Effect of human dental bacterial plaque extract on the connective tissue of in-vitro cultured fetal rat calvaria.
Plaque extract (50 micrograms protein/ml) stimulated the synthesis of glycosaminoglycans (GAG) in cultured calvaria explants. The production of hyaluronic acid was increased (206-309 per cent) in the medium of bone explants cultured without fetal calf serum. In the presence of serum the synthesis of GAG was increased in control bones to the level of plaque-treated bones. The bone nitrogen content remained relatively unchanged, but dry weights, DNA and collagen contents were all decreased in plaque-treated bones. Bone resorption measured as 45Ca-release was enhanced in plaque-treated (173 +/- 18 per cent) and also parathormone-treated (155 +/- 10 per cent) bones. Serum in culture medium reduced the differences between treated and control bones by increasing the release of 45Ca from control bones. Plaque-induced bone resorption may be caused by increased cell secretion of GAG and inhibition of collagen synthesis or by increased collagen breakdown. Loss of mineral accompanies this modification of the organic substrate.
D000818:Animals; D001862:Bone Resorption / Q000209:etiology* / Q000378:metabolism; D003094:Collagen / Q000032:analysis; D046508:Culture Techniques; D004247:DNA / Q000032:analysis; D003773:Dental Plaque / Q000378:metabolism*; D005333:Fetus; D006025:Glycosaminoglycans / Q000096:biosynthesis; D006801:Humans; D006820:Hyaluronic Acid / Q000096:biosynthesis; D051381:Rats; D012886:Skull / Q000378:metabolism
D006025:Glycosaminoglycans; D006820:Hyaluronic Acid; D003094:Collagen; D004247:DNA