The mechanism of release of hepatic enzymes in various liver diseases. II. Altered activity ratios of GOT to GPT in serum and liver of patients with liver diseases.

The activities of glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) and glutamate dehydrogenase (GLD) were determined in liver biopsy specimens and sera of patients with various liver diseases. Mitochondrial and cytosol isozymes of GOT were also separated for their assay. The activity ratio of GOT/GPT in serum was found to reflect the ratio in liver cytosol. The increased ratio in advanced or severe liver diseases, such as liver cirrhosis, was due to the greater decrease in liver cytosol GPT activity, this being pronounced in primary hepatoma. The activity of GLD decreased similarly but less markedly. The relatively greater decrease in GPT compared with GOT in advanced liver diseases was not mainly due to leakage of the enzyme from the liver, but to a specific mechanism associated with hepatic injury or its progression. Other pathological conditions of the liver such as those in obstructive jaundice and alcoholic liver injury also appeared to result in reduced liver GPT activity, which was reflected in the serum as an increased GOT/GPT ratio.