| Metabolic syndrome(caused by obesity)and periodontitis as the two kinds of chronic diseases that endanger human health,has earned widespread attention among researchers.Recent studies have shown that obesity-induced metabolic disorders and inflammatory states have some synergistic effect on periodontitis,but what is the certain effect of interaction between them,and what is the mechanisms of the reciprocity between the two diseases still need a lot of research to reveal.In this study,we used insulin resistance as an access to study the relationship of the two diseases.We established experimental animal models of obesity and periodontitis,observe the changes of insulin resistance,metabolic level,organs change in experimental animals,and protein expression of insulin-related signal pathways,to explore the mechanism of interaction between obesity and periodontitis.This study was divided into three parts:Part 1:Establishment of experimental animal models of obesity and periodontitisOBJECTIVE:To establish an obese rat model and a rat model of obesity with periodontitisMethod(1)Divided group:All SD rats were randomly divided into control group(group C),obese group(group O),obese group with periodontitis(P group)and periodontal treatment(group T).(2)Establishment of obese animal models:high fat diet induction.Measurement of body weight,body length,Abdominal circumference,and LEE'S index.(3)Establishment of animal models of obesity combined with periodontitis:3-0 mussel periodontal line ligated molar teeth of experimental rats to induce experimental periodontitis.Measured periodontal pocket,attachment loss and observed pathological section.Statistical methodAll data were calculated by SPSS18.0 statistical software.The data were expressed as mean± standard deviation(x±s).The comparison between the two groups was analyzed by one-way ANOVA.The comparison of the two groups was based on the independent sample T test,Paired t test was used before and after comparison of the same group.Test level ? = 0.05(bilateral).Result(1)obese model results:obese rats induced by high fatty diet weighed was 15%heavier than the control group.LEE'S index comparison:whatever comparison of in obese group before and after feed by high fatty food or comparison of between obese group and control group,the difference of the LEE's index was statistically significant(P<0.05).,(2)periodontitis modeling results:after periodontal ligament,the periodontal tissue of experimental rats appeared attachment loss,deep periodontal pocket.Conclusion:Animal model of obesity and periodontitis was successfully established.Part II:Effects of periodontitis and periodontal therapy on metabolic levels in obese rats and changes in organsObjectiveTo investigate the effects of experimental periodontitis and periodontal basic therapy on metabolic status and organs change in experimental rats.MethodsBlood samples were collected to detect blood lipids,blood glucose and other indicators.Observed organ changes like liver,kidney,pancreas,and jaw by HE staining slice and weighing.Statistical method:same as the former part.Result(1)The area under the curve of blood glucose and HOMA-IR:OGTT,HOMA-IR:the values of P group were the highest(P<0.05).(2)Comparison of serum lipids:except TG,the levels of TC,LDL-C and FFA in the three group of obese rats were higher than those in the control group,the values in P group was highest among three groups of obese rats.And the HDL-C values were the highest in the C group and the lowest in the P group.After periodontal therapy,the levels of TC,LDL-C and FFAin T group decreased,HDL-C value increased(P<0.05).(3)Liver:wet weight:the weight of three groups of rats fed by high fat diet was higher than control group(P<0.05).And adipose degeneration was found in liver cells.(4)Kidney:wet weight:Compared with control group,the weight of liver in other groups was increased,and those in P group,T group was highest.(5)jaw:HE staining slice of jaw in P group and T group by periodontal ligament could be found alveolar bone resorption,inflammatory infiltration and other pathological changes.(6)pancreas:islet cell of rats in O group,P group,T group could be observed varying degrees of vacuolar degeneration.ConclusionPeriodontitis can aggravate the metabolic disorder and inflammation state of organs caused by obesity.Periodontal therapy may play a role in the alleviation of metabolic disorder and inflammatory state of obesity.Part ?:Effects of periodontitis and periodontal therapy on insulin resistance in obese rats and its mechanismObjectiveTo explore the possible mechanism of the interaction between periodontitis and obesity.MethodsThe mRNA expression of IRS-1,IRS-2,PDX-1,GK and GLU were detected by QPCR.The protein expression of IRS-1 and IRS-2 was detected by Western blot.Result(1)HOMA-?,MBCI value inP group was the lowest,which in C group was the highest,After periodontal therapy,HOMA-?,MBCI value in T group was increasing.The expression of IRS-1,IRS-2,PDX-1,GK and GLUT in group P were the lowest and promoting a little in group T(P<0.05).(2)The expression of IRS-1 and IRS-2 which mediate insulin signaling pathway was restricted,and PDX-1,GK,GLUT expression were inhibited,it may be mechanism of insulin resistance aggravation by periodontitis related to obesity. |
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