title: Growth hormone stimulates bone healing in a critical-sized bone defect model.
abstract: Growth hormone plays an important role in bone metabolism. Treating bone deficits is a major topic in orthopaedic surgery. Our hypothesis was that local continuous growth hormone administration stimulates bone healing in a canine critical-sized bone defect model. Bone formation in the defects was quantified using densitometric image analysis and histomorphometry. After growth hormone treatment, expression levels of insulin-like growth factors-I and II, and growth hormone receptor were determined in the bone regenerate of the original defects. Circulating plasma concentrations of insulin-like growth factors-I and II, and insulin- like growth factor binding proteins-4, and 6 were measured during treatment. Growth hormone administration resulted in healing of bone defects but without an additional effect of local infusion. Expression of insulin-like growth factor-I in the bone regenerate was lower in the growth hormone-treated dogs, whereas insulin-like growth factor-II and growth hormone receptor expression were not increased. Growth hormone increased circulating insulin-like growth factor-I and growth factor-II plasma concentrations. Continuous infusion of growth hormone stimulated bone healing in a canine critical-sized bone defect model. Local delivery of growth hormone did not additionally enhance bone healing. Increased circulating plasma concentrations of insulin-like growth factors-I and II most likely induced bone formation.
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. L.F.H.Theyse@vet.uu.nl
authors.forename: L F H
authors.initials: LF
authors.lastname: Theyse
authors.forename: M A
authors.initials: MA
authors.lastname: Oosterlaken-Dijksterhuis
authors.forename: J
authors.initials: J
authors.lastname: van Doorn
authors.forename: W J A
authors.initials: WJ
authors.lastname: Dhert
authors.forename: H A W
authors.initials: HA
authors.lastname: Hazewinkel
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D013006:Growth Hormone / Q000627:therapeutic use*; D008297:Male; D011859:Radiography; D011986:Receptors, Somatotropin / Q000097:blood; D011994:Recombinant Proteins / Q000627:therapeutic use*; D016896:Treatment Outcome; D014458:Ulna Fractures / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy*
chemical_list: D011986:Receptors, Somatotropin; D011994:Recombinant Proteins; D013006:Growth Hormone