Aldose reductase mediates endothelial cell dysfunction induced by high uric acid concentrations
Tumors were studied in 38 patients, tissues located far away from tumor being used as control. Breast and stomach tumors revealed relatively high levels of glutathione reductase, glutathione-S-transferase (I) and, particularly, gamma-glutamyl transferase (II). The said changes were not observed in colorectal tumors. Gamma-glutamyl transferase (II) may be used as a marker for breast and stomach malignancies in man but it is not a universal and absolutely specific marker for all tumors. The activity of glutathione peroxidase (III) either did not change or decreased. The activating effect of cAMP on III and I remained generally unchanged in all tumors studied.