Chondrons from articular cartilage (II): Analysis of the glycosaminoglycans in the cellular microenvironment of isolated canine chondrons.
A chondron rich preparation was isolated from mature canine tibial cartilage using low-speed homogenization techniques. Proteoglycans were extracted from this preparation by exhaustive treatment with 4M guanidine-HCl. A significant proportion of the total proteoglycan, measured as uronic acid, was resistant to extraction and represented 27.9% in intact cartilage chips and 18.6% in the chondron fraction. Histochemical examination of chondrons confirmed that extraction resistant proteoglycans remained within the capsule of the chondron after 4M guanidine-HCl treatment. Electrophoretic analysis of the glycosaminoglycans extracted from intact cartilage chips and the chondron fraction showed approximately equivalent amounts of chondroitin sulphate (79.3%), keratan sulphate (16.3%) and hyaluronic acid (4.3%) present. In contrast, the extraction resistant residue in the chondron fraction was significantly enriched for hyaluronic acid (10.5%, p less than 0.05) but was depleted of chondroitin sulphate (70.9%, p less than 0.05). The major chondroitin sulphate isomer in the resistant fraction was chondroitin 6-sulphate while in the soluble fraction, the quantities of the two isomers were approximately equivalent. Comparison with previously published data suggests a role for minor collagens in the retention of proteoglycans in the cellular microenvironment.
Poole
C A
CA
Department of Surgery, University of Auckland, School of Medicine, New Zealand.
Honda
T
T
Skinner
S J
SJ
Schofield
J R
JR
Hyde
K F
KF
Shinkai
H
H
D000818:Animals; D002358:Cartilage, Articular / Q000032:analysis* / Q000166:cytology; D004285:Dogs; D005109:Extracellular Matrix / Q000032:analysis; D006025:Glycosaminoglycans / Q000032:analysis*; D006651:Histocytochemistry; D011509:Proteoglycans / Q000302:isolation & purification
D006025:Glycosaminoglycans; D011509:Proteoglycans