title: Specific insulin-like growth factor-I receptors on circulating bovine mononuclear cells.
abstract: We have examined the presence and properties of specific receptors for IGF-I on bovine mononuclear cells. Competitive binding studies showed that binding of [125I]IGF-I to mononuclear cells was inhibited by unlabelled peptides with the rank of IGF-I greater than IGF-II greater than insulin. The binding of [125I]IGF-I was a function of the cell concentration. Equilibrium dissociation constant and receptor concentration values for the average of 9 adult cows were 1.13 +/- 0.11 nM and 108.9 +/- 24.1 fMol/10(7) cells, respectively. Moreover, IGF-I stimulated thymidine incorporation into bovine mononuclear cells in the absence of serum and phytohemagglutinin (PHA). The existence of specific and functional IGF-I receptors on circulating bovine mononuclear cells would provide an easily accessible source for studying IGF-I receptor changes in the bovine, both in physiologic and pathologic states.
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
authors.forename: X
authors.initials: X
authors.lastname: Zhao
authors.forename: B W
authors.initials: BW
authors.lastname: McBride
authors.forename: L M
authors.initials: LM
authors.lastname: Trouten-Radford
authors.forename: J H
authors.initials: JH
authors.lastname: Burton
mesh_terms: D000818:Animals; D002417:Cattle; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000737:chemistry*; D011956:Receptors, Cell Surface / Q000032:analysis*; D017451:Receptors, Somatomedin
chemical_list: D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D007334:Insulin-Like Growth Factor I