finals - non protein nitrogen Flashcards
The term ___originated in the early days of clinical
chemistry when analytic methodology required removal of protein from a
specimen before analysis
nonprotein nitrogen (NPN)
The concentration of nitrogen-containing compounds in this protein-free
filtrate was quantified
____
spectrophotometrically
The concentration of nitrogen-containing compounds in this protein-free
filtrate was quantified spectrophotometrically by converting nitrogen to
___
ammonia
The concentration of nitrogen-containing compounds in this protein-free
filtrate was quantified spectrophotometrically by converting nitrogen to
ammonia and subsequent reaction with what reagent?
Nessler’s reagent
nessler’s reagent components
double iodide of potassium mercury
end color of converting nitrogen to ammonia using nessler’s reagent
yellow
nonprotein nitrogen (NPN)
The majority of these compounds arise from the catabolism of ___
proteins and nucleic acids
list down the non protein nitrogen compounds
urea
amino acids
uric acid
creatinine
creatine
ammonia4
Major excretory product of protein
metabolism
UREA
Formed in the liver from amino groups (-NH2)
and free ammonia generated during protein
catabolism
urea
Concentration of urea in the plasma is
determined by ___
renal function and perfusion,
the protein content of the diet,
and the rate of protein catabolism
marker of dialysis
urea
In severe liver damage, levels of urea
___.
decreases
why do urea level decreases in liver damage?
ammonia is deaminated in liver from proteins that will subsequently turned as a urea, if there’s no liver that can deaminate ammonia to become urea, urea level will decrease
It is used as a screening test for kidney
disease.
BLOOD UREA
NITROGEN (BUN)
Major organic solid in the urine
BLOOD UREA
NITROGEN (BUN)
Major inorganic solid in the urine
chloride
Urea is readily removed by ___
dialysis
____ Urea is excreted; 10% remain in the
blood
90%
(<10% of the total BUN) are excreted through the ___
gastrointestinal (GI) tract and skin
The concentration of urea in the plasma is
determined by the __
protein content of the diet,
the rate of protein catabolism,
and renal function and perfusion
clinical application of BUN
evaluate renal function,
to assess hydration status,
to determine nitrogen balance,
to aid in the diagnosis of renal disease, and
to verify adequacy of dialysis
oldest technique for urea determination
MICRO-KJELDAHL NESSLER
end product of MICRO-KJELDAHL NESSLER
Dimercuric ammonium iodide
___ process
Mixture of sulfuric acid and phosphoric acid
Kjeldahl
a nesslerization with a use of enzyme
UREASE-NESSLER
METHOD
in UREASE-NESSLER
METHOD
urea is splitted into
carbon dioxide and nh3 (ammonia)
then the ammonia is subjected to nesslerization to produce dimercuric ammonium iodide
what is the coupling enzyme used in BUN enzymatic method; urease?
gldh - glutamic dehydrogenase
what is being measured in urease kinetic enzymatic method
the rate of disappearance of NAD to its reduced form NADH which is measured to 340 nm
a BUN method which is Greater specificity: More expensive
enzymatic kinetic method of urease
Greater specificity: More expensive
enzymatic kinetic method of urease
Urea is hydrolyzed to ammonium
carbonate by urease and ammonia
reacts with phenol and sodium
hypochlorite in an alkaline medium
forming a blue indophenol.
Urease Berthelot Method
in Urease Berthelot Method:
what elements do ammonia reacts with?
phenol and sodium
end product of Urease Berthelot Method:
blue indophenol.
Urea is hydrolyzed by
urease forming ammonia
which is then titrated
with a weak acid.
ENZYMATIC AND
ACID TITRATION
2 methods of ENZYMATIC AND
ACID TITRATION
a. Van Slyke Cullen
b. Urograph
DIRECT MEASUREMENT OF UREA measures
urea itself, no need to use urease to convert it to ammonia
DIRECT MEASUREMENT OF UREA measures
urea itself, no need to use urease to convert it to ammonia
however, it is only a what type of method?
colorimetric method
a method under DIRECT MEASUREMENT OF UREA
Diacetyl Monoxime Method (DAM)
in Diacetyl Monoxime Method (DAM)
Urea is made to react with diacetyl monoxime to produce a yellow diazine
derivative known as
Fearon’s reaction
what is the end product color of Diacetyl Monoxime Method (DAM)
yellow diazine derivative
in Diacetyl Monoxime Method (DAM)
we are adding a color enhancer and to exclude the protein interferences called as ___
Arsenic thiosemicarbazide
comments for Diacetyl Monoxime Method (DAM)
inexpensive but lacks specificity
CONSIDERATION IN BUN DETERMINATION
The determination is affected by __.
high protein diet, hydration and other physiologic functions
CONSIDERATION IN BUN DETERMINATION
Whole blood should be ___ to
eliminate interferences of hemoglobin
deproteinized
CONSIDERATION IN BUN DETERMINATION
what anticoagulants are contraindicated in enzymatic methods.
Ammonium oxalate-containing anticoagulants
CONSIDERATION IN BUN DETERMINATION
Sodium fluoride and Citrate inhibits the action of __.
urease
CONSIDERATION IN BUN DETERMINATION
Upon prolonged standing, ammonia concentration in the sample rises____ times the original value due to enzymatic deamination of labile amide-like
glutamine
2-3 times
NORMAL VALUE of BUN
6-20 mg/dL (2.1 – 7.1 mmol/L)
8-23 mg/dl in stan bio
Normal value of BUN in 24hr urine
12-20g/dL
CONVERSION FACTOR of BUN
0.357
Urea nitrogen concentration can be converted to urea concentration by multiplying by ____
2.14
the enzymatic method that used pH indicator
indicator dye
proposed reference method of urea
isotope dilution mass spectrophotometry
quantification using isotopically labelled compounds measuring the fragments of urea
idms - isotope dilution mass spectrophotometry
___ is the principal waste product of muscular metabolism derived mainly from creatine (alpha-methyl guanidoacetic acid)
Creatinine
CREATININE
It is synthesized forming three amino acids (____)
methionine, arginine and lysine
chemical name of creatine
alpha-methyl guanidoacetic acid
Used to monitor renal function (an index of overall renal function)
creatinine
used to measure Fetal kidney maturity
creatinine
the most commonly used assay for Renal Blood Flow
createnine
is easily removed by Dialysis
nope
is creatinine The production is constant
yes
Creatinine is formed from __ and __ in muscle and is
excreted into the plasma at a constant rate related to muscle mass.
creatine and creatine phosphate
relationship of GFR to plasma creatinine
inversely proportional
it is commonly
filtration function
plasma creatinine
increased creatine normal creatinine means
problem in muscle
increased in both creatinine and creatine means
problem in kidney
Creatinase Method, uses what enzymes?
creatininase
creatinase
sarcosine oxidase
peroxidase
Creatinase Method is available on what analyzer
Available on Ektachem analyzer
in creatinase coupled enzymatic Method uses what enzymes
creatinine aminohydrolase, creatinine kinase,
pyruvate kinase, and lactate dehydrogenase
in Creatinine Aminohydrolase Method what enzyme is used to hydrolyzed creatinine to creatin
creatinine aminohydrolase
creatinine aminohydrolase method measures
the disappearance of the reduced form nadh to NAD
the working solution of direct jaffe reaction method wherein the acid is added to a base is called as
alkaline sodium picrate solution
the alkaline sodium picrate solution in direct jaffe reaction method will result to what end color
red orange tautomer