Effectiveness of scaling and root planing versus modified Widman flap on nitric oxide synthase and arginase activity in patients with chronic periodontitis.
BACKGROUND
Nitric oxide (NO) is synthesized from the conversion of L-arginine to L-citrulline by NO synthase (NOS). Arginase, which is an arginine-depleting enzyme, can compete with NOS for the common substrate L-arginine and thus inhibit NO production.


OBJECTIVE
In the present study, we aimed to examine the correlation between the arginase and NOS activity in patients with chronic periodontitis and to compare the effects of scaling and root planing and modified Widman flap procedures on enzyme activity.


METHODS
The study included 13 patients diagnosed with chronic periodontitis. Using a split-mouth design, the defects showing>or=7 mm of attachment loss were treated either with scaling and root planing or with modified Widman flap. Gingival biopsies from both sites were obtained at baseline and 2 months after periodontal treatment. Immunohistochemical staining was performed for evaluating NOS expression and specific arginase activity was determined spectrophotometrically.


RESULTS
Although inflamed periodontal tissues demonstrated a strong inducible NOS (iNOS) expression at baseline, immunostaining decreased after periodontal treatment. iNOS expression intensity and the number of inflammatory cells showing iNOS expression were found to be higher in the scaling and root planing group compared to the modified Widman flap group. The specific activity of arginase was measured as 0.18+/-0.07 IU/mg protein in the modified Widman flap group and 0.25+/-0.11 IU/mg protein in the scaling and root planing group at baseline. After periodontal therapy, the enzyme level was increased to 0.68+/-0.14 IU/mg protein in the modified Widman flap and to 1.10+/-0.23 IU/mg protein in the scaling and root planing group.


CONCLUSIONS
This study was the first report of evaluating the involvement of the arginine-NO pathway in chronic periodontitis and this might be considered to be of value in understanding the periodontal disease mechanisms.
Güllü
Cigdem
C
Department of Periodontology, Faculty of Dentistry, Gazi University, Ankara, Turkey.
Ozmeric
Nurdan
N
Tokman
Benay
B
Elgün
Serenay
S
Balos
Köksal
K
D000328:Adult; D001119:Arginase / Q000378:metabolism*; D002908:Chronic Disease; D012534:Dental Scaling; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D010518:Periodontitis / Q000201:enzymology* / Q000628:therapy; D016745:Root Planing; D018709:Statistics, Nonparametric; D013379:Substrate Specificity; D013524:Surgical Flaps
C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D001119:Arginase