Epidermal growth factor, epidermal growth factor receptors, intestinal growth, and adaptation

Epidermal growth factor (EGF) is an important constituent of several gastro intestinal secretions. Many studies in both animals and humans have shown E GF to have multiple effects upon gut epithelial cells. These include cytopr otection, stimulatory effects on cell proliferation and migration, inductio n of gene expression such as mucosal enzymes and trefoil proteins, and inhi bitory effects on gastric acid secretion. The main conundrum associated wit h EGF action is the disparity between experimental studies on its luminal a nd systemic actions. Opinion is sharply divided as to whether or not EGF ha s any action when given luminally and on the site of the EGF receptors on g ut epithelial cells. Most studies agree that the EGF receptors are located on the basolateral surface, ih which case EGF should only be active if surf ace ulceration has occurred-unless there is translocation across the epithe lium. There are several clinical situations in which EGF might be useful in cytoprotection and in stimulating repair and regeneration in the gut. Thes e include necrotizing enterocolitis and mucositis, and it is to be hoped th at the solid basis of experimental studies on EGF might stimulate work on t his topic.