NON PROTEIN NITROGEN, BLOOD UREA NITROGEN, BUN LABORATORY METHODS (TOPIC 3 NON PROTEINS)

Question 1

These are substances that contain element nitrogen but are not protein.

Answer 1

Non Protein Nitrogen (NPN)

Question 2

In the body they are waste products of metabolism.

Answer 2

Non Protein Nitrogen (NPN)

Question 3

Majority are excrete in the urine, some are reabsorb.
They are increase in renal disease.
Use to evaluate renal function and some for liver function.

Answer 3

Non Protein Nitrogen (NPN)

Question 4

Major NPN in the body

Answer 4

Blood urea nitrogen (BUN)
Creatinine
Blood uric acid (BUA)
Ammonia

Question 5

Product of protein (dietary) and amino acid catabolism . Formed from the liver under the urea cycle.

Answer 5

Blood urea nitrogen (BUN)

Question 6

Major NPN in the blood (75 %).

Answer 6

Blood urea nitrogen (BUN)

Question 7

Produce in the liver and excreted in the urine (40 % reabsorbed).

Answer 7

Blood urea nitrogen (BUN)

Question 8

Increases in renal and non-renal conditions, hence not reliable for renal function evaluation.

Answer 8

Blood urea nitrogen (BUN)

Question 9

Metabolism of BUN

Answer 9

Protein (from diet catabolize into amino acids) –> Amino Acids (Oxidation to from energy or synthesize new proteins, process produce ammonia and nitrogen) –> Ammonia (combined with CO2 [deaminization] converted to urea) –> Urea (carried to blood, filtered from the glomerulus, majority excreted in urine)

Question 10

is the process of removing ammonia in the body, it occurs in the liver.

Answer 10

Urea Cycle

Question 11

Amino acids involved in urea production:

Answer 11

Citrulline
Arginine
Ornithine

Question 12

refers to the nitrogen component of urea.

Answer 12

BUN

Question 13

refers to concentration of urea as a whole.

Answer 13

Urea

Question 14

BUN specimen

Answer 14

Non-fasting specimen

Question 15

anticoagulant that inhibits urea

Answer 15

Sodium flouride
Citrate

Question 16

Conditions that affect increase in UREA

Answer 16

Increase protein diet
Dehydration
Starvation
Steroid theraphy

Question 17

BUN general reaction

Answer 17

Hydrolysis of urea to form ammonia and carbon dioxide by urease enzyme

UREA + H2O –(Hydrolysis)(Urease)–> NH3 + CO2

Question 18

BUN Nesslerization (Kan-Gentzkow)

Answer 18

ammonia is combined with pottasium mercuric iodide

NH4 + K2HgI2 –> Dimercuric NH4 (yellow)

Question 19

BUN Berthelot Reaction (Chaney and Marbach)

Answer 19

NH4 + hypochlorite + phenol –(alkali nitroprusside)–> indophenol blue (540 nm)

Question 20

BUN Diacetyl monoxime/Fearon reaction

Answer 20

Condensation of urea with diacetly monoxime

Urea + diacetyl monoxomine –> diacetyl + hydroxylamine

Diacetyle + thiosemicarbazide + arsenic ions –> yellow color

Question 20

BUN normal value

Serum/Plasma:
Conversion Factor:
Urea:

Answer 20

6-20 mg/dl
0.357 (2.1-7.1 mmol/L)
BUN x 2.14

Question 21

increased of nitrogenous waste products primarily BUN and creatinine in the blood.
Indicates developing renal disease.

Answer 21

Azotemia

Question 22

more severe form of azotemia accompanied by signs and symptoms such as edema, nausea, vomiting, acid base disturbance and electrolyte disorders.

Answer 22

Uremia

Question 23

What are some clinical significance that decrease BUN

Answer 23

Low protein intake
Liver disease
Over hydration
Pregnancy
Sydrome of inappropriate anti-diuretic secretion (SIADH)