Effect of epidermal growth factor/urogastrone on glycosaminoglycan synthesis and accumulation in vitro in the developing mouse palate.

Epidermal growth factor/urogastrone (EGF-URO) has previously been implicated in murine secondary-palate formation. We report here that, in correlation with its effects on palate fusion, EGF-URO in physiological amounts (1.7 nmol/l) markedly affects glycosaminoglycan (GAG) production in organ cultures of mouse palate tissue; the effects of EGF-URO are dependent on the developmental stage of the palate. GAG production, particularly that of hyaluronic acid (HA), is stimulated two- to eight-fold by EGF-URO in cultures of palate tissue obtained between days 11-12 and 13-15 of development; by the time of birth, EGF-URO no longer stimulates GAG production in such cultures. EGF-URO increases the amount and alters the distribution of HA within the palate. The results suggest a role for EGF-URO and for HA in the process of normal palatal development.