Effect of epidermal growth factor on gastric blood flow in rats: Possible role in mucosal protection

Abstract

Background: The mechanism by which epidermal growth factor (EGF) protects the gastric mucosa against injury is unclear. Whether EGF has any effect on gastric blood flow has not been reported. Methods: Using an ex vivo gastric chamber preparation, the effect of EGF on gastric blood flow in rats was studied by laser Doppler flowmetry. Measurements of blood flow and mucosal damage were made in both intact and sialoadenectomized rats with graded doses of EGF at basal condition and after topical application of absolute ethanol. Results: Sialoadenectomy alone increased ethanol-induced gastric mucosal lesions (P < 0.05) but had no significant effect on blood flow. EGF pretreatment resulted in both a reduction in ethanol-induced gastric mucosal injury as well as a significant increase in blood flow compared with controls (both P < 0.05). Graded doses of EGF (3.12-25 μg) resulted in an dose- dependent increase in gastric blood flow (r = 0.68; P < 0.001), which correlated inversely with the degree of mucosal damage (r = -0.72; P < 0.001). Conclusions: Mucosal protection by EGF is accompanied by an increase in gastric blood flow; this action may contribute to its mucosal protective effect.