Epidermal growth factor (EGF) and transforming growth factor α (TGFα) bind to a common receptor and are both present in the normal gastrointestinal tract. Although many studies have examined their function in isolation, there is little information directly comparing their actions. We examined the relative potency of TGFα and EGF in stimulating 3 H-thymidine uptake into primary rat hepatocytes at various doses in vitro and on the crypt cell production rate (CCPR) within the gastrointestinal tract when infused intravenously at 49 nmol/kg/day into rats receiving total parenteral nutrition. In vitro, maximal stimulatory activity was similar in EGF- and TGFα-treated cells, however, the dose of EGF required to stimulate 3 H-thymidine uptake to 50% of maximal levels was only one third of that required using TGFα. In vivo, EGF and TGFα significantly increased the weight and proliferative indices throughout the gastrointestinal tract. The response (as determined by CCPR) was about 80% higher in animals which had received EGF when compared to animals receiving TGFα. Treatment with EGF also caused significant rises in plasma PYY, enteroglucagon and gastrin levels, whereas the equivalent dose of TGFα only caused a significant rise in plasma gastrin levels. We conclude that TGF-α, like EGF, is trophic to the entire gastrointestinal tract of the rat, however, it is a less effective mitogen, and has differential hormonal effects. © 1996 S. Karger AG, Basel.

Item Type:	Refereed Article
Research Division:	Biomedical and Clinical Sciences
Research Group:	Clinical sciences
Research Field:	Gastroenterology and hepatology
Objective Division:	Health
Objective Group:	Clinical health
Objective Field:	Clinical health not elsewhere classified
UTAS Author:	Playford, RJ (Professor Ray Playford)
ID Code:	72847
Year Published:	1996
Web of Science® Times Cited:	25
Deposited By:	Research Division
Deposited On:	2011-09-01
Last Modified:	2011-09-05
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