The alanine aminotransferase (ALAT) enzyme in the liver is used as an indicator to detect impaired function. What does the fact mean if AlAT is elevated?
Among the many enzymes that are indicators of hepatocellular disorders, the most useful and necessary are alanine aminotransferase (AlAT) and aspartate aminotransferase (AsAT). Thanks to them, the reactions of transfer to the gamma group of the ketoglutarate of the gamma groups of alanine and aspartate are accelerated. As a result of this process, pyruvic and oxalic-acetic acids are formed.
Both AlAT and AsAT are cellular enzymes of the kidneys, liver, and heart. But alanine aminotransferase, first of all, is in the liver and is considered its main indicator, and aspartate aminotransferase is a part of many (in addition to the above) organs and tissues, including skeletal muscles, the brain, etc. That is why the key enzyme AsAT is less characteristic as an indicator of liver function, and it takes part in the metabolism of amino acids.
If liver, heart, and kidney cells are destroyed, alanine aminotransferase (AlAT) enters the bloodstream. The increase in this cellular enzyme in the blood indicates hidden diseases. When the studies show that the blood contains a high content of ALAT, the development of quite serious diseases, such as:
- cirrhosis,
- viral hepatitis,
myocarditis
- liver cancer,
- heart failure,
- a heart attack.
And an increase in aspartate aminotransferase in the blood can lead to
- a heart attack,
- liver cancer,
- muscular dystrophy ,
- pancreatitis,
- paroxysmal myoglobinuria,
- hepatitis A,
- dermatomyositis,
- heart failure.
If the total rate of AsAT and AlAT is increased, the following are possible:
- extensive hepatic necrosis,
- toxinogenic liver damage,
severe viral hepatitis,
- prolonged vascular collapse.
In almost all human diseases, blood tests show that both AsAT and AlAT are elevated, that is, the level of both enzymes in these cases is almost the same and indicates the presence of pathology. But there is still one difference. If AlAT is increased to a greater extent than aspartate aminotransferase, this indicates an incubation period for the development of infectious hepatitis. If there is more AsAT in the blood, it is most often a heart problem.
In a healthy person, the content of these cellular enzymes should be at the level of:
- in men, up to 41 units per liter (unit / l);
- in women up to 31 units per liter (unit / l).
To determine the level of these protein metabolism enzymes, a biochemical blood test is taken. The norm for AlAT in it will be 28-190 nmol / (s l) or 0.1-, 68 μmol / (ml h), and for AcAt - 28-25 nmol / (s l) or 0.1-, 45 μmol / (ml h). This norm for both cases is given for the Wrightman-Frenkel method (colorimetric research method).
Usually, blood tests for alanine aminotransferase are performed to find out about the state of the liver, and for aspartate aminotransferase, to see in what condition the myocardium (cardiac muscle) is. If the analysis shows their increased content in the blood, it means that in these organs processes of destruction and cell death occur. So, if AsAT exceeded its level in the blood by 2-20 times, then it is quite possible to develop myocardial infarction. If ALAT is elevated, there is a pathological process in the liver.
With a reduced blood level of alanine aminotransferase and aspartate aminotransferase, experts know that the body lacks pyridoxine (vitamin B6). This usually happens during pregnancy, with frequent hemodialysis and renal failure.
Unfortunately, where these enzymes come from in the blood serum of a healthy person is still unknown, therefore the mechanism of their clearance is not clear (an indicator of the speed of cleaning plasma, other biofluids and tissues from any substances due to their redistribution, biotransformation, excretion from the body).