Clinical value of the determination of serum guanase activity. Studies on patients and experimental data from mongrel dogs and cultured rat hepatocytes.

Serum guanase activity was measured by a new method and compared with serum glutamic oxalacetic transaminase and glutamic pyruvic transaminase levels in 150 patients with various disorders, 21 dogs with experimental myocardial infarction, and 2 CCl4-treated dogs. Additionally, studies of the effect of CCl4 on enzyme release were undertaken using cultured rat hepatocytes. Glutamic oxalacetic transaminase, glutamic pyruvic transaminase, and guanase activities were found to be significantly elevated in patients with various liver disorders, those with acute myocardial infarction with prominent congestion of the liver, and also in CCl4-treated dogs. However, serum guanase activity was normal in patients with a variety of non-liver-related diseases including acute myocardial infarction, and in dogs with experimental myocardial infarction without liver damage, even when the serum glutamic oxalacetic transaminase and glutamic pyruvic transaminase activities were increased. The glutamic oxalacetic transaminase, glutamic pyruvic transaminase, and guanase activities in the culture medium of rat hepatocytes indicated in the presence of 0.5 mM CCl4 were elevated. These findings indicate that serum guanase activity is a more specific indicator of liver damage than serum glutamic oxalacetic transaminase and glutamic pyruvic transaminase.