Influence of periodontal therapy on serum interleukin-6 and carotid metalloproteinases in animals with chronic periodontitis associated with atherosclerosis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of periodontal mechanical treatment on serum interleukin-6 (IL-6) and carotid artery matrix metalloproteinase (MMP)-2 and MMP-9 expression in chronic periodontitis (CP) SD rats with atherosclerosis (As).</p><p><b>METHODS</b>Forty-four six-week-old male SD rats were randomly divided into three groups: control group (group A), As group (group B), As+CP group(group C). According to different periodontal interventions, group C was randomly subdivided into four groups: natural process group (C1), the periodontal mechanical treatment group (C2), the periodontal mechanical treatment+ local drugs group (C3), and the periodontal mechanical treatment+local and system drugs group (C4). Each group received the appropriate treatment and periodontal interventions. Serum IL-6 levels were determined by enzyme linked immunosorrbent assay (ELISA). MMP-2 and MMP-9 levels in the proximal aorta were examined by immunohistochemistry.</p><p><b>RESULTS</b>The gray value of MMP-2 and MMP-9 was basically the same in all groups. Compared with group A, the gray value of MMP-2 and MMP-9 of group B and C were decreased. C1 group showed the formation of atherosclerotic plaque and fibrous cap. Compared with group B (126.4 ± 2.0, 124.8 ± 2.8) , the gray value of group C1 (101.3 ± 2.4, 101.2 ± 4.1) was significantly weaker (P < 0.05). The staining depth of MMP-2 and MMP-9 of groups C1, C2, C3 and C4 were sequentially decreased, and the differences of gray value were statistically significant(P < 0.05). The levels of serum IL-6 in groups B and C1 increased gradually with time and became significantly higher than that of group A (P < 0.01). The levels of serum IL-6 in groups C2, C3, and C4 increased gradually and reached the peak 5 weeks after the establishment of model (P < 0.001). After that, the levels of serum IL-6 decreased gradually and was lower than baseline. The levels of serum IL-6 in groups C3 and C4 were significantly lower than that in group C2 7 weeks after the establishment of model(P < 0.01).</p><p><b>CONCLUSIONS</b>In rats with periodontitis and cardiovascular diseases, chronic periodontal inflammation may significantly increase the severity of As and promote the formation of atherosclerotic plaque. Mechanical periodontal therapy may cause short-term systemic inflammation and then reduce vascular inflammation in long term.With supplement use of local and systemic antibiotics, the mechanical periodontal therapy may get the vascular disease and systemic inflammation improved.</p>

Effect of oral intervention on matrix metalloproteinase-2, 9 expression in carotid arteries and serum interleukin-6 in rats with chronic periodontitis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To establish chronic periodontitis model in SD rats, and to investigate the effect of oral intervention on atherosclerosis.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>