Determination of glycosaminoglycans (mucopolysaccharides) from tissues on the microgram scale

Microgram quantities of glycosaminoglycans can be quantitatively liberated from tissues, fractionated and determined by the following procedure: (1) Digestion of the tissue sample with papain (EC 3.4.4.10). (2) Precipitation of the glycosaminoglycans as their cetylpyridinium complexes on an inert support of powdered cellulose packed in a column. (3) Fractional elution of the complexes from the column with salt solutions of increasing concentration. (4) Estimation of the amount of glycosaminoglycans in each fraction after hydrolysis followed by determination of the hexosamines by a modified Elson and Morgan method.

Experimental data are presented to validate the various steps of the procedure. The results were found to be reproducible and accurate for fractions down to 2–5 μg of hexosamine. Small differences in the solubility properties of the glycosaminoglycan-cetylpyridinium complexes could be detected and visualized by the construction of “solubility profiles”.

Application of the procedure to histological sections of the intervertebral disc and the nasal septum cartilage revealed differences in the amount and properties of glycosaminoglycans in tissue structures 100–200 μ apart. The method should be useful to study the distribution of glycosaminoglycans at the tissue level.