title: Vascular calcification is associated with cortical bone loss in chronic renal failure rats with and without ovariectomy: the calcification paradox.
abstract: BACKGROUND
  Increased bone loss has been associated with the development of vascular calcification in patients with chronic renal failure (CRF). In this study, the effect of impaired bone metabolism on aortic calcifications was investigated in uremic rats with or without ovariectomy.
  
  
  METHODS
  CRF was induced by administration of a 0.75% adenine/2.5% protein diet for 4 weeks. In one group, osteoporosis was induced by ovariectomy (CRF-OVX), while the other group underwent a sham-operation instead (CRF). A third group consisted of ovariectomized rats with normal renal function (OVX). At regular time intervals throughout the study, bone status and aortic calcifications were evaluated by in vivo micro-CT. At sacrifice after 6 weeks of CRF, bone histomorphometry was performed and vascular calcification was assessed by bulk calcium analysis and Von Kossa staining.
  
  
  RESULTS
  Renal function was significantly impaired in the CRF-OVX and CRF groups. Trabecular bone loss was seen in all groups. In the CRF-OVX and CRF groups, trabecular bone density was restored after adenine withdrawal, which coincided with cortical bone loss and the development of medial calcifications in the aorta. No significant differences with regard to the degree of aortic calcifications were seen between the two CRF groups. Neither cortical bone loss nor calcifications were seen in the OVX group. Cortical bone loss significantly correlated with the severity of vascular calcification in the CRF-OVX and CRF groups, but no associations with trabecular bone changes were found.
  
  
  CONCLUSIONS
  Cortical rather than trabecular bone loss is associated with the process of calcification in rats with adenine- induced CRF.
authors.affiliation: Laboratory of Pathophysiology, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Tineke M
authors.initials: TM
authors.lastname: De Schutter
authors.forename: Ellen
authors.initials: E
authors.lastname: Neven
authors.forename: Veerle P
authors.initials: VP
authors.lastname: Persy
authors.forename: Geert J
authors.initials: GJ
authors.lastname: Behets
authors.forename: Andrei A
authors.initials: AA
authors.lastname: Postnov
authors.forename: Nora M
authors.initials: NM
authors.lastname: De Clerck
authors.forename: Patrick C
authors.initials: PC
authors.lastname: D'Haese
mesh_terms: D000225:Adenine / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000473:pathology; D001835:Body Weight; D001842:Bone and Bones / Q000473:pathology; D002114:Calcinosis / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D007676:Kidney Failure, Chronic / Q000503:physiopathology*; D010024:Osteoporosis / Q000503:physiopathology; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D061205:Vascular Calcification / Q000473:pathology*; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D000225:Adenine