Epidermal growth factor stimulates type-V collagen synthesis in cultured murine palatal shelves

The effects of epidermal growth factor (EGF) on the synthesis of collagen and fibronectin in murine palatal shelves in serum-free organ culture have been examined. Palatal shelves grown in the presence of EGF were substantially larger and showed dramatic increases in immunofluorescent localization of fibronectin, possibly reflecting in-creased synthesis compared to controls cultured without EGF. EGF also prevented the normal dissolution of the medial palatal epithelium. Net protein synthesis in experimental palatal shelves increased by 18%, whereas net collagen synthesis was approximately 10% of protein synthesis in both conditions. There was, however, an apparent shift in collagen isotypes. Under the influence of EGF, there was a significant increase in synthesis of the α1 (V) and α2 (V) chains of type-V collagen.