An Experimental Study On The Role Of Substance P And Calcitonic Gene-related Peptide In Periodontitis.

AIMS: 1. To investigate the concentration of SP and CGRP in gingival crevicular fluid of both periodontally healthy teech and teeth suffering from periodontitis and to learn the relationship between SP, CGRP and the attack of periodontitis.2. To explore the influence of SP and CGRP on proliteration of human periodontal ligament cells in vitro and the possible role of SP and CGRP in the development of periodontitis.METHODS: 1. Gingival crevicular fluid(GCF) was collected from: (1) posterior teeth in 20 subjects with generalized severe periodontitis; (2) healthy posterior teeth in 20 subjects with localized severe periodontitis; (3) morbid posterior teeth in 20 subjects with localized severe periodontitis; (4) healthy posterior teeth in 20 subjects without periodontitis. The volume of GCF was measured and each sample was subsequently analysed for the content and concentration of SP and CGRP by radioimmunoassay.2. Tissue culture technique, MTT method were used to study the response of human periodontal ligament cells to different concentration (10-12mol/L, 10-9mol/l, 10-6mol/L, 10-4mol/L) of SP, CGRP and their mixture.3. Tissue culture and flow cytometer technique were used to study the influence of SP,CGRP (10-12mol/L, 10-9mol/L, 10-6mol/L, 10-4mol/L) and their mixture on the proliferating index of human periodontal ligament cells. RESULTS: 1. There were significant differences for SP among all 4 groups. CGRP-IR was not detected in any posterior teeth with periodontitis, nor in 25% of periodontally-healthy posterior teeth of localized periodontitis patients. CGRP-IR was detected in all posterior teeth of subjects without periodontitis.2. SP and CGRP of different concentration (10-12mol/L, 10-9mol/L, 10-6mol/L, 10-4mol/L) promoted the proliferation of human periodontal ligamentcells. The most effective concentration being 10-6mol/L. When SP and CGRP were added up, there was no additive effect.3. Compared with the control group, SP and CGRP (10-12mol/L, 10-9mol/L, 10-6mol/L, 10-4mol/L) significantly increased me proliferating index of human periodontal ligament cells. The most effective concentration was 10~6mol/L. When SP and CGRP were added up, there was no additive effect. CONCLUSION: 1. SP and CGRP may play a role in the pathogenesis of periodontitis.2. SP and CGRP may play a role in the reparation of periodontal tissue during periodontitis.