Bone Abstracts

The aim of this study was to determine morphological and densitometric properties of lumbar vertebrae obtained from male and female silver foxes. Five lumbar vertebrae (L2–L6) were isolated from 1-year-old males (n=5) and females (n=6) and cleaned from remaining soft tissues to determine bone weight and vertebral body length. Quantitative computed tomography (QCT) and SOMATOM EMOTION SIEMENS apparatus (Siemens, Erlangen, Germany) were used to determine the volumetric bone mineral density (vBMD) of trabecular bone (Td) and cross-sectional area (A_VB) of the vertebral body. Td was measured using 2 mm thick, cross-sectional QCT scans, placed at 60% of each vertebral body length, and A_VB the at this place was measured automatically. Total bone volume (Bvol) of each lumbar vertebra and mean volumetric bone mineral density (MvBMD) were determined and the volume-of-interest (VOI) was defined by limiting the minimum and maximum density for the investigated bone at 0 and 3000 Hounsfield units (HU) respectively. The quantitative determination of calcium hydroxyapatite (Ca-HA) in middle part of vertebral body was performed. Bone mineral density (BMD) and bone mineral content (BMC) of whole femur were determined using dual-energy X-ray absorptiometry (DEXA) and Norland Excell Plus Densitometer (Fort Atkinson, WI, USA) equipped with Research Scan Software. Mean values obtained from all measurements were averaged for each single vertabrae (L2–L6) and were compared using non-paired Student’s t-test. Differences showing P>0.05 were not considered statistically significant. Mean values of bone weight, length, A_VB, Bvol and BMC were found to be significantly higher by 22.7, 14.1, 13.1, 23.8, and 14.8% in males when compared to the females respectively (P≤0.05). However, MvBMD of the whole vertebra was significantly lower in males by 2.5% when compared to the females (P=0.0006).

This study has shown sex-related differences of morphometric and densitometric parameters of lumbar spine in silver foxes. The obtained results indicate that silver foxes may serve as an attractive experimental model for further studies on axial skeleton properties and bone metabolism regulation in mammals in response to physiological, pharmacological, nutritional, and toxicological factors, being an alternative model for other species of monogastric animals such as dogs.