ABSTRACT
At present there are many techniques available for determining bone mass, measurement of which is essential for monitoring osteopenia. Rats are preferred to other laboratory species when designing animal studies on osteoporosis. The precision and accuracy of dual energy X-ray absorptiometry (DXA) for the assessment of bone mineral density (BMD) and bone mineral content (BMC) in laboratory animals were assessed. Precision, expressed as a coefficient of variation (CV), was measured, making five determinations (Hologic QDR-1000) on lumbar spine (in vivo) and femur (in vitro), both with and without repositioning. The correlation (r) between densitometric parameters and mineral content of bone ashes was calculated both in lumbar spine (in vivo) and in femur (in vitro). In our study, DXA had good precision, better in femur (CV 0.53%) than in lumbar spine (L2-L4) (CV 1.0%). Repositioning did not increase significantly the coefficients of variation (CV 0.61% and 1.2%, respectively). The linear regression between BMD and ash weight, calcium and phosphorous content showed high correlation coefficients (r = 0.64-0.85, p < 0.05). Although we found an overestimate of values of BMC with respect to ash weight (21% in lumbar spine and 31% in femur), the correlation between BMC and mineral content was high (r = 0.96-0.99, p < 0.05). The results suggest that the DXA technique has the precision necessary when used to assess BMD and BMC in small laboratory animals.
Subject(s)
Absorptiometry, Photon , Bone Density , Animals , Calcium/analysis , Female , Femur/chemistry , Femur/physiology , Linear Models , Lumbar Vertebrae/chemistry , Lumbar Vertebrae/physiology , Osteoporosis/diagnosis , Phosphorus/analysis , Rats , Rats, Wistar , Reproducibility of ResultsABSTRACT
Rapid detection of the exact changes in bone remodelling is exceptionally important. In this paper, the latest bone remodelling biochemical markers are reviewed. Some of them have already been used for a long time, and their utility has been widely demonstrated. The newest ones, in experimental stage, can be used as a complement to the others. The bone remodelling markers reviewed are: 1) Alkaline phosphatase; 2) osteocalcin; 3) other noncollagen of bone matrix such as osteonectin, GLA-protein of the matrix, osteopontine and alpha 2-HS-glycoprotein; 4) Procollagenous and other collagenous peptides of the matrix (C terminal of type I procollagen and urinary elimination of non-dialysis hydroxyproline. Amongst the bone resorption markers studied are: 1) Calcium/creatinine urinary quotient; 2) Tartrate resistant acid phosphatase; 3) Urinary hydroxyproline; 4) Other substance derived from collagen disruption such as hydroxylysine glycoside, piridinolinic intermolecular bridges and the enzymatic activity of proline iminopeptidase. We endeavored to collect all the most important references on the matter, especially those relating to Paget's disease of the bone, primary hyperparathyroidism, tumoral hypercalcemia and postmenopausal osteoporosis.
Subject(s)
Bone Resorption , Hypercalcemia/metabolism , Hyperparathyroidism/metabolism , Osteitis Deformans/metabolism , Osteoporosis, Postmenopausal/metabolism , Acid Phosphatase/blood , Adult , Biomarkers , Child , Female , Follow-Up Studies , Humans , Hydroxyproline/urine , Hypercalcemia/diagnosis , Hypercalcemia/etiology , Hyperparathyroidism/diagnosis , Male , Neoplasms/complications , Osteitis Deformans/diagnosis , Osteoporosis, Postmenopausal/diagnosisABSTRACT
Rapid detection of the exact changes in bone remodelling is exceptionally important. In this paper, the latest bone remodelling biochemical markers are reviewed. Some of them have already been used for a long time, and their utility has been widely demonstrated. The newest ones, in experimental stage, can be used as a complement to the others. The bone remodelling markers reviewed are: 1) Alkaline phosphatase; 2) osteocalcin; 3) Other noncollagen of bone matrix such as osteonectin, GLA-protein of the matrix, osteopontine and alpha 2-HS-glycoprotein; 4) Procollagenous and other collagenous peptides of the matrix (C terminal of type-I procollagen and urinary elimination of nondialysis hydroxyproline. Amongst the bone resorption markers studied are: 1) Calcium/creatinine urinary quotient; 2) Tartrate resistant acid phosphatase; 3) Urinary hydroxyproline; 4) Other substances derived from collagen disruption such as hydroxilysin glycoside, piridinolinic intermolecular bridges and the enzymatic activity of proline iminopeptidase. We endeavoured to collect all the most important references on the matter, especially those relating to Paget's disease of the bone, primary hyperparathyroidism, tumoral hypercalcemia and postmenopausal osteoporosis.
Subject(s)
Bone Regeneration/physiology , Hypercalcemia/diagnosis , Hyperparathyroidism/diagnosis , Neoplasms/diagnosis , Osteitis Deformans/diagnosis , Osteoporosis, Postmenopausal/diagnosis , Biomarkers/chemistry , Female , Follow-Up Studies , Humans , Hypercalcemia/etiology , Hypercalcemia/metabolism , Hyperparathyroidism/metabolism , Male , Neoplasms/complications , Neoplasms/metabolism , Osteitis Deformans/metabolism , Osteoporosis, Postmenopausal/metabolismABSTRACT
The influence of 24,25-dihydroxyvitamin D on different seric levels of osteocalcin in Paget's disease of the bone and in 11 of the control group, other parameters were also determined such as: seric levels of calcium, phosphate, parathormone, osteocalcin, 25-hydroxyvitamin D an 1,25 dihydroxyvitamin D. We observed that patients with Paget's disease showed increased or normal levels of seric osteocalcin, despite the high bone remodelling and significantly low level of 24,25-dihydroxyvitamin D observed in patients with high levels of osteocalcin. At the same time, we noticed a negative lineal correlation between both parameters. We suggest that 24,25-hydroxyvitamin D can be one of the important factors in producing increased or normal levels of osteocalcin in patients with Paget's disease of the bone.
