糖尿病大鼠骨折愈合过程中相关细胞因子水平及行为变化的实验研究

Experimental study on the levels of related cytokines and behavior changes during the course of fracture healing in streptozotocin-induced diabetic rats

目的观察糖尿病大鼠骨折前、后血清转化生长因子β2（TGF-β2）、碱性成纤维细胞生长因子（BFGF）、血小板源性生长因子（PDGF）、白细胞介素-6（IL-6）、白细胞介素-8（IL-8）及肿瘤坏死因子-α（TNF—α）水平及行为变化，并分析其相关性。方法制备糖尿病大鼠模型，同时随机数字表法分为各实验组。实验组、对照组大鼠折断右胫腓骨，然后复位外固定。骨折后拍X线片观察骨折愈合情况，操作完毕分笼饲养。测不同时间段两组大鼠血清相关细胞因子含量。结果糖尿病骨折组大鼠行为变化显著：出现运动迟缓，呆滞，表现多饮、多食、多尿、消瘦症状明显。骨折后1，2，4周，测定实验组、对照组相关细胞因子水平，两者差异有统计学意义[TNF-α：对照组分别为（9．87±1．06）ng／ml，（14．07±1．43）ng／ml，（12．02±1．02）ng／ml；实验组分别为（11．65±1．18）ng／ml，（16．29±1．24）ng／ml，（13．87±1．25）ng／ml，P〈0．05]，X线片上实验组骨痴延迟对照组。结论骨折早期TGF-β2、BFGF、PDGF水平降低、IL-6、IL-8及TNF—α含量增加是导致糖尿病大鼠骨折延迟愈合及不愈合的重要原因之一，且具有协同作用。

Objective To investigate the change of levels of related cytokines, inciuding transforming growth factor-β2 （TGF-β2） , basic fibroblast growth factor （bFGF）, platelet-derived growth factor （PDGF）, in- terleukin-6 （ IL-6 ）, interleukin-8 （ IL-8 ） and tumor necrosis factor-α （ TNF-α ） and behavior in streptozotocin-in- duced diabetic rats between the before and after fracture, at the same time, to analyse the relativity of them. Meth- ods The rat models of diabetic were induced by intraperitoneal injection of streptozotocin, which were divided into different diabetes mellitus group （DM group） randomly. The right tibiofibula of all the rats of diabetes mellitus group and normal control group （NC group） were broken, and then treated with external fixation. The bone callus formation was evaluated by X-ray. When all the operation above was completed, the rats were domesticated in dif- ferent cages. The concentration of related eytokines of the DM groups and NC group was detected at different time. Results The behavior changes of diabetes fracture rats were distinct and appeared a series symptoms such as bra- dykinesia, dull, polydipsia, polyphage, polyuria, emaciated obviously. The concentration of related cytokines （ TGF- β2,BFGF,PDGF,IL-6,IL-8 and TNF-α） of the two groups was detected at 1,2 and 4 weeks. The difference be- tween them was significantly （ TNF-α ： the concentration of NC group were （9.87 ± 1.06 ） ng/ml, （ 14.07 ±1.43 ） ng/ml and （ 12.02± 1.02 ） ng/ml ; the concentration of DM group were （ 11.65 ± 1.18 ） ng/ml, （ 16.29 ± 1.24 ） ng/ml and（ 13.87 ± 1.25）ng/ml; P〈0.05）. X-ray films showed that the fracture healing of NC group was more superior than that of DM group. Conclusion The reduction of TGF-β2, BFGF, PDGF and the increase of IL-6, IL-8 ,TNF-α in early fracture are one of important reasons for delayed union and nonunion in diabetic rats. At the same time, there is a cooperative action between them. Dynamic observation of the concentration of related cyto- kines will provide eliable experimental data to estimate fracture healing, delayed union and nonunion. It is favoura- ble to acquaint the regulatory mechanism of fracture healing at molecular level.