(LEC) AST, ALT, ALP Flashcards
AST EC No.
E.C. 2.6.1.1
AST Systematic Name
L-Asapartate: 2-Oxaloglutarate Aminotransferase
AST Old Name
Serum Glutamic Oxaloacetate Transaminase (SGOT)
AST Coenzyme
Pyridoxal Phosphate (Vit.B6)
Keto acids formed are oxidized by
Tricarboxylic Acid Cycle
Enzyme that produces alpha ketoglutarate
Glutamate dehydrogenase
AST Indicator Enzyme
Malate dehydrogenase
Products of AST
Oxaloacetate & Glutamate
3 Tissue sources w/ highest AST concentration
Cardiac Tissue
Liver
Skeletal Muscle
Intracellular AST concentration is how much more higher than extracellular concentration?
7000x
AST Isoenzymes
GOT1 (Cell Cytoplasm)
GOT2 (Mitochondria)
AST Isoenzyme that is predominant from occurring in serum
GOT1
AST Isoenzyme that increases in disorder producing cellular necrosis
GOT2
Reference of AST
5 - 35 U/L
In a heart attack, when do AST levels peak
at 24hrs
In the absence of CK MB, this enzyme is used to detect Myocardial Infarction
AST
Illness w/ highest AST elevations
Acute Hepatocellular disorders
AST Assay Optimal pH
7.3 - 7.8
Hemolysis in AST Assay affect results how
Increases Serum AST concentration
How long can AST be stable in serum
3-4 days in refrigerated temp
ALT E.C. No.
E.C. 2.6.1.2
ALT Systematic Name
L-Alanine: 2-oxaloglutarate aminotransferase
ALT Old Name
Serum Glutamic Pyruvic Transaminase (SGPT)
ALT Coenzyme
Pyridoxal Phosphate (Vit B6)
Product of Anaerobic energy produciton
Lactate
Product of Aerobic energy production
Glutamate
Intracellular ALT levels is how much more higher than that in plasma
3000x
ALT reference
7 - 45 U/L
Half Life of ALT and AST according to Bishop
ALT - 24hrs
AST - 16hrs
In Acute hepatocellular injury, what is the ratio of AST to ALT concentration
7000:3000
In hepatocyte injury, which enzyme initially has higher levels of
AST
Expresses the disproportionate elevation of AST over ALT
DeRitis Ratio (4:1)
Indicator Enzyme for ALT Assay
LDH
Optimal pH for for ALT Assay
7.3 - 7.8
Hemolysis in ALT Assay effects
None
Alkaline Phosphatase E.C. No.
E.C. 3.1.3.1
Alkaline Phosphatase Systematic Name
Orthophosphoric Monoester Phosphohydrolase (Alkaline Optimum)
Optimal pH of Alkaline Phosphatase
9.0 - 10.0
Activators of Alkaline Phosphatase
Mg2+ and Zn2+
Tissue source with highest ALP concentration
Intestine
Liver
Bone (Osteoblasts)
Spleen
Placenta
Kidney
Increased ALP Activity in Pregnancy. Normal or Abnormal?
Normal
Condition with absence of Bone ALP
hypophosphatasia
4 ALP isoenzymes
Liver ALP
Bone ALP
Intestinal ALP
Placental ALP
isoenzyme that migrates the fastest in ALP Electrophoresis
Liver ALP
Bone ALP is normally elevated in which patients
Children (in periods of growth)
Adults older than 50
Intestinal ALP are mostly common in which blood types
O & B
Most heat stable ALP Isoenzyme
Placental ALP
Inhibits intestinal ALP and placental ALP
Phenylalanine
Inhibits bone ALP and Liver ALP
Levamisole
Inhibits bone ALP
3M Urea
Abnormal Fractions of ALP Isoenzymes
Regan Isoenzyme
Nagao Isoenzyme
Regan Isoenzyme is inhibited by
Phenylalanine
Nagao Isoenzyme is inhibited by
Phenylalanine & L-leucine
ALP reference for children
54 - 369 U/L
ALP reference for adult males
53 - 128 U/L
ALP reference for males above 60yrs old
56 - 119 U/L
ALP reference for Female adults
42 - 98 U/L
ALP Assay Method
Bowers and McComb
Calculation of ALP Activity based on the molar absorptivity of p-nitrophenol
Bowers and McComb
In Bowers and McComb Assay, P-nitrophenyl phosphate is hydrolyzed to become
p-nitrophenol
Absorbance measured in Bowers and McComb
405nm
ALP should be run how long after collection?
ASAP
Why is Hemolysis a source of error for ALP Assay
Causes slight ALP elevations