Enzymes of glutamine metabolism in the developing chick embryo. A study of glutamotransferase and glutamine synthetase

Lactic and malic dehydrogenases in the developing chick embryo

“…Again, in contrast with GDH, the LDH and MDH activity of the blastoderm and yolk sac, instead of being at a similar level to that of the 15-day-old liver, is only about one-hundredth of the maximum liver LDH and MDH activity. LDH and MDH both increase equally with total protein in the whole chick embryo, as was also found for glutamotransferase and glutamine synthetase (Rudnick, Mela & Waelsch, 1953). The levels of MDH and LDH are about 100 times as great as that of GDH in the whole embryo.…”

Glutamine Synthetase. Determination of Its Distribution in Brain during Development*

“…The glutamyl transferase assay was carried out in the system described by Rudnick et al (1954). Similar aliquots of the tissue homogenates used for the synthetase assay were also used for the transferase assay.…”

Glutamic dehydrogenase in the developing chick embryo

“…It appears that these peaks of activity in the early chick embryo follow the ontogenic sequence, dipeptidase, GDH and aminopeptidase, during 1-5-2-5 days of incubation. These peaks of activity in early embryos were not found for glutamotransferase and glutamine synthetase (Rudnick, Mela & Waelsch, 1953), which increase pari pas8u with total protein in the embryo and yolk sac (as did GDH after the fourth and sixth day respectively). Transferase activity (per mg. of protein) increased steadily in the liver between the sixth and 18th day of incubation but there was no peak of activity as with GDH.…”