Maturative effects of hormones on the developing mammalian gastrointestinal tract

Abstract

In the past two decades there has been considerable interest in the development of gastrointestinal functions, both in man and experimental animals (1‐3). A large body of data on the human fetus and infant is described in detail elsewhere (3, 4).

Permeability and modulation of the intestinal epithelial barrier in vitro

“…As cells move away from the lower part of the crypts towards the villi, they stop proliferating and start to differentiate into several cell types of which the enterocyte is the most abundant. This differentiation process is regulated by matrix factors, cell-cell interactions, growth factors and hormones (Koldovsky, 1994;Quaroni and Hochman, 1996) and it is characterized by an irreversible loss of the proliferative potential, by an increase in the expression and polarization of many enzymes and transporter systems, and by the development of the epithelial barrier function (Henning et al, 1994). The epithelial barrier is composed of a transcellular and a paracellular component.…”

“…Thus the mechanism by which the paracellular barrier function was increased in these mammary epithelial 31EG4 cells has not been resolved, but it was suggested that glucocorticoids provide a signal for rearrangement of regulatory or structural junctional components (Zettl et al, 1992). Moreover, dexamethasone is reported to have maturing effects on brush-border enzyme expression in the developing mammalian gastrointestinal tract in vivo (Beaulieu and Calvert, 1985;Koldovsky, 1994), and on differentiating human fetal intestinal crypt cells in vitro (Quaroni and Beaulieu, 1997).…”

Permeability and modulation of the intestinal epithelial barrier in vitro

“…As cells move away from the lower part of the crypts towards the villi, they stop proliferating and start to differentiate into several cell types of which the enterocyte is the most abundant. This differentiation process is regulated by matrix factors, cell-cell interactions, growth factors and hormones (Koldovsky, 1994;Quaroni and Hochman, 1996) and it is characterized by an irreversible loss of the proliferative potential, by an increase in the expression and polarization of many enzymes and transporter systems, and by the development of the epithelial barrier function (Henning et al, 1994). The epithelial barrier is composed of a transcellular and a paracellular component.…”

“…Thus the mechanism by which the paracellular barrier function was increased in these mammary epithelial 31EG4 cells has not been resolved, but it was suggested that glucocorticoids provide a signal for rearrangement of regulatory or structural junctional components (Zettl et al, 1992). Moreover, dexamethasone is reported to have maturing effects on brush-border enzyme expression in the developing mammalian gastrointestinal tract in vivo (Beaulieu and Calvert, 1985;Koldovsky, 1994), and on differentiating human fetal intestinal crypt cells in vitro (Quaroni and Beaulieu, 1997).…”

Permeability and modulation of the intestinal epithelial barrier in vitro

“…As cells move away from the lower part of the crypts towards the villi, they stop proliferating and start to differentiate into several cell types of which the enterocyte is the most abundant. This differentiation process is regulated by matrix factors, cell-cell interactions, growth factors and hormones (Koldovsky, 1994;Quaroni and Hochman, 1996) and it is characterized by an irreversible loss of the proliferative potential, by an increase in the expression and polarization of many enzymes and transporter systems, and by the development of the epithelial barrier function (Henning et al, 1994). The epithelial barrier is composed of a transcellular and a paracellular component.…”

“…Thus the mechanism by which the paracellular barrier function was increased in these mammary epithelial 31EG4 cells has not been resolved, but it was suggested that glucocorticoids provide a signal for rearrangement of regulatory or structural junctional components (Zettl et al, 1992). Moreover, dexamethasone is reported to have maturing effects on brush-border enzyme expression in the developing mammalian gastrointestinal tract in vivo (Beaulieu and Calvert, 1985;Koldovsky, 1994), and on differentiating human fetal intestinal crypt cells in vitro (Quaroni and Beaulieu, 1997).…”

Permeability and modulation of the intestinal epithelial barrier in vitro

“…As cells move away from the lower part of the crypts towards the villi, they stop proliferating and start to differentiate into several cell types of which the enterocyte is the most abundant. This differentiation process is regulated by matrix factors, cell-cell interactions, growth factors and hormones (Koldovsky, 1994;Quaroni and Hochman, 1996) and it is characterized by an irreversible loss of the proliferative potential, by an increase in the expression and polarization of many enzymes and transporter systems, and by the development of the epithelial barrier function (Henning et al, 1994). The epithelial barrier is composed of a transcellular and a paracellular component.…”

“…Thus the mechanism by which the paracellular barrier function was increased in these mammary epithelial 31EG4 cells has not been resolved, but it was suggested that glucocorticoids provide a signal for rearrangement of regulatory or structural junctional components (Zettl et al, 1992). Moreover, dexamethasone is reported to have maturing effects on brush-border enzyme expression in the developing mammalian gastrointestinal tract in vivo (Beaulieu and Calvert, 1985;Koldovsky, 1994), and on differentiating human fetal intestinal crypt cells in vitro (Quaroni and Beaulieu, 1997).…”