A comparison of the high buoyant density proteoglycans isolated from the intervertebral discs of chondrodystrophoid and non-chondrodystrophoid dogs.
Groups of purebred beagles and greyhounds of similar ages (1.5-2.5 years) were used for the study. Intervertebral disc proteoglycans (PGs) were radiolabelled in vivo (with [35SO4(2-)], 24 hours and 60 days prior to euthanasia, when lumbar discs were dissected into nucleus pulposus (NP) and annulus fibrosus (AF). Aliquots of each disc region were separately analysed for total PG content as hexuronate. The remaining tissue was subjected to extraction with 4.0 M GuHCl. High buoyant density PGs were isolated from these extracts by CsCl density gradient ultracentrifugation. The hydrodynamic size and aggregatability of the 24-hour, 60-day-old, and resident PG populations were determined by Sepharose CL2B chromatography in the presence or absence of excess hyaluronic acid. While the hydrodynamic sizes of the newly synthesized (24-hour) disc PG preparations appeared to be similar, the 60-day-old greyhound disc PGs were found to be larger than the corresponding beagle disc PG populations. However, the keratan sulphate-core protein complexes prepared by chondroitinase ABC digestion of the newly synthesized (24 hour) disc PGs showed that the greyhound disc preparations were also larger than those from beagle discs. Approximately 80% of the newly synthesized PGs from beagle and greyhound discs were capable of aggregating with hyaluronic acid, however, this was reduced to 55% for the 60 day-old PGs in NP and AF and even less for the resident PG populations (as determined by hexuronate analysis). Significantly, PG aggregation was lower in the greyhound NP and AF preparations than in the corresponding PGs isolated from the beagle disc.(ABSTRACT TRUNCATED AT 250 WORDS)
Ghosh
P
P
Raymond Purves Research Laboratory, University of Sydney, Royal North Shore Hospital, St. Leonards, N.S.W., Australia.
Melrose
J
J
Cole
T C
TC
Taylor
T
T
D000818:Animals; D002499:Centrifugation, Density Gradient; D004283:Dog Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D006820:Hyaluronic Acid / Q000378:metabolism; D007403:Intervertebral Disc / Q000737:chemistry* / Q000473:pathology; D010009:Osteochondrodysplasias / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D011509:Proteoglycans / Q000302:isolation & purification*; D013045:Species Specificity
D011509:Proteoglycans; D006820:Hyaluronic Acid