Application of new techniques to separation of proteoglycan aggregates from normal and destabilized rabbit articular cartilages.

Proteoglycans were prepared from rabbit articular cartilages by classical techniques employing 4.0 M guanidine. HCl by transport ultracentrifugation techniques on the purified proteoglycans, present. A new method of extracting the cartilage with 0.4 M guanidine. HCl in the presence of highly purified collagenase is presented. The same yield of proteoglycans on extraction of normal cartilage was obtained as with the classical technique, but a larger proportion of intermediate and large aggregates was obtained with the new than with the classical methodologies. The osteoarthritic cartilage was obtained from 6 month old animals, 3 months after a partial medial meniscectomy had been performed. The profile of proteoglycans from osteoarthritic cartilage consisted predominately of monomers, and a small content of aggregates spread over intermediate and large size ranges. It is postulated that by the methods of extraction, the profile of proteoglycan aggregates present in vivo is more faithfully reproduced than obtained by the classical methodologies.