NGF对骨折愈合影响的研究

STUDY ON EFFECT OF NGF ON FRACTURE HEALING

目的探讨NGF对骨折愈合的影响,以及对BMP-2诱导成骨的作用。方法清洁级雄性6～8周昆明小鼠60只,体重23～25g,随机分为4组,每组15只。建立股骨中段不稳定软骨内成骨骨折模型,A、B、C、D组分别于骨折断端局部使用NGF/生理盐水、BMP-2、BMP-2/NGF/生理盐水、生理盐水。各组分别于术后14、21和28d各处死5只小鼠,并于骨折部位取材行大体、X线片观察、生化检测及组织学观察。处死小鼠前取小鼠眼球球后动静脉血液行血清ALP活性测定。结果术后各时间点,大体观察A、B、C组局部新生硬组织大小、硬度,骨折断端骨痂生长依次增加,均高于D组。X线片观察A、B、C组骨折线逐渐模糊,钙化面积依次增大,均快于D组。组织学观察A、B、C组骨小梁成熟度依次增加,均优于D组。术后各时间点,A、B、C组成骨面积和成骨区灰度值、血清ALP含量、骨痂组织中ALP含量和钙含量、骨痂湿重均高于D组。术后各时间点各组成骨面积和成骨区灰度值比较、术后14d各组血清中ALP含量比较、术后14d和21d各组骨痂组织中ALP含量比较、术后21d和28d各组骨痂组织中钙含量及骨痂湿重比较差异均有统计学意义(P<0.05)。术后14d,B、C组与A、D组比较骨痂湿重差异有统计学意义(P<0.05)。术后21、28d,骨组织形态计量分析显示各组新生骨骨小梁表面成骨细胞指数、平均骨小梁面积百分比和平均骨小梁宽度随时间增大依次减小,A、B、C组依次增大,均高于D组,各组间比较差异均有统计学意义(P<0.05)。结论NGF有促进骨折愈合作用,且具有协同BMP-2诱导成骨的作用。

Objective To investigate the e ect of NGF on fracture healing, and to study the role of BMP-2 induced osteoblast.Methods Sixty cleaned male Kunming mice（aging 6-8 weeks and weighing 23-25 g） were made fracture models in the middle of femoral shaft and randomly divided into four groups（groups A, B, C and D, n=15）.Fracture was treated with NGF/ normal saline, BMP-2, BMP-2 /NGF/normal saline, and normal saline in groups A, B, C and D, respectively.After 14, 21 and 28 days, the specimens were selected from 5 mice each group to do the biochemical and histological analysis.Before the mice were killed, the arteriovenous blood was taken from their eye-ball to test the ALP activity.Results After 14 days, 21 days and 28 days, the gross observation showed that the size and hardness of bone tissue, and callus tissue growth increased in groups A, B and C order and were higher than those in group D;the X-ray lms showed that the calci ed area increased in groups A, B and C order and were higher than those in group D;the histological observation showed that the trabecular maturity increased in groups A, B and C order and were higher than those in group D.The osteoblast area, the gray degree value of the radiographs in callus tissue, the ALP contents of serum and callus tissue, calcium content of callus tissue and net weight of callus were higher in groups A, B and C than in group D.There were signi cant di erences（P 〈 0.05） in osteoblast area and gray degree values of the radiographs at 14, 21 and 28 days;in ALP contents of serum at 14 days;in ALP contents of callus tissue at 14 days and 21 days;in calcium content of callus tissue at 21 days and 28 days among 4 groups.There were signi cant di erences in net weight of callus between groups B, C and groups A, D at 14 days（P 〈 0.05）.At 21 days and 28 days, the trabecular surface index of osteoblast, the average trabecular volume and the mean trabecular width decreased as time went on, having an increase order of groups A, B, C and was higher in groups A, B, C than in group D, showing signi cant di erences among 4 groups（P 〈 0.05）.Conclusion NGF promotes the healing of fractures.NGF possesses synergistic e ect on ectopic bone formation induced by BMP-2.