Table 1

Comparison of various growth factors for the small intestine. The first column lists whether the growth factor has increased levels/activity in the mucosa during intestinal growth, the second lists the effect of pharmacological doses (or transgenically) of the growth factor in vivo, the third lists the effect of the growth factor in cell or explant culture, and the fourth column lists the effect of ablation, blockade, or state of intestinal development in the growth factor or the corresponding receptor knockout mouse

Growth factorGrowth factor activityPharmacological actionIn vitro effectBlockade
*Corticosteroids do not promote expression of sucrase and other brush border genes in humans but they do induce expression in laboratory animals. They do not cause proliferation in human explant culture and are antitrophic to both the suckling and adult rat intestine.
†GLP-2 receptors are mainly distributed in the distal small intestine and colon.
‡Some of the actions of thyroxine are mediated via corticosteroids.
§Knockout animals have generally only been examined for major abnormalities of intestinal and other organ development and not the small intestine morphometrically
EGF, epidermal growth factor; Epo, erythropoietin; bFGF, fibroblast basic growth factor; GH, growth hormone; GLP, glucagon-like polypeptide; HGF, hepatocyte growth factor; IGF-1, insulin-like growth factor 1; KGF, keratinocyte growth factor; PGE2, prostaglandin E2; TGF, transforming growth factor; KO, knockout mouse; ND, not determined; Yes, has been determined.
EGFPresent in milkYesYesYes, KO§
EpoPresent in milkYesYesLethal KO
HGFPresent in milkYesYesLethal KO
IGF-1Present in milkYesYesNo, KO§
KGFPresent in milkYesNDNo, KO§
PolyaminesPresent in milkYesNDYes
TGFαPresent in milkYesNDNo, KO§
Thyroxine‡YesYesVariableYes, KO§