Ca-enriched amorphous mineral deposits associated with the plasma membranes of chondrocytes and matrix vesicles of rat epiphyseal cartilage

1983 ◽  
Vol 35 (1) ◽  
pp. 486-495 ◽  
Author(s):  
William J. Dougherty
Keyword(s):  
Plasma Membranes ◽  
Matrix Vesicles ◽  
Epiphyseal Cartilage ◽  
Mineral Deposits

Effects of EDTA, Hyaluronidase and Collagenase on Epiphyseal Cartilage Matrix

1968 ◽  
Vol 26 ◽  
pp. 56-57
Author(s):  
H. Clarke Anderson ◽  
Priscilla R. Coulter
Keyword(s):  
Light And Electron Microscopy ◽  
Matrix Vesicles ◽  
Cartilage Matrix ◽  
Collagen Fibrils ◽  
Epiphyseal Cartilage ◽  
Dense Matrix ◽  
Type Iv ◽  
Bovine Testicular Hyaluronidase ◽  
The Matrix ◽  
Testicular Hyaluronidase

Epiphyseal cartilage matrix contains fibrils and particles of at least 5 different types: 1. Banded collagen fibrils, present throughout the matrix, but not seen in the lacunae. 2. Non-periodic fine fibrils <100Å in diameter (Fig. 1), which are most notable in the lacunae, and may represent immature collagen. 3. Electron dense matrix granules (Fig. 1) which are often attached to fine fibrils and collagen fibrils, and probably contain protein-polysaccharide although the possibility of a mineral content has not been excluded. 4. Matrix vesicles (Fig. 2) which show a selective distribution throughout the epiphysis, and may play a role in calcification. 5. Needle-like apatite crystals (Fig. 2).Blocks of formalin-fixed epiphysis from weanling mice were digested with the following agents in 0.1M phosphate buffer: a) 5% ethylenediaminetetraacetate (EDTA) at pH 8.3, b) 0.015% bovine testicular hyaluronidase (Sigma, type IV, 750 units/mg) at pH 5.5, and c) 0.1% collagenase (Worthington, chromatograhically pure, 200 units/mg) at pH 7.4. All digestions were carried out at 37°C overnight. Following digestion tissues were examined by light and electron microscopy to determine changes in the various fibrils and particles of the matrix.

Calcium Enriched Plasma Membrane-Associated Amorphous Deposits in Chondrocytes of Calcifying Cartilage

1980 ◽  
Vol 38 ◽  
pp. 580-581
Author(s):  
W.J. Dougherty
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Alveolar Bone ◽  
Matrix Vesicles ◽  
Conclusive Evidence ◽  
Energy Dispersive ◽  
Fixed Tissue ◽  
Tissue Samples ◽  
Proliferative Zone ◽  
Ultrathin Sections

In previous studies on rat and mouse alveolar bone and rat incisor mantle predentin, amorphous-appearing deposits approximately 5 to 35 nm in diameter were seen to be associated with matrix vesicles in each of these mineralized tissues and with the plasma membranes of osteoblasts and young odontoblasts. It was concluded that these membrane-associated amorphous appearing deposits (MAADs) were mineral because of (1) their inherent electron density in gl utaraldehyde-only fixed tissue and (2) their extract-ability from ultrathin sections by neutral solutions of EDTA (ethylene diamine tetraccetic acid) and EGTA (ethylene glycol bis-(β-aminoethyl ether) N,N1-tetracetic acid). Distilled water and 50% ethanol failed to extract the MAADs from ultrathin sections. While these observations are indicative, they do not offer conclusive evidence for the mineral nature the MAADs. It was considered important to demonstrate the presence of Ca in the deposits by non-destructive analytical methods and to show that these deposits occurred in other calcifying tissues. For these purposes, tibial epiphyses of young growing rats were prepared for routine electron microscopy and energy-dispersive x-ray analysis in the STEM mode of a JE0L-100-CX using previously published procedures (Dougherty, 1978). Ultrathin sections of gl utaral dehyde/osmi urn tetroxide fixed tissue samples were viewed unstained. Figure 1 shows a low magnification TEM image of two chondrocytes in the proliferative zone of the tibial epiphyseal plate. MAADs are present. Figure 2 illustrates in a STEM image at higher magnification two MAADs on another chondrocyte in the proliferative zone. The energy dispersive spectra of point C (an MAAD) and point E (plasma membrane lacking an MAAD) are illustrated in figures 3 and 4. It can be seen that the MAAD at point C is enriched in Ca, while point E is lacking in Ca. Other MAADs on other chondrocytes were enriched in Ca also. Thus, it can be concluded that the MAADs are mineral in nature and that they occur in another major calcifying tissue. It is possible that the MAADs represent the initial nucleation centers in calcifying tissues.

scholarly journals Ultrastructural cytochemistry and immunocytochemistry of proteoglycans associated with epiphyseal cartilage calcification.

1983 ◽  
Vol 31 (9) ◽  
pp. 1089-1100 ◽  
Author(s):  
M Takagi ◽  
R T Parmley ◽  
F R Denys
Keyword(s):  
Chondroitin Sulfate ◽  
Tannic Acid ◽  
Keratan Sulfate ◽  
Matrix Vesicles ◽  
Enzyme Digestion ◽  
Epiphyseal Cartilage ◽  
Fe Method ◽  
Cartilage Calcification ◽  
Testicular Hyaluronidase ◽  
Chondroitin Sulfate A

Proteoglycans (PGs) are closely associated with cartilage calcification. We have examined the hypertrophic zone of rat epiphyseal cartilage, in which calcification is occurring, using the high-iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) method for sulfated glycosaminoglycans, an immunoferritin method specific for chondroitin sulfate A, and the tannic acid-ferric chloride (TA-Fe) method to stain cartilage matrix granules (MGs) presumed to be PG monomers. HID-TCH-SP produced stain deposits with a diameter of 11.2 +/- 3.2 nm (mean +/- SD; n = 200) in the MGs. However, HID-TCH-SP staining was not discernible in membrane-limited matrix vesicles (MVs). In areas of advanced calcification, partially disrupted MVs and globular bodies (GBs), derived in part from disrupted and/or degenerated MVs, contained a few too many small HID-TCH-SP stain deposits. Further down the epiphyseal cartilage, intact MVs markedly decreased and the GBs, containing many small HID-TCH-SP stain deposits, significantly increased in number. These GBs were found exclusively in the longitudinal septa rather than in the transverse septa. After enzyme digestion with testicular hyaluronidase, small (7.2 +/- 1.2 nm in diameter) stain deposits remained in the MGs and GBs, presumably localized to keratan sulfate. Immunoferritin localizing chondroitin sulfate strongly stained MGs, whereas MVs and GBs lacked staining. TA-Fe staining of glycoconjugates in the GBs demonstrated a striking decrease in the diameter of MGs associated with calcification in the GBs as compared with those in the noncalcifying area around the GBs. These results indicate that the GBs containing needle-like apatite crystals in morphologic preparations represent sites of chondroitin sulfate degradation. Testicular hyaluronidase-resistant sulfated glycosaminoglycans presumed to be keratan sulfate and partially degraded PGs selectively remain within the GBs as a probable requisite for expansion of the initial calcification in MVs.

Localization of phosphatidylserine in isolated chick epiphyseal cartilage matrix vesicles with trinitrobenzenesulfonate

1979 ◽  
Vol 27 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Robert J. Majeska ◽  
Dennis L. Holwerda ◽  
Roy E. Wuthier
Keyword(s):  
Matrix Vesicles ◽  
Cartilage Matrix ◽  
Epiphyseal Cartilage
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