Biomechanical properties of bones from rats treated with sevelamer

Scientific paper - Original scientific paper

• Title (croatian): Biomehanička svojstva kostiju štakora tretiranih sevelamerom
• Author: Nataša Drača
• Author: Ana Tikvica
• Author: Domagoj Eljuga
• Author: Damir Semenski
• Author: Mladen Brnčić
• Author: Slobodan Vukičević
• Author's institution: University of Zagreb; School of Medicine
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Basic Medical Sciences

Abstract (english)

Sevelamer hydrochloride is used for ten years in patients on dialysis as a phosphate binder. We have previously shown that oral application of sevelamer prevents the bone loss and increases the bone volume in ovariectomized rats. In this study we further analysed the biomechanical properties of bones from rats treated with sevelamer utilizing a threepoint bending test to determine the mechanical properties of the cortical bone of the mid-shaft femur, while the indentation test was used to determine the mechanical properties of cancellous bone in the marrow cavity of the distal femoral metaphysis. Parameters analyzed included: maximum load (F(u)), stiffness (S), energy absorbed (W), toughness (T) and ultimate strength (sigma). The intrinsic properties, stress, elastic modulus and toughness were determined from measured maximum load, strains, stiffness, energy absorbed, outer and inner diameters, and calculated bone cross-sectional moment of inertia. Sevelamer was given to rats for 25 weeks with a content of 3% of sevelamer in a standard diet, starting immediately following ovariectomy (OVX). Animals were divided to the following groups: (1) Sham; (2) Sham + sevelamer 3%; (3) OVX; (4) OVX + sevelamer 3%. Our results showed that sevelamer particularly influenced the rat trabecular bone by increasing the maximum load for 26.2%, energy absorbed for 24.2% and the ultimate strength for 26.2% in sham animals treated with sevelamer 3%, as compared to sham rats. Sevelamer 3% in OVX rats also increased the maximum load for 71.4%, stiffness for 70.7%, energy absorbed for 55.9% and the ultimate strength for 71.3% as compared to OVX controls. In the three bending test sevelamer had a very little effect on preventing loss of bone strenght in the cortical bone. These results collectively suggest that sevelamer improves bone biomechanical properties, mainly affecting trabecular bone quality in both normal and ovariectomized rats.

Abstract (croatian)

Sevelamer hidroklorid koristi se već 10 godina u pacijenata na dijalizi kao fosfatni vezač. Naša prethodna istraživanja
pokazala su da oralna primjena sevelamera sprečava gubitak koštane mase i povećava koštani volumen u ovarijektomiranih
štakora(1). U ovom ispitivanju analizirali smo biomehaničke karakteristike kostiju štakora tretiranih sevelamerom
pomoću »threepoint bending» testa kako bi se odredila biomehanička svojstva kortikalne kosti središnjeg dijela
femura, dok se za mehaničke karakteristike trabekularne kosti distalne femoralne metafize koristio test indentacije.
Analizirani parametru su bili: maksimalno opterećenje (F(u)), rigidnost (S), apsorbirana energija (W), čvrstoća (T) i maksimalna
jakost (sigma). Endogene karakteristike, stres, elastični modul i čvrstoća kostiju dobivene su pomoću izmjerenog
maksimalnog opterećenja, rigidnosti, apsorbirane energije, vanjskih i unutarnjih dijametara kosti te izračunatog inercijskog
momenta koštanog presjeka. Štakori su dobivali sevelamer 25 tjedana sa standardnom prehranom, počevši odmah
nakon ovarijektomije (OVX). Životinje su podijeljene u slijedeće grupe : (1) Sham (lažno operirane životinje); (2)
Sham + sevelamer 3%; (3) OVX; (4) OVX + sevelamer 3%. Naši rezultati su pokazali da je sevelamer osobito utjecao na
trabekularnu kost povećavajući maksimalno opterećenje za 26,2%, apsorbiranu energiju za 24,2% i maksimalnu jakost
za 26,2% u životinja koje su dobivale 3% sevelamera u usporedbi sa životinjama koje su dobivale standardnu prehranu.
Sevelamer 3% u ovarijektomiranim štakorima je također povećao maksimalno opterećenje za 71,4%, rigidnost za 70,7%,
apsorbiranu energiju za 55,9% i maksimalnu jakost za 71,3% u usporedbi sa OVX kontrolama. U »threepoint bending«
testu sevelamer je imao mali utjecaj na sprečavanje gubitka jakosti kortikalne kosti. Ovi rezultati pokazuju da sevelamer
poboljšava biomehanička svojstva kosti, prvenstveno djelujući na trabekularnu kost u normalnih i ovarijektomiranih
štakora.

• Keywords (english): Animals; Biomechanics/drug effects; Chelating Agents/pharmacology; Elastic Modulus/drug effects; Female; Femur/drug effects; Femur/physiology; Polyamines/pharmacology; Rats; Rats, Sprague-Dawley; Shear Strength/drug effects
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review
• Publication version: Published version
• Journal title: Collegium Antropologicum
• Numbering: vol. 35, no. 2, pp. 557-563
• p-ISSN: 0350-6134
• URN:NBN: urn:nbn:hr:105:819886
• Publication: 2011-06
• Document URL: https://hrcak.srce.hr/69151
• Type of resource: Text
• Access conditions: Open access
• Created on: 2024-03-27 19:06:31