Effects Of Apical Periodontitis Induced By Several Pathogens On Inflammatory Responses Of Aorta In Rats

Aim:The purpose of this study was to investigate effects of CAP induced by Ef or Pg on serum inflammatory cytokines,blood lipid and inflammatory response of aorta in rats.Methodology: Eighteen animals were divided into three groups with six rats in each group: control group,Ef-CAP group and Pg-CAP group.Mono-species bacteria-induced CAP was established in the first and second molars of the right maxilla and mandible of male SD rats.At 12 th week,the maxilla and mandible were harvested and then scanned by micro-CT.Alveolar bone destruction was evaluated by measuring the volume of alveolar bone resorption,BV/TV,Tb.Th,Tb.N and Tb.Sp.Serum TC,TG,HDL-C,LDL-C and TNF-α,IL-6,IL-1α,MCP-1 were detected.Histological examinations of aorta were performed by HE staining.The m RNA expression of TNF-α,IL-6,MCP-1 and ICAM-1 of aorta were measured by quantitative Real-time PCR in aorta.Results:(1)The alveolar bone resorption volume of the Pg-CAP group was significantly larger than that of the Ef-CAP group(P<0.01).In the maxilla,both Pg-CAP and Ef-CAP groups had a significant decrease in BV/TV and increase in Tb.Sp(P<0.01)with the more significant changes of trabecular bone in the Pg-CAP group.A significant reduction of Tb.N was only found in the Pg-CAP group(P<0.05).In the mandible,only an increase in Tb.Sp in the Pg-CAP group(P<0.05).(2)Serum TNF-α,IL-6 and IL-1α in Pg-CAP group or Ef-CAP were significantly higher than that of control group(P<0.05).Eleved serum MCP-1 was only in Pg-CAP group(P<0.05).Serum TNF-α,IL-6,IL-1α and MCP-1 in Pg-CAP group were significantly higher than that of Ef-CAP group(P<0.05).(3)Serum TC and LDL-C in Pg-CAP group were significantly higher than that of control group(P<0.05).Only HDL-C was significantly higher in Ef-CAP group than that of control group(P<0.05).Serum TC,LDL-C and HDL-C in Pg-CAP group were significantly higher than that of Ef-CAP group(P<0.05).(4)Inflammatory cells were found in muscularis and adventitia of Pg-CAP group and Ef-CAP group.The m RNA expressions of TNF-α,MCP-1 and ICAM-1 were markedly elevated in Pg-CAP than that of control group or Ef-CAP group(P<0.05).There was no significant changes of m RNA expressions of TNF-α,MCP-1,IL-6 and ICAM-1 in Ef-CAP group.Conclusions:(1)Pg-CAP caused more substantial alveolar bone destruction than Ef-CAP.Tb.Sp was the most sensitive index for evaluating the residual alveolar bone of CAP.The maxilla was more susceptible to CAP in terms of microstructural changes of trabecular bone than the mandible.(2)Both Pg-CAP and Ef-CAP can elevate serum concentration of inflammatory meditor,and Pg-CAP can cause more serious.Pg-CAP and Ef-CAP can change serum lipid differently.(3)Both Pg-CAP and Ef-CAP can cause inflammatory cells infiltration in rat aorta.The effects of CAP induced by Pg on inflammatory response of aortas was worse than that induced by Ef-CAP.