Uric Acid

Question 1

• Metabolic waste product of purine metabolism

– from the breakdown of ingested nucleic acids

– from tissue destruction

Answer 1

Uric Acid

Question 2

Uric Acid

• Metabolic waste product of____

– from the breakdown of ingested___

– from___ destruction

Answer 2

purine metabolism

nucleic acids

tissue

Question 3

Uric acid

• Filtered by the glomerulus

•_____ reabsorbed by PCT

• Small amount are secreted by DCT

Answer 3

98-100%

Question 4

• Uric acid is formed from the breakdown of _____and is an end product of purine metabolism.

• Uric acid is transported by the plasma from the____ to the _____, where it is filtered and where about 70% is excreted.

• The remainder of uric acid is excreted into the___ tract.

Answer 4

nucleic acids

liver to the kidney

Gl

Question 5

Gmp
Amp

Answer 5

guanosine monophosphate

adenosine monophosphate

Question 6

GMP > nucleotidase > Guanosine > nucleosidase > Guanine > guanine deaminase > _____

Answer 6

Xanthine

Question 7

AMP nucleotidase > Adenosine > adenosine deaminase > Inosine > nucleosidase > Hypoxanthine > xanthine oxidase > ____

Answer 7

Xanthine

Question 8

Xanthine > ____ > Uric Acid

Answer 8

xanthine oxidase

Question 9

Uric Acid

• Present as_____ in the plasma

Answer 9

monosodium urate

Question 10

Relatively____ (blood pH)

– At concentrations greater than_____/dL, the plasma is saturated

• Resulting to urate crystals formations

• Precipitation in the tissues and joints

Answer 10

insoluble

6.8 mg/ dL

Question 11

Uric Acid analytical method

Answer 11

1. Caraway Method
2. Uricase Method
3. Couple Enzymatic Methods

Question 12

– Based on the oxidation of UA in PFF, with subsequent reduction of phosphotungstic acid to tungsten blue

Answer 12

Caraway Method

Question 13

Sodium carbonate

– Provides alkaline pH for color development

– Lacks specificity

Answer 13

Caraway method

Question 14

– Uricase catalyzes the oxidation of UA to allantoin

– Measures the differential absorption of uric acid and allantoin at____

Answer 14

Uricase Method

293 nm

Question 15

– More specific

– hemoglobin and xanthine can cause negative interference

Answer 15

Uricase method

Question 16

Uricacid + H,0+02&raquo_space;> allantoin + CO, + H,02

Answer 16

Uricase

Question 17

– Measures the hydrogen peroxide produced as UA is converted to allantoin

• Peroxidase or catalase
– Catalyze a chemical indicator reaction

Answer 17

Couple Enzymatic Methods

Question 18

Couple Enzymatic Methods

Interference:

Answer 18

• Bilirubin and ascorbic acid (destroy peroxide)

Question 19

• Uric acid is oxidized to allantoin by____.

•The generated _____reacts with 4-aminophenazone/ESPT to quinoneimine.

Answer 19

uricase

hydrogen peroxide

Question 20

specimen requirement

Answer 20

Heparinized Plasma, serum, or urine

Question 21

specimen requirement

• Should be removed from cells ASAP to prevent dilution by intracellular contents
• Fasting is not required
• Avoid lipemic and hemolyzed specimens
• May be refrigerated for 3-5 days

Answer 21

Serum

Question 22

interfering substances

Answer 22

• High bilirubin Concentration
• Ascorbic acid

• Drugs
- Salicylates
- Thiazides

Question 23

• Falsely decrease results to Peroxidase methods
• Addition of Potassium ferricvanide and ascorbate oxidase

Answer 23

• High bilirubin Concentration
• Ascorbic acid

Question 24

• Falsely increase results

Answer 24

Drugs
- Salicylates
- Thiazides