(18) ALP - LIVER ENZYMES

Question 1

ALP aka

Answer 1

Alkaline Orthophosphoric monoester phosphohydrolase

Question 2

• Catalyze the hydrolysis of various phosphomonoesters at an alkaline pH
• Liberate inorganic phosphate from an organic phosphate ester with production of alcohol

Answer 2

ALP (Alkaline phosphatase)

Question 3

ALP activator

Answer 3

Mg2+

Question 4

Most of ALP in healthy human sera are derived from

Answer 4

liver & bones (specifically osteoblast)

Question 5

ALP Major tissue sources:

Answer 5

o Liver, Bones, Placenta, Intestine, Kidneys

Question 5

ALP Major tissue sources:

Answer 5

o Liver, Bones, Placenta, Intestine, Kidneys

Question 6

NOTE:

ALP Diagnostic significance:

Answer 6

o For evaluation of hepatobiliary & bone disorders.

Question 7

• Assay for Enzyme Activity for ALPs
• Based on molar absorptivity of p-Nitrophenol
• Absorbance is measured @ 405nm

Answer 7

Bowers & McComb

Question 8

Bessy, Lowry & Brock
Bowers & McComb

Answer 8

ALP SUBSTRATE: p-nitrophenyl phosphate
ALP END PRODUCT: p-nitrophenol (yellow)

Question 9

ALP SUBSTRATE: B-glycero-phosphate
ALP END PRODUCT: Inorganic PO4
Glycerol

Answer 9

Bodansky method
Shinowara method
Jones method
Reinhart method

Question 10

King & Armstrong

Answer 10

ALP SUBSTRATE: Phenyl Phosphate
ALP END PRODUCT: Phenol

Question 11

ALP isoenzymes are differentiated thru

Answer 11

Electrophoresis

Question 12

• fastest isoenzyme to migrate; most anodic
• ↑in hepatobiliary disorder / liver dsz

Answer 12

Liver ALP

Question 13

contributes to the abundance of ALP among healthy individual.

Answer 13

Major liver band

Question 14

responsible for the fast migration

Answer 14

Fast liver (a1) band

Question 15

• 2nd fastest to migrate
• Heat labile fraction
  o ↑temp = ↓ bone ALP activity
  o Significant ↓ @56°C

Answer 15

Bone ALP

Question 16

• ↑ in bone dsz (pathologic cause), healing of bone & fractures physiologic bone growth
  o ↑↑ in Paget’s dsz (osteitis deformans)

Answer 16

Bone ALP

Question 17

• Most heat-stable fraction
• ↑in pregnancy on 16th-20th wk of gestation
• Associated w/ malignancy → Carcinoplacental ALP

Answer 17

Placental ALP

Question 17

• Most heat-stable fraction
• ↑in pregnancy on 16th-20th wk of gestation
• Associated w/ malignancy → Carcinoplacental ALP

Answer 17

Placental ALP

Question 18

• slowest isoenzyme to migrate; least anodic
• ↑ on certain blood groups
  o Type B or O secretors: ↑ALP secretions (physiologic cause)
• ↑ in fatty meal consumption
• ↑intestinal ALP: pathologic conditions in the GIT

Answer 18

Intestinal ALP

Question 19

Chemical inhibitor of Placental & intestinal ALP

Answer 19

Phenylalanine

Question 20

Chemical inhibitor for bone ALP

Answer 20

3M Urea reagent

Question 21

Chemical inhibitor for bone & liver ALP

Answer 21

Levamisole

Question 22

Inhibits activity of certain enzymes so that specific isoenzyme is measured.

Answer 22

Chemical inhibitors

Question 23

Total ALP elevations by liver or Bone ALP is differentiated by heating of serum at

Answer 23

56°C for 10mins

Question 24

differentiates bone ALP as cause of elevation of ALP in serum

Answer 24

Heat stability test

Question 25

Most heat-stable to least isoenzyme:

Answer 25

P> I > L > B

Question 26

most heat-stable

Answer 26

Placenta

Question 27

most heat-labile

Answer 27

Bone

Question 28

After heating ALP isoenzymes are surely ↓ but:

Answer 28

* Liver ALP o ALP residual activity is ↓to >20% activity * Bone ALP o ALP residual activity is ↓ to <20% activity

Question 29

NOTE: ALP

Answer 29

Probable ALP present in 1 & 4 is probably LIVER (bcos >20%)

Question 30

▪ Lung, Breast, & gynecological CA, bone ALP co-migrator ▪ Most heat stable ALP * Can remain stable even though u heat it at 65°C for 30mins

Answer 30

Regan ALP

Question 31

▪ Adenocarcinoma of the Pancreas & Bile duct, Pleural CA

Answer 31

Nagao ALP

Question 32

Carcinoplacental ALP Inhibitors:

Answer 32

Phenylalanine : Can inhibit Nagao and Regan L-leucine : Can inhibit Nagao

Question 33

stage where there’s growth hormone surge

Answer 33

Puberty

Question 34

most active in bone growth which also increases ALP levels.

Answer 34

Osteoblast

Question 35

Reference range ng ALP

Answer 35

refer to handout (page 13)