慢性氟中毒环境对大鼠正畸牙移动过程中牙周组织VEGF和eNOS表达的影响

Effect of Chronic Fluorosis Environment on Expression of VEGF and eNOS in Periodontal Tissue During Orthodontic Tooth Movement in Rats.

目的:通过观察慢性氟中毒大鼠牙移动过程中牙周组织内血管内皮生长因子(vascular endothelial growthfactor,VEGF)、内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)的表达变化,初步探究机体慢性氟中毒状态对大鼠正畸牙移动过程中牙周组织血管生成的影响。方法:选取3周龄SPF级SD大鼠120只,体重(60±5)g,随机分为空白组(C)、染氟组(F)、正畸组(O)、染氟正畸组(FO),每组雌雄各15只,根据正畸加力时间分为0、3、7、14、28 d组,共5个时间亚组。分别相应时间点处死各组大鼠,苏木精-伊红染色观察牙周组织血管情况,免疫组织化学染色观察大鼠牙周组织VEGF及eNOS蛋白表达情况。结果:(1)慢性氟中毒大鼠及正畸牙移动大鼠模型复制成功;(2)O组牙周纤维排列较C组紊乱,牙周血管数量增多,管腔不规则。FO组血管新生分布不及O组突出。(3)各组雌雄大鼠间VEGF、eNOS表达无明显性别差异,O组、FO组张力侧VEGF、eNOS表达与压力侧相比无明显统计学差异。(4)FO组VEGF、eNOS的蛋白平均表达水平高于F组,但低于O组,且差异有统计学意义。(5)O组、FO组VEGF、eNOS蛋白表达随时间延长呈先升高后降低趋势,第3天表现为峰值。结论:慢性氟中毒会抑制大鼠牙移动过程中牙周组织VEGF、eNOS的表达。

Objective:To observe the expression changes of periodontal tissue,vascular endothelial growth factor(VEGF),and endothelial nitric oxide synthase(eNOS)during tooth movement in SD rats with chronic fluorosis,and to preliminarily explore the possible effects of chronic fluorosis on the angiogenesis of periodontal tissue in orthodontic tooth movement rats.Methods:One hundred and twenty 3-week-old SPF grade SD rats weighing(60±5)g were selected and randomly divided into blank group(C),fluoride group(F),orthodontic group(O),and fluoride orthodontic group(FO),with 15 males and 15 females in each group.According to the duration of orthodontic force,they were divided into 0,3,7,14,and 28 day groups.Each group of rats was euthanized at corresponding time points,and HE staining was used to observe the vascular status of periodontal tissue.Immunohistochemical staining was used to observe the expression of VEGF and eNOS proteins in rat periodontal tissue.Results:The models of chronic fluorosis rats and orthodontic tooth movement rats were successfully established.The arrangement of periodontal fibers in Group O was more disordered than that in Group C,with an increase in the number of periodontal blood vessels and irregular lumens.The distribution of angiogenesis in the FO group was less prominent than that in the O group.There was no significant gender difference in the expression of VEGF and eNOS between male and female rats in each group.There was no significant statistical difference in the expression of VEGF and eNOS on the tension side compared to the pressure side in the O and FO groups.The average protein expression levels of VEGF and eNOS in the FO group were higher than those in the F group,but lower than those in the O group(P<0.05).The expression of VEGF and eNOS proteins in the O and FO groups showed an increasing trend followed by a decreasing trend over time,with a peak on the third day.Conclusion:Chronic fluorosis can inhibit the expression of VEGF and eNOS in the periodontal tissue of rats during tooth movement.