Peroxidase enzyme activity in gingival tissues associated with aggressive periodontitis : Histochemical investigation *

168 Abstract Background: Cytochemical studies on peroxidase have contributed significantly to understanding of the movement of lysosomal enzymes and secretory protein through the various compartments of secretary pathway. The peroxidase in leukocytes (myeloperoxidase) could help in determining the severity of inflammation. Aim: To determine the severity of inflammation in gingival tissue associated with aggressive periodontitis by histochemical method and to determine peroxidase enzyme activity semiquantativity. Material and Method: Five gingival biopsies and five blood smears, three with aggressive periodontitis and two from healthy gingiva. Histochemical method for peroxidase activity using the technique described by Deimann et al (1991) was used. Results: sections clearly show a wide and intense distribution of the enzyme activity in gingival tissue with inflammation specifically in the subepithelial connective tissue, while a discrete low activity was obtained in the epithelial tissue. Control section showed small or few amounts of enzyme activity. In blood smears from aggressive periodontitis and control showed similar peroxidase activity in the section. Conclusion: PMNs dysfunction observed in periodontal lesions may be a localized phenomenon caused by plaque bacterial products not found in healthy sites.