Morphological Observation Of Periodontal Tissue And Lung Tissue In Passive Smoking Rats Suffering From Periodontitis

Objective: To establish periodontitis and passive smoking model of ratsthrough observing the periodontal tissue and the lung tissue morphologicalchanges and detecting the expression of MMP-9by immunohistochemicalmethod in the periodontal tissue and the lung tissue.Discuss the differenteffect of passive smoking on the periodontal tissue and the lung tissue and therelationship between the periodontitis and morphological changes of the lungtissue.Methods: Forty6-month-old male SD rats were randomly divided intofour groups: normal group, passive smoking group, simple periodontitisgroup (periodontitis group) and passive smoking with periodontitisgroup(smoking periodontitis group) Each group had10rats.Rats ofperiodontitis group and composite group were anesthetic and then ligated thebilateral maxillary first molar teeth of cervical using a wire diameter of0.20mm. High-sugar (glucose100g/L) drinking water was used after theoperation. Rats of passive smoking group and composite group were placed ina confined space,then lighted cigarettes.After12weeks, killed the rats of allgroup under general anesthesia, cutting off maxillary,lungs,and put them into10%formaldehyde buffer solution for fixing48hours, then lung tissue sliceswas made for HE staining and immunohistochemistry staining (PV method).Decalcified of maxillary by10%EDTA solution for8weeks,then periodontaltooth continuous slices was made for HE staining and immunohistochemistrystaining (PV method).The morphological changes,the expression anddistribution of MMP-9in the periodontal tissue and the lung tissue of eachgroup were observed under light microscope. The date was processed forstatistical analysis. Results:1Establishment of the rat periodontitis model:Maxillary first molar periodontal slices were observed dunder opticalmicroscope: ligated in4weeks，within the connective tissue inflammatory cellinfiltration，vascular dilatation in periodontal membrane,junctional epitheliummoved to the root,periodontal pocket has formed,emergence of alveolar boneresorption,All of that indicate: periodontitis of experimental model of rats hadbeen successfully established.2Observation of the rat periodontal tissue and lung tissue morphology afterthe HE staining:2.1Observation of the rat periodontal tissue morphology by the HE staining:Normal group:Gingival papillae morphology basically intact,gingivalepithelium had no significant infiltration of Inflammatory cells,junctionalepithelium was located in the cementum-enamel junction boundaries.Gingivalfibers and periodontal ligament fibers arranged regularly and orderly. Theframe of alveolar bone was integrity.Passive smoking group: Connective tissue with in the visible inflammatorycells and absorption of alveolar bone was mild.Periodontitis group: Within the connective tissue inflammatory cellinfiltration,vascular dilatation in periodontal membrane,junctional epitheliummoved to the root,periodontal pocket has formed,emergence of alveolar boneresorption.Smoking periodontitis group: Gingival papilla structure was destroyed,shown extensive infiltration of inflammatory cells, some were neutrophils andlymphocyte predominance,the gingival junctional epithelium further toproliferated to the root side,deep periodontal pocket formed,vertical alveolarabsorption appeared.2.2Observation of the rat lung tissue morphology by the HE staining:Normal group: Only trace amounts of inflammatory cell infiltration inbronchial wall,the bronchioles and the pulmonary interstitial structure werebasic good. Periodontitis group: Lung tissue structure in normal group andPeriodontitis group is consistent,only in the pulmonary interstitial occasionallyseen mild vascular congestion.Passive smoking group: Some place appeared inflammatory cellinfiltration in bronchial wall and the bronchioles wall and vascular congestionin pulmonary interstitial,but no widespread change.Smoking periodontitis group: Some place appeared a large number ofinflammatory cell infiltration in bronchial wall,the bronchioles wall andpulmonary interstitial, and some vascular dilatation,but no widespread change.3Immunohistochemical detection of the expression of MMP-9in ratperiodontal tissue,lung tissue:3.1The MMP-9expressed in rat periodontal tissue:The positive staining of MMP-9was yellow or brown granules, andmainly located in the cytoplasm of the neutrophils, fibroblasts,osteoblasts andother cells. MMP-9in the normal group of periodontal tissues showed weakpositive expression; in periodontitis group and passive smoking group showedpositive expression; in smoking periodontitis group showed strong positiveexpression. The OD values of the four groups were: the normal group:0.1374;the passive smoking group:0.2044; the periodontitis group:0.2100; thesmoking periodontitis group:0.2822.3.2The MMP-9expressed in rat lung tissue:The positive staining of MMP-9was yellow or brown granules, andmainly located in the cytoplasm of the neutrophils, alveolarcell,macrophages,and other cells. MMP-9in the normal group and theperiodontitis group of lung tissues showed weak positive expression; inpassive smoking group showed positive expression; in smoking periodontitisgroup showed strong positive expression. The OD values of the four groupswere: the normal group:0.1230; the periodontitis group:0.1244; the passivesmoking group:0.2380; the smoking periodontitis group:0.2998.Conclusion:1Periodontal ligation successfully established a periodontitis model of rat.2Passive smoking is an important risk factor for periodontitis.3In the passive smoking conditions the expression of MMP-9wasup-regulated in lung tissue. Suggesting that:passive smoking is a risk factorsfor pulmonary tissue changes.4In passive smoking and periodontitis coexisting conditions,theexpression of MMP-9was up-regulated in lung tissue. Suggestingthat:periodontitis may increase the inflammation symptom of the lung tissue.