Effect of calcipenia on proteoglycan metabolism and aggregation in normal articular cartilage in vitro.
Glycosaminoglycan synthesis in normal adult dog knee cartilage cultured in medium containing 0, 0.3 MM- and 0.9 mM-Ca2+ was 52, 67 and 78%, respectively, of that in cartilage from the same joints cultured in a normal concentration of Ca2+, i.e. 1.8 mM. Pulse-chase experiments indicated that the rate of degradiation of glycosaminoglycans in cartilage cultured in the absence of Ca2+ was similar to that of glycosaminoglycans in cartilage cultured in 1.8 mM-Ca2+. Although [35S]sulphate incorporation into glycosaminoglycans was decreased in the presence of calcipenia, [3H]leucine incorporation into protein was unaffected. The average hydrodynamic size of newly synthesized proteoglycan aggregates and purified disaggregated proteoglycans from cartilage cultured in the absence of Ca2+ was similar to that of aggregates and disaggregated proteoglycans from cartilage cultured in 1.8 mM-Ca2+.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002358:Cartilage, Articular / Q000187:drug effects / Q000378:metabolism*; D002850:Chromatography, Gel; D046508:Culture Techniques; D004285:Dogs; D006025:Glycosaminoglycans / Q000096:biosynthesis; D007930:Leucine / Q000378:metabolism; D046911:Macromolecular Substances; D014176:Protein Biosynthesis; D011509:Proteoglycans / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism
D006025:Glycosaminoglycans; D046911:Macromolecular Substances; D011509:Proteoglycans; D013431:Sulfates; D007930:Leucine; D002118:Calcium