ANALYSIS OF CHONDROITIN SULFATE IN LUMBAR INTERVERTEBRAL DISCS AT 2 DIFFERENT STAGES OF DEGENERATION AS ASSESSED BY DISCOGRAM

Previous studies have presented evidence that an underlying cause of i ntervertebral disc degeneration is related to changes in the sulfation of the proteoglycans. The sulfation of the chondroitin in cadaveric l umbar intervertebral discs, at two different stages of degeneration as assessed by discogram, were analyzed. Fourteen of 28 lumbar discs wer e graded 2 and the other 14 were graded 4 (i.e., more degenerated). Fr om each disc, six regional segments were carefully isolated. Proteogly cans were solubilized from the disc tissue with 4 M GuHCl. Chondroitin sulfate chains were analyzed by diethylaminoethyl (DEAE)-Sephacel and high-performance liquid chromatography (HPLC) anion exchange chromato graphy. The major differences in sulfation of the chondroitin between the grade 2 and grade 4 discs only occurred in the posterior central a nnulus and nucleus segments. The chondroitin in the posterior central and nucleus segments of the grade 2 and grade 4 intervertebral discs w ere undersulfated as compared with the other segments, and the differe nces between these segments and the others were more accentuated in th e grade 4 discs than in grade 2 discs.