Glutamate Pyruvate Transaminase Assay Kit (GPT/ALT)
Alanine Aminotransferase (ALT), also referred to as glutamate pyruvate transaminase (GPT), is an enzyme involved in amino acid metabolism. It is found in many tissues, and the highest levels are found in liver and kidney tissues. Tissues destruction leads to the release of the intracellular enzyme into the circulating blood. Markedly elevated serum ALT levels may be found in a variety of diseases which involve the liver, such as hepatitis, mononucleosis, and cirrhosis. These very high levels of ALT are not usually observed in other disease processes, e.g., myocardial infarction; thus, ALT is regarded as a reasonably specific indicator of liver disease.
ALT present in the sample catalyzes the transfer of the amino group from L-alanine to α-ketoglutarate, forming pyruvate and L-glutamate. Pyruvate in the presence of NADH and lactate dehydrogenase is reduced to Llactate. In this reaction NADH is oxidized to NAD. The reaction is monitored by measuring the rate of decrease in absorbance at 340 nm due to the oxidation of NADH to NAD.
ALT
L-alanine +α-ketoglutarate → pyruvate +L-glutamate
LDH
pyruvate + NADH + H+ → L-lactate + NAD+ + H2O
- Wroblewski F, La Due J.S: Ann Intern Med. 1956; 45:801.
- Wroblewski F, La Due J.S: Proc Soc Exp Biol Med 1956; 91:569.
- Bergmeyer HU, Bowers GN Jr, et al: Clin Chem 1977; 23: 887.