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 ?
Milk urea nitrogen (MUN) was determined using Sigma kits #640 (Sigma Diagnostics, St.
The variables, daily gain, feed conversion, plasma urea nitrogen and nitrogen retention, were regressed against supplemental lysine intake.
Prasertsak P, Freney JR, Saffigna PG, Denmead OT, Prove BG (200 la) Fate of urea nitrogen applied to a banana crop in the wet tropics of Queensland.
Increases in blood urea nitrogen (BUN) concentrations can be seen in mammals with gastrointestinal hemorrhage because blood contains highly digestible proteins (albumin and hemoglobin).
8) They also found fluctuations in hearing during single dialysis events; these fluctuations were transient and independent of changes in levels of sodium, potassium, calcium, blood urea nitrogen, glucose, blood pressure, and weight.
Table 1 shows the serum urea nitrogen and Cr levels obtained from the three experiments with different administration periods or reperfusion times.
As a result of these metabolic transactions, you can tell whether a diet is optimized for the protein-to-energy ratio by checking the urea nitrogen levels in the blood," says Hammond.
Blood urea nitrogen of female spotted deer is presented in Table 4.
Both urea nitrogen and creatinine concentrations are usually increased, as are markers of liver or pancreatic injury (e.
0 Bilirubin [mu]mol/L - - mg/dL - - Chloride mmol/L 75 (8) 60-90 Osmolality mmol/kg 250 (13) 230-280 Urea nitrogen mmol/L - - mg/dL - - Uric acid [mu]mol/L - - mg/dL - - CSF glucose mmol/L 2.
Wayne PA) was cleared to sell its Trilogy Analyzer, a bodily fluids analysis system intended for use in analyzing glucose, creatine and urea nitrogen in serum.
This blood test measures the level of blood urea nitrogen, a chemical that is produced when the body breaks down protein molecules.