[The action of acetylcholine antagonists on preimplantation mouse embryos cultured in vitro]. / Deistvie antagonistov atsetilkholina na doimplantatsionnykh zarodyshei myshei, kul'tiviruemykh in vitro.

The effects of acetylcholine antagonists on development of the two-cell mouse embryos was studied. Etpenal-3 and etpenal-14 were shown to delay cleavage, affect cytokinesis, induce fusion of the blastomeres and arrest development at the stage of two-eight blastomeres with respect to the concentration used. Atropine, an M-cholinolytic, affects the early embryogenesis at a higher concentration than the cholinolytics with mixed effect. Acetylcholine does not prevent cleavage and compactization of the embryos and exerts a protective effect against the cholinolytics with mixed effect at the early developmental stages. The effect of atropine is weaker. The data obtained suggest the presence of structures sensitive to cholinolytics in the early mouse embryos and a possible involvement of acetylcholine in the early development of mammals.

[The effect of cyclic nucleotides on the sensitivity of early mouse embryos to biogenic monoamine antagonists]. / Vliianie tsiklicheskikh nukleotidov na chuvstvitel'nost' rannikh zarodyshei myshei k antagonistam biogennykh monoaminov.

The effect of lipophilic cAMP analogs on the sensitivity of preimplantation mouse embryos of two strains to cytotoxic serotonin and adrenalin antagonists was studied. Dioctanoyl-cAMP significantly decreased the sensitivity of embryos to inmecarb and cyproheptadine: experimental embryos developed to the stage of morula or blastocyst, in contrast to control embryos incubated without this protector. A somewhat weaker effect was observed in experiments with propranolol: embryos incubated in the propranolol-containing medium after the addition of dioctanoyl-cAMP were capable of one to two cleavage divisions. 8-bromomonobutyryl-cAMP partially suppressed the inhibitory effect of cyproheptadine and did not affect the sensitivity of embryos to propranolol. These data suggest cAMP involvement in the regulatory activity of neurotransmitters in the early mouse embryos.

[The effect of biogenic monoamine antagonists on the development of preimplantation mouse embryos cultured in vitro]. / Vliianie antagonistov biogennykh monoaminov na razvitie doimplantatsionnykh zarodyshei myshei, kul'tiviruemykh in vitro.

The effect of serotonin and adrenaline antagonists was tested on the early embryos of mice of three lines. All the substances tested produced an arrest or inhibition of cleavage division and the appearance of anomalies. Serotonin introduced in the incubation medium was effective against some serotoninolytics. We were unable to test the protective effect of adrenaline, as in the concentrations used it has its own effect on the development. From the data obtained, a conclusion is made of the existence in early mouse embryos of the structures sensitive to serotonin and adrenaline antagonists. The assumptions is made from the previously obtained data on the presence of biogenic monoamines in early mouse embryos, of functional activity of prospective mediators of the nervous system at the earliest stages of embryonic development of mammals.

[Biogenic monoamines in ovum cells and preimplantation embryos of mice]. / Biogennye monoaminy v iaitsekletkakh i doimplantsionnykh zarodyshakh myshei.

Histofluorescence technique using glyoxylic acid revealed a specific fluorescence suggesting the presence of biogenic monoamines in early developmental stages of CBA x C57 Black mice. A yellow fluorescence observed in the blastomere surface from the stage of zygote up to that of four blastomere points to the presence of indole derivates. As development proceeds, the fluorescence increases and its colour becomes more and more green, which is characteristic of catecholamines. From the stage of eight blastomeres up to stage of blastocyst specific fluorescence is revealed in the cytoplasm. The inhibitors of monoamine oxidase, introduced into pregnant mice, markedly increased the specific fluorescence. An assumption is made of functional activity of biogenic monoamines in early mouse embryos.

Gangliosides of sea urchin embryos. Their localization and participation in early development.

The influence of antibodies to gangliosides of sea urchin Strongylocentrotus intermedius eggs on early embryos of this species was studied. gamma-Globulins were isolated from rabbit anti-ganglioside serum by micropreparative electrophoresis. These gamma-globulins produced anomalies in the development of embryos permeabilized in Triton X-100. The anomalies were not observed when anti-ganglioside gamma-globulins were added to the incubation medium together with gangliosides or when the permeabilized embryos were incubated with gamma-globulins of normal rabbit serum. Pretreatment of S. intermedius embryos with serotonin, tryptamine or some other indole derivatives led to the disappearance of ganglioside determinants from the cell surface and sharply increased immunofluorescence within the cell. Such pretreatment of embryos increased the amount of cell-associated gangliosides more than threefold as compared to untreated embryos. Serotonin was shown to bind specifically to sea urchin gangliosides immobilized on octyl-Sepharose. These observations suggest that cell-surface gangliosides, after binding drugs, are internalized and that serotonin and its antagonists inhibit the transport of newly synthesized gangliosides to the cell-surface membrane.