370
J. T. DINGLE AND M. WEBB
It is of interest that in experiments by Grossfeld et al. (1957) no
chondroitin sulphate-B was detected, although this mucopolysaccharide
has been reported to occur in adult skin. Loewi and Meyer (1958),
for example, showed that embryonic pig skin contained much hyaluronic acid and chondroitin sulphate-C, but only traces of chondroitin
sulphate-B. Adult skin, however, contained more chondroitin sulphateB than hyaluronic acid. These authors suggest that the appearance
of mature coarse collagen fibres, as in adult skin, is connected in time,
and perhaps also casually with chondroitin sulphate-B. The relatively
high percentage of chondroitin sulphate-C in embryonic skin, as in
other tissues, and in tissue cultures, appears to be associated with
young, fine collagen fibres.
2. Mucopolysaccharide Production by Cell Cultures
The suggestion of Loewi and Meyer (1958) mentioned above may
be relevant to the studies of Daniel et al. (1961), in which histological
evidence was obtained for the production of intercellular fibrils that
stained blue with Heidenhain's Azan in cultures of rat dermal fibroblasts. This material was more abundant in cultures of freshly isolated
cells; the latter were so enmeshed in the fibrils that many remained
in clumps after trypsinization. T o determine the nature of this material,
cultures of freshly isolated cells were treated with trypsin after one
week in culture. The residual fibres were teased out, the cells removed
by repeated washing in Tyrode's solution and the fibrils washed, dried
and hydrolysed. From the high hydroxyproline content and relatively
high proportion of glycine in the hydrolysate the presence of collagen
was inferred, although the proportions of these two amino acids,
relative to the other amino acids, were not sufficiently high for the
material to consist solely of collagen. These cells produced quantities
of hyaluronic acid at the same time as the fibres were being formed.
Studies by Berenson et al. (1958) demonstrated the production of
hyaluronate, chondroitin sulphate-B (but cf. Grossfeld et al., 1957),
and also some chondroitin sulphate, either A or C, by cells, presumed
morphologically to be fibroblasts, cultivated in a chemically defined
medium. These cells, which were derived from minced chick embryos
(7-12 days) were found to yield mucopolysaccharide after growth for
1 week, this relatively rapid synthesis being regarded as consistent
with information gained from isotopic studies of the in vivo turnover
rate of mucopolysaccharides. Morris (1960), in a well documented
study of the production of acid mucopolysaccharides by replicate cell
cultures of rat fibroblasts, has shown that both hyaluronic acid and, to
a lesser extent, chondroitin sulphate, can be produced by cells freshly
isolated from calvaria of young rats, and from cells of similar origin
J. T. DINGLE AND M. WEBB
It is of interest that in experiments by Grossfeld et al. (1957) no
chondroitin sulphate-B was detected, although this mucopolysaccharide
has been reported to occur in adult skin. Loewi and Meyer (1958),
for example, showed that embryonic pig skin contained much hyaluronic acid and chondroitin sulphate-C, but only traces of chondroitin
sulphate-B. Adult skin, however, contained more chondroitin sulphateB than hyaluronic acid. These authors suggest that the appearance
of mature coarse collagen fibres, as in adult skin, is connected in time,
and perhaps also casually with chondroitin sulphate-B. The relatively
high percentage of chondroitin sulphate-C in embryonic skin, as in
other tissues, and in tissue cultures, appears to be associated with
young, fine collagen fibres.
2. Mucopolysaccharide Production by Cell Cultures
The suggestion of Loewi and Meyer (1958) mentioned above may
be relevant to the studies of Daniel et al. (1961), in which histological
evidence was obtained for the production of intercellular fibrils that
stained blue with Heidenhain's Azan in cultures of rat dermal fibroblasts. This material was more abundant in cultures of freshly isolated
cells; the latter were so enmeshed in the fibrils that many remained
in clumps after trypsinization. T o determine the nature of this material,
cultures of freshly isolated cells were treated with trypsin after one
week in culture. The residual fibres were teased out, the cells removed
by repeated washing in Tyrode's solution and the fibrils washed, dried
and hydrolysed. From the high hydroxyproline content and relatively
high proportion of glycine in the hydrolysate the presence of collagen
was inferred, although the proportions of these two amino acids,
relative to the other amino acids, were not sufficiently high for the
material to consist solely of collagen. These cells produced quantities
of hyaluronic acid at the same time as the fibres were being formed.
Studies by Berenson et al. (1958) demonstrated the production of
hyaluronate, chondroitin sulphate-B (but cf. Grossfeld et al., 1957),
and also some chondroitin sulphate, either A or C, by cells, presumed
morphologically to be fibroblasts, cultivated in a chemically defined
medium. These cells, which were derived from minced chick embryos
(7-12 days) were found to yield mucopolysaccharide after growth for
1 week, this relatively rapid synthesis being regarded as consistent
with information gained from isotopic studies of the in vivo turnover
rate of mucopolysaccharides. Morris (1960), in a well documented
study of the production of acid mucopolysaccharides by replicate cell
cultures of rat fibroblasts, has shown that both hyaluronic acid and, to
a lesser extent, chondroitin sulphate, can be produced by cells freshly
isolated from calvaria of young rats, and from cells of similar origin