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 1 week at +37, +4 and -20 degrees C, 1 month at -20 degrees C and 6 months at -80 and -196 degrees C. 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.