[Change in protein synthesis and enzyme activity in avian endocrine glands during ontogenesis]

The synthesis of cytoplasmic proteins and the activity of cAMP-dependent protein kinase were studied in the thyroid gland and thymus of intact and irradiated (0.05 Gr) embryos and chicks. The increase in labeled amino acid incorporation into proteins of irradiated chicken endocrine organs during postnatal development was more apparent in thyrocytes. Stimulation of protein kinase activity in the thyroid gland and thymus was observed at the same periods of time. It was supposed that minor doses of ionizing radiation stimulate synthetic processes as well as phosphorylation of proteins responsible for differentiation of avian endocrine organs.