右美托咪定对股骨骨折模型大鼠疼痛因子及LRP5表达水平的影响

Effect of Dexmedetomidine on Pain Factors and LRP5 Expression in Rats with Femoral Fracture

目的探讨右美托咪定对骨折模型大鼠疼痛因子及LRP5水平的影响。方法选取健康清洁大鼠40只,随机分为正常组、模型组、右美托咪定组、丙泊酚组,每组各10只。正常组大鼠分离股骨肌腱组织后迅速缝合,其余三组均建立股骨骨折模型。建模成功后,连续1周右美托咪定组和丙泊酚组大鼠经腹腔分别注射右美托咪定(1.5μg/kg)和丙泊酚(1.5μg/kg),模型组和正常组大鼠注射同体积生理盐水。分别检测四组大鼠炎性因子水平、疼痛行为MWT与TWL值、LRP5与β-catenin蛋白表达,进行行为能力评分,观察病理组织改变情况。结果与正常组比较,三组骨折模型大鼠TNF-α、IL-6水平、行为能力累计评分与运动能力评分、骨组织内LRP5与β-catenin均升高(P<0.05);且三组骨折大鼠中右美托咪定组上述指标最低,丙泊酚组次之,而模型组最高,差异均有统计学意义(P<0.05)。骨折模型大鼠IL-10水平及MWT、TWL值均低于正常组(P<0.05),且三组中右美托咪定组以上指标最高,丙泊酚组次之,模型组最低,差异均有统计学意义(P<0.05)。HE染色显示:正常组大鼠骨组织完好,细胞间排列整齐且分布均匀;模型组大鼠骨细胞排列紊乱,出现一定量纤维组织,骨基质中大量骨细胞沉积,部分出现坏死区域;右美托咪定组纤维组织密度增加,排列趋于有序,且有新生组织形成;丙泊酚组纤维组织排列稍整齐,但仍有部分坏死区域。结论右美托咪定对骨折大鼠在抑制术后疼痛、缓解骨折机械痛敏及热痛敏、调节LRP5表达等方面具有一定效果,但在减轻炎性反应、抑制炎症表达等方面仍需进一步研究。

Objective To investigate the effect of dexmedetomidine on pain factors and LRP5 expression levels in femoral fracture rats.Methods A total of forty healthy rats were randomly divided into normal group,model group,dexmedetomidine group and propofol group,with 10 rats for each group.The normal group was sutured rapidly after the dissection of femoral tendon tissue,and the femoral fracture model was established in the other three groups.After successful modeling,the rats of dexmedetomidine group and propofol group were injected with dexmedetomidine(1.5μg/kg)and propofol(1.5μg/kg)respectively for one week,and both model group and normal group were injected with the same volume of normal saline for one week.The levels of inflammatory factors(TNF-α、IL-6、IL-10),pain behavior(MWT and TWL),behavioral ability evaluation(accumulative score and motor function score),LRP5 andβ-catenin protein expression were measured,and HE staining of pathological tissue was observed.Results The levels of TNF-α,IL-6,accumulative score and motor function score of behavior ability,LRP5 andβ-catenin of bone tissue in three fracture groups were higher than those in the normal group(P<0.05);In the three fracture groups,the indexes mentioned above was the lowest in the dexmedetomidine group and the highest in model group(P<0.05).The IL-10 level,MWT and TWL of three fracture groups were lower than those of the normal group(P<0.05);In the three fracture groups,IL-10,MWT and TWL were the highest in dexmedetomidine group and the lowest in model group(P<0.05).HE staining showed that the bone tissue of rats was normal,the cells distributed orderly and evenly in the normal group;the bone arrangement was disordered,a certain amount of fibrous tissue appeared and a large number of bone cells were deposited in the bone matrix and necrosis was found in the model group;The density of fibrous tissue increased,the arrangement was orderly and new tissues were formed in the dexmedetomidine group;The fibrous tissue was slightly orderly and necrosis appeared in the propofol group.ConclusionDexmedetomidine can achieve a certain effect in inhibiting postoperative pain,relieving mechanical and thermal pain sensitivity and regulating LRP5 expression in fracture rats,but its value need to be further studied in reducing inflammatory response and expression.