Chondroitin sulphate, examination

In two children exhibiting the clinical symptoms of fucosidosis, the diagnosis has been confirmed biochemically by the demonstration of a marked a-L-fuco-sidase deficiency in cultured skin fibroblasts. Examination of the urinary levels of keratan sulphate and chondroitin sulphate of the two patients showed a five- and eight-fold increase over those of normal children of the same age. Since a number of the terminal non-reducing positions of keratan sulphate molecules are occupied by a-L-fucosyl residues, the increased excretion of keratan sulphate in fucosidosis could result from the impaired degradation of keratan sulphate, due to ae-L-fucosidase deficiency. 

A substrate-film technique has been used to examine the enzyme system that hydrolyses hyaluronic acid (and chondroitin sulphate) in isolated macrophages and in developing and healing tuberculosis lesions in rabbits. The pH optimum of the enzyme shifted towards neutrality in intact cells and tissues. The level of hyaluronidase in the kidneys of rats suffering from dehydration has been investigated. ... 

In rheumatic disease, the main pathological manifestations appear in connective tissue, the chief constituents of which are collagen, elastin and mucopolysaccharides. The last, apart from hyaluronic acid and chondroitin of cornea, are all sulphate esters , the sulphate groups of which are in a dynamic state with a short biological half-life. The sulphate exchange is under enzymic control and can be decreased in vitro and in vivo by corticosteroids " . Bostrom and Mansson examined the effects of a number of salicylates on the incorporation of S into calf costal cartilage slices in vitro. 

The influence of steroidal and non-steroidal antirheumatic drugs on the in vitro formation of cartilage and its constituent polysaccharides has been studied in tissue culture so that an examination of the biosynthesis rather than the turnover of any constituents of preformed cartilage could be made . Cortisone, hydrocortisone and salicylate in high concentrations inhibit chondrogenesis and S-incorporation, but cinchophen and phenylbutazone are inactive. The sulphation of chondroitin may be more dependent upon the supply of energy from respiration than is the biosynthesis of chondroitin. 

An examination of cartilage indicated that chondroitin 4-sulphate is involved in calcification, whereas chondroitin 6-sulphate is important in maintaining the integrity of articular surfaces. The interactions of proteoglycans with tropo-elastin have been implicated in elastogenesis, ... 

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