[Total protein content of cells as a factor regulating their proliferation]. / Soderzhanie summarnogo belka v kletkakh kak faktor reguliatsii ikh proliferatsii.

Proliferation kinetics in stimulated stationary cultures of chick embryo fibroblasts was studied using cytophotometric and autoradiographic methods. Part of 4c cells are blocked at G2 when the culture becomes stationary. A fraction is formed among them which fails to divide in response to proliferation stimulus. Such cells differ from cycling G2 cells by a higher total protein content. Cells with an elevated total protein content are found among 2c cells too, and these also fail to synthesize DNA in response to stimulation to proliferation. It is concluded that the quantity of protein accumulated in the cytoplasm may be one of the factors controlling cell proliferation.

[DNA content and synthesis in the nuclei of rat cerebellar cells in organotypic cultures]. / Soderzhanie i sintez DNK v iadrakh kletok mozzhechka krysy v usloviiakh organotipicheskoi kul'tury.

Using cytophotometric and autoradiographic methods, it has been shown for the first time that in condition of an organotypic culture the replicative synthesis of DNA is induced in the Purkinje neurons of the cerebellum of newborn rats completing their terminal differentiation. This synthesis is accompanied by polyploidization of the initially diploid population of these cells (4c, much more rarely 8c, and a single 16c cell appear) rather than by cell division. In constant, the granular cells mostly retain their diploid state and only a few of them synthesize DNA to H2c values. The glial cells divide actively. Hence, evidence is presented that neurons, at least those of cerebellum, retain their potential of replicative synthesis of DNA in the organotypic culture. The important point is that DNA synthesis in their nuclei proceeds simultaneously with processes of differentiation.

[In vitro culture of the hypothalamic supraoptic nucleus. I. General morphological characteristics]. / Kul'tura supraopticheskogo iadra gipotalamusa in vitro. I. Obshchaia morfologicheskaia kharakteristika.

Kinetics and morphology of supraoptic nuclei (SON) organ culture of newborn rat hypothalamus have been described. Explants of SON were cultured for 7-90 days. Cell migration, growth of neuron sprouts, formation of nerve bundles and growth zone, and mitotic activity were followed. Neurosecretory cells (NSC) differing in size, shape and degree of activity, were identified in addition to other cell elements of SON. The neurosecret was shown to appear at the beginning of the second week of cultivation in large and middle size NSC. In small and old cultures of NSC no neurosecrete was discovered. It was established that NSC complete the terminal differentiation and maintain for a long time their viable and functional activity in vitro.