ChemPath: Enzymes and Cardiac Markers Flashcards
What are the two types of intracellular enzymes?
- Cytosolic
- Subcellular (within organelles)
Describe the order of release of intracellular enzymes when cells are damaged.
Cytosolic are released first, followed by subcellular
In which tissues is ALP present in high concentration?
BILP
* Bone
* Intestine
* Liver (bile ducts)
* Placenta
What is an increase in bone ALP caused by?
Increased osteoblast activity
What technique is used to separate isoenzymes?
Electrophoresis
List some physiological causes of high ALP.
- Pregnancy - 3rd trimester (from placenta)
- Childhood - growth spurt
- Afro-caribbean patient
List some causes of very high ALP (>5 x upper limit of normal).
- Bone - Paget’s disease, osteomalacia
- Liver - cholestasis, cirrhosis
List some causes of moderately raised ALP (< 5 x upper limit of normal).
- Bone - tumours, fractures, osteomyelitis
- Liver - infiltrative disease, hepatitis
Describe the ALP levels in osteoporosis.
It is NORMAL unless there is a fracture.
Which markers are used in acute pancreatitis and how many xUL is significant?
Amylase >x10UL
Lipase >3x UL
Where else is amylase found?
Salivary glands
NOTE: will be raised in parotitis / mumps
What are the three forms of creatine kinase?
- CK-MM = skeletal muscle
- CK-BB = brain
- CK-MB = cardiac muscle
List some risk factors for statin-related myopathy.
- Polypharmacy (in particular, fibrates and cyclosporin and other drugs metabolised by CYP3A4)
- High dose
- Genetic predisposition
- Previous history of myopathy with another statin
- Vitamin D deficiency (increased risk of statin intolerance)
List some causes of high CK.
- Muscle damage (rhabdomyolysis)
- Myopathy (e.g. Duchenne muscular dystrophy)
- MI
- Statins
- Severe exercise
- Physiological (Afro-Caribbeans)
List 5 cardiac enzymes that are elevated in MI/cardiac damage
Myoglobin
Troponin
CK-MB
AST
LDH