Residual kidney function and plasma urea concentration in patients with chronic renal failure

1990 ◽  
Vol 22 (6) ◽  
pp. 573-579 ◽  
Author(s):  
O. Schück ◽  
J. Erben ◽  
H. Nádvorníková ◽  
V. Teplan ◽  
O. Marečková ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Kidney Function ◽  
Urea Concentration ◽  
Plasma Urea ◽  
Residual Kidney Function ◽  
Plasma Urea Concentration

Genome-wide association for plasma urea concentration in sheep

2021 ◽  
Vol 248 ◽  
pp. 104483
Author(s):  
Taiana Cortez de Souza ◽  
Tatiana Cortez de Souza ◽  
Gregorí Alberto Rovadoscki ◽  
Luiz Lehmann Coutinho ◽  
Gerson Barreto Mourão ◽  
...  
Keyword(s):  
Urea Concentration ◽  
Genome Wide Association ◽  
Plasma Urea ◽  
Genome Wide ◽  
Plasma Urea Concentration

Urea Excretion in the Camel

1957 ◽  
Vol 188 (3) ◽  
pp. 477-484 ◽  
Author(s):  
Bodil Schmidt-Nielsen ◽  
Knut Schmidt-Nielsen ◽  
T. R. Houpt ◽  
S. A. Jarnum
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Urea Concentration ◽  
Nitrogen Excretion ◽  
Renal Tubules ◽  
Urea Clearance ◽  
Plasma Urea ◽  
Urea Excretion ◽  
Plasma Urea Concentration

The nitrogen excretion was studied in the one-humped camel, Camelus dromedarius. When a growing camel was maintained on a low N intake (dates and hay) the amount of N excreted in the form of urea, NH3 and creatinine decreased to 2–3 gm/day. This decrease was caused by a drop in urea excretion from 13 gm to 0.2–0.5 gm/day. Urea given intravenously during low N intake was not excreted but was retained. (The camel like other ruminants can utilize urea for microbial synthesis of protein.) The renal mechanism for urea excretion was investigated by measuring urea clearance and glomerular filtration rate during a period of 7 months. During normal N intake about 40% of the urea filtered in the glomeruli were excreted in the urine while during low N intake only 1–2% were excreted. The variations in urea clearance were independent of the plasma urea concentration and of glomerular filtration rate, but were related to N intake and rate of growth. No evidence of active tubular reabsorption of urea was found since the urine urea concentration at all times remained higher than the simultaneous plasma urea concentration. The findings are not in agreement with the current concept for the mechanism of urea excretion in mammals. It is concluded that the renal tubules must either vary their permeability to urea in a highly selective manner or secrete urea actively.

Plasma Urea Concentration in Older People

1972 ◽  
Vol 14 (1) ◽  
pp. 32-35 ◽  
Author(s):  
J.S. Milne ◽  
J. Williamson
Keyword(s):  
Older People ◽  
Urea Concentration ◽  
Plasma Urea ◽  
Plasma Urea Concentration

Correction formula for carbamylated haemoglobin in diabetic uraemic patients

2001 ◽  
Vol 38 (2) ◽  
pp. 115-119 ◽  
Author(s):  
A M A Hammouda ◽  
G E Mady
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Free Amino ◽  
Urea Concentration ◽  
Diabetic Patients ◽  
Amino Groups ◽  
Correction Formula ◽  
Significant Difference ◽  
And Control

The measurement of carbamylated haemoglobin is a useful indicator of uraemic state during the preceding few weeks in patients with renal failure. In diabetic uraemic patients with hyperglycaemia, glycation of haemoglobin may interfere with its carbamylation, as both reactions involve the free amino groups of the protein. The aim of this study was to investigate the carbamylation of haemoglobin in the presence of hyperglycaemia. The study included 29 patients with chronic renal failure on regular haemodialysis, 14 diabetic and 15 non-diabetic patients, and 10 healthy controls. We found a significant correlation between the degree of haemoglobin carbamylation and mean blood urea concentration in both uraemic and control subjects. Carbamylation of haemoglobin was higher in both diabetic and non-diabetic chronic renal failure patients, but there were no significant differences between the groups regarding mean blood urea concentration or level of haemoglobin carbamylation. Carbamylated haemoglobin per unit of blood urea concentration was lower in the diabetic patients. Using a correction formula to account for the degree of haemoglobin glycation, there was no longer a significant difference in carbamylation per unit of blood urea concentration. In vitro incubation of red blood cells from six healthy and six diabetic non-uraemic patients in 70mmol/L urea showed a significantly lower carbamylation in the diabetic patients, but there was no significant difference when using corrected carbamylated haemoglobin values. We conclude that glycation of haemoglobin affects its carbamylation and that monitoring of uraemia in a diabetic patient necessitates the use of carbamylated haemoglobin value corrected for the degree of glycation.

Age-dependent blood pressure response to increased salt intake in rats influenced by a transient renal ischaemia

1986 ◽  
Vol 70 (2) ◽  
pp. 185-189 ◽  
Author(s):  
J. Kuneš ◽  
J. Jelínek ◽  
J. Zicha
Keyword(s):  
Blood Pressure ◽  
Renal Dysfunction ◽  
Renal Mass ◽  
Urea Concentration ◽  
Ischaemic Injury ◽  
Pronounced Increase ◽  
Plasma Urea ◽  
Renal Ischaemia ◽  
Salt Hypertension ◽  
Plasma Urea Concentration

1. The influence of renal dysfunction (induced by ischaemic injury) on the development of salt hypertension was studied in rats which were exposed to 60 min of renal ischaemia when either immature or adult. Saline-drinking age-matched animals served as controls. The blood pressure, plasma urea concentration, extracellular fluid volume (ECFV) and renal mass were measured 21 and 50 days after renal ischaemia. 2. Increments of plasma urea concentration and ECFV were considered to be indicators of renal dysfunction. Increased renal mass was used as an estimate of the degree of renal injury. 3. In adult rats, both plasma urea concentration and ECFV were increased 3 weeks after renal ischaemia. This correlated with a pronounced increase of renal mass. A similar relation of renal mass to ECFV was still present 50 days after renal ischaemia. 4. In rats treated when immature the increment of plasma urea concentration was much smaller and ECFV did not differ significantly from the control volumes. 5. A mild salt hypertension developed only in those rats which were treated when immature. On the other hand, the blood pressure tended to decrease in animals treated when adult. 6. It is concluded that mild renal dysfunction facilitates the development of salt hypertension in immature rats. This is in contrast with the reversed effects of extensive renal dysfunction in adult animals. 7. It is suggested that the age of animals is more important for the induction of salt hypertension than the degree of renal dysfunction.

Salvage of blood urea nitrogen in sheep is highly dependent on plasma urea concentration and the efficiency of capture within the digestive tract1,2

2007 ◽  
Vol 85 (4) ◽  
pp. 1006-1013 ◽  
Author(s):  
N. E. Sunny ◽  
S. L. Owens ◽  
R. L. Baldwin ◽  
S. W. El-Kadi ◽  
R. A. Kohn ◽  
...  
Keyword(s):  
Blood Urea Nitrogen ◽  
Urea Concentration ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Plasma Urea Concentration

Factors affecting the urinary excretion of urea nitrogen in cattle. II. The plasma urea nitrogen concentration

1970 ◽  
Vol 21 (1) ◽  
pp. 145 ◽  
Author(s):  
RF Thornton
Keyword(s):  
Nitrogen Concentration ◽  
Urine Flow ◽  
Urea Concentration ◽  
Urea Clearance ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Factors Affecting ◽  
Urea Excretion ◽  
Plasma Urea Concentration ◽  
Filtered Load

The relationships between the plasma urea concentration and clearance variables associated with urinary urea excretion were investigated in urea-supplemented cattle. The plasma urea concentration was related to the urinary urea output, and thus to the urea clearance and the fraction of filtered urea excreted. It is suggested that the urine flow rate was influenced by urinary urea excretion, which in turn was influenced by the plasma urea concentration and therefore by the filtered load of urea. The probable influence of the recycling of urea to the rumen on the excretion of urinary urea is discussed.

scholarly journals Nonrecovery of Kidney Function and Death after Acute on Chronic Renal Failure

2009 ◽  
Vol 4 (5) ◽  
pp. 891-898 ◽  
Author(s):  
Chi-yuan Hsu ◽  
Glenn M. Chertow ◽  
Charles E. McCulloch ◽  
Dongjie Fan ◽  
Juan D. Ordoñez ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Kidney Function

Effect of rumen degradable protein and lactation on nitrogen metabolism in dairy goats

1991 ◽  
Vol 71 (4) ◽  
pp. 1111-1124 ◽  
Author(s):  
J. Brun-Bellut ◽  
J. M. Kelly ◽  
G. W. Mathison ◽  
R. J. Christopherson
Keyword(s):  
Amino Acids ◽  
Digestive Tract ◽  
Urea Concentration ◽  
Dairy Goats ◽  
Rumen Microorganisms ◽  
Plasma Urea ◽  
Available N ◽  
Lactation Stage ◽  
Plasma Urea Concentration ◽  
Degradable Protein

Nitrogen flow and exchanges in the digestive tract were measured in three goats during a dry stage and a subsequent hormonally induced lactation stage. Two diets, formulated with and without urea to contain either a high or low level of crude protein and rumen-degradable protein (RDP), were tested in a crossover experimental design within each stage. The amount of urea nitrogen (N) recycled to the ruminoreticulum was higher (P < 0.05) during lactation (3.5 g d−1) than in the dry stage (0.9 g d−1), as was plasma urea concentration. However, the mean amount of urea recycled was lower (P < 0.05) when the high-RDP diet was fed (1.4 g N d−1) than when the low-RDP diet was fed (3.0 g N d−1), even though the plasma urea concentration tended to be higher in goats fed the high-RDP diet. Of the estimated ruminally available N, 90–110% was incorporated into microbial cells. The proportion of bacterial N derived from rumen ammonia (0.77–0.89) was not influenced by protein source or lactation. Of the amino acids flowing into the duodenum, 69–75% were apparently absorbed in the small intestine, whereas total digestive tract apparent digestibility ranged from 81 to 83%. No more than 60% of the fecal N was derived from undigested bacteria from the rumen. It was concluded that the amount of urea which is recycled to the rumen is under metabolic control and that there is efficient use of ruminally available N by rumen microorganisms. Key words: Goats, lactation, rumen-degradable protein, 15N, urea recycling, amino acids

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