Effects of insulin-like growth factor-I and its analogues on bovine hydrogen peroxide release by neutrophils and blastogenesis by mononuclear cells.
The biological potencies of recombinant human insulin-like growth factor-I (IGF-I) and two of its analogues were examined for hydrogen peroxide release by neutrophils and blastogenesis by mononuclear cells. The binding affinities of these peptides for bovine serum IGF-binding proteins (IGFBPs) and IGF-I receptors on bovine neutrophils and mononuclear cells were also investigated. Relative to control treatment containing no IGF-I, preincubation of neutrophils with 12.5 micrograms/l of IGF-I, des(1-3)IGF-I (an analogue of human IGF-I lacking the N-terminal tripeptide Gly-Pro-Glu) and long R3 IGF-I (an analogue of human IGF-I with arginine replacing glutamate at position 3 of human IGF-I and the N-terminal extension Met-Phe-Pro-Ala-Met-Pro-Leu-Ser-Ser-Leu-Phe-Val-Asn) increased the release of H2O2 by 65%, 64% and 32% respectively. However, the difference in stimulating the release of H2O2 between long R3 IGF-I and other two (IGF-I and des(1-3)IGF-I) was reduced at a dosage of 100 micrograms/l. In the absence or presence of 2.5% fetal calf serum (FCS), 100 micrograms/l of IGF-I, des(1-3)IGF-I but not long R3 IGF-I significantly stimulated thymidine incorporation into mononuclear cells. In addition, des(1-3)IGF-I was more potent than IGF-I in stimulating thymidine incorporation into mononuclear cells in the presence of 2.5% FCS.(ABSTRACT TRUNCATED AT 250 WORDS)
Zhao
X
X
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
McBride
B W
BW
Trouten-Radford
L M
LM
Burton
J H
JH
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D006861:Hydrogen Peroxide / Q000378:metabolism*; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000031:analogs & derivatives / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010446:Peptide Fragments / Q000494:pharmacology; D011869:Radioligand Assay; D013268:Stimulation, Chemical; D013936:Thymidine / Q000378:metabolism
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D010446:Peptide Fragments; C085700:long R(3)-insulin-like growth factor-I; C058957:insulin-like growth factor 1, des-(1-3)-; D007334:Insulin-Like Growth Factor I; D006861:Hydrogen Peroxide; D013936:Thymidine