Creatine Kinase (CK) Flashcards
storage of high-energy creatine phosphate in muscle
Creatine kinase
high energy resorvoir for muscles
Creatine phosphate
Creatine kinase is widely distributed; high activities in
Skeletal muscle, Brain, Heart
Creatine kinase structure
dimeric enzyme
2 monomer subunits of CK
Brain
Muscle
Enzymatic Reaction of CK
Creatine + ATP –> Creatine phosphate + ADP
CK-3 (MM)
Muscle Type
Slowest to migrate towards anode
CK-3 Muscle Type
CK-3 is found in
Striated muscles
Healthy individuals
CK-2 (MB)
Hybrid Type
Second fastest to migrate towards anode
CK-2 (MB)
CK-2 (MB) is found in
Heart tissue
Cardiac muscles
CK-1 (BB)
Brain Type
CK-1 is found in
CNS
GI tract
Uterus
type of CK isoenzyme that is least found in healthy individuals
CK-1 (BB)
Fastest to migrate towards anode
CK-1 (BB)
Improves test specificity;
Isoenzyme measurement
Total CK
CK-1, CK-2, CK-3
After MI, CK-MB values:
Rise, Peak, Normalize
Rise: 4-8 hrs
Peak: 12-24 hrs
Normalize: 48 hrs-72 hrs (3 days)
Among AMI markers, CK-MB is the last enzyme to elevate
True or false
False (CK-MB IS THE FIRST ENZYME TO ELEVATE IN AMI)
first PROTEIN to elevate upon onset of AMI
Myoglobin (faster than CK-MB)
Reference value of CK-MM
94%-98%
Reference value of CK-MB
2%-6%
Increased CK-BB indicates
CSF leakage; Blood Brain Barrier damage
Other CK isoenzyme that is with Antibodies/lipoprotein
Macro-CK
Macro-CK with Antibodies
CK-BB
Antibodies found in Macro CK-BB
IgG
IgA
Lipoprotein is found in what isoenzyme
CK-MM
Isoenzyme of CK that migrates towards CATHODE
Mitochondrial CK
Methods of Determination for CK
Forward Reaction (Tanzer-Gilvarg)
Reverse Reaction (Oliver Rosalki)
Forward Reaction (Tanzer Gilvarg):
pH
9.0
Forward Reaction (Tanzer Gilvarg):
Product and absorbance
Oxidized (NAD)
Decrease absorbance @340 nm
Forward Reaction (Tanzer Gilvarg):
Reagent
PK (Pyruvate Kinase)
Lactate Dehydrogenase
Forward Reaction (Tanzer Gilvarg):
PK Reaction
ADP + phosphoenulpyruvate —–> Pyruvate + ATP
Forward Reaction (Tanzer Gilvarg):
Lactate Dehydrogenase Reaction
Pyruvate + NADH + H —> Lactate + NAD
Reverse Reaction for CK
Oliver Rosalki
Reverse Reaction CK:
pH
6.8 acidic
Reverse Reaction (Oliver Rosalki):
Product and absorbance
Reduced: NADH + H
; Increased Absorbance @340 nm
Reverse Reaction (Oliver Rosalki):
Reagent
Hexokinase
G-6-PD
Reverse Reaction (Oliver Rosalki):
Hexokinase Reaction
ATP + Glucose —> Glucose-6-phosphate + ADP
Reverse Reaction (Oliver Rosalki):
G-6-PD Reaction
Glucose-6-phosphate + NADP –> 6-phosphogluconate + NADPH + H
CK: Source of Error
Hemolysis (false increased)
Exposure to light (false decreased)
Physical Activity and IM injections (falsely increased)
A type of kinase enzyme that is released once blood is hemolyzed; causing false elevation of CK
Adenylate Kinase
Reference Value of CK:
Male
15-160 U/L