Development of Intestinal Transport Function in Mammals

Abstract

Considerable progress has been made over the last decade in the understanding of mechanisms responsible for the ontogenetic changes of mammalian intestine. This review presents the current knowledge about the development of intestinal transport function in the context of intestinal mucosa ontogeny. The review predominantly focuses on signals that trigger and/or modulate the developmental changes of intestinal transport. After an overview of the proliferation and differentiation of intestinal mucosa, data about the bidirectional traffic (absorption and secretion) across the developing intestinal epithelium are presented. The largest part of the review is devoted to the description of developmental patterns concerning the absorption of nutrients, ions, water, vitamins, trace elements, and milk-borne biologically active substances. Furthermore, the review examines the development of intestinal secretion that has a variety of functions including maintenance of the fluidity of the intestinal content, lubrication of mucosal surface, and mucosal protection. The age-dependent shifts of absorption and secretion are the subject of integrated regulatory mechanisms, and hence, the input of hormonal, nervous, immune, and dietary signals is reviewed. Finally, the utilization of energy for transport processes in the developing intestine is highlighted, and the interactions between various sources of energy are discussed. The review ends with suggestions concerning possible directions of future research.

Effects of dietary caprylic and capric acids on piglet performance and mucosal epithelium structure of the ileum

“…They serve also as a barrier against antigens and bacteria and keep a proper viscosity of the luminal contents (Pacha, 2000). The epithelial cells near the villus tip have the greatest digestive and absorptive capacity and hence villus height gives an indication of the functional capacity of enterocytes (Hampson, 1986).…”

Desempenho de bezerros alimentados com dietas líquidas à base de leite integral ou soro de leite

“…Finalmente, substâncias tróficas como o fator de crescimento epidermal (EGF) e o fator de crescimento semelhante à insulina (IGF) também podem estar presentes em menores concentrações em formulações que não contêm leite integral, afetando negativamente o desenvolvimento do trato gastrintestinal (Xu, 1996;Pácha, 2000;Roffler et al, 2003).…”

Ontogenetic expression and regulation of Na+-d-glucose cotransporter in jejunum of domestic chicken

“…Although there is a lack of agreement on the pattern of development of these parameters in mammals (20), in chickens all reports (16,30) find these parameters to be increased during development.…”

“…Na ϩ -Dglucose cotransport is detected in the chicken embryo at the end of incubation, increases until just after hatch, and then declines (18,25). The peak of sugar absorption around hatching coincides with a complete differentiation of the epithelium (20).…”