Transforming growth factor-alpha in vivo stimulates epithelial cell proliferation in digestive tissues of suckling rats.
BACKGROUND
The role that exogenous transforming growth factor-alpha (TGF-alpha) may exert on cell proliferation in vivo is poorly understood.


OBJECTIVE
To investigate the effect of rat TGF-alpha on epithelial cell proliferation in all suckling rat digestive tissues and to compare it with that of rat epidermal growth factor (EGF). ANIMAL AND METHODS: TGF-alpha and EGF were given three times daily either subcutaneously (10 or 20 micrograms/kg) or intraperitoneally (100 micrograms/kg) to rats from the ninth postnatal day. Cell proliferation was assessed through 5-bromo- 2-deoxyuridine incorporation and estimation of labelling indices.


RESULTS
For both growth factors, the highest dose given for only two days significantly increased stomach and intestinal weights compared with controls (p < 0.05 to p < 0.001). The proliferative responded depended on the dose given, colonic mucosa being the most sensitive whereas oxyntic mucosa remained unresponsive. TGF-alpha was as potent as EGF in stimulating epithelial cell proliferation in antral, duodenal, and colonic mucosae. However, EGF was more active on oesophageal and jejunal cell proliferation whereas TGF-alpha was more active on pancreatic exocrine cell proliferation and the differences between the two growth factor treated groups were significant.


CONCLUSIONS
These results prove for the first time the stimulating effect in vivo of exogenous rat TGF-alpha on epithelial cell proliferation in rat digestive tissues during the developmental period and support a functional role for TGF-alpha at that time.
Hormi
K
K
Unité 10 INSERM of Gastroenterology, Hospital bichat-Claude Bernard, Paris, France.
Lehy
T
T
D000818:Animals; D000833:Animals, Suckling / Q000254:growth & development*; D002455:Cell Division / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004848:Epithelium / Q000254:growth & development; D007422:Intestines / Q000187:drug effects / Q000254:growth & development*; D051381:Rats; D017208:Rats, Wistar; D013268:Stimulation, Chemical; D013270:Stomach / Q000187:drug effects / Q000254:growth & development*; D016211:Transforming Growth Factor alpha / Q000494:pharmacology*
D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor