In vitro studies of iron absorption and activity of glutathione peroxidase in intestinal mucosa of the chicken

We examined the absorption of iron, the activity of selenoprotein glutathione peroxidase (GSH·Px) and cellular compartmentalization of metal in the chicken duodenum and ileum. The method of accumulating mucosa preparation (AMP) was used. It was shown that the intestinal iron accumulation is dose-dependent process, which has two components: transcellular and paracellular. The realization of these pathways is region-specific and depends on exposed iron levels. Slightly elevated iron status of intestinal mucosa does not influence activity of GSH·Px. At the same time the results indicate that the activity of glutathione peroxidase can be altered by iron overload. Immunohistochemistry revealed that stainable iron could be co-localized to the endolysosomal compartment. How the activity of enzyme can be affected by oxidative stress and competitive interactions of iron with selenium are discussed.