ISSN:
0002-9106
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Alterations in morphology and composition of ossifying turkey leg tendons were followed using biophysical and histochemical procedures in combination with improved methods of tissue preparation. The principal biophysical changes accompanying calcification were loss of water, increase in shrinkage temperature, shifts in form birefringence curves and increased resistance to the disrupting effects of potassium iodide. Fibroblasts of the tendon were modified to cuboidal cells; at the same time, intracellular lipid increased and presumptive secretion of glycoproteins and lipids into the contiguous matrix was observed. As the bony tendon matured, osteocytes appeared and the stainability of the matrix with the periodic acid-Schiff reagent and dinitrofluorobenzene was markedly diminished. The matrix changes were interpreted as representing increased cross-linking of a negatively charged biological polyelectrolyte. Concurrently, diminished binding of calcium, the formation of hydrophobic lipid-containing phases and the lowering of dielectric constant favor the precipitation of bone salts. During calcification, barriers to diffusion, including low vascularity, tend to create a closed, or partially closed, system in the tissue. Then, the mineral phases form with minimal transfer of electrolytes to the circulation. According to the phase rule, the formation of insoluble bone salts stabilizes the heterogeneous biological structure.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aja.1001200306
