OBJECTIVETo study the correlations between the bone quality and level of u-DPD and serum 1,25-dihydroxyvitamin D3 in the ovariectomized osteoporosis rats.

METHODSForty female rats were randomly divided into the ovariectomy group (the OVX group) and the sham-operation group (the Sham group), and draw materials in 12 and 24 weeks after operation. Bone mineral density (BMD) of the 1st lumbar, the femoral neck and femur was measured by dual-energy X-ray absorptionetry. The level of urine DPD was measured by ELISA. The concentration of 1,25-dihydroxyvitamin D3 in serum was measured by radioimmunoassay (RIA). The limit of compressive strength and elastic modulus of 1st lumbar and bending load of right femur were measured by photoelasticity meter. The osseous morphology of upper tibia was measured by the non-decalcifing section. The correlation of experimental data was analyzed by statistical method.

RESULTSIn ovariectomy group, except the level of urine DPD/Cr was increase, all data decreased significantly compared with the samp group,and descending continually with the lapse of time. The results showed that there was a negative correlation between the urine DPD/Cr and BMD of the 1st lumbar, femur, the limit of compressive strength of 1st lumbar, bending load of femur and trabecular bone area. But there was a positive correlation significantly between the concentration of 1,25-dihydroxyvitamin D3 in serum and BMD of the 1st lumbar, the femoral neck and femur, trabecular bone area, the limit of compressive strength of 1st lumbar, bend load of femur.

CONCLUSIONThe correlation is remarkable between the bone quality and the level of urine DPD/Cr, 1,25-dihydroxyvitamin D3 in serum. We can predict the bone quality by measuring the level of urine DPD/Cr and 1,25-dihydroxyvitamin D3 in serum.