Amino Acids, Proteins and Porphyrins
Which of these is a mitochondrial enzyme? (AIPG 2010)
Refer to this review article “A review on laboratory liver function tests by ShivarajGowda et al”
alcohol metabolism (ALDH2)
Other/to be sorted
Aspartate amino transferase (AST)
a. AST catalyse transamination reaction. AST exist two different isoenzyme forms which are genetically distinct, the mitochondrial and cytoplasmic form. AST is found in highest concentration in heart compared with other tissues of the body such as liver, skeletal muscle and kidney.
b. Normal serum AST is 0 to 35U/L. Elevated mitochondrial AST is seen in extensive tissue necrosis during myocardial infarction and in chronic liver diseases like liver tissue degeneration and necrosis.
c. About 80% of AST activity of the liver is contributed by the mitochondrial isoenzyme, whereas most of the circulating AST activity in normal people is derived from the cytosolic isoenzyme.
d. However the ratio of mitochondrial AST to total AST activity has diagnostic importance in identifying the liver cell necrotic type condition and alcoholic hepatitis.
e. AST elevations often predominate in patients with cirrhosis and even in liver diseases that typically have an increased ALT.
f. AST levels in symptomatic pregnant patient in hyperemesis gravidarum were 73U/L, in pre-eclampsia 66U/L, and 81U/L was observed in hemolysis with low platelet count and elevated liver enzymes.