title: Glutathione level and glutathione-dependent enzyme activities in blood serum of patients with gastrointestinal tract tumors.
abstract: OBJECTIVE
  Glutathione (GSH) and enzymes cooperating with it - glutathione peroxidase (GSHPx), glutathione S-transferase (GST) and glutathione reductase (GSHR) - play crucial role in cell defence against reactive oxygen species (ROS), which are implicated in tumor disease. The aim of this study was to determine if neoplastic diseases of gastrointestinal tract may influence blood GSH level and its dependent enzyme activity.
  
  
  METHODS
  Blood serum was obtained before and after surgery from patients with gastric, liver and colorectal cancers, and colorectal cancer liver metastases. Lipid peroxidation and GSH levels, and GSH-dependent enzyme activities were determined by means of spectrophotometric methods.
  
  
  RESULTS
  Increased level of lipid peroxidation and significant differences in GSH level and GSHPx, GST and GSHR activities were observed in serum taken before and after surgery from patients with gastrointestinal tract tumors compared to those in control serum (from healthy blood donors).
  
  
  CONCLUSIONS
  Increase of lipid peroxidation and changes in GSH level and related enzyme activities, suggest oxidative stress in serum of patients with gastrointestinal tract tumor causes, which probably arise as a result of enormous production of ROS in the system. These alterations reflect the presence of functional defence mechanism against oxidative stress related firmly to the glutathione metabolism.
authors.affiliation: Department of Biochemistry, Warsaw Medical University, 02-097 Warsaw, Banacha 1, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Scibior
authors.forename: Michał
authors.initials: M
authors.lastname: Skrzycki
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Podsiad
authors.forename: Hanna
authors.initials: H
authors.lastname: Czeczot
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D015179:Colorectal Neoplasms / Q000097:blood / Q000201:enzymology; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000097:blood* / Q000201:enzymology; D005978:Glutathione / Q000097:blood*; D005979:Glutathione Peroxidase / Q000097:blood; D005980:Glutathione Reductase / Q000097:blood; D005982:Glutathione Transferase / Q000097:blood; D006801:Humans; D015227:Lipid Peroxidation; D008113:Liver Neoplasms / Q000097:blood / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D017382:Reactive Oxygen Species / Q000097:blood
chemical_list: D014408:Biomarkers, Tumor; D017382:Reactive Oxygen Species; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005978:Glutathione