EFFECTS OF EPIDERMAL GROWTH-FACTOR ADMINISTRATION ON REPAIR OF ACETICACID-INDUCED COLONIC ULCERATIONS IN RATS

The effect of subcutaneous and luminal epidermal growth factor (EGF) a dministration on acetic acid-induced colonic ulceration was determined in adult rats, Application of acetic acid to the distal colonic lumen caused epithelial denudation, mucosal ulceration and inflammation in the exposed segment, Re-epithelialization was detectable 5 to 7 days l ater, with near-complete resolution of the lesion by 14 days post-inju ry. Luminal EGF (1.6 mg/kg bw/day) or subcutaneous EGF (200 mu gmg/kg bw/day), administered for 4 or 6 days from the time of ulceration fail ed to enhance re-epithelialization of the acid-exposed segment, Howeve r, mucosal and submucosal thickening was attenuated 20-40% by subcutan eous EGF, reflecting a reduction in edema, Luminal EGF had a similar b ut less substantial effect in the submucosa, but was more effective at attenuating muscularis thickening adjacent to the lesion, In conclusi on, administration of exogenous EGF for up to 6 days failed to enhance re epithelialization of acetic acid-induced colonic ulcerations but d id attenuate the associated edematous response.