1 1 . M U C O P O L Y S A C C H A R I D E S IN T I S S U E C U L T U R E
371
maintained for 3 years in tissue culture. No apparent difference between
freshly isolated and long-term cultures in the production of the mucopolysaccharides could be found. By the use of
3 5
S 0 4
2 _
, the chondroitin
sulphate component was estimated to be between 5 and 10% of the
whole.
3. Mucopolysaccharide Production in Organ Cultures
Although in many ways organ cultures appear to be suitable for
the study of the production of mucopolysaccharides by organized
tissue, little work has been done on such systems. Evidence for the
presence of a chondroitin sulphate and other mucopolysaccharides in
organ cultures of 7-day chick embryonic bone rudiments may be inferred from the studies of Dingle, Lucy and Fell (1961). Both glucosamine and galactosamine were detected in the explants, and by the
action of certain enzymes these amino sugars were released from the
rudiments (Lucy, Dingle and Fell, 1961) as polymeric mucopolysaccharides which could be degraded by the action of testicular
hyaluronidase. A study of the action of hyaluronidase on embryonic
cartilaginous rudiments in culture by Paff and Seifter (1950) also
indicated the presence of chondroitin sulphate.
Evidence for the presence of at least three mucopolysaccharides
in explanted long-bone rudiments of embryonic chicks was obtained
by Biggers, Lawson, Lucy and Webb (1961) from studies on the extraction of amino sugars with trichloroacetic acid. Exhaustive extraction
of embryonic tibiae yielded a soluble fraction in which the content of
galactosamine was greater than that of glucosamine, and an insoluble
residue, which contained glucosamine as the principal amino sugar.
The content of this latter mucopolysaccharide, which was higher in
bone than in cartilage, appeared to increase disproportionately to
other components when the embryonic rudiments were cultivated for
24 h on a chemically defined medium. The three mucopolysaccharides
inferred from these studies may be chondroitin sulphate, a polysaccharide similar to but not identical with orosomucoid (Kent and
Herring, 1962) and keratosulphate. Thus Glegg and Eidinger (1955)
isolated two mucopolysaccharides from the organic matrix of bone, one
of which was considered to be chondroitin sulphate, and the other
contained fucose, mannose, galactose and glucosamine. In later work,
Herring and Kent (1961) and Kent and Herring (1962) also obtained
two acidic mucopolysaccharides from cortical bone, one of which was
identified as chondroitin sulphate; the other, which unlike chondroitin
sulphate gave the positive reaction to the periodate-SchifF reagents,
contained 6-4% amino sugar (essentially glucosamine), 0-7% uronic
acid, 13-6% hexose (glucose : galactose : mannose : 1 : 8 : 5), 2-4%
371
maintained for 3 years in tissue culture. No apparent difference between
freshly isolated and long-term cultures in the production of the mucopolysaccharides could be found. By the use of
3 5
S 0 4
2 _
, the chondroitin
sulphate component was estimated to be between 5 and 10% of the
whole.
3. Mucopolysaccharide Production in Organ Cultures
Although in many ways organ cultures appear to be suitable for
the study of the production of mucopolysaccharides by organized
tissue, little work has been done on such systems. Evidence for the
presence of a chondroitin sulphate and other mucopolysaccharides in
organ cultures of 7-day chick embryonic bone rudiments may be inferred from the studies of Dingle, Lucy and Fell (1961). Both glucosamine and galactosamine were detected in the explants, and by the
action of certain enzymes these amino sugars were released from the
rudiments (Lucy, Dingle and Fell, 1961) as polymeric mucopolysaccharides which could be degraded by the action of testicular
hyaluronidase. A study of the action of hyaluronidase on embryonic
cartilaginous rudiments in culture by Paff and Seifter (1950) also
indicated the presence of chondroitin sulphate.
Evidence for the presence of at least three mucopolysaccharides
in explanted long-bone rudiments of embryonic chicks was obtained
by Biggers, Lawson, Lucy and Webb (1961) from studies on the extraction of amino sugars with trichloroacetic acid. Exhaustive extraction
of embryonic tibiae yielded a soluble fraction in which the content of
galactosamine was greater than that of glucosamine, and an insoluble
residue, which contained glucosamine as the principal amino sugar.
The content of this latter mucopolysaccharide, which was higher in
bone than in cartilage, appeared to increase disproportionately to
other components when the embryonic rudiments were cultivated for
24 h on a chemically defined medium. The three mucopolysaccharides
inferred from these studies may be chondroitin sulphate, a polysaccharide similar to but not identical with orosomucoid (Kent and
Herring, 1962) and keratosulphate. Thus Glegg and Eidinger (1955)
isolated two mucopolysaccharides from the organic matrix of bone, one
of which was considered to be chondroitin sulphate, and the other
contained fucose, mannose, galactose and glucosamine. In later work,
Herring and Kent (1961) and Kent and Herring (1962) also obtained
two acidic mucopolysaccharides from cortical bone, one of which was
identified as chondroitin sulphate; the other, which unlike chondroitin
sulphate gave the positive reaction to the periodate-SchifF reagents,
contained 6-4% amino sugar (essentially glucosamine), 0-7% uronic
acid, 13-6% hexose (glucose : galactose : mannose : 1 : 8 : 5), 2-4%