304
J . A . L U C Y
Skeletal myoblasts formed muscle fibres which contracted for up to 3
days in the protein-free, defined media. Measurable quantities of
amino acids were utilized in less than 24 h. A pattern of amino-acid
utilization was observed in which leucine was utilized in large quantities
while glutamic acid accumulated. The amino-acid compositions of
the proteins of embryonic chick breast-muscle cells and of fully differentiated adult fowl breast-muscle were determined for comparison
with the pattern of amino-acid utilization. There was no close correlation between amino-acid utilization and protein composition, but
the high utilization of leucine and isoleucine, relative to that of tyrosine
and phenylalanine, reflected the proportions in which these amino
acids occurred in the protein.
Utilization of certain amino acids by cartilaginous limb-bone rudiments from the 7-day embryonic chick has been determined quantitatively and reproducible patterns observed (Lawson and Lucy, 1961).
The rudiments were cultured for 48 h in chemically defined media and
during this time they increased in length by 5 0 % and also increased in
nitrogen content. The hypertrophic zone lengthened and mitotic
figures were found in the epiphyses. All the amino acids studied
decreased in the medium, with the exception of alanine which accumulated. Glycine and proline were utilized on a relatively large
scale and this was probably related to the formation of collagen in
the cartilage. Leucine was also utilized in considerable quantity; this
amino acid is important in the non-collagenous protein of these
rudiments (Biggers et al., 1961). There was only slight utilization of
methionine and tyrosine, an observation that may have been related
to the small amounts of these amino acids in both collagen and the
non-collagenous protein.
Ion-exchange chromatography has also been used to study the
quantitative utilization of amino acids by organ cultures of the mouse
prostate gland (Lasnitzki and Lucy, 1961). The glands were grown for
10 days in "natural" medium and then cultured for a further 3 days
in chemically defined media; under these conditions, the typical
histological structure was preserved. Leucine, isoleucine, cystine and
arginine were utilized by the prostate gland while, in contrast to the
findings with cartilage cultures, glutamic acid and glycine accumulated. Ornithine was produced during cultivation; in cultures of
monkey kidney cells, disappearance of arginine was also accompanied
by the appearance of ornithine (Pasieka et al., 1958). Prostate glands
that were grown in "natural" medium containing 20-methylcholanthrene before transfer to the defined medium showed a similar pattern
of utilization to that of the control cultures, despite the presence of
many hyperplastic alveoli in the treated explants. Measurements
J . A . L U C Y
Skeletal myoblasts formed muscle fibres which contracted for up to 3
days in the protein-free, defined media. Measurable quantities of
amino acids were utilized in less than 24 h. A pattern of amino-acid
utilization was observed in which leucine was utilized in large quantities
while glutamic acid accumulated. The amino-acid compositions of
the proteins of embryonic chick breast-muscle cells and of fully differentiated adult fowl breast-muscle were determined for comparison
with the pattern of amino-acid utilization. There was no close correlation between amino-acid utilization and protein composition, but
the high utilization of leucine and isoleucine, relative to that of tyrosine
and phenylalanine, reflected the proportions in which these amino
acids occurred in the protein.
Utilization of certain amino acids by cartilaginous limb-bone rudiments from the 7-day embryonic chick has been determined quantitatively and reproducible patterns observed (Lawson and Lucy, 1961).
The rudiments were cultured for 48 h in chemically defined media and
during this time they increased in length by 5 0 % and also increased in
nitrogen content. The hypertrophic zone lengthened and mitotic
figures were found in the epiphyses. All the amino acids studied
decreased in the medium, with the exception of alanine which accumulated. Glycine and proline were utilized on a relatively large
scale and this was probably related to the formation of collagen in
the cartilage. Leucine was also utilized in considerable quantity; this
amino acid is important in the non-collagenous protein of these
rudiments (Biggers et al., 1961). There was only slight utilization of
methionine and tyrosine, an observation that may have been related
to the small amounts of these amino acids in both collagen and the
non-collagenous protein.
Ion-exchange chromatography has also been used to study the
quantitative utilization of amino acids by organ cultures of the mouse
prostate gland (Lasnitzki and Lucy, 1961). The glands were grown for
10 days in "natural" medium and then cultured for a further 3 days
in chemically defined media; under these conditions, the typical
histological structure was preserved. Leucine, isoleucine, cystine and
arginine were utilized by the prostate gland while, in contrast to the
findings with cartilage cultures, glutamic acid and glycine accumulated. Ornithine was produced during cultivation; in cultures of
monkey kidney cells, disappearance of arginine was also accompanied
by the appearance of ornithine (Pasieka et al., 1958). Prostate glands
that were grown in "natural" medium containing 20-methylcholanthrene before transfer to the defined medium showed a similar pattern
of utilization to that of the control cultures, despite the presence of
many hyperplastic alveoli in the treated explants. Measurements