title: Age related changes in biochemical markers of bone metabolism in horses.
abstract: Biochemical markers of bone metabolism were analysed in serum samples obtained from 60 horses with no history of orthopaedic disease (age 3 months-20 years). Serum levels of the carboxyterminal propeptide of type I procollagen (PICP), a marker of bone formation and the pyridinoline cross linked telopeptide domain of type I collagen (ICTP), a putative marker of bone resorption, were measured by radioimmunoassay (RIA). Serum levels of the bone specific isoenzyme of alkaline phosphatase (BALP), another marker of bone formation, were measured by a wheatgerm agglutinin affinity (WGA) method. Total alkaline phosphatase levels were also determined. Serum levels of PICP were significantly correlated with bone ALP (r = 0.78, P < 0.0001) and ICTP (r = 0.87, P < 0.0001). ICTP levels also correlated significantly with bone ALP (r = 0.81, P < 0.0001). However, total alkaline phosphatase did not correlate significantly with PICP, ICTP and BALP in horses over 1 year of age. There was an inverse correlation between serum levels of all biochemical markers and age of animals, with the most significant changes seen over the first 2 years. In animals less than 1 year of age, the reference ranges (mean +/- s.d. 1.96) were as follows: PICP 1216-2666 micrograms/l, ICTP 13.8-26.7 micrograms/l, bone ALP 134-288 u/l and total ALP 223-498 u/l. In 2-year-olds, the equivalent reference ranges were: PICP 550-1472 micrograms/l, ICTP 7.96-22.8 micrograms/l, bone ALP 32.7-125 u/l and total ALP 134-238 u/l.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Veterinary Basic Sciences, Royal Veterinary College, London, UK.
authors.forename: J S
authors.initials: JS
authors.lastname: Price
authors.forename: B
authors.initials: B
authors.lastname: Jackson
authors.forename: R
authors.initials: R
authors.lastname: Eastell
authors.forename: A E
authors.initials: AE
authors.lastname: Goodship
authors.forename: A
authors.initials: A
authors.lastname: Blumsohn
authors.forename: I
authors.initials: I
authors.lastname: Wright
authors.forename: S
authors.initials: S
authors.lastname: Stoneham
authors.forename: L E
authors.initials: LE
authors.lastname: Lanyon
authors.forename: R G
authors.initials: RG
authors.lastname: Russell
mesh_terms: D000375:Aging / Q000097:blood / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001842:Bone and Bones / Q000737:chemistry / Q000378:metabolism*; D003094:Collagen / Q000032:analysis / Q000378:metabolism; D024042:Collagen Type I; D005260:Female; D006736:Horses / Q000097:blood / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D010455:Peptides / Q000032:analysis / Q000378:metabolism; D011347:Procollagen / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D011863:Radioimmunoassay; D014909:Wheat Germ Agglutinins
chemical_list: D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; D014909:Wheat Germ Agglutinins; C052929:collagen type I trimeric cross-linked peptide; C042813:procollagen type I carboxy terminal peptide; D003094:Collagen; D000469:Alkaline Phosphatase