The occurrence and activity of extracellular matrix vesicles in rat alveolar bone after the induction of local inflammation by bacterial products

Periodontal inflammation was induced in rats by injection of bacterial sonic extracts isolated from Gram negative gingival pathogens: Capnocytophaga sputigena and Actinobacillus actinomycetemcomitans. The inflammatory reaction was characterized by a massive leukocytic infiltration, granulation tissue, and abscess formation. In addition, bone resorption and primary bone formation via extracellular matrix vesicles were observed. Matrix vesicle fractions obtained from the alveolar bone of rats with inflammation revealed an increase of acid phosphatase activity as compared to controls. Studies of alkaline phosphatase activity in the vesicular fractions revealed no differences between experimental and control groups. The possible role of bacterial products in alveolar bone remodeling in the light of the enzymatic alterations and morphological observations is discussed.