Salivary, blood and plasma concentrations of nitric oxide in patients with periodontal disease before and after non-surgical periodontal treatment

Author(s)

Leonardo Raphael Zuardi

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto (PCARP/BC)
• Defense date: 2012-05-11

Examining board members

Raquel Fernanda Gerlach; Mario Taba Junior; Paula Cristina Trevilatto

• Advisor: Raquel Fernanda Gerlach

Abstract

The Nitric Oxide (NO) is part of a family of free radicals that are involved in various bodily functions such as cardiovascular control, homeostasis, bone formation, neurotransmission and immune functions. It has been reported that NO act in response to host defense against infection of the oral tissues. Moreover, it has also been described that excessive amounts of NO can contribute to the periodontal tissue destruction. In addition to these very important aspects in the mouth, NO is a molecule of major importance to human health, since its release by the endothelium of blood vessels is a critical component to blood pressure control. It has been demonstrated that commensal bacteria of the mouth would be responsible for production of nitrites, in the stomach, be converted to NO and this be absorbed. The amount of nitrite in the saliva is about one thousand times greater than those detected in whole blood, it is believed that the nitrite saliva may have the effect of whole blood and NO can also possibly have an effect on regulation of systemic events as the proper blood pressure. The number of papers on NO in the saliva found in the literature of the English language does not add 2 tens, and the importance of the subject, it is necessary to know in detail the concentrations of nitrite in different types of saliva, whole blood, erythrocytes and plasma in patients with periodontal disease and controls before and after treatment. The hypotheses of this study are: 1 - That the nitrite concentrations are lower in whole saliva of individuals with periodontal disease and that they increase after periodontal treatment, 2 - What there would be the same profile of variation in the concentrations of nitrite in blood, erythrocytes and plasma seen in the whole saliva. In the present study were evaluated the concentrations of NO in whole saliva, salivasumandibular / sublingual, parotid, whole blood, erythrocytes and plasma of control patients and patients with chronic periodontits, with collections before and three months after non-surgical periodontal treatment. The following were tested if significant differences between the values obtained before and after treatment were compared and the profiles of the the results of nitrite in the saliva and blood. Were performed measurements of NO by Chemiluminescence analysis method. The results showed that in all clinical parameters were statistically significant differences before and after periodontal treatment (DPA and DPD) in the control groups before and after treatment (CA and CD) and controls before and patients before treatment (CA and DPA). Bleeding on Probe (DPA versus DPD) p<0,0001, (CA versus CD) p=0,0005, (CA versus DPA) p<0,0001. Clinical attachment level: (DPA versus DPD) p<0,0001, (CA versus CD) p=0,01 , (CA versus DPA) p<0,0002. Probing depth: (DPA versus DPD) p<0,0001, (CA versus DPA) p<0,0001. Sites larger than 4 mm: (DPA versus DPD) p<0,0001, (CA versus DPA) p<0,0001. This fact confirms a periodontal treatment performed successfully. In whole saliva, a significant decrease in NO concentration between controls and patients before treatment (CA versus PDA), with p = 0.04. Whole blood decreased NO concentration before and after periodontal treatment (DPA versus DPD), p = 0.026. Already in erythrocytes before and after treatment (DPA versus DPD) there was a significant decrease, p = 0.02. The concentrations of nitrite in whole saliva had median equal to 0.69 (Q1: 0.46 / Q3:1.44) in group CA, a median of 0.55 (Q1: 0.39 / Q3: 1.55) in CD group, median 0.44 (Q1: 0.26 / Q3: 0.81) in the DPA and a median of 0.38 (Q1: 0.22 / Q3: 0.69) in the DPD. The concentrations of nitrite in saliva submandibular / sublingual medians were equal to 1.86 (Q1: 0.61 / Q3: 4.59) in group CA, a median of 0.64 (Q1: 1.82 / Q3: 4.37 ) in the CD and a median of 2.37 (Q1: 0.47 / Q3: 4.79) in the DPA and a median of 2.69 (Q1: 1.69 / Q3: 3.43) in the DPD. The nitrite concentrations in parotid saliva showed mean of 0.58 and standard desviation of 0.32 in the CA group, mean 0.69 and standard deviation of 0.33 in CD group, mean 0.69 and standard deviation of DPA and 0.36 in the group average of 0.85 and standard deviation of 0.58 in the DPD group. The concentrations of nitrite in whole blood were median equal to 1.41 (Q1: 1.1 / Q3: 2.21) in group CA, a median of 0.99 (Q1: 0.58 / Q3: 2.11) in CD group, median 1.61 (Q1: 1.12 / Q3: 2.3) in the DPA and a median of 1.45 (Q1: 0.61 / Q3: 0.87) in the DPD. The plasma concentrations of nitrite in the medians were equal to 0.51 (Q1: 0.36 / Q3: 1.09) in group CA, a median of 0.63 (Q1: 0.56 / Q3: 1.82) in group CD and a median of 0.60 (Q1: 0.37 / Q3: 0.97) in the DPA and a median of 0.5 (Q1: 0.39 / Q3: 0.83) in the DPD. The concentrations of nitrite in erythrocytes showed averages of 0.45 and standard deviation of 0.41 in the CA group, mean 0.46 and standard deviation of 0.47 in the CD group, mean 0.57 and standard deviation of 0, 44 DPA and the group average of 0.29 and standard deviation of 0.22 in DPD group. The nitrite concentrations were in the order of micromolar and nanomolar saliva in whole blood, keeping a ratio of about 1000-fold between the two fluids. The concentrations of nitrite were obtained in the following descending order: whole saliva, saliva submandibular / sublingual, parotid saliva, whole blood, erythrocytes and plasma. In saliva, the patients in the PDA and DPD showed lower concentrations of nitrite in relation to CA and CD (p <0.05), and periodontal treatment had no effect on concentrations of nitrite. There was also a statistically significant decrease in nitrite concentrations in whole blood and erythrocytes after periodontal treatment (DPA versus DPD). The results suggest that there is no relationship between the salivary and blood concentrations of nitrite. Salivary levels decreased after treatment in patients with periodontal disease may perhaps be associated with increased levels of arginase. Furthermore, increased blood concentration of nitrite may be associated with increases in inflammatory mediators such as IL-6, C-reactive protein, among others. The nitrite concentrations in whole blood suggest that reduced after treatment may be a consequence of diminished inflammatory activity in patients with periodontal disease, characterized already earlier in this group of patients. (AU)

• FAPESP's process: 09/13586-8 - Charaterization of a 150 kDa gelatinase found in the gengival crevicular fluid from periodontal disease patients
• Grantee: Leonardo Raphael Zuardi
• Support Opportunities: Scholarships in Brazil - Master