (p<0.05) acceleration (by 21.2 (8.2)%) of gastric emptying while feeding with a low protein diet was followed by a significant (p<0.05) delay (by 24.0 (6.2)%) in the emptying rate. When the time course of the effect of dietary adaptation on gastric emptying was studied, it appeared that at least two weeks are required for dietary protein to be effective. The regulatory effect of dietary protein on gastric emptying proved to be dependent on meal composition. Only the emptying rate of a protein containing meal (40% peptone) was significantly modified by previous dietary intake. No significant (p>0.05) changes were observed with glucose and methylcellulose meals whose emptying rates were similar in rats receiving a high protein or low protein diet. A peptone meal strongly and significantly (p<0.05) increased plasma CCK levels in rats fed a medium protein (regular) diet. Results were similar in rats receiving a low protein diet (p<0.05) but not in rats on a high protein diet (p>0.05). As a consequence, postprandial plasma levels of CCK in rats fed with a medium or low protein diet were significantly (p<0.05) higher than those in rats receiving a high protein diet. In rats on high and low protein diets, dose response curves to CCK-8 were virtually identical, suggesting that dietary protein intake has no influence on the effect of exogenous CCK.Conclusions—These results clearly show that gastric emptying of a protein containing meal can be modified by previous dietary protein intake. This effect, which is time dependent and meal specific, may be related to changes in endogenous CCK release which will affect emptying rate. While the exact mechanisms underlying this adaptive response need to be studied and clarified further, these results emphasise the importance of dietary history in the evaluation and interpretation of gastric emptying data.

scholarly journals Renal responses of reindeer to high and low protein diet and sodium supplement

1979 ◽  
Vol 51 (1) ◽  
pp. 381-419 ◽  
Author(s):  
Maija Valtonen
Keyword(s):  
Sodium Chloride ◽  
Urine Osmolality ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Plasma Urea ◽  
Urea Excretion ◽  
Low Protein ◽  
Urea Reabsorption ◽  
Solute Excretion ◽  
Sodium Chloride Intake

The effects of reducing dietary nitrogen and increasing sodium chloride intake on renal function were studied in reindeer in order so elucidate the extent of urea conservation and solute excretion by the reindeer kidney. The fall in plasma urea concentration and urea excretion on the low protein diet was accompanied by a significant reduction in the glomerular filtration rate (GFR) and urine osmolality. The fraction of filtered urea reabsorbed increased. However, the contribution of the fall of the GFR to restriction of urinary losses of urea was far more significant than the increase in fractional urea reabsorption. The increase in sodium chloride intake reflected in icreased urinary sodium excretion, inducing a rise in urine osmolality on the low protein diet. Increased excretion of sodium was accompanied by decreased urea excretion. This interdependence of urea and sodium in urine excretion was particularly pronounced during the mating season in the autumn, when prominent retention of electrolytes and water was observed. On low protein diet, when reindeer were exposed to cold, the energy intake proved insufficient. The use of body protein as energy source resulted in increased plasma urea values. The fractional reabsorption of urea decreased, but the GFR stayed low. The GFR seems to be unaffected by plasma urea concentrations but is in some way regulated by the intake of dietary protein. Also on lichen diet the intake was not sufficient to satisfy the energy requirements and the plasma urea concentrations increased. The urea excretion was still low due to a decreased GFR. The high moisture content of lichen caused an increase in the urine water excretion, but no increase occured in the solute excretion. The rumen ammonia concentrations correlated significantly with the plasma urea concentrations, showing that urea is readily returned to the rumen in reindeer. The restriction of urea excretion on low protein intake contributes to the nitrogen economy and in reindeer it is brought about by a marked decrease in the GFR together with an increase in the urea reabsorption.

scholarly journals POSTPARTUM CONCENTRATIONS OF ESTRADIOL AND PROGESTERONE IN THREE GENOTYPE OF SHEEP FED VARYING LEVELS OF PROTEIN

2021 ◽  
Vol 5 (1) ◽  
pp. 495-501
Author(s):  
A. M. Hassan ◽  
M. Nasir ◽  
A. Y. Abdullahi ◽  
M. H. Zango
Keyword(s):  
Protein Concentration ◽  
High Protein ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Ovarian Activity ◽  
Protein Levels ◽  
Low Protein ◽  
Ovarian Cyclicity ◽  
High Protein Diets ◽  
Protein Diets

The study aims to evaluate the effects of feeding different protein levels on the resumption of postpartum ovarian activity by measuring serum estradiol (E2) and progesterone (P4) concentrations bi-weekly starting one week postpartum in three genotypes of sheep (Yankasa, Uda and Balami). Eighteen (18) multiparous sheep with aged range of 2.5 – 3 years old consisting of six (6) each of Yankasa, Uda and Balami breeds were divided into three groups and reared on different protein concentrations. The protein concentrations were 15.2% (high), 9.5% (medium) and 6.5% (low). Results showed a gradual increase of estradiol in both Yankasa and Uda breeds fed low protein diet from 100 – 3000 concentration. However, Uda breed had the highest value of estradiol when both medium and high protein diets were fed to the three genotypes of sheep. Nevertheless, Yankasa sheep had more consistent values of progesterone when fed low protein diet compared to Balami and Uda. Also Uda breed recorded the highest progesterone values in both medium and high protein diets among the three genotypes followed by Yankasa sheep. All the three genotypes returned to estrous earlier on high protein concentration followed by those on medium protein level. It is concluded that increase protein concentration hastened resumption of ovarian cyclicity and thereby leading to increase fertility in sheep

Body composition studies with the milk-fed lamb. II. The effect of the age of the lamb and the protein content of the diet on the chemical composition of the body and its organs

1970 ◽  
Vol 75 (2) ◽  
pp. 279-285 ◽  
Author(s):  
K. T. Jagusch ◽  
B. W. Norton ◽  
D. M. Walker
Keyword(s):  
Chemical Composition ◽  
Protein Content ◽  
High Protein Diet ◽  
The Body ◽  
High Protein ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Chemical Components ◽  
Available N ◽  
Low Protein

SUMMARYEighteen male cross-bred lambs (aged 2–5 days) in two equal groups were given artificial milk diets of either low- or high-protein content; subgroups of three lambs were slaughtered after 2, 4 and 6 weeks on experiment. The composition of the change in empty body weight (E.B.W.), and the chemical composition of the change in weight of the separate compartments and organs, were determined by the comparative slaughter method.Lambs given the high-protein diet made significant gains in weight and in all chemical components in all periods. The composition of their E.B.W. was closely related to E.B.W. regardless of age. Lambs given the low-protein diet made only small gains in weight in 6 weeks, of which 76% was fat. The chemical composition of their E.B.W. was closely related to E.B.W. within each age group. The net gain of protein of these lambs in 6 weeks represented only 1% of the total weight gain, and over 50% of the protein gain was in wool. The skin and blood lost protein during the first 2 weeks, and failed to recover this loss during the remaining 4 weeks. Other organs lost protein initially but recovered this loss between 2 and 6 weeks.It was concluded that the initial loss of protein represented the labile protein reserves of the lamb, and the subsequent recovery was an adaptation to the low-protein diet. Furthermore, the results with both diets indicated that the skin and blood were the most inefficient of the organs in the body in utilizing the available N during a period of protein deficiency, or during a period of abundance in the dietary supply of N.

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