title: Effects of peroral insulin and glucose on circulating insulin-like growth factor-1, its binding proteins and thyroid hormones in neonatal calves.
abstract: There is disagreement in the literature about the ability of neonatal calves to absorb perorally administered insulin. This study evaluated the absorption of a bolus of insulin administered alone or with an energy souce and its effects on the circulating insulin-like growth factor system and thyroid hormones in newborn Holstein-Friesian calves. Within 1 h of dosing, mean serum insulin and triiodothyronine (T3) concentrations had increased considerably, whether the insulin was applied alone (n = 4) or together with glucose (n = 4), accompanied by marked hypoglycemia. No significant changes were observed in control calves (n = 4) given the vehicle solution. Increased serum glucose and T3 concentrations with no change in insulinemia occurred in a 4th group of calves given glucose alone. At 32 h of age and after 3 meals of colostrum there were no differences in glycemia, insulinemia, or proteinemia among the 4 groups of calves examined. Mean serum insulin-like growth factor-I (IGF-I) tended to decrease over this period in the control group. The decrease was more pronounced in the insulin-treated group but absent in both groups that received glucose. These differences were associated with equivalent differences in abundance of the 40-45K IGF-binding protein-3 (IGFBP-3); however, lower molecular mass IGFBPs were not affected. The results show that a pharmacological peroral dose of insulin can lead to rapid systemic alterations in the IGF/IGFBP system in neonatal calves that can be modified by simultaneous administration of a small energy supply in the form of glucose.
authors.affiliation: Department of Physiology and Biochemistry, Faculty of Veterinary Medicine, University of Belgrade, Belgrade Serbia. dani@vet.bg.ac.yu
authors.forename: Danijela
authors.initials: D
authors.lastname: Kirovski
authors.forename: M
authors.initials: M
authors.lastname: Lazarević
authors.forename: Ivona
authors.initials: I
authors.lastname: Baricević-Jones
authors.forename: Olgica
authors.initials: O
authors.lastname: Nedić
authors.forename: Romana
authors.initials: R
authors.lastname: Masnikosa
authors.forename: Judith Anna
authors.initials: JA
authors.lastname: Nikolie
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000097:blood / Q000378:metabolism; D002417:Cattle / Q000097:blood / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D007328:Insulin / Q000097:blood / Q000493:pharmacokinetics*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism; D018969:Insulin-Like Growth Factor Binding Proteins / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D011897:Random Allocation; D013963:Thyroid Hormones / Q000097:blood*
chemical_list: D007328:Insulin; D018972:Insulin-Like Growth Factor Binding Protein 3; D018969:Insulin-Like Growth Factor Binding Proteins; D013963:Thyroid Hormones; D007334:Insulin-Like Growth Factor I; D005947:Glucose