Nitric Oxide Synthase Activity in Neutrophils From Patients With Localized Aggressive Periodontitis

Abstract

Background: Localized aggressive periodontitis (LAgP) is associated with neutrophil dysfunction including defective chemotaxis and reduced calcium influx factor activity. Nitric oxide (NO) and its enzyme, nitric oxide synthase (NOS), have been suggested to be involved in chemotaxis. Some reports, however, were unable to detect either NO or NOS in human neutrophils. In this study, we focused on NOS activity in LAgP neutrophils and examined the involvement of NOS in chemotaxis of normal neutrophils and NOS activity in neutrophils from normal subjects and patients with LAgP. Methods: Neutrophils from 10 normal subjects and 10 LAgP patients were isolated from peripheral venous blood. Membrane associated‐NOS (MA‐NOS) and soluble NOS (S‐NOS) were extracted from cells with or without FMLP stimulation. NOS activity was measured using the radiolabeled L‐arginine to L‐citrulline conversion assay. Results: N^ω‐nitro‐L‐arginine methyl ester (L‐NAME), an inhibitor of NOS, significantly inhibited FMLP‐induced chemotaxis (P P P J Periodontol 2001;72:1052‐1058.