To detect the influence of raloxifene (RLX) on fracture heal ing in rabbit. Methods Eighty healthy New Zealand white rabbits (44 females and 36 males) weighing 1.9-2.1 kg were used. A 0.5-cm bone defect model in the mid-diaphysis of the left forel imb radius was establ ished in 72 rabbits, which thereafter were divided into 4 groups (n=18 per group, 10 females and 8 males): groups A, B and C received 7.5, 15.0 and 30.0 mg/ (kg• d) RLX, respectively, from the 2nd to the 50th postoperative day; group D received no further treatment. The rest untreated 8 rabbits (4 females and 4 males) served as normal control for serum osteocalcin detection. At different postoperative time points, bone mineral density detection, X-ray scanning, biomechanics measurement, histology and immunohistochemistry observations were conducted; serum estradiol, plasma cholesterol, serum osteocalcin and the ratio of uterine weight to body weight were detected. Results The bone mineral density of each group reached a peak 20 days after operation, showing a significant difference between groups A, B and C and group D (P lt; 0.05), and no significant differences among groups A, B and C (P gt; 0.05). On the 30th and 50th postoperative day, the maximum failure load and the maximum displacement of groups A, B and
C were greater than those of group D (P lt; 0.05), but no significant differences among groups A, B and C were evident (P gt;
0.05). On the 7th, 20th and 30th postoperative day, the X-ray score of fracture heal ing of groups A, B and C was greater than group D (P lt; 0.05); on the 50th postoperative day, there was significant difference between groups B and C and group D, and between group A and group C (P lt; 0.05), and no significant difference was evident between group B and group C (P gt; 0.05). The percentage of new bone formation in the fractured area of groups A, B and C was greater than that of group D on the 30th and 50th postoperative day (P lt; 0.05). For the type II collagen protein secretion in the fractured area, groups B and C were superior to group D on the 30th postoperative day (P lt; 0.05), and there was no significant difference between group A and group D (P gt; 0.05); no significant differences among four groups were evident on the 50th postoperative day (P gt; 0.05). On the 10th, 30th and 50th postoperative day, the serum osteocalcin of groups A, B, C and D was higher than that of normal control (P lt; 0.05), groups B and C were higher than group D (P lt; 0.05), and there was no significant difference between groups A, B and C, and between group A and group D (P gt; 0.05). For the plasma cholesterol, on the 30th postoperative day, no significant change was detected in each group (P gt; 0.05); on the 50th postoperative day, obvious decrease was observed in groups A, B and C, showing a significant difference compared with group D (P lt; 0.05). On the 30th and 50th postoperative day, there was significant difference between groups B and C and group D in serum estradiol (P lt; 0.05), and no significant differences were evident among other groups (P gt; 0.05). On the 30th and 50th postoperative day, the ratio of uterine weight to body weight in groups B and C was less than that of group D (P lt; 0.05), and no significant difference was evident between group A and group C (P gt; 0.05). Conclusion Oral administration of 7.5 mg/ (kg• d) RLX can promote the fracture heal ing of rabbit radius defect models safely and effectively.
Citation： LI Zhang,ZHENG Hu,LI Xiuqun,WENG Lingling,LU Xiaoyan,LI Li,ZHONG Ying,DENG Li. EFFECT OF RALOXIFENE ON FRACTURE HEALING OF RABBITS. Chinese Journal of Reparative and Reconstructive Surgery, 2009, 23(6): 683-689. doi: Copy