Human Atherosclerotic Plaques Contain Gamma-Glutamyl Transpeptidase Enzyme Activity
During the last decade, growing evidence has shown that serum gamma-glutamyl transpeptidase (GGT) is an independent prognostic marker for cardiac death and reinfarction, both in unselected populations and in patients with coronary artery disease. Clinical and epidemiological evidence indicates that the prognostic value of GGT is largely independent of other risk factors for cardiovascular disease and alcohol consumption. The catalytic activity of GGT, which is present on the surface of cell membranes and in serum, is responsible for the extracellular catabolism of the antioxidant glutathione. Cysteinyl glycine deriving from the hydrolysis of glutathione performed by GGT has been found to trigger iron-dependent production of reactive oxygen species as well as low-density lipoprotein oxidation in vitro. The localization of GGT within the coronary plaque (Figure) provides a pathological basis for the hypothesis of a direct participation of GGT in low-density lipoprotein oxidation within the plaque and in atherogenesis and coronary artery disease progression.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
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