Present Concepts of the Role of Ground Substance in Calcification

Bowness, J. M.

doi:10.1097/00003086-196807000-00022

Cited by 71 publications

(11 citation statements)

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“…Current data on Cfi (Table III, IV) can, in the authors' view, be best explained by the sampling of this stored mineral suspended by and bound to a PPL. These findings are consistent with the concepts discussed elsewhere (22) that the hypertrophic cells adjacent to the calcifying zone degenerate under the influence of invading capillaries and liberate factors destined to degrade PPLs (23,24) or alter those properties of proteinpolysaccharides which repress mineral growth (25). Thereby rapid mineral phase formation at the zone of provisional calcification could be initiated.…”

Section: Methodssupporting

confidence: 91%

Demonstration of macromolecular inhibitor(s) of calcification and nucleational factor(s) in fluid from calcifying sites in cartilage

Howell¹,

Pita²,

Marquez³

et al. 1969

J. Clin. Invest.

102

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An extracellular fluid phase (Cf 1), aspirated by micropuncture techniques from the hypertrophic cell zone of calcifying epiphyseal cartilage, has been characterized in a calcifying system in vitro in respect to the behavior of sedimenting and supernatant fractions after high speed ultracentrifugation. To perform these tests on the starting samples of 20 nI of Cf 1, macroscopic analytical methods were scaled down for the identification of relevant organic components, including hexuronic acid and proteinpolysaccharides (PPL). The mineral accretion system was designed to simulate physiologic conditions in the calcifying cartilage septa of normal rats, and the mineral used for seeding was an immature calcium phosphate similar to native cartilage mineral. Normal Cf1 or its dilutions in synthetic lymph up to 1: 4 completely prevented mineral accretion in vitro. The inhibitory action was localized to the sedimented fractions after ultracentrifugation and could be destroyed by incubation with trypsin or hyaluronidase. The sediment of Cf1 contained 2 mg of hexuronic acid per ml of Cfi and gave a strong reaction of identification for a light fraction of PPL by fluorescent antibodies to rat PPL. PPL fractions were tested in the same mineral accretion systems as Cfi and exhibited responses similar to those of Cf1. Also, there was evidence of a mineral phase in Cf of normal rats, in Cf of rats with healing rickets, but not in Cf of untreated rachitic rats. These results are interpreted to indicate that certain PPLs function as an inhibitor of crystal growth at extracellular sites premonitory to calcification. Evidence for a low density inhibitor of mineral accretion was found in normal serum but not in Cfl.

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Section: Methodssupporting

confidence: 91%

Demonstration of macromolecular inhibitor(s) of calcification and nucleational factor(s) in fluid from calcifying sites in cartilage

Howell¹,

Pita²,

Marquez³

et al. 1969

J. Clin. Invest.

102

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“…Bonucci (6) believes that the material does not contain collagen but rather represents proteins of the ground substance. There is ample evidence of protein polysaccharide interaction witfi hydroxyapatite crystals (24). Further, Scherft (7) showed that the organic matrix of developing islands of mineralization contains Thorotrast-stainable mucopolysaccharides.…”

Section: Discussionmentioning

confidence: 99%

“…The ruthenium red positive nature of the material would indicate the presence of protein polysaccharides and possibly phospholipids (25). It has been speculated that protein polysaccharides aid in the delivery of calcium ions necessary for the nucleation of apatite crystals (24,26,27). Acid phospholipids have also been shown to be associated with the calcification process (28)(29)(30).…”

Section: Discussionmentioning

confidence: 99%

An ultrastructural study of the role of calcification nodules in the mineralization of woven bone

1979

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Summary. Osteolathyrism has been used as an experimental model for the study of calcification nodules during the mineralization process. Periosteal exostoses developing in osteolathyrism characteristically have spherical basophilic structures (calcification nodules) in the vicinity of developing bone spicules. In thin sections, the nodules were seen scattered between collagen fibers in the intercellular matrix. Collagen fibers did not appear to be present within the nodules but sometimes were packed just outside them. Matrix vesicles were also present in areas of early mineralization.After EDTA decalcification, the majority of the nodules consisted of a fine granular material surrounded by an electron-dense peripheral zone. The peripheral dense zone was occasionally incomplete in small nodules in areas of early mineralization. An electron-dense central area could be observed in the center of the nodules.Evidence has been presented indicating that the calcification nodules arise from smaller mineralization foci, presumably matrix vesicles. The calcification nodules enlarge to approximately 1.0/xm in size, at which point development is slowed or halted allowing the formation of the peripheral dense zone.Although coalescence of nodules was observed, this was more a random event. The further mineral- ization of the trabeculae was achieved by the calcification of the collagen fibers. The mineralized trabeculae reflected this pattern of nodular and collagenous calcification. It is suggested that this pattern of calcification is characteristic of rapidly developing woven bone.

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“…Several possible mechanisms have been advanced to account for this action. These include: restriction of the permeability and diffusivity of reactant ions in the matrix surrounding the sites of mineral formation (Glimcher, 1976;Blumenthal, 1981); depletion of free calcium levels at these sites by sequestration (Bowness, 1968;Tenenbaum and Hunter, 1987); limitation of the tissue space available for deposition and/or growth of the mineral phase (Glimcher, 1976); and direct interaction with growth sites, thereby effectively shielding the latter from reactant ion incorporation (Chen and Boskey, 1985). A recent review of the role of proteoglycan in the provisional calcification of cartilage by Hunter (1991) highlighted a number of important areas of interest, and suggests that, in the calcification of cartilage, the proteoglycan has yielded two apparently different roles.…”

Section: Crystal Growthmentioning

confidence: 99%

Fluoride Modulates the Inhibition of in Vitro Hydroxyapatite Crystal Growth by Small Dentin Proteoglycan: Relevance to Dental Calculus

Hall

Embery²,

Shellis

1995

Adv Dent Res.

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Glycosaminoglycan constituents of the periodontium have been detected in supragingival and subgingival dental calculus. They are polyanionic heteropolysaccharides containing -COOH and SO 3 H residues. The non-sulfated hyaluronan is present in supragingival calculus, whereas chondroitin sulfate, dermatan sulfate, and heparan sulfate are detected in subgingival calculus. They are implicated in both ectopic and endogenous mineralization, and have been used in the present study to investigate seeded hydroxyapatite crystal growth, and the influence of fluoride on the process. All glycosaminoglycans examined inhibited crystal growth, with chondroitin-4-sulfate and dermatan sulfate being more effective than the hyaluronan. Fluoride alone enhanced growth and reduced the inhibitory influence of the glycosaminoglycans and the parent proteoglycan, which is a potent inhibitor. The results yield important information on the role of fluoride and proteoglycan in ectopic mineralization.

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Present Concepts of the Role of Ground Substance in Calcification

Cited by 71 publications

References 0 publications

Demonstration of macromolecular inhibitor(s) of calcification and nucleational factor(s) in fluid from calcifying sites in cartilage

Demonstration of macromolecular inhibitor(s) of calcification and nucleational factor(s) in fluid from calcifying sites in cartilage

An ultrastructural study of the role of calcification nodules in the mineralization of woven bone

Fluoride Modulates the Inhibition of in Vitro Hydroxyapatite Crystal Growth by Small Dentin Proteoglycan: Relevance to Dental Calculus

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