The developing gastrointestinal tract and milk-borne epidermal growth factor.

In adult mammals, epidermal growth factor (EGF) is produced mainly in the submandibular and Brunner’s glands1–3. The production of EGF in suckling mammals is considered to be very low. Popliker et a1.4 reported absence of EGF mRNA in suckling mice; others described only very small amounts of EGF to be present in submandibular glands of suckling rodents1,5–7. EGF is known to play an important regulatory role in the mammals; many studies suggest that EGF is a trophic factor for various regions of the developing gastrointestinal tract8–17 and liver18,19.