Stimulation of rat oxyntic gland mucosal growth by epidermal growth factor

Epidermal growth factor (EGF) inhibits gastric acid secretion, but its effects on the growth of gut mucosa have not been examined. Fasted male rats were given six injections of EGF (10 micrograms/kg) over a 48-h period. The animals were killed and the incorporation of [3H]thymidine into various tissues was examined and compared to rats treated with NaCl, pentagastrin, and EGF plus secretin. EGF and pentagastrin significantly increased DNA synthesis of the oxyntic gland mucosa. Pentagastrin, but not EGF, stimulated DNA synthesis of duodenal and colonic mucosa as well. Neither peptide altered skin DNA synthesis. Secretin inhibited the effects of pentagastrin but not EGF. Chronic administration of EGF (5 days) caused significant increases in oxyntic gland mucosal DNA, RNA, and protein content. These results not only demonstrate that EGF is a trophic agent for the oxyntic gland mucosa but lend further support to the hypothesis that acid secretion and mitogenesis are the result of two separate mechanisms.