Liver enzymes

Enzymes are protein found in the body that
speeds up (catalyze) certain chemical reaction. Liver enzymes test formerly
called liver function test (LFT) are group of blood test that inflammation and
damage of the liver. They also give information about the state of the
patient’s liver. Liver enzymes include the following:

1.
Nucleotide

2.
Gamma-glutamyl
transferase (GGT)

3.
Alkaline
phosphate (ALP)

4.
Aspartate
aminotranseferase (ALT or SGOT)

5.
Alamine
amiontransferase (ALT)

ALT and
AST are collectively known as bransaminanse or transferase while ALP, GGT and
5’ nucleotidase are collectively known as cholestetic liver enzymes. Their
function is the production of bile which help in the digestion of fat.
Elevation of these enzymes indicate the presence of liver diseases.

Alkaline phosphatase

Reference Brange; 56.8 – 128u/c

Alkaline phosphatase are group of
enzymes that are found primarily in the liver (Iso enzymes ALP-1) and bone (Iso
enzyme ALP-2). These are also small amount produced by the cells lining the
intestine (Iso enzymes ALP-2), the placenta and the kidney (proximal convoluted
tubules), this enzymes is a hydrolase enzyme that is responsible for removing
phosphatase groups from many types of molecules including nucleotides, protein
and alkalides the process of removing the phosphatase is known as
dephosphorylation.

What is measured in the blood is the
total amount of alkaline phosphatase release from these tissues into the blood.
Alkaline phosphatase as the name implies work best at an alkaline pH (A pH of
10) and thus the enzyme itself is inactive in the blood. Alkaline phosphatase
act by splitting off phosphorous (an acidic mineral) creating and alkaline pH
(Jeremy, 2015).

Clinical significance

The
primary importance of measuring alkaline phosphatase is to check the
possibility of bone or liver disease. Symptoms of liver disease can include
jaundice, stomach pain and vomiting.

ALP
test can be used to check the liver when drugs that can be damage the liver such
as oral contraceptive are taken it can also be used to check how well treatment
for peget disease or vitamin D deficiency is working.

Significantly,
elevated levels of alkaline phosphatase may be due to congestion or obstruction
of the biliary tract, which occur within the liver, the liver duct leading from
the gall bladder through the pancreas that empty into the duodenum (small
intestine) while a decrease serum alkaline phosphatase may be due to zinc
deficiency, vitamin D intake pernicious and aplasic anemia. In alkaline
phosphatase (Igba, 2011).

Aspartate aminotransferase (AST)

Reference;
up to 120/1

Aspartate
aminotransferase (AST) is also known as gluten icoxoloacetic transferase
(SGOT). It catalyze the reversible transfer of an α-amino
group between aspartate and glutamate and such is an important enzyme in amino
acid metabolism. Aspartate aminotransferase is found in the liver, heart,
skeletal muscles, brain, kidney and red blood cells. Elevated AST values are
seen in parendymal liver disease characterized by a destruction of heaptocyte
(Mayo, 2015).

Function of AST

Aspartate
aminotransferase catalyzed the interconversion of aspartate and α-ketoglutarate
to oxaloacetate and glutamate. Aspartate + α-ketoglutarate ↔
oxaloacetate + glutamate (Nyblom et al.,
2006).

Clinical significance

AST
is considered to be the most important test to detect liver injury and its
compared directly and a ratio is calculated the ratio may be used to
distinguish between different causes of liver damage and distinguish liver
hygiene from damage to heart or muscle (Nyblom et al., 2006).