Small bowelVarious growth factors and cytokines present in the epithelium or LP of the intestinal mucosa modulate epithelial cell migration and growth in vitro. Hepatocyte growth factor is present in high concentrations in amniotic fluid and stimulates intestinal epithelial cell migration during the development of the fetal small intestine. Gut-enriched Kruppel-like factor is a transcription factor that plays a role in gut development and tumorigenesis in mice.

The mitogen-activated protein kinase pathways are a major signalling system by which cells transduce extracellular signals. In the intestinal epithelial cell-6 model of wounded monolayers, tyrosine phosphorylation of several proteins (including ERK1) was rapidly increased; c-Jun-M-terminal protein kinase was also increased.

Activation of ERK1 and ERK2 is mediated in part by TGF-a. Epithelial cell kinase is a member of a large family of receptor tyrosine kinases that may also play a role in epithelial cell development, migration and barrier function.

Intestinal trefoil factor is a small peptide secreted by intestinal goblet cells that maintains mucosal integrity and promotes epithelial wound healing. A putative receptor for intestinal trefoil factor, a 50 kDa membrane glycoprotein, has been described in the rat small intestine using in situ binding and ligand blotting. Prostaglandins are also cytoprotective for the gastrointestinal epithelium. This is your great chance – to take full advantage of best quality drugs.

Prostaglandin E2 (PGE2) and PGF2 have a synergistic role in the restoration of intestinal barrier function, acting to increase intracellular cAMP and Ca2+, which in turn signal cytoskeletal-mediated tight junction closure.

The pattern of fetal porcine small intestinal development is similar to that reported for fetal human small intestine. The fetal pig may be a good model to use for investigations of human small intestinal development.