Gene expression in human small intestinal mucosa in vivo is mediated by iron-induced oxidative stress

Background Iron-induced oxidative stress in the small intestine may alter gene expression in the intestinal mucosa. The present study aimed to determine which genes are mediated by an iron-induced oxidative challenge in the human small intestine. Methods Eight healthy volunteers (22+/-2 y) were tested on two separate occasions, in a randomized cross-over design. After duodenal tissue sampling by gastroduodenoscopy, a perfusion catheter was inserted orogastrically to perfuse a 40-cm segment of the proximal small intestine with saline and, subsequently, with either 80 or 400 mg iron as ferrous gluconate. After the intestinal perfusion, a second duodenal tissue sample was obtained. Results Thiobarbituric acid reactive substances (TBARS), an indicator of lipid peroxidation, in intestinal fluid samples increased significantly and dose-dependently at 30 min after the start of perfusion with 80 or 400 mg iron, respectively (P<0.001). During the perfusion with 400 mg iron, the increase in TBARS was accompanied by a significant, momentary rise in trolox equivalent antioxidant capacity (TEAC), an indicator of total antioxidant capacity (P