Oral administration of epidermal growth factor in suckling rats stimulates cell DNA synthesis in fundic and antral gastric mucosae as well as in intestinal mucosa and pancreas

Abstract

The effect of orogastrically given epidermal growth factor (EGF) on the development of the digestive system was examined in suckling rats. In particular, DNA synthesis in progenitor cells of the fundic, antral and ileal mucosae and of the exocrine pancreas was analyzed through tritiated thymidine injection and histoautoradiographic study. EGF (10 or 100 μg/kg, 3 times daily) was instilled in pups between the 11th and the 13th day of life. Controls received distilled water in a similar manner. All rats were killed 14h after the last orogastric instillation and 45 min after one pulse injection of tritiated thymidine. The highest dose of EGF increased the antral mucosal height ( P < 0.005), the mean number of epithelial cells per crypt column in ileal mucosa, as well as the cell labeling indices of fundic, antral, ileal mucosae and of pancreatic acinar tissue ( P < 0.001) as compared with controls. The lowest dose of EGF increased the cell labeling indices of antral and ileal mucosae and of the exocrine pancreas ( P < 0.001) but did not modify that of fundic mucosa as compared with controls. It is concluded that (a) orally given EGF stimulates cell proliferation in the digestive system of suckling rats, (b) antral mucosa is more sensitive to EGF than fundic mucosa, (c) it is likely that EGF is absorbed and acts systemically on the pancreas. It remains to be determined whether EGF acts systemically or by activation of luminal receptors, on fundic, antral and ileal mucosae.