Observations on decreased serum glutamic oxalacetic transaminase (SGOT) activity in azotemic patients.

Serum glutamic oxalacetic transaminase (SGOT) activity may be decreased or even absent in patients with uremia. We correlated urea concentration with SGOT activity by the automated Rush (AutoAnalyzer, Techicon Instruments Corp., Tarrytown, New York) method (SGOT, SMA) and by the Henry-Karmen kinetic assay (SGOT, K). Extremely low SGOT (SMA) activity (less than 10 IU) was found in 6% of 5030 consecutive samples, and 71% of them occurred in patients with azotemia. SGOT activity was inversely proportional to urea concentration. A similar but less obvious pattern was observed with the SGOT (K) assay. SGOT activity increased significantly after hemodialysis in a group of 16 patients studied by both methods. It was not inhibited either by urea or uremic serum added in vitro. The explanation for this phenomenon is not known.