Immunocytochemical and Biochemical Studies of Glutathione-Peroxidase(GSH-PO) in Rat Gastric Parietal Cells.

Abstract

Histamine as an acid secretagogue and H 2 -blocker (roxatidine acetate hydrochloride) and a proton pump inhibitor (Omeprazole) as acid secretion inhibitors, in single and repeated doses, were administered to investigate associated lipid peroxidation in rat gastric parietal cells. Methods used included immunohistocytochemical localization and biochemical enzyme activity of glutathione-peroxidase, an enzyme that effectively reduces lipid peroxides. No changes in lipid peroxidation, in response to the H 2 -blocker, were observed, however its accumulation in the vicinity of vacuole-like structures was specific to proton pump inhibition. This finding suggests that lipid peroxidation occurs in local parietal cells.

Helicobacter pylori infection can modulate the susceptibility of gastric mucosa cells to MNNG

“…The response of these cells to exogenous substances can be modulated by a non-dietary, potentially genotoxic factor, namely H. pylori infection, which is a source of neutrophil-generated free radicals, which increase lipid peroxidation in gastric mucosa, resulting in DNA damage [12]. The aim of our investigation was to assess the influence of four antioxidants, melatonin, quercetin and vitamins C and E, on DNA damage and repair induced by surrogate of nitrosamines (MNNG) in association with H. pylori infection in GMCs.…”

Involvement of Lipid Peroxidation in the Alteration of Protein Kinase C Signaling

“…Most H 2 O 2 and LOOH are reduced by glutathione peroxidase (GPX). In mammalian cells, classical GPX (cGPX), plasma GPX (pGPX), intestinal GPX (iGPX) and phospholipid hydroperoxide glutathione peroxidase (PHGPX) have been isolated and functionally characterized [5,20,26,27,33,37,46]. Our study showed that PHGPX could reduce DAG-OOH to DAG-OH, an inactive form of neutrophil stimulation, in the presence of reduced form of glutathione, whereas cGPX and pGPX could not [19].…”