The Study Between Serum Biochemical Markers Of Bone And The Changes Of Bone Microstructure In Different Periods After Rats,Bilateral Ovariectomy

Objective To observe the relationship between bone biochemical changes and bone histological changes in rats, bilateral ovariectomy. Methods 32 about 6 months of age female SD rats were randomly divided into control group(Sham) and bilateral ovariectomy (OVX) group, choose four time points after surgery (2, 4, 8, 12 weeks) random samples, each group shall be put to death at each time point 4 animals, extract the measurement of serum estradiol (E2),bone alkaline phosphatase (BALP), tartrate resistant acid phosphatase (TRACP 5 b) - 5 b concentrations, invasive surgery in the tibia and microscopic CT(Micro - CT) and microscope HE dyeing method to observe the tibia bone trabecular microstructure changes..Results At 2 weeks after operation, E2 in OVX group began to reduce compared with Sham group ,it was significantly different from Sham group at postoperative 4 weeks(P<0.05), which lasted until postoperative 12 weeks. The level of E2 in Sham group was not changed too much with time; Serum BALP activity in OVX group reached a peak at 2 weeks after operation, and then decreased rapidly, equal to preoperative level at postoperative 12 weeks. Serum TRACP-5B activity in OVX group increased rapidly, and reached a peak at 4 weeks after operation, and then decreased,which was still higher than that of Sham group at postoperative 12 weeks and preoperative level. Micro-CT analysis showed no significant difference in relative bone volume (BV/TV), trabecular number (N Tb.), trabecular separation(Tb.Sp), Conn.D, bone mineral density (BMD) in OVX group compared with Sham group. At 4 postoperative weeks they began to appear obvious difference,the difference was more obvious at postoperative 12 weeks, trabecular thickness(Th Tb.) always had no obvious difference. Micro-CT reconstruction showed trabecular bone was sparse and seriously missing in OVX group at postoperative 12 weeks compared with Sham group.HE staining showed that the trabecular bone under tibia epiphyseal plate in OVX group became thin and arranged sparsely compared with Sham group at postoperative 12 weeks .The trabecular bone structure was not mature, trabecular connectivity was decreased, part of them was broken, there were a large number of trabecular bone blind ends,trabecular thickness was inconsistent. Conclusions In the establishment of OVX osteoporosis model, the osteoblast and osteoclast activity of the rats were increased and then decreased, and the osteoclasts were higher and longer than those of osteoblasts , Bone resorption is greater than bone formation leading to osteoporosis, histological test results show that trabecular bone immature structure.