[Electron immunocytochemistry of lymphocyte surface immunoglobulins in the bursa of Fabricius in the pre- and early postnatal ontogeny of chickens]. / Elektronnaia immunotsitokhimiia poverkhnostnykh immunoglobulinov limfotsitov bursy Fabritsiusa v pre- i rannem postnatal'nom ontogeneze kur.

The appearance and localization of surface immunoglobulins on B-lymphocytes of the bursa of Fabricius of developing chick embryos and chicks were studied by immuno-electron-cytochemical peroxidase-antiperoxidase (PAP) method. Ultrastructural characteristics of marked and unmarked lymphocytes of the bursa of Fabricius was shown. The increase in the density of reaction product on PAP-complex in the course of lymphocytes differentiation was established.

[Cyclic nucleotides in the ontogeny of the chick thymus]. / Tsiklicheskie nukleotidy v ontogeneze vilochkovoi zhelezy kur.

The dynamics of cAMP and cGMP content of the thymus homogenate from developing chick embryos and chickens was studied during ante- and postnatal development. Changes in the content of cyclic nucleotides bear an oscillatory pattern. At the early stages of embryogenesis (9 to 11 days of incubation) the content of cyclic nucleotides was low and gradually increased by 13 days of incubation. As the development proceeded, the quantitative and qualitative rearrangement of the thymus cellular composition reflected in changes in the content of cyclic nucleotides. At the same time the curves of cyclic nucleotide content became antiphasic. These reciprocal cAMP to cGMP ratios might reflect the cyclic and synchronous reproduction and functional development of the main bulk of the thymus cellular elements. The maximum content of cAMP and the minimum content of cGMP were recorded on the 17th day of embryogenesis.

[Effect of small doses of gamma radiation on the activity of marker enzymes in the plasma membranes of chick embryo liver]. / Deistvie malykh doz gamma-oblucheniia na aktivnost' markernykh fermentov plazmaticheskikh membran pecheni émbrionov kur.

A study was made of marker enzyme activity in plasma membranes of chick liver during embryogenesis in normal conditions and after exposure to ionizing radiation. It was shown that irradiation with small doses of eggs prior to incubation and of chick embryos during different periods of the prenatal ontogenesis caused essential changes in activity of membrane-bound enzymes of liver plasmolemma. Stimulation with small radiation doses was most effective with preincubation irradiation of eggs and most manifest at later stages of the prenatal ontogenesis. Thus, the marker enzymes were shown to play a significant role in the realization of the stimulatory effect of low-level radiation.