title: Restoration of bone mineralization by cinacalcet is associated with a significant reduction in calcitriol-induced vascular calcification in uremic rats.
abstract: The present study investigated to what extent normalization of bone turnover goes along with a reduction of high-dose calcitriol-induced vascular calcifications in uremic rats. Five groups of male Sprague-Dawley rats were studied: sham-operated controls (n = 7), subtotally nephrectomized (SNX) uremic (CRF) animals (n = 12), CRF + calcitriol (vitD) (0.25 μg/kg/day) (n = 12), CRF + vitD + cinacalcet (CIN) (10 mg/kg/day) (n = 12), and CRF + vitD + parathyroidectomy (PTX) (n = 12). Treatment started 2 weeks after SNX and continued for the next 14 weeks. High-dose calcitriol treatment in hyperparathyroid rats went along with the development of distinct vascular calcification, which was significantly reduced by >50 %, in both CIN-treated and PTX animals. Compared to control animals and those of the CRF group, calcitriol treatment either in combination with CIN or PTX or not was associated with a significant increase in bone area comprising ±50 % of the total tissue area. However, whereas excessive woven bone accompanied by a dramatically increased osteoid width/area was seen in the CRF + vitD group, CIN treatment and PTX resulted in significantly reduced serum PTH level, which was accompanied by a distinct reduction of both the bone formation rate and the amount of osteoid. These data indicate that less efficient calcium and phosphorus incorporation in bone inherent to the severe hyperparathyroidism in vitamin D-treated uremic rats goes along with excessive vascular calcification, a process which is partially reversed by CIN treatment in combination with a more efficacious bone mineralization, thus restricting the availability of calcium and phosphate for being deposited in the vessel wall.
authors.affiliation: Laboratory of Pathophysiology, Department of Biomedical Sciences, University of Antwerp, Campus Drie Eiken, Building T.3, Universiteitplein 1, 2610, Wilrijk, Belgium.
authors.forename: Tineke M
authors.initials: TM
authors.lastname: De Schutter
authors.forename: Geert J
authors.initials: GJ
authors.lastname: Behets
authors.forename: Susanne
authors.initials: S
authors.lastname: Jung
authors.forename: Ellen
authors.initials: E
authors.lastname: Neven
authors.forename: Patrick C
authors.initials: PC
authors.lastname: D'Haese
authors.forename: Uwe
authors.initials: U
authors.lastname: Querfeld
mesh_terms: D000818:Animals; D002113:Calcification, Physiologic / Q000187:drug effects*; D002117:Calcitriol / Q000009:adverse effects*; D002118:Calcium / Q000097:blood* / Q000378:metabolism; D000069449:Cinacalcet; D006961:Hyperparathyroidism / Q000188:drug therapy*; D008297:Male; D009281:Naphthalenes / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D014511:Uremia / Q000139:chemically induced* / Q000378:metabolism; D061205:Vascular Calcification / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D014815:Vitamins / Q000009:adverse effects*
chemical_list: D009281:Naphthalenes; D014815:Vitamins; D002117:Calcitriol; D002118:Calcium; D000069449:Cinacalcet