Epidermal growth factor promotes rapid response to epithelial injury in rabbit duodenum in vitro.

Abstract

Growth factors are mainly involved in the regulation of intestinal epithelial barrier function. This study investigated the effect of epidermal growth factor (EGF) and insulin-like growth factor 1 (IGF-1) on epithelial restitution of rabbit duodenum in vitro. Rabbit duodenal mucosal strips mounted in an Ussing chamber were luminally exposed to 10 mmol/L HCl for 10 minutes and then incubated with buffer alone or luminal buffer containing various concentrations of EGF and IGF-1 for 3 hours. Resistance was calculated from potential difference and short-circuit current. Damage was assessed by morphometry on H&E-stained sections. HCl caused resistance to decrease from 112 +/- 2 to 51 +/- 4 ohms x cm2 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 ohms x cm2, respectively, vs. 81 +/- 3 omega x cm2 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. IGF-1 did not impair epithelial restitution. EGF, but not IGF-1, promoted epithelial restitution of rabbit duodenum in vitro.