Role of epidermal growth factor and transforming growth factor alpha  in the developing stomach

Abstract

Aims-To determine whether epidermal growth factor (EGF) or the related transforming growth factor (TGF ) may have a role in the developing human stomach; to substantiate the presence of EGF in human liquor in the non-stressed infant and whether EGF in amniotic fluid is maternally or fetally derived. Methods-The temporal expression and localisation of EGF, TGF , and their receptors during fetal and neonatal life were examined in 20 fetal and five infant stomachs. Simultaneously, samples of amniotic fluid and fetal urine from 10 newborn infants were collected and assayed for EGF by radioimmunoassay. Results-EGF immunoreactivity was not noted in any of the specimens examined. In contrast, TGF immunoreactivity was shown in mucous cells from 18 weeks of gestation onwards. EGF receptor immunoreactivity was seen on superficial mucous cells in gastric mucosa from 18 weeks of gestation onwards. The median concentration of EGF was 30 and 8.5 pg/ml in amniotic fluid and fetal urine, respectively, suggesting that EGF is not produced by the fetus. Conclusions-This study adds weight to the hypothesis that swallowed EGF, probably produced by the amniotic membranes, and locally produced TGF , may have a role in the growth and maturation of the human stomach. (Arch Dis Child 1997;76:F158-F162)

Terminal differentiation of palatal medial edge epithelial cells in vitro is not necessarily dependent on palatal shelf contact and midline epithelial seam formation

“…EGF and TIMPs (tissue inhibitors of matrix metalloproteinases) may be intrauterine epigenetic modifiers for MEE cell differentiation, because they are contained in amniotic fluid (Sundell et al, 1980;Murphy et al, 1981;Bunning et al, 1984;Kelly, et al, 1997) and can inhibit MEE cell disappearance in the fusing palate in vitro (Dixon and Ferguson, 1992;Blavier et al, 2001;Yamamoto et al, 2003). However, since amniotic fluid could prevent MEE cell differentiation only when the MEE was exposed directly to the fluid, palatal shelf contact and midline seam formation are prerequisite for MEE cell differentiation as well as palatal fusion to occur in utero (Fig.…”

Mitogenic activity of high molecular weight forms of insulin-like growth factor-II in amniotic fluid

“…By infusing insulin-like growth factor (IGF)-I to the foetus Kimble et al (1999) were able to restore the disorders induced by ligation of the foetal oesophagus and therefore established the importance of the swallowing of AF growth factors, particularly of the IGFs, in normal foetal development. In the human, epidermal growth factor, transforming growth factor-and hepatocyte growth factor are present in the AF and are thought to act in the development of the stomach and the respiratory tract (Kelly et al 1997, Itakura et al 1997. Growth factors or hormones present in the AF can be taken up by the foetus not only by AF deglutition, but can also penetrate the lung by inhalation (Haddad et al 1995), can diffuse through the foetal skin and can be absorbed by the vascularized foetal surface of the placenta (Lind et al 1972).…”

Enteral Absorption of Erythropoietin in the Suckling Rat

“…However, EpoR have been identified in gastrointestinal cells, and in vitro studies support physiologic roles of rhEpo in these cells (3,4). Before birth, the fetus swallows amniotic fluid rich in trophic and protective growth factors needed for gastrointestinal development (8,33,34). Epo, one of these growth factors, is present at high levels in amniotic fluid and at higher levels during fetal hypoxia (35,36).…”