urea nitrogen


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Related to urea nitrogen: uric acid, Urine urea nitrogen

urea

 [u-re´ah]
1. the diamide of carbonic acid found in urine, blood, and lymph, the chief nitrogenous constituent of urine, and the chief nitrogenous end-product of protein metabolism; it is formed in the liver from amino acids and from ammonia compounds.
2. a pharmaceutical preparation of this compound, administered intravenously as an osmotic diuretic to lower intracranial or intraocular pressure, injected transabdominally into the amniotic sac to induce abortion of a second trimester pregnancy, and included in topical preparations to moisten and soften rough, dry skin.



The amount of urea in the urine increases with the quantity of protein in the diet because urea is an endogenous and exogenous waste product: endogenous because some of it is derived from breakdown of body protein as tissues undergo disintegration and repair, and exogenous because some of it is derived from the deamination of amino acids absorbed from the intestinal tract but not utilized by the body. In severe nephritis or other disorders leading to renal failure, the concentration of urea in the blood may be greatly increased, as revealed by measurement of the blood urea nitrogen (BUN).
urea concentration test a test of renal efficiency, based on the fact that urea is absorbed rapidly from the stomach into the blood and is excreted unaltered by the kidneys; 15g of urea is given with 100mL of fluid, and the urine collected after 2 hours is tested for urea concentration.
urea nitrogen the urea concentration of serum or plasma, conventionally specified in terms of nitrogen content and called blood urea nitrogen (BUN), an important indicator of renal function.

u·re·a ni·tro·gen

the portion of nitrogen in a biologic sample, such as blood or urine, that derives from its content of urea.
See also: blood urea nitrogen.

urea nitrogen

urea nitrogen

See BUN.

urea

1. the diamide of carbonic acid found in urine, blood and lymph, the chief nitrogenous constituent of urine, and the chief nitrogenous end product of protein metabolism; it is formed in the liver from amino acids and from ammonia compounds.
2. a pharmaceutical preparation of urea occasionally used to lower intracranial pressure.
3. industrial urea is used as a fertilizer and feed additive for ruminants. Overfeeding or accidental access to large amounts can cause fatal poisoning.

urea cycle
see urea cycle.
urea cycle enzyme deficiency
urea hydrogen peroxide
see carbamide peroxide.
urea nitrogen
the urea concentration of serum or plasma, conventionally specified in terms of nitrogen content and called blood urea nitrogen (BUN), an important indicator of renal function.
urea poisoning
causes tremor, dyspnea, abdominal pain, incoordination, bellowing, convulsions and death in 2 to 4 hours. Due to hyperammonemia.
References in periodicals archive ?
Blood urea nitrogen (BUN) concentrations were significantly different, whereas, the blood pH remained unaltered across all treatments (Table 5).
2005) reported that PUN or blood urea nitrogen (BUN) was useful as an indicator of protein status and there was a strong linear relationship between BUN and urinary N excretion for cattle.
Therefore, the objective of the current study was to establish the optimum dietary ratio of methionine to methionine plus cystine for growing pigs using the nitrogen balance technique and plasma urea nitrogen.
The reasons for increasing urea nitrogen are eating foods with high nitrogen content,
For trained male swimmers significant positive correlations among CSS, blood urea and serum urea nitrogen were found.
To avoid this interference, patient monitoring should be performed by drawing samples from peripheral veins, by measuring creatinine using Jaffe methods, and/or by following blood urea nitrogen concentrations (1,3).
Table 4: Blood urea nitrogen, blood glucose and blood creatinine in Kajli lambs fed different dietary rumen undegradable protein (RUP) levels
Blood urea nitrogen, total protein (TP), albumin (ALB), and glucose concentrations were measured using an Automatic Biochemistry Analyzer (Hitachi 7020, Japan).
Effect of amino acids supplement on blood glucose and blood urea nitrogen of early lactating Nili-Ravi buffaloes.
Plasma creatinine and urea nitrogen were determined using commercial kits (sarcosine oxidase-peroxidase-antiperoxidase; Zixing, Shanghai, China).
However, the concentrations of ruminal ammonia, urea and blood urea nitrogen were lower for cows fed raw soybean than for cows fed the other nitrogen sources.