Serum γ-glutamyltransferase as Oxidative Stress Marker in Pre-and Postmenopausal Iraqi Women

Abstract

The primary role of γ-glutamyltransferase is to metabolize reduced glutathione by assimilating and utilizing precursor amino acids for intracellular glutathione synthesis. The aim of this study is to investigate the exact role of γ- glutamyltransferase enzyme in the oxidative stress associated with menopause. This study was carried out at the Chemistry and Biochemistry department, Al-Nahrain University from October 2009 to January 2010. The study participants were categorized into two groups; premenopausal group (n=17) and postmenopausal group (n=16). Blood specimens were collected from each participant by vein puncture procedure. The γ-glutamyltransferase enzyme was measured by kinetic spectrophotometric method while glutathione and malondialdehyde were measured by spectrophotometric methods. Serum glutathione levels in pre- and postmenopausal women were 0.62±0.17 and 0.47±0.11 mmol/L respectively. Serum γ-glutamyltransferase levels increased significantly in the postmenopausal women group (p=0.025) compared to the premenopausal women group. Serum malondialdehyde levels were 1.04±0.06 and 1.32±0.05 μmol/L in pre- and postmenopausal groups respectively. Serum γ-glutamyltransferase may be considered as an index of oxidative stress associated with menopause.