Rapid spectrophotometric method for serum glutathione S-transferases activity

Background: Glutathione S-transferases (GST) are a family of polymorphic enzymes responsible for the metabolism of a broad range of xenobiotics including carcinogens and endogenous compounds. Methods: The aim of this study was to develop a fully automated spectrophotometric method to determine serum GST activity. Results: The method had a detection limit of 7 U/l. The within- and between-run repeatability reached 2% and 3%, respectively. The reproducibility tested over a 6-month period was 7%. Serum GST activity is stable for at least I week at + 37, + 4 and - 20 degreesC, I month at - 20 degreesC and 6 months at - 80 and - 196 degreesC. The GST activities were determined on 374 supposedly healthy subjects coming to the Center of Preventive Medicine for a health screening. The sample population comprised 178 males and 196 females 4-80 years of age. The mean value of the serum GST activity calculated for this healthy population was 28.2 +/- 3.0 U/l without gender difference (range from 20.0 to 38.0 U/l). The global interindividual variability reached 11%. Conclusions: This report describes a spectrophotometric assay for monitoring the serum GST activities in human. This method will be useful in examining the relationships between serum GST activities and the GST polymorphisms, especially pi-GST. (C) 2002 Elsevier Science B.V. All rights reserved.