Altered gamma-glutamylcysteinylglycine homeostasis has been implicated in a wide variety of human diseases. The measurement of the rates of synthesis or loss of gamma-glutamylcysteinylglycine is necessary in order to make meaningful inferences about changes in gamma-glutamylcysteinylglycine concentration in these diseased states. In this review, we discuss methods for measuring gamma-glutamylcysteinylglycine concentration in biological samples as well as how improvements in the sensitivity of gas chromatography-mass spectrometric analyses have permitted the development of new and convenient stable isotope tracer methods for the in-vivo measurement of gamma-glutamylcysteinylglycine kinetics.
USDA/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.