二膦酸盐对骨质疏松大鼠下颌牙槽骨牙本质基质蛋白1表达的影响

目的 :观察二膦酸盐对去卵巢骨质疏松大鼠下颌牙槽骨内破骨细胞以及牙本质基质蛋白1(dentin matrix protein1,DMP1)表达的影响。方法 :取6月龄SD大鼠30只,随机分为假手术组(Sham)、去卵巢模型组(OVX)和二膦酸盐药物治疗组(RIS),每组10只。Sham组大鼠仅术中暴露卵巢不切除,OVX组大鼠行"双侧卵巢切除术+生理盐水皮下注射",RIS组行"双侧卵巢切除术+利塞磷酸钠(2.4μg/kg)皮下注射"。术后3个月取各组大鼠下颌骨常规脱钙,甲苯胺兰染色观察下颌第一磨牙(M1)区域牙槽骨组织学结构,抗酒石酸酸性磷酸酶(tartrate-resistant acid phosphatase,TRAP)染色观察M1区域牙槽纵隔破骨细胞的骨吸收情况,免疫组化染色观察各组M1牙槽骨DMP1分布表达情况,并进行相关半定量图像分析。结果:与Sham组相比,OVX组TRAP阳性细胞数增加;而较OVX组而言,RIS组TRAP阳性细胞数显著减少(P<0.05)。免疫组化染色显示,各组DMP1不仅表达在牙槽骨骨细胞内,牙槽间隔的松质骨骨基质、牙周韧带中均可见其表达,OVX组M1牙槽骨DMP1表达较Sham组减少(P<0.05),而RIS组表达较OVX组有升高。结论:二膦酸盐能减少骨质疏松大鼠下颌牙槽骨破骨细胞数量,并上调DMP1表达,从而影响下颌牙槽骨矿化。     

不同去势时间对大鼠牙槽骨微结构影响的比较研究

目的 比较不同去势时间对大鼠牙槽骨微结构的影响,探讨牙槽骨骨质疏松大鼠模型建立成功的参数。方法 24只6月龄雌性SD大鼠,随机分为4组：（1）对照组1（Sham1）;（2）去势组1（OVX1）;（3）对照组2（Sham2）;（4）去势组2（OVX2）。分别在全麻下行假手术和双侧卵巢去势术。于术后3个月和4个月处死各组大鼠,取双侧上颌骨标本,通过Micro-CT扫描、HE染色、抗酒石酸酸性磷酸酶（TRAP）染色、Van Gieson染色、荧光双标观察并分析牙槽骨微结构的变化。结果 去势3个月后OVX1组与Sham1组大鼠相比,体重增加25.09%（P<0.01）;牙槽骨骨体积分数（BV/TV）、骨小梁数目（Tb.N）、骨小梁分离度（Tb.Sp）,牙骨质界-牙槽嵴顶（CEJ-ABC）距离无改变（P>0.05）,骨小梁宽度（Tb.Th）降低了12.44%（P<0.05）,破骨细胞数量增加了40.12%（P<0.01）;骨形成沉积率（MAR）无明显改变（P>0.05）;去势4个月后OVX1组与Sham1组大鼠相比,体重进一步增加了26.25%（P<0.01）,BV/TV、Tb.Th、MAR分别降低了11.15%、17.22%和38.45%（P<0.01）,Tb.Sp和破骨细胞数量分别增加了81.89%和35.67%（P<0.01）,Tb.N和CEJ-ABC距离无变化（P>0.05）,HE和Van Gieson染色均表明OVX2组大鼠牙槽骨骨量降低,骨髓腔面积增加,骨小梁微结构破坏、变细,部分区域发生断裂。结论 6月龄雌性SD大鼠去势4个月后,牙槽骨发生明显骨质疏松,可作为合适的牙槽骨骨质疏松大鼠模型参数的理论依据。     

淫羊藿苷口服给药对骨质疏松牙周炎小鼠牙槽骨吸收的影响

目的:研究口服淫羊藿苷（ICA）对骨质疏松小鼠牙周炎引起的牙槽骨吸收的抑制作用。方法:3月龄、雌性、C57BL/6J小鼠随机分为3组,即正常组（SHAM组）、卵巢切除+口腔涂布牙龈卟啉单胞菌（Pg）+淫羊藿苷组（OVX+Pg+ICA）、卵巢切除+Pg口腔涂布组（OVX+Pg）。小鼠适应性喂养1周,第2周进行双侧卵巢切除术,诱导小鼠骨质疏松形成。从第4周开始,对小鼠牙周涂布Pg,1次/d,连续1周。第12周收集左侧下颌骨进行固定切片及染色,分析各组之间牙槽骨吸收高度的差异。收集右侧下颌骨进行亚甲蓝染色,分析各组间牙槽骨吸收面积的差异;收集双侧上颌骨牙周组织蛋白,分析成骨相关蛋白的表达差异。采用SPSS16.0软件包对数据进行统计学分析。结果:小鼠股骨及牙周组织切片染色显示,成功建立了小鼠骨质疏松牙周炎模型。对牙槽骨吸收距离和面积的测量分析显示,相比于OVX+Pg组,口服淫羊藿苷可显著减少釉-牙骨质界-牙槽嵴顶（CEJ-ABC）的距离及颊舌侧牙槽骨吸收面积（P<0.05）;Western免疫印迹显示,相比于OVX+Pg组,OVX+Pg+ICA组中Runx2、OSX、OCN及OPN蛋白表达水平显著升高（P<0.05）。结论:口服淫羊藿苷在预防小鼠骨质疏松发生的同时,可有效减少牙周炎引起的牙槽骨吸收。     

MicroCT定量研究去势大鼠颌骨与胫骨的骨改变

目的:应用MicroCT对Sprague-Dawley(SD)雌性大鼠去除双侧卵巢三个月后的下颌骨和胫骨进行对比研究。方法:分别从假手术对照(Sham)组和卵巢切除骨质疏松(OVX)组各取大鼠8只。将全部大鼠深度麻醉后处死。取一侧下颌骨和胫骨,去净软组织。行MicroCT检查、骨组织病理学研究。所得数据经SPSS13.0统计分析。结果:大鼠去除双侧卵巢3月后,经MicroCT检查发现,OVX组大鼠胫骨:骨小梁数目减少,排列稀疏,骨小梁断裂;骨小梁面积比和体积比、厚度和数目,骨矿含量和骨体积密度等均较Sham组显著降低,骨小梁分离度增加,P<0.05。OVX组大鼠下颌骨:骨组织体积比、骨小梁厚度和单位体积骨小梁数目,均比Sham组升高,骨小梁分离度较Sham组降低,P<0.05。与胫骨改变比较,结果完全相反。另外,大鼠下颌骨的三维骨矿含量和骨体积密度也升高,P<0.05。骨组织切片病理学观察:Sham组胫骨松质骨呈条索状,骨小梁相互连接成网;下颌骨松质骨较致密,呈板状。OVX组胫骨骨小梁变细,分离度增大,新生骨基质减少。磨牙下方松质骨骨髓腔增大,牙槽突新生骨基质减少。结论:SD雌性大鼠切除卵巢3月后,下颌骨与胫...     

姜黄素对去势骨质疏松大鼠下颌骨和股骨EZH2基因表达的影响

目的 研究姜黄素对去势骨质疏松大鼠下颌骨和股骨EZH2（enhancer of zeste homolog 2,EZH2）表达的影响,探讨其对骨质疏松大鼠的保护作用及机制。方法 将30只6月龄SD雌性大鼠随机分为假手术组（SHAM组）、去势模型组（OVX组）和姜黄素治疗组(OVX+C组)。治疗组将姜黄素溶于羧甲基纤维素钠溶液后,按110 mg/kg·d灌胃给药;假手术组和去势模型组灌胃同等剂量羧甲基纤维素钠溶液,每天1次,连续12周后取材。检测大鼠血清钙、磷、碱性磷酸酶的指标变化,采用Micro-CT对左侧下颌骨和股骨的骨形态计量学参数进行测定。取右侧下颌骨和股骨,采用PT-PCR法检测骨组织EZH2mRNA的表达。采用SPSS22.0软件包对数据进行统计学分析。结果 OVX组骨组织中EZH2mRNA的表达显著高于SHAM组（P<0.05）。与OVX组相比,姜黄素可以改善骨质疏松大鼠的骨微结构,增加骨密度,降低骨质疏松大鼠血清碱性磷酸酶含量,使骨组织EZH2mRNA表达显著下调（P<0.05）。结论 姜黄素能够防治去势大鼠的骨量丢失和改善骨微结构,其机制可能与下调EZH2mRNA的表达水平有关。     

实验性糖尿病牙周炎诱导骨细胞凋亡的初步研究

目的初步探讨糖尿病牙周炎条件下骨细胞的凋亡情况。方法选用6wk雄性SD大鼠62只,随机分为糖尿病牙周炎组（DP,n=22）、牙周炎（P,n=20）以及正常对照组（N,n=20）。采用一次性腹腔注射STZ（55mg/kg）的方法建立大鼠糖尿病模型,注射STZ后1wk检测血糖,血糖≥16.65mmol/L者定为糖尿病大鼠。采用丝线结扎大鼠上颌第二磨牙联合口内接种细菌的方法建立牙周炎模型。动物分别于丝线结扎后3wk和6wk分批处死,进行HE染色和原位细胞凋亡检测。观察指标包括：牙槽骨丧失（ABL）,骨细胞计数,骨细胞凋亡百分率。资料采用单因素方差分析统计学处理。结果丝线结扎后3周和6周,大鼠牙槽骨丧失在N组与P组、N组与DP组、P组与DP组不同,组间两两比较均有统计学意义（P〈0.05）,牙槽骨丧DP组〉P组〉N组。与N组比较,P组和DP组单位面积骨细胞数均减少,与P组比较,DP组单位面积骨细胞数亦显著减少（P〈0.05）。在丝线结扎后3周和6周,糖尿病牙周炎组（DP）骨细胞凋亡百分率均达到牙周炎组（P）的2倍左右。结论糖尿病条件下牙周炎骨丧失明显增加,糖尿病可加强牙周炎条件下牙周组织中骨细胞的凋亡,降低骨细胞的数量。     

阿仑膦酸钠对骨质疏松种植体骨结合影响的力学研究

目的 通过力学评估研究全身应用骨吸收抑制剂阿仑膦酸钠对骨质疏松模型种植体周围骨整合的影响.方法 27只5月龄日本大耳白兔随机分成3组,每组9只:单纯卵巢切除组(OVX组),伪手术组(S组),卵巢切除加阿仑膦酸钠组CALN组).卵巢摘除后12周,双侧股骨远心端、胫骨近心端植入4枚种植钉,ALN组腹腔给予阿仑膦酸钠,OVX...     

去势大鼠骨质疏松模型的综合评定

目的：多种方法评定大鼠去除双侧卵巢三个月后是否形成明显骨质疏松状态。方法：分别从6月龄SD雌性大鼠假手术对照（Sham）组和卵巢切除骨质疏松（0VX）组各取大鼠8只。将全部大鼠取血后处死。取一侧胫骨、股骨,去净软组织。分别行血生化骨代谢指标检测、MicroCT检查、骨组织计量学测量及组织病理学观察、三点弯曲试验。所得数据经SPSS13．0统计分析。结果：OVX组大鼠ALP、OC较Sham组明显升高,P〈0．05。骨小梁数目减少,排列稀疏,骨小梁断裂;骨小梁面积比和体积比、厚度和数目,骨矿含量和骨体积密度等均较Sham组显著降低,骨小梁分离度增加,P〈0．05。OVX组弹性载荷与Sham组升高明显,P〈0．05;最大应力和弹性应力显著降低P〈0.05。结论：经多种方法评定,3月龄SD雌性大鼠切除卵巢3月后,形成明显骨质疏松状态。OVX大鼠,骨量降低,骨小梁结构改变,骨生物力学性能变差。     

二甲双胍对骨质疏松大鼠晚期糖基化终产物影响的研究

目的:探讨通过应用二甲双胍干预双侧卵巢摘除大鼠血清中晚期糖基化终产物变化从而调控骨代谢的可行性。方法:使用SD雌鼠通过行双侧卵巢摘除术或假手术建立停经后骨质疏松症模型(OVX组)及对照组模型(Sham组),3月后给予不同剂量二甲双胍灌胃,分为4组,分别是Sham组,OVX组,OVX+50 mg/kg/d二甲双胍组 ,OVX+100 mg/kg/d二甲双胍组,3月后处死大鼠,应用组织学方法检测不同组别大鼠骨质差异,应用酶联免疫吸附试验(ELISA)比较晚期糖基化终产物(AGEs)在血清中的表达差异。结果:与Sham组相比,OVX组大鼠的胫骨骨质明显呈现疏松多孔样,血清中AGEs含量明显升高;灌胃二甲双胍后,胫骨骨质量改善,骨小梁分布较OVX组密集,同时血清中AGEs含量较OVX组显著降低,但尚未达到Sham组水平,而OVX+50 mg/kg/d二甲双胍组与OVX+100 mg/kg/d二甲双胍组大鼠血清中AGEs含量无明显差异。结论:二甲双胍可能通过降低绝经后骨质疏松大鼠血清中的AGEs含量进而改善骨代谢。[关键词] 二甲双胍 绝经后骨质疏松症 晚期糖基化终产物     

Long-term changes in trabecular structure of aged rat alveolar bone after ovariectomy

OBJECTIVE: Trabecular structural changes in the jaw after long-term estrogen deficiency are not well understood. Therefore, we sought to observe the changes in rat alveolar bone for 1 year. METHODS: Six-month-old female rats were ovariectomized (OVX) or underwent a sham operation. After 1 year, bone histomorphometry and a node-strut analysis were performed on the interradicular septum of the mandibular first molar by using micro computed tomography and confocal laser scanning microscopy. Statistical analysis was carried out by using analysis of variance. RESULTS: The alveolar trabeculae of rats in the sham group had network structures, whereas the trabeculae of rats in the OVX group became fragmented. The trabecular bone volume, number, and thickness in the OVX group were significantly lower than those found in the sham group, and the trabecular separation was 4-fold higher in the OVX group than in the sham group. Bone resorptive and formative activity appeared to be moderately higher in the OVX group than in the sham group, but only the difference in bone formation was of statistical significance. CONCLUSION: By 1 year after ovariectomy, bone loss and trabecular fragmentation had occurred in the rat mandibular alveolar bone.     

不同去势时间大鼠牙槽骨微结构变化的Micro-CT研究

目的： 观察不同去势时间大鼠牙槽骨微结构的改变,探讨去势时间对牙槽骨骨质疏松程度的影响。方法： 健康未孕雌性SD大鼠24只,随机分为去势组(OVX)与假手术组（sham）,每组各12只,分别在全麻下行双侧卵巢去势术与假手术。于术后3个月及6个月2个不同时间点分别处死每组大鼠各6只,取右侧上颌骨标本行Micro-CT扫描;观察去势3个月及6个月后大鼠上颌第一磨牙根分叉区牙槽骨微结构的改变。采用SPSS16.0软件包对数据进行统计学分析。结果： Micro-CT水平面、矢状面二维图像及三维重建均显示,去势3个月及6个月大鼠牙槽骨骨髓腔面积增加、骨小梁变细、部分发生断裂。骨结构参数分析显示,去势3个月及6个月后,大鼠牙槽骨骨密度（BMD）及骨体积分数（BV/TV）、骨小梁宽度（Tb.Th）均显著低于相应时间假手术大鼠（P<0.05）;去势6个月组较3个月组大鼠牙槽骨骨密度(BMD)、骨体积分数(BV/TV)、骨小梁宽度(Tb.Th)显著降低（P<0.05）。去势3个月及6个月大鼠骨小梁数目（Tb.N）及骨小梁分离度（Tb.Sp）显著高于相应假手术组（P<0.05）,且去势6个月组骨小梁数目(Tb.N)显著高于去势3个月组（P<0.05）。结论： 随着去势时间延长,大鼠牙槽骨骨量降低、骨小梁微结构破坏加剧,骨质疏松程度加重。     

雌孕激素缓释凝胶对去势牙周炎大鼠牙槽骨吸收部位修复再生作用的研究

目的:研究雌孕激素缓释凝胶对去势牙周炎大鼠牙槽骨修复再生的作用。方法:选取6月龄雌性大鼠,随机分为去势组和假手术组,去势术后12周检测血清钙、磷、碱性磷酸酶和E2浓度。用0.2 mm结扎线于单侧第一磨牙牙颈部结扎,结扎4周后,建立大鼠牙周炎模型,用Micro-CT观察骨丧失情况。移除结扎线,将大鼠分为假手术生理盐水组,假手术上药组,去势生理盐水组和去势上药组。将配制好的雌孕激素缓释凝胶和生理盐水分别注入大鼠牙周袋内,治疗8周后,进行Micro-CT分析和HE组织学染色。结果:去势大鼠骨密度降低,血清钙、磷浓度降低,碱性磷酸酶活性升高,E2浓度降低。牙周结扎后,假手术组牙槽骨有水平吸收,去势组牙槽骨不仅水平方向上的吸收,垂直方向上也同样有吸收,牙槽嵴高度降低明显,根分叉暴露。雌孕激素缓释凝胶联合应用后,牙槽骨骨密度(BMD)升高、骨小梁数量(Tb.n)增加、骨小梁分离度(Tb.Th)增加、骨小梁连接数(Tb.Pf)增多,破骨细胞减少,新骨形成。结论:雌孕激素缓释凝胶能够促进去势大鼠牙槽骨吸收部位的修复再生。     

Alendronate may protect against increased periodontitis-related bone loss in estrogen-deficient rats

BACKGROUND: The aim of this study was to evaluate the impact of alendronate (ALD) and estrogen (EST) therapies and their withdrawal on bone loss in experimental periodontitis in ovariectomized rats. METHODS: Eighty-seven Wistar rats were divided into six groups: group 1 (N = 15): sham surgery; group 2 (N = 15): ovariectomy (OVX); group 3 (N = 15): OVX plus alendronate administration for 80 days (AT); group 4 (N = 14): OVX plus alendronate administration for 40 days (AW); group 5 (N = 14): OVX plus 17beta estradiol administration for 80 days (ET); and group 6 (N = 14): OVX plus 17beta estradiol administration for 40 days (EW). Twenty-one days after ovariectomy or sham surgery, one mandibular molar was randomly assigned to receive a ligature, while the contralateral tooth was left unligated. Sixty days later, the animals were sacrificed and the specimens processed. RESULTS: OVX presented a direct impact on alveolar bone, regardless of plaque accumulation and significantly increased bone loss resulting from periodontitis (P < 0.05). The effect of OVX on unligated sites was significantly reduced by AT, AW, and ET (P < 0.05), but not by EW (P > 0.05). In addition, alendronate administration (AT/AW) significantly reduced the impact of OVX on periodontitis-related bone loss (P < 0.05), while estradiol did not (P > 0.05). CONCLUSION: Within the limits of this study, alendronate administration, but not estrogen replacement, may protect against the impact of estrogen deficiency on alveolar bone presenting a significant residual effect after its withdrawal.     

Effects of Estrogen Deficiency and/or Caffeine Intake on Alveolar Bone Loss,Density, and Healing: A Study in Rats

Background: The aim of this study is to evaluate the effects of caffeine and/or estrogen deficiency on ligature‐induced bone loss (BL), trabecular bone area (TBA), and postextraction bone healing (BH). Methods: Rats were assigned into one of the following groups (15 each): 1) control = non‐ingestion of caffeine/sham surgery; 2) caffeine = ingestion of caffeine/sham surgery); 3) ovariectomized (OVX) = non‐ingestion of caffeine/ovariectomy; or 4) caffeine/OVX = ingestion of caffeine/ovariectomy. The rats were under caffeine administration for 65 days and/or estrogen deficiency for 51 days. On day 21 after ovariectomy, one first mandibular molar received a ligature and the contralateral tooth was not ligated. The first maxillary molars were extracted 8 days before sacrifice. BL, TBA, the positive cells for tartrate‐resistant acid phosphatase (TRAP), receptor activator of nuclear factor‐κB ligand (RANKL), and osteoprotegerin (OPG) were analyzed in the furcation area of mandibular molars. Histometric BH and gene expression of bone morphogenetic protein (BMP)‐2, BMP‐7, osteopontin, and bone sialoprotein were evaluated in alveolar sockets. Results: The caffeine group presented the greatest BL and the OVX group the highest number of TRAP‐positive (TRAP⁺) cells around ligated teeth (P <0.05). The control group presented higher TBA and BH than the other groups (P <0.05). All test groups presented higher RANKL/OPG⁺ cells than the control group around ligated/unligated teeth. The OVX and caffeine/OVX groups presented a greater number of TRAP⁺ cells around unligated teeth than the control group (P <0.05). There were no differences among groups for gene expression (P >0.05). Conclusions: Caffeine increased BL in ligated teeth. Caffeine and/or estrogen deficiency decreased TBA in the unligated teeth and reduced BH after tooth extraction.     

Raloxifene therapy inhibits osteoclastogenesis during the alveolar healing process in rats

Objective

To investigate the expression of OPG, RANKL and TRAP during alveolar healing process (7, 14, 21, 28 and 42 postoperative days) in ovariectomized rats treated with raloxifene or with oestrogen replacement therapy, using immunohistochemistry reaction approach.

Materials and methods

Wistar female rats (10 weeks age) were submitted to ovariectomy surgery (OVX) or sham surgery. The female rats were divided in four groups: (1) sham; (2) OVX/O (ovariectomy and oil); (3) OVX/E2 (ovariectomy and oestrogen replacement); (4) OVX/RLX (ovariectomy and raloxifene therapy).

Results

It was observed high amount of OPG immunolabelling with predominance at 14 and 21 postoperative days on sham and OVX/RLX groups, respectively. At 7 postoperative days, there was no difference between the groups for TRAP protein. Otherwise, to the other periods, it was observed greater expression of TRAP and RANKL protein on OVX/O group compared to sham, OVX/E2 and OVX/RLX groups. It was also observed a discrete TRAP immunolabelling at 28 and 42 postoperative days on OVX/RLX group.

Conclusions

Oestrogen deficiency induces osteoclastogenesis in the alveolar healing process. Quantitative changes in the osteoclastic activity could be prevented through the raloxifene therapy.     

雌激素对骨质疏松大鼠牙槽骨改建及IL-1表达的影响

目的：探讨雌激素对骨质松牙槽骨改建中ＩＬ－１的表达与分布的影响及意义。方法：在建立ＳＤ大鼠骨质疏松模型的基础上,用免疫组化染色方法,观察ＩＬ－１在骨质疏松以及雌激素治疗后的牙槽骨中的表达变化。结果：ＩＬ－１在骨质疏松牙槽骨中有较强的表达,阳性反应主要分布于破骨细胞,部分成骨细胞及骨细胞中,而在用雌激素治疗骨质疏松组中,ＩＬ－１的阳性表达程度明显下降。