Proteases augment the effects of lipopolysaccharide in rat gingiva.
OBJECTIVE
Lipopolysaccharide (LPS) and proteases have been implicated as important factors in the initiation and progression of human periodontal diseases. A single application of LPS or proteases is insufficient to induce periodontal pocket formation or periodontitis. The aim of the present study was to assess the combined effect of lipopolysaccharide and proteases on rat periodontal tissues, and create a periodontal disease model.


METHODS
Forty male Wistar rats were divided into four groups: combination group (treated with both LPS and proteases solutions); LPS group; proteases group; and control. Each solution was introduced daily into the palatal gingival sulcus of maxillary molars for 8 weeks. The tissues were evaluated histometrically and immunohistochemically.


RESULTS
In the LPS group, elongation of rete ridge, apical migration of junctional epithelium (JE), increased numbers of B cells in connective tissue, and resorption of alveolar bone were observed. In the proteases group, the increase in the number of infiltrating polymorphonuclear leukocytes and blood vessels in the connective tissue was greater than that of the LPS group.


CONCLUSIONS
The effects of LPS on periodontal tissues differed from those of proteases. The addition of proteases augmented and increased the effects of LPS, which were apical migration, intraepithelial cleavage of JE, and increased B cell density. The lesions in the combination group resembled established lesions of human periodontitis, with the exception of the low density of plasma cells.
Ekuni
D
D
Department of Oral Health, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
Yamamoto
T
T
Yamanaka
R
R
Tachibana
K
K
Watanabe
T
T
D016301:Alveolar Bone Loss / Q000209:etiology / Q000473:pathology; D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000473:pathology; D002465:Cell Movement / Q000187:drug effects; D003238:Connective Tissue / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D004195:Disease Models, Animal; D004357:Drug Synergism; D010450:Endopeptidases / Q000008:administration & dosage / Q000494:pharmacology*; D004846:Epithelial Attachment / Q000187:drug effects / Q000473:pathology; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D004926:Escherichia coli; D005881:Gingiva / Q000187:drug effects* / Q000473:pathology; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology; D010510:Periodontal Diseases / Q000209:etiology; D051381:Rats; D017208:Rats, Wistar; D013305:Streptomyces griseus
D008070:Lipopolysaccharides; D010450:Endopeptidases