Ca/P concentration ratio at different sites of normal and osteoporotic rabbit bones evaluated by Auger and energy dispersive X-ray spectroscopy

Abstract

Osteoporosis is a systemic skeletal disorder associated with reduced bone mineral density and the consequent high risk of bone fractures. Current practice relates osteoporosis largely with absolute mass loss. The assessment of variations in chemical composition in terms of the main elements comprising the bone mineral and its effect on the bone's quality is usually neglected. In this study, we evaluate the ratio of the main elements of bone mineral, calcium (Ca), and phosphorus (P), as a suitable in vitro biomarker for induced osteoporosis. The Ca/P concentration ratio was measured at different sites of normal and osteoporotic rabbit bones using two spectroscopic techniques: Auger electron spectroscopy (AES) and energy-dispersive X-ray spectroscopy (EDX). Results showed that there is no significant difference between samples from different genders or among cortical bone sites. On the contrary, we found that the Ca/P ratio of trabecular bone sections is comparable to cortical sections with induced osteoporosis. Ca/P ratio values are positively related to induced bone loss; furthermore, a different degree of correlation between Ca and P in cortical and trabecular bone is evident. This study also discusses the applicability of AES and EDX to the semiquantitative measurements of bone mineral's main elements along with the critical experimental parameters.

Alveolar process changes associated with administration of nucleos(t)ide analogue (sofosbuvir) in rat model

“…18 EDX is a sensitive qualitative and semiquantitative technique for the assessment of the mineral content variations in calcified tissue. 19 The EDX results in the herein study support the SEM findings. The analysis of the Ca concentration (%) revealed the highest concentration in the control group while the lowest was found in group 3.…”

Assessment of Trabecular Bones Microarchitectures and Crystal Structure of Hydroxyapatite in Bone Osteoporosis with Application of the Rietveld Method

“…The physical tests MEV and EDS were correlated, the ratio Ca / P is higher for normal bone events reflecting less probability to present fractures as reported by Fountos et al [17] and Kourkoumelis et al [18]. The probable replacement by ions of atomic radius with different values from calcium ions, Costa et al, [19] decreases bone quality due to the increased amount of punctiform defects in the crystalline hydroxyapatite net, which characterizes the metabolic bone disease osteopenia and osteoporosis.…”

An Investigation of the Mineral in Ductile and Brittle Cortical Mouse Bone

“…Phillips et al (10) measured a reduction of Ca/P in oim −/− femora using neutron activation analysis. Reductions in Ca/P ratio have also been reported in human bone suffering osteogenesis imperfecta (42) and in osteoporotic bone(43,44). Our results further indicate that pathologic bone mineral tends to be less stoichiometric (22,28).…”