[Changes of urinary deoxypyridinoline crosslink/creatinine in rats after ovariectomy and anti-osteoporotic intervention].

ABSTRACT

OBJECTIVE: To observe the changes of urinary deoxypyridinoline crosslink/creatinine (UDpd/Cr) in rats after OVX and intervention by estrogen and bisphosphonate and investigate the possible application of deoxypyridinoline in osteoporosis diagnosis and treatment. METHODS: 40 female 6-month-old virginal Wistar rats were divided into 5 groups, ovariectomized or sham ovariectomized. (1) Ovxb (n = 8) sacrificed at 6 weeks after OVX; (2) Sham (n = 8) sham ovariectomized; (3) Ovxe (n = 8) sacrificed at 14 weeks after OVX; (4) O + E (n = 9)OVX + 17 beta estradiol [20 micrograms/(kg.d) ih]; (5) O + C (n = 7)OVX + cimadronate [0.2 mg/(kg.d)]; Treatment started 6 weeks after OVX and lasted 8 weeks. Rats in group 2-5 were sacrificed at 14 weeks after OVX. Urinary and serum biochemical parameters were measured, pQCT scanning of femur, bone biomechanical test in femur were determined. RESULTS: OVX resulted in increasing of UDpd/Cr 133.3% (P < 0.01). The ratio of UCa/Cr also increased in OVX groups but without any significant compared with Sham (P > 0.05). UDpd/Cr were reduced by 54.6% and 51.8% (P < 0.01) in O + E, O + C group respectively compared with Ovxe. The significant negative correlationships were found between UDpd/Cr and bone mass, BMD and biomechanic characteristics. CONCLUSIONS: UDpd/Cr ratio is a sensitive bone resorption marker, a marked changes were observed when the rats ovariectomized or treated with estradiol and cimadronate. There were best correlation between UDpd/Cr and bone mineral density and bone biomechanic characteristics. It is fair to apply UDpd/Cr ratio for osteoporosis diagnosis and treatment.