EPIDERMAL GROWTH-FACTOR PROMOTES RAPID RESPONSE TO EPITHELIAL INJURY IN RABBIT DUODENUM IN-VITRO

Background & Aims: Growth factors are mainly involved in the regulatio n of intestinal epithelial barrier function. This study investigated t he effect of epidermal growth factor (EGF) and insulin-like growth fac tor 1 (IGF-1) on epithelial restitution of rabbit duodenum in vitro. M ethods: Rabbit duodenal mucosal strips mounted in an Ussing chamber we re luminally exposed to PO mmol/L HCI for 10 minutes and then incubate d with buffer alone or luminal buffer containing various concentration s of EGF and IGF-1 for 3 hours. Resistance was calculated from potenti al difference and short-circuit current. Damage was assessed by morpho metry on H&E-stained sections. Results: HCI caused resistance to decre ase from 112 +/- 2 to 51 +/- 4 Omega x cm(2) 10 minutes after injury ( n = 6; P < 0.05). Postinjury treatment with 25 or 50 ng/mL luminal EGF for 3 hours stimulated resistance to recover to 94 +/- 3 and 104 +/- 3 Omega x cm(2), respectively, vs. 81 +/- 3 Omega x cm(2) in controls (P < 0.05). Ten minutes after injury, 62% of the mucosa was damaged; 3 hours after injury, damage was reduced to 24% +/- 1.09% and 10% +/- 1 .42% in the 25 and 50 ng/mL EGF group, respectively, vs. 38% +/- 0.93% in controls (n = 6 per group). EGF stimulated enterocyte migration. I GF-1 did not impair epithelial restitution. Conclusions: EGF, but not IGF-1, promoted epithelial restitution of rabbit duodenum in vitro.