Glutathione and GSH-dependent enzymes in the tumorous and nontumorous mucosa of the human colon and rectum

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. gamma-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.

Oxidative Stress and Its Relationship With Adenosine Deaminase Activity in Various Stages of Breast Cancer

“…In the present study, significantly low GSH levels were observed in female patients of carcinoma breast as compared to normal females. Other workers also reported similar findings [11,12]. Similar to SOD the GSH levels also seemed to improve in female patients after surgery in comparison to the pre operative levels.…”

“…Similar trend has been reported in case of reduced glutathione concentration. Increased [8][9][10] as well as decreased [11][12][13] levels of GSH have been reported in patients of breast cancer. This clearly emphasises the need to further evaluate the role of these parameters in breast cancer because increased oxidative stress gives rise to inflammation which could further aggravates the disease.…”

Glutathione localisation in benign and malignant human breast lesions

“…GSH has a role in the detoxification of drugs and carcinogens, protection of cells from free radical damage and reactive oxygen compounds, participates in protein and DNA synthesis and in the regulation of enzyme activity (Meister & Anderson, 1983;Orrenius & Moldeus, 1984;Chasseaud, 1979). Altered levels of GSH are frequently observed in experimental animal neoplasia (Roomi et al, 1985, Fiala et al., 1976 but GSH levels in human neoplasia have been reported only for carcinomas of the stomach and colon (Siegers et al, 1983;Siegers et al, 1984). GSH in human breast tissue has not been investigated previously, although GSH-associated enzymes have been studied both biochemically (Di Ilio et al, 1985) and histochemically (Levine et al, 1983;Bard et al, 1986).…”

Effects of Fasting and Glutathione Depletors on the GSH-Dependent Enzyme System in the Gastrointestinal Mucosa ofthe Rat

“…Glutathione and the GSH-dependent enzymes provide de fense against nucleophilic and radicalic toxic agents formed by the microflora or in the mucosal cells during absorption [11][12][13], High concentrations of GSH were found in the stomach of rodents [1] and humans [7]; the same proved to be true in human colonic and rectal tissue [14], where also GSH-Stransferase and GSH-peroxidase activities were measured in appreciable amounts. In a previous study we described a typical distri bution of GSH and GSH-dependent en- zymes along the gastrointestinal wall and a lack of enzyme induction upon the applica tion of phénobarbital and transstilbene ox ide [ 15], The aim of the present study was to look at the effects of fasting and chemicals known to deplete hepatic reduced gluta thione.…”