イヌの実験的歯周炎における歯肉グリコサミノグリカン代謝について

Abstract

The metabolism of glycosaminoglycans (GAGs) was studied in the development of the periodontitis in dogs. Periodontitis was induced by silk ligature placement in the gingival crevices. The gingiva showed various signs of inflammation. Acute destructive gingivitis was observed shortly after ligature placement and developed into the complicated phase which consisted of less acute inflammatory responses in the gingiva and periodontium on day 7 and 10. And chronic periodontitis with alveolar bone destruction was established from day 20 to 90 after ligature placement.The healthy gingiva contained much higher amounts of hyaluronic acid (HA) and dermatan sulfate (DS), and lower amounts of heparan sulfate (HS) and chondroitin sulfate (CS). HA content in the inflamed gingiva was lower than that in the control on day 3, 7 and 10. DS content was also lower in the inflamed gingiva on day 3 and 7. Then, HA and DS restored to the control levels. On the other hand, CS and HS content were always higher in the inflamed gingiva.Insoluble collagen and total collagen decreased, but soluble collagen increased in the inflamed gingiva during the entire experiment. The increase of soluble collagen was drastic in acute destructive gingivitis.These above findings suggested that the destruction of extracellular matrix happened in the acute destructive phase, and tissue repair and destruction coexisted in the complicated phase.High activities of β-glucuronidase and UDP-glucose dehydrogenase and high amount of [3H]-glucosamine incorporation into GAGs were found on day 10. It was suggested that the degradation and the synthesis of GAGs might be markedly stimulated in the gingiva of the complicated phase.Heparin was detected in the gingiva of the chronic inflammation with alveolar bone destruction, but was not detected in the healthy gingiva and in the acute destructive inflammatory gingiva. It was suggested that heparin might be one of the important bone-resorption stimulating factors.