title: [Effect of oral intervention on matrix metalloproteinase-2, 9 expression in carotid arteries and serum interleukin-6 in rats with chronic periodontitis].
abstract: OBJECTIVE
  To establish chronic periodontitis model in SD rats, and to investigate the effect of oral intervention on atherosclerosis.
  
  
  METHODS
  Fifty male SD rats were randomly divided into three groups, group A (normal control), group B (atherosclerosis,As) and group C (chronic periodontitis, CP). Group C was further divided into group C1 (natural process), group C2 (simple mechanical treatment), group C3 (systemic antibiotics), group C4-1 (teeth extraction) and group C4-2 (teeth extraction+systemic antibiotics), each group consisted of 7 rats. Every group received oral intervention. Serum interleukin (IL)- 6 levels were detected in five different time points (1, 3, 5, 7, 9 weeks after a successful modeling) by enzyme linked immunosorbent assay. All animals were killed after 24 weeks. Matrix metalloproteinase (MMP)- 2, 9 in the proximal aorta was detected by immuno histochemistry.
  
  
  RESULTS
  The levels of serum IL-6 in groups B and C1 increased gradually with time and became significantly higher than that in group A (P < 0.01). Levels of serum IL-6 were increased gradually in each intervention group (C2, C3, C4-1, C4-2) and reached its peak at 5 weeks after modeling [C2:(62.3 ± 14.3) ng/L, C3:(58.2 ± 8.7) ng/L, C4-1:(127.0 ± 29.9) ng/L, C4-2:(120.6 ± 23.1) ng/L]. Compared with group B, group C4- 1 and C4- 2 increased most significantly (P < 0.01). Levels of serum IL- 6 decreased gradually. Eventually, group C2 [(28.6 ± 8.1) ng/L], C3 [(40.8 ± 15.1) ng/L] and C4-2 [(32.7 ± 11.1) ng/L] were significantly lower than group B (P < 0.05), and in group C2 IL- 6 was the lowest. Although levels of serum of IL-6 significantly decreased in group C4-1 [(72.8 ± 16.4) ng/L], but remained the highest. Immunohistochemistry showed that MMP-2, 9 were expressed in group B, C1 and C4-1, and significantly higher than in group A (183.0 ± 2.0, 181.3 ± 2.0), the gray value differences were statistically significant (P < 0.01). Group C4-1 (123.1 ± 2.9, 121.0 ± 3.2) was the strongest, group B (126.4 ± 2.0, 124.8 ± 2.8) and C1 (140.0 ± 2.2, 139.7 ± 3.2) were decreased (P < 0.01). While group C2(169.3 ± 3.4, 169.7 ± 2.3), C3 (149.0 ± 1.7, 145.1 ± 2.5) and C4-2 (157.7 ± 1.2, 155.8 ± 2.7) were significantly lower than group C1 (P < 0.01), and group C2 was close to normal.
  
  
  CONCLUSIONS
  Periodontitis could increase the risk of atherosclerosis in rats with chronic periodontitis. Periodontal mechanical treatment and teeth extraction may increase the risk of As in the short time. However, the risk would gradually reduce in a long time.
authors.affiliation: Department of Periodontology, School of Stomatology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Jieting
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Periodontology, School of Stomatology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Yujiao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Periodontology, School of Stomatology, Shanxi Medical University, Taiyuan 030001, China. Email: rxy611@163.com.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Ren
authors.affiliation: Department of Periodontology, School of Stomatology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Le
authors.initials: L
authors.lastname: Chang
authors.affiliation: Department of Periodontology, School of Stomatology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Zijie
authors.initials: Z
authors.lastname: Yue
authors.affiliation: Department of Periodontology, School of Stomatology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Xuexue
authors.initials: X
authors.lastname: Shi
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D050197:Atherosclerosis / Q000209:etiology*; D002339:Carotid Arteries / Q000201:enzymology; D055113:Chronic Periodontitis / Q000150:complications / Q000201:enzymology*; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D010518:Periodontitis; D051381:Rats; D017207:Rats, Sprague-Dawley; D014081:Tooth Extraction
chemical_list: D000900:Anti-Bacterial Agents; D015850:Interleukin-6; D020778:Matrix Metalloproteinase 2; C522363:Mmp2 protein, rat; D020780:Matrix Metalloproteinase 9; C572337:Mmp9 protein, rat