Serum Enzymes. III. The Significance of Abnormalities of Glycolytic Enzymes in the Serum of Cancer Patients2

Abstract

The abnormal serum activity of aldolase, lactic dehydrosenase, phosphohexose isomerase, and glutamic-oxalacetic transaminase, often found in patients with cancer, may decrease to normal following the administration of large amounts of protein. In some patients with liver metastases, protein administration fails to lower the serum enzyme activity. Similar studies in patients with muscular dystrophy, all with high serum activity of these enzymes, do not demonstrate any effect of protein feeding on serum enzyme activity. In cancer patients the fall in serum enzyme activity after protein feeding is not a result of enzyme inhibition by albumin or Amigen. Protein feeding in some patients with cancer may be associated with an explosive increase in the apparent rate of tumor growth.