title: Endotoxin administration decreases plasma insulin-like growth factor (IGF)-I and IGF-binding protein-2 in Angus x Hereford steers independent of changes in nutritional intake.
abstract: Endotoxemia and sepsis cause severe shifts in metabolism towards catabolic events. The objective of the research was to determine whether endotoxin administration changes plasma concentrations of IGF-I and IGF-binding protein-2 (IGFBP-2) in Angus x Hereford steers. In Experiment 1, mean feed intake in endotoxin-treated steers (n = 6) decreased 60% within the first 24 h after endotoxin and averaged, for the duration of the 96 h test period, an intake 35.5% lower than the mean ad libitum intake recorded prior to endotoxin. Plasma concentrations of IGF-I averaged 182 ng/ml in steers before endotoxin (E. coli, 055:B5, 0.2 micrograms/kg, i.v. bolus) and decreased an average of 24.2% at 24 to 96 h after endotoxin. In Experiment 2, a paired feeding strategy was used to determine whether the reduced feed intake was a significant factor in changing plasma concentrations of IGF-I and IGFBP-2 after endotoxin challenge. Steers were divided into endotoxin (0.2 micrograms/kg, i.v., n = 6) or control (saline, i.v., n = 3) treatments. Each of three endotoxin-treated steers was paired to a specific control. In this fashion, the adjusted feed intake of each endotoxin-treated steer was fed to it's paired control every 24 h through 96 h after endotoxin.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: US Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705.
authors.forename: T H
authors.initials: TH
authors.lastname: Elsasser
authors.forename: T J
authors.initials: TJ
authors.lastname: Caperna
authors.forename: T S
authors.initials: TS
authors.lastname: Rumsey
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002352:Carrier Proteins / Q000097:blood*; D002417:Cattle / Q000378:metabolism*; D004731:Endotoxins / Q000494:pharmacology*; D006854:Hydrocortisone / Q000097:blood; D015151:Immunoblotting; D018971:Insulin-Like Growth Factor Binding Protein 2; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D011869:Radioligand Assay; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D004731:Endotoxins; D018971:Insulin-Like Growth Factor Binding Protein 2; D014409:Tumor Necrosis Factor-alpha; D007334:Insulin-Like Growth Factor I; D006854:Hydrocortisone