甲状旁腺激素(1-34)对大鼠下颌骨骨折愈合的短期和长期影响的实验研究

目的 探究甲状旁腺激素(1-34)(PTH1-34)对大鼠下颌骨骨折愈合的短期和长期影响。方法 选择60只雄性SD大鼠构建下颌骨骨折模型,并根据随机数字表法分为5组:阴性对照组、地塞米松组、PTH1-34低剂量组、PTH1-34中剂量组和PTH1-34高剂量组,每组各12只。阴性对照组肌内注射等剂量0.9%氯化钠溶液,地塞米松组肌内注射1 mg/kg地塞米松,3个PTH1-34剂量组分别肌内注射15、30和60μg/kg,共连续治疗28 d。分析各组第1、2、3、4周骨折愈合处平均骨密度值、骨折愈合平均灰度值、骨小梁面积百分比和骨小梁厚度、骨痂形成评分、骨痂区骨保护素(OPG)水平以及血清骨形态发生蛋白(BMP-7)、转化生长因子β1(TGF-β1)和碱性成纤维生长因子(b FGF)浓度。结果随着时间的延长,3个PTH1-34剂量组不同时间段骨折愈合处平均骨密度值、骨折愈合平均灰度值、骨小梁面积百分比和骨小梁厚度、骨痂形成评分、骨痂区OPG水平以及血清BMP-7、TGF-β1及b FGF浓度均显著高于阴性对照组和地塞米松组,差异均有统计学意义(P <0.05),且中剂量PTH1-...

Experimental study on the short-term and long-term effects of parathyroid hormone(1-34)on mandibular fracture healing in rats

Objective To investigate the short-term and long-term effects of parathyroid hormone(1-34)(PTH_1-34)on mandibular fracture healing in rats.Methods Sixty male SD rats were selected to construct the mandibular fracture model and divided into 5 groups according to the random number table method:negative control group,dexamethasone group,PTH_1-34low-dose group,PTH_1-34medium-dose group and PTH_1-34high-dose group,12 rats in each group.The negative control group was intramuscularly injected with an equal dose of normal saline,and the dexamethasone group was intramuscularly injected with 1 mg/kg dexamethasone,and the three PTH_1-34dose groups were intramuscularly injected with 15μg/kg,30μg/kg and 60μg/kg,respectively,for a total of 28 days of continuous treatment.The mean bone mineral density(BMD),the mean gray value of fracture union,the percentage of bone trabecular area,the thickness of bone trabecular,the callus formation score,the level of osteoprotege(OPG)in the callus area,and the concentration of serum bone morphogenetic protein 7(BMP-7),transforming growth factor beta 1(TGF-β1)and basic fibroblast growth factor(bFGF)at the fracture healing site in the 1st,2nd,3rd,and 4th weeks of each group was analyzed.Results Over time,the three PTH_1-34dose groups compared with the normal saline group and dexamethasone group.The mean bone mineral density,the mean gray value of fracture union,the percentage of bone trabecular area,the thickness of bone trabecular,the callus formation score,the level of bone protection hormone(OPG)in the callus area,and the concentration of serum BMP-7,TGF-β1 and bFGF were significantly higher than those of normal saline group and dexamethasone group,the differences were statistically significant(P<0.05),and the effect of medium dose PTH_1-34was the most significant.Conclusion PTH_1-34has a significant effect on promoting mandibular fracture healing in rats.In terms of short-term effects,PTH_1-34can promote the increase of bone mineral density and osteoprotectin levels.In terms of long-term effects,PTH_1-34can promote the formation of callus and trabecular bone,which may be related to the promotion of serum BMP-7,TGF-β1 and bFGF growth factor,but there was an optimal dose(30μg/kg)for its effect,and the effect would decrease below or above this dose.