The effect of glycosylaminoglycans on the mineralization of sheep periodontal ligament in vitro.
The effect of removal of glycosylaminoglycans on the mineralization of sheep periodontal ligament was determined using enzyme digests followed by incubation in solutions supersaturated with respect to hydroxyapatite at pH 7.4. TEM revealed that control periodontal ligament remained unmineralized. However, tissue from which glycosylaminoglycans had been removed contained plate-like crystals arranged parallel to and within the collagen fibrils. Electron probe and electron diffraction studies suggested that the crystals were apatitic with a similar order of crystallinity to dentine, and a Ca:P ratio of 1.61. In addition, the glycosylaminoglycan content of periodontal ligament, cementum and alveolar bone was compared using cellulose acetate electrophoresis. Periodontal ligament contained predominantly dermatan sulfate while cementum and alveolar bone contained mostly chondroitin sulfate. A role for glycosylaminoglycans in maintaining the unmineralized state of the periodontal ligament is suggested. Control of expression of specific proteoglycan species on a spatially restricted basis is presumably central to this role.
Kirkham
J
J
Division of Oral Biology, Leeds Dental Institute, University of Leeds, United Kingdom.
Brookes
S J
SJ
Shore
R C
RC
Bonass
W A
WA
Robinson
C
C
D000539:Alveolar Process / Q000737:chemistry; D000818:Animals; D001031:Apatites / Q000032:analysis; D002114:Calcinosis / Q000378:metabolism / Q000473:pathology; D002118:Calcium / Q000032:analysis; D002809:Chondroitin Sulfates / Q000032:analysis; D003094:Collagen / Q000032:analysis / Q000378:metabolism; D003460:Crystallization; D003739:Dental Cementum / Q000737:chemistry; D003804:Dentin; D003871:Dermatan Sulfate / Q000032:analysis; D004577:Electron Probe Microanalysis; D004588:Electrophoresis, Cellulose Acetate; D005260:Female; D006025:Glycosaminoglycans / Q000032:analysis / Q000037:antagonists & inhibitors / Q000502:physiology*; D008854:Microscopy, Electron; D008903:Minerals / Q000032:analysis / Q000378:metabolism*; D010513:Periodontal Ligament / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D010758:Phosphorus / Q000032:analysis; D012756:Sheep
D001031:Apatites; D006025:Glycosaminoglycans; D008903:Minerals; D003871:Dermatan Sulfate; D010758:Phosphorus; D002809:Chondroitin Sulfates; D003094:Collagen; D002118:Calcium