urea Flashcards
urea methods
inexpensive, lacks specificity
diacetyl (colorimetric)
urea methods
- enzymatic reaction of 2-oxoglutarate, and NADH to form glutamate and NAD+
- used on may automated instruments; best as a kinetic measurement
GLDH-coupled enzymatic
- high concentration in the blood
- major excretory product of protein
- carried in the blood to the kidney, where it is readily filtered from the plasma by the glomerulus and then is secreted in the urine
urea
very high plasma urea concentration accompanied by renal failure is called (?)
uremia / uremic syndrome
urea methods
- detection of characteristic fragments following ionization; quantification using isotopically labeled compound
- proposed reference method
isotope dilution mass spectrometry (IDMS)
clinical application
* evaluate renal function
* assess hydration status
* aid in the diagnosis of renal disease
* verify frequency of dialysis
urea
causes of abnormal plasma urea conc.
- acute and chronic renal failure
- renal disease, including glomerular nephritis and tubular necrosis
renal
causes of abnormal plasma urea conc.
- congestive heart failure
- shock, hemorrhage
- dehydration
- increased protein catabolism
- high-protein diet
prerenal
urea nitrogen concentration is converted to urea concentration by multiplying (?)
2.14
urea methods
greater specificity, more expensive
NH3 formation (enzymatic)
urea methods
- conversion of unionized urea to and results in increased conductivity
- specific and rapid
conductometric
an elevated concentration of urea in the blood is called (?)
azotemia
most frequently used method in clinical laboratories
enzymatic methods
concentration in plasma is determined by
* freanal function and perfusion
* protein content of the diet
* rate of protein catabolism
urea
urea methods
- +pH indicator»_space; color change
- used in automated systems, multilayer film reagents, and dry reagent strips
indicator dye
