Insulin-like growth factor II/mannose-6-phosphate receptors are transiently increased in the rat distal intestinal epithelium after resection.
The levels of insulin-like growth factor II/mannose-6-phosphate (IGF-II/Man-6-P) receptor and the insulin-like growth factor I (IGF-I) receptor were measured in the intestinal epithelium after 50% resection of the small intestine. Controls were either pair-fed to match the reduced food intake of the resected group or fed ad libitum. [125I]IGF-II binding was transiently increased 2-fold in the distal segment of the small intestine 3 days after resection compared with the pair-fed control. Receptor levels increased from 2.60 nmol/mg protein (pair-fed) to 4.63 nmol/mg protein (resected; p less than 0.001) with no significant change in affinity of IGF-II binding (Kd = 11.2 vs. 9.8 nmol/l). The increase in IGF-II/Man-6-P receptors coincided with increased activity of thymidine kinase in the distal intestinal segment after the resection. [125I]IGF-I binding remained unchanged after the resection. However, the decreased food intake of the pair-fed and resected groups caused a 2-fold increase in the amount of IGF-I receptors (0.18 nmol/mg protein; p less than 0.001) compared with the control fed ad libitum (0.08 nmol/mg protein). IGF-II/Man-6-P receptors were only moderately increased during restricted food intake (2.60 vs. 1.78 nmol/mg protein; p less than 0.005). These results suggest that the IGF-II/Man-6-P receptor may play a role in the adaptive regenerative response of the intestinal epithelium.
Grey
V
V
Centre de Recherche, Hôpital Sainte-Justine, Montreal, Quebec, Canada.
Rouyer-Fessard
C
C
Gammeltoft
S
S
Bourque
M
M
Morin
C
C
Laburthe
M
M
D000818:Animals; D004247:DNA / Q000032:analysis; D004848:Epithelium / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism* / Q000601:surgery; D008297:Male; D008360:Mannosephosphates / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D017527:Receptor, IGF Type 2; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017451:Receptors, Somatomedin; D013937:Thymidine Kinase / Q000378:metabolism
D008360:Mannosephosphates; D017527:Receptor, IGF Type 2; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D007335:Insulin-Like Growth Factor II; D004247:DNA; D013937:Thymidine Kinase