Creatinine

Question 1

Creatine

• Synthesized primarily in the liver from (3)

Answer 1

arginine, glycine, and methionine

Question 2

Creatine is transported to tissues and is converted to_______, which serves as a high-energy source

Answer 2

phosphocreatine

Question 3

EC 2.1.4.1

Answer 3

L-ARGININE: GLYCINE AMIDINOTRANSFERASE (AGAT)

Question 4

EC 2.1.1.2

Answer 4

GUANIDINOACETATE METHYLTRANSFERASE (GAMT)

Question 5

(GAA)

Answer 5

GUANIDINOACETATE

Question 6

arginine&raquo_space;> guanidoacetate

Happens in the

Answer 6

in kidney

Question 7

guanidoacetate&raquo_space;> creatine

Happens in the

Answer 7

Liver

Question 8

creatine&raquo_space;> creatine phosphate

What enzyme caused the conversion?

Answer 8

creatine phosphokinase

Question 9

creatine phosphate&raquo_space;> creatinine

Unsa gitanggal?

Answer 9

P + H2O

Question 10

Creatinine&raquo_space;> creatine phosphate

What enzyme is added?

Answer 10

Creatine kinase

Question 11

Creatinine&raquo_space;> ______&raquo_space;> Glomerular filtration&raquo_space;> _____

Answer 11

Plasma

Urine

Question 12

• Endogenous substance
• With a MW of 113 Da

Answer 12

Creatinine

Question 13

Creatinine

• Waste product of____ metabolism

Answer 13

muscle

Question 14

Creatinine

Produced by the muscle from creatine and creatine phosphate thru non-enzymatic (2) process

Answer 14

dehydration and dephosphorylation

Question 15

Disease Correlation:

^^^______
Muscle diseases
Muscular dystrophy
Poliomyelitis
Hyperthyroidism
Trauma

Answer 15

Creatine

Question 16

Disease correlation

^^^^______
Associated with abnormal renal function

Answer 16

Creatinine

Question 17

• Most widely used marker for GFR

Answer 17

Creatinine

Question 18

Creatinine

Advantages:

Answer 18

~ Endogenous substance with constant rate of production

~ Not bound to plasma proteins
Not reabsorbed by the tubules

~ Only a small amount is secreted by the tubules

Question 19

Creatinine

Disadvantages:

Answer 19

× Depends mainly on muscle mass
× Quantity of meat ingestion can substantially influence the total
daily production
× Method is subjected to many interferences

Question 20

The Diagnostic Function of
Creatinine

If the kidneys are damaged or impaired and cannot work normally

The amount of creatinine in urine goes____ while its level in blood goes____

Creatinine has been found to be a fairly reliable indicator of kidney function.

Serum creatinine level is an important diagnostic tool to asses renal function

Answer 20

down; up.

Question 21

How is Creatinine Used to Monitor Renal Function..?

In renal failure the kidney will not be able to excrete creatinine in urine leading to an_____ in serum creatinine level.

Answer 21

elevation

Question 22

Is there other factors mav affect creatinine level in the blood…’
?

Answer 22

The amount of muscle tissue you have.

Protein in diet.

Question 23

:
Measures how well creatinine is removed from blood by kidneys which reflects glomerular filtration rate (GFR)]

Answer 23

Creatinine Clearance Test

Question 24

• Creatinine reacts with picric acid (trinitrophenol)
in alkaline solution to form a red-orange chromogen

Answer 24

Direct Jaffe Reaction (1886)

Question 25

Direct Jaffe Reaction (1886) • Creatinine reacts with_____ in alkaline solution to form a____ chromogen

Answer 25

picric acid (trinitrophenol) red-orange

Question 26

DJR

Answer 26

- Folin-Wu Method (1919) - Fuller's Earth - Method of Hare (addition to Lloyd's Reagent)

Question 27

- Fuller's Earth - Method of Hare (addition to Lloyd's Reagent)

Answer 27

- Folin-Wu Method (1919)

Question 28

Hare (addition to Lloyd's Reagent) - PFF + sodium aluminum silicate • Eluted and reacted with alkaline pirate

Answer 28

• Method of Hare (addition to Lloyd’s around for and in wannabee

Question 29

- PFF + sodium aluminum silicate • Eluted and reacted with alkaline pirate

Answer 29

• Method of Hare (addition to Lloyd's Reagent)

Question 30

Creatinine + Picric acid

Answer 30

Yellow color

Question 31

Creatinine Picrate Orange color Measured at

Answer 31

colorimetrically 520 nm

Question 32

• performed directly on sample • serum is mixed with alkaline picrate and the rate of change in absorbance is measured

Answer 32

Kinetic Jaffe Reaction

Question 33

• Interferences: (2)

Answer 33

- a-ketoacids - cephalosporins

Question 34

Coupled-Enzymatic Method (2) Creatininase

Answer 34

a. Creatininase-CK Method b. Creatininase-Hydrogen Peroxide Method

Question 35

Creatininase-CK Method

Answer 35

• Creatininase • CK, PK, LDH - NADH to NAD+ (340 nm)

Question 36

Creatininase-Hydrogen Peroxide Method

Answer 36

• Creatininase Creatinase Sarcosine oxidase Peroxidase

Question 37

specimen requirement

Answer 37

Plasma; serum Urine

Question 38

- Hemolyzed and icteric samples should be avoided - Lipemic samples produce erroneous results - Fasting is not required

Answer 38

Plasma, serum

Question 39

should be refrigerated or frozen if longer than 4 days

Answer 39

Urine

Question 40

Creatinine in serum or urine is stable for at least__ days at___

Answer 40

7 4°C

Question 41

interfering substances

Answer 41

False increase; reacts with picrate solution • Ascorbic Acid • Glucose • Protein, urea • Alpha-keto acids/ ketones • Cephalosporins, Dopamine, Lidocaine false decrease • Hemoglobin and bilirubin • Uric acid - Decreased in kinetic methods