title: [Expression of OPG/RANK/RANKL in the rat dental pulp tissue of periodontitis combined with vascular calcification and its clinical significance].
abstract: OBJECTIVE
  To study the expression and possible role of OPG/RANK/RANKLin the rat dental pulp of periodontitis combined with vascular calcification.
  
  
  METHODS
  Thirty-six male Wister rats were randomly divided into 4 groups: control group(group C), periodontitis group(group CP), vascular calcification group(group VDN) and compound group(group CP+VDN). Each group underwent corresponding management to establish animal model. When the model was successful, the maxillae including molars were sectioned, pulp tissue was examined by H-E staining; Immunohistochemical staining method was used to evaluate the expression and ratio of OPG and RANKL in pulp tissues. Statistical analysis was carried out using SPSS 19.0 software package.
  
  
  RESULTS
  The pulp tissue of group CP, VDN, CP+VDN showed varied degrees of damage, neutrophil infiltration, pulp vascular congestion, odontoblasts vacuolar changes, pulp necrosis by H-E staining, and the changes in CP+VDN group was the most significant, followed by CP group, VDN group. Immunohistochemistry showed OPG in pulp tissues in group CP, VDN, CP+VDN were significantly lower than that in normal group (P<0.05), and the expression in group CP+VDN was the least;Expression of RANKL in pulp tissues in group CP, VDN, CP+VDN were significantly higher than that in normal group(P<0.05)，and the expression in group CP+VDN was the highest. The ratio of OPG/RANKL in normal group was the highest, and the ratio in CP+VDN group was the lowest.
  
  
  CONCLUSIONS
  Periodontitis and vascular calcification can damage the pulp tissue, periodontitis compound with vascular calcification may aggravate the injury; OPG/RANKL/RANK system may play an important role in pulp tissue injury.
authors.affiliation: Department of Stomatology, Affiliated Hospital of Qingdao University；Key Laboratory of Clinical Stomatology. Qingdao 266003, Shandong Province,China. E-mail:pankeqing77@sina.com.
authors.forename: Ke-Qing
authors.initials: KQ
authors.lastname: Pan
authors.forename: Peng-Mei
authors.initials: PM
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Deng
authors.forename: Xiu-Xiu
authors.initials: XX
authors.lastname: Lou
authors.forename: Yun
authors.initials: Y
authors.lastname: Meng
authors.forename: Gui-Rong
authors.initials: GR
authors.lastname: Liu
mesh_terms: D000818:Animals; D003782:Dental Pulp; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D007249:Inflammation; D008297:Male; D008963:Molar; D053244:Osteoprotegerin; D010518:Periodontitis; D053245:RANK Ligand; D051381:Rats; D017208:Rats, Wistar; D061205:Vascular Calcification
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand