Yaremkevych O. "The influence of thiosulfonates on Na+, K+-АТPase and membrane potential of embryos loach Misgurnus fossilis"

The dissertation is devoted to the investigation of influence of novel biologically active substances - derivatives of thiosulfoacids on plasma membranes biophysical parameters of loach embryos Misgurnus fossilis L., namely, the processes of transmembrane bioelectrogenesis and functioning of Na+,K+-ATPase of embryos at different stages of early embryogenesis. It has been shown that the influence of thiosulfoacids derivatives germ cell during early embryogenesis of loach is implemented on the membrane level, namely, by infringing of plasma membrane electrogenesis of loach embryos and inhibition of Na+,K+-ATPase. It has been found that the presence of biologically active substances in the incubation medium in high concentrations (4·10-3 mol/l) has the most inhibiting effect, while addition of derivatives of thiosulfoacids into the media in low concentration (4·10-8 mol/l) leads to the restoration of Na+,K+-ATPase activity in embryos compared with controls. Decreasing of TMP occurs according to the increasing of ionic permeability of membrane as well as leveling of electrogenic ions concentration due to the exclusion of cell pumps by direct action on Na+,K+-ATPase or during reduction of ATP due to violation of bioenergetics processes in mitochondria. These have been confirmed by results of ultrastructural studies of germ cells by the impact of thiosulfoacids derivatives in high concentrations, where the destruction of mitochondria have been observed, that causes a disturbance of cellular bioenergetics, swelling of organelle due to osmotic imbalance, the violation of oxidative phosphorylation, depletion of mitochondrial pool of ATP and inactivation of ion-transport enzymes. Aforementioned processes can lead to disruption of metabolic processes and to the progress of necrotic phenomena in the blastomers embryos. Moreover, the yield of cytochrome c and apoptosis proteins from intermembrane space of mitochondria leads to programmed cell death. A hypothetical scheme of thiosulfoacids derivatives action on cell of loach embryos has been proposed.