Journal ArticleDOI
Glutathione and GSH-dependent enzymes in the tumorous and nontumorous mucosa of the human colon and rectum.
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TLDR
The presence and high activity of the GSH-dependent enzyme system in different segments of the human intestinal mucosa may reflect its role in the defense against toxic and putative carcinogenic xenobiotics entering the body via the gastrointestinal tract.Abstract:
A high content of total glutathione and high activities of both GSH S-aryltransferase (CDNB) and GSH peroxidase were found in different segments of the human intestinal mucosa comparable to findings in human gastric mucosa. Intraindividual comparisons of tumorous and nontumorous tissue specimens in patients with adenocarcinomas of the colon and rectum revealed no marked differences in their glutathione content and enzyme activities except in the sigma, where we found significantly lower GSH concentrations and higher GSH S-aryltransferase activities in the carcinomatous tissue. γ-Glutamyl-transpeptidase activity, a marker of neoplastic cell growth in experimental hepatocarcinogenesis, did not differ between tumorous and nontumorous tissue areas. The presence and high activity of the GSH-dependent enzyme system in different segments of the human intestinal mucosa may reflect its role in the defense against toxic and putative carcinogenic xenobiotics entering the body via the gastrointestinal tract.read more
Citations
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Journal ArticleDOI
Free radicals, antioxidant enzymes, and carcinogenesis
TL;DR: Free radicals are found to be involved in both initiation and promotion of multistage carcinogenesis, and antioxidants, the free radical scavengers, are shown to be anticarcinogens.
Journal ArticleDOI
Glutathione levels in human tumors.
TL;DR: Clinical studies in which glutathione was measured in tumor tissue from patients with brain, breast, gastrointestinal, gynecological, head and neck and lung cancer are summarized and approaches that may improve the clinical value of glutATHione as a biomarker are recommended.
Journal ArticleDOI
Special article the glutathione S‐transferases: An update
TL;DR: The focus of current research is to define the role of the numerous isozymes in cell function, to ascertain the relationship between structure and function of different isoz enzymes and to determine how the expression of GST is regulated in different tissues.
Journal ArticleDOI
Biotransformation enzymes in human intestine: critical low levels in the colon?
TL;DR: In the normal human colon enzymes are less active and there are fewer isoenzymes present in the mucosa than in the small intestine, which implies a lower level of the detoxifying potential in the Colon, which might be important in regard to the high rates of carcinogenesis in the colon.
Journal ArticleDOI
A case-control study on selenium, zinc, and copper in plasma and hair of subjects affected by breast and lung cancer
TL;DR: Investigation of the relationship between plasma and hair levels of Se, Zn, and Cu, and cancer found subjects who developed lung cancer were significantly lower in hair Zn and Cu than controls, whereas there was no difference with regard to Se.
References
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Journal Article
Protein Measurement with the Folin Phenol Reagent
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.
Journal ArticleDOI
Glutathione S-transferases. The first enzymatic step in mercapturic acid formation.
TL;DR: The purification of homogeneous glutathione S-transferases B and C from rat liver is described, and only transferases A and C are immunologically related.
Journal ArticleDOI
Estimation of total, protein-bound, and nonprotein sulfhydryl groups in tissue with Ellman's reagent
Jozef Sedlak,Raymond H. Lindsay +1 more
TL;DR: A simple spectrophotometric method for the routine concomitant determination of sulfhydryl groups in PB- SH, NP-SH, and T-SH fractions in various tissues is reported.
Book ChapterDOI
The role of glutathione and glutathione S-transferases in the metabolism of chemical carcinogens and other electrophilic agents.
TL;DR: The knowledge of the way in which mutagens and carcinogens are metabolized is essential to a better understanding of their mode of action and of the processes for their detoxication.