Platelets XXI. Glutamic Pyruvic Transaminase Activity of Human Platelets.

Abstract

This work is a continuation of a previous one indicating the presence of glutamic oxalacetic transaminase in human platelets. Using essentially the same techniques, activity of the related enzyme glutamic pyruvic acid transaminase has been studied in platelet-rich and platelet-poor plasma and in variously prepared platelet suspensions. The following conclusions have been reached: (1) platelets are a source of glutamic oxaloacetic transaminase in human blood; (2) platelets contain, however, only traces of glutamic pyruvic transaminase in normal and pathologic conditions. This finding is not explained by the presence of enzyme inhibitors or by lack of a co-enzyme; (3) the significance of the dissociation between glutamic oxaloacetic and glutamic pyruvic transaminases cannot be explained at the present time, with reference to platelets.