抄録
The present histochemical study was made to clarify the mechanism of the disappearance of salt-insoluble collagen fibers in the periodontal membrane after abrupt discontinuance of occlusal function and in acute osteolathyrism induced by Aminoacetonitrile (2.5%) in Wistar rats. The salt-insoluble collagen fibers were stained with van Gieson mixture consisting of only picric acid and acid fuchsin on formalin fixed paraffin sections after extraction of salt-soluble collagen in 1M NaCl solution. On the other hand, acid phosphatase was stained by azo-dye method (Barka and Anderson 1963) to demonstrate activity of lysosomal enzyme of fibroblasts in the periodontal membrane after decalcification in Tetrasodium ethylenediaminetetraacetate solution. The following results were obtained: 1) The discontinuance of occlusal function resulted in rapidly progressing disappearance of the salt-insoluble collagen fiber from the alveolar side of the periodontal membrane in molar. Concurrently with the disappearance of the insoluble collagen fiber the acid phosphatase of the fibroblast in the alveolar side of the periodontal membrane increased considerablly in activity. 2) In Aminoacetonitrile induced osteolathyrism the salt-insoluble collagen fiber in the periodontal membrane progressively extensively disappeared from the alveolar bone side. Pathologic osteoid matrix appeared in relatively regular arrangement in the periodontal membrane with reduced insoluble collagen fiber. The acid phosphatase of the fibroblasts did not increase considerablly in activity of the enzyme. 3) These findings suggest that in the discontinuance of occlusal function more active degradation and subsequent intracellular digestion of collagen by fibroblast may be responsible for the disappearance of the insoluble collagen fiber in the periodontal membrane. In acute osteolathyrism the impaired maturation of newly synthesized collaen molecule and not impaired process of extracellular degradation as well as intracellular digestion of collagen by the fibroblast probably result in the disappearance of the insoluble collagen fiber in the periodontal membrane.
