SIGNIFICANCE OF TRANSAMINASE ACTIVITY OF SERUM
THE MEASUREMENT of enzyme activity of serum as an indicator of disease has a long history in medicine. In the past, it has been the aim of the designers of these methods to make them as specific as possible for assay of an enzyme characteristic of a particular system or group of similar organs. Examples of these venerable tests are those for amylase, acid phosphatase, alkaline phosphatase and choline esterase in the serum. Warburg made the first departure from this specificity by demonstrating that the activity of triosephosphate dehydrogenase in the serum of animals with cancer was much greater than that of controls. This test was partially specific, for as Warburg had earlier shown, the glycolytic activity of tumors is much greater than that of normal tissues. The non-specific approach became extreme with the introduction of the measurement of the glutamic-oxalacetic transaminase reaction in the diagnosis of acute coronary disease.