The existence of some specific liver enzymes in your blood can
help determine the amount of damage to your liver. Normally,
these enzymes exist within the liver. However if the liver is
damaged or injured these enzymes are thrown out into the blood
stream. Enzymes help speed up the routine chemical reactions in
the body. Aminotransferases are the most widely used liver
enzymes. This enzyme includes alanine aminotransferase (ALT or
SGPT) and aspartate aminotransferase (AST or SGOT). These
enzymes therefore are normally present in the liver, but when
liver is damaged, these enzymes are spilled into the blood
signaling liver damage. The liver uses these enzymes to
metabolize amino acids and make protein. The normal range of
values for AST (SGOT) is from 5 to 40 units per liter of serum
(the liquid part of the blood). The normal range of values for
ALT (SGPT) is from 7 to 56 units per liter of serum. AST and ALT
signal damage or disease in the liver, but higher than normal
levels of these enzymes do not always in