[Kinetic model of changes in genetic controlling systems in cells into a state of proliferation and differentiation].

A kinetic model of changes in genetic controlling systems in cells into a state of proliferation and differentiation was built. A mathematical description of that model in a form of differential equations systems was made. Solutions of those systems were presented graphically. It was shown that at minimum values of reaction rate constants linear time changes were observed in kinetic model parameters and at maximum levels they were non-linear that was characteristic of the living systems. These results point to the fact that changes in genetic controlling systems in living cells occur when reaction rate constants are maximum.

[Characteristics of the electrophysiological parameters of the embryonic cell membranes in the loach during Na+, K+-ATPase inhibition]. / Kharakteristiki élektrofiziologicheskikh parametrov membran émbrional'nykh kletok v'iuna pri ingibirovanii Na+, K+-ATFazy.

Influence of ouabain on changes in transmembrane potential (TMP) and the membrane conductance has been studied in developing embryos of the loach Misgurnus fossilis L. Ouabain does not cause any significant changes in TMP level within 10-15 min after treatment but the membrane was then depolarized to a degree depending on developmental stage. Exposure to ouabain increases the conductance and changes the selectivity of membranes. Reversion potential of ionic current is then decreased from -70- -100 to -5- -30 mV. It is supposed that gradual membrane depolarization owing to the decrease of K+ gradient favors the membrane conductance changes under the influence of ouabain. It has been established that the active transport of Na+ and K+ takes part in realization of the rhythm of TMP level periodical oscillations during synchronous cleavage division.

[Influence of adrenaline on the transmembrane potential changes in developing loach embryos]. / Vliianie adrenalina na dinamiku transmembrannogo petentsiala razvivaiushchikhsia zarodyshei v'iuna.

Changes of transmembrane potential (TMP) in loach embryos developing for 7--8 hours in the medium supplemented with different adrenalin concentrations and in its mixtures with insulin or actinomycin D are studied. It was shown that value and mode of TMP changes, and its depolarizing effect and removal of periodic TMP oscillations in particular, which coincided with normal cycles of synchronous blastomere divisions depended on adrenalin level in the medium. Actinomycin D gradually eliminated the adrenalin influence on embryos only in the second half of the above mentioned period of their development, whereas insulin exerted its effect already at the early stages of embryogenesis.

[Changes in the transmembrane potential of developing loach embryos under the influence of insulin, inhibition of transcription and translation]. / Izmeneniia transmembrannogo potentsiala u razvivaiushchikhsia zarodyshei v'iuna pod vliianiem insulina, ingibirovaniia transkriptsii i transliatsii.

Results of continuous 7-8 hour registration of transmembrane potential (TMP) at the early stages of the loach (Misgurnus fossilis) development in normal conditions and in media with different insulin concentrations (the hormone with actinomycin D and cycloheximid and these antibiotics alone) are presented in this paper. The dependence of the absolute value and the mode of TMP changes in developing embryos upon insulin concentration has been established. It is shown that actinomycin D reduces the hormonal effect at the initial stages, while alone it does not cause any visible changes of TMP. Inhibition of translation with cycloheximid leads to sharp depolarizaton of the membrane and completely abolishes the periodicity of TMP oscillations, which in the norm corresponds to the time-course of the mitotic cycles during the synchronous cleavang of the blastomeres.