Comparison of the effects of concanavalin-A and epidermal growth factor on epithelial cell proliferation in the rat intestine.
BACKGROUND
Concanavalin-A, the lectin present in Jack beans, binds to mannose- and glucose-containing residues and can interact with the epidermal growth factor receptor and moderate cell proliferation in vitro.


OBJECTIVE
To compare the actions of concanavalin-A and epidermal growth factor on the gastrointestinal tract in vivo.


METHODS
Rats maintained on total parenteral nutrition were given intragastric concanavalin-A, intravenous epidermal growth factor or concanavalin-A and epidermal growth factor. Cell proliferation and crypt fission were assayed in 'micro-dissected' crypts.


RESULTS
Concanavalin-A and epidermal growth factor both significantly elevated proliferation in the small intestine and colon. No significant interaction between the effects of these two agents was seen, except in the mid small intestine where there was a synergistic interaction. Concanavalin-A had no effect on crypt branching. Epidermal growth factor significantly reduced branching in the distal small intestine and mid colon.


CONCLUSIONS
The effects of the two agents appeared to be separate, except in the mid small intestine where they were additive. This is in marked contrast with the actions reported in vitro, where concanavalin-A is a powerful inhibitor of epidermal growth factor-induced cell proliferation. Concanavalin-A thus has potential for enhancing the functions of the small intestine.
Fitzgerald
A J
AJ
Department of Histopathology, Division of Investigative Science, Imperial College School of Medicine, Hammersmith Hospital, London, UK.
Jordinson
M
M
Rhodes
J M
JM
Singh
R
R
Calam
J
J
Goodlad
R A
RA
D000818:Animals; D002455:Cell Division / Q000187:drug effects*; D003208:Concanavalin A / Q000494:pharmacology*; D004347:Drug Interactions; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D007262:Infusions, Intravenous; D007422:Intestines / Q000187:drug effects* / Q000254:growth & development*; D008297:Male; D010289:Parenteral Nutrition, Total; D051381:Rats; D017207:Rats, Sprague-Dawley
D003208:Concanavalin A; D004815:Epidermal Growth Factor