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B N Veprintsev

Publications and source records attributed to B N Veprintsev.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

[Metabolic regulation of neuron functions].

A short analytical review of Soviet and foreign studies devoted to metabolic regulation of neuron functioning is presented. It is shown that the electrical activity of neuron is accompanied by structural changes and an increase in RNA content. It is assumed that these changes are initiated by calcium ions, coming to the neuron during its excitation. The principles of metabolic regulation of functioning of electro- and chemoexcitable neuronal membranes are considered. It is shown that the metabolic reactions can be an intermediate between the activated chemoreceptor and the electrical response of the cell. Evidence is presented that the electroexcitable and chemosensitive structures in the membrane modulate each other. The role of intracellular messengers in regulating the activity of receptors and channels is considered. Possible mechanisms for their modifications under the influence of cellular factors are discussed. It is shown that the work of neuron is controlled by several metabolic regulatory systems simultaneously.

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[The effectiveness of the microsurgical removal of the nuclei in early mouse embryos depending on the time before cleavage division].

The efficiency of microsurgical enucleation of zygote and two-cell mice embryos was found to increase sharply 1-1.5 h before cleavage in "late" embryos, and 5-6 h before cleavage in "early" embryos. In "late" embryos, the share of successful enucleations constitutes 80-90%, and in "early" ones, 10-30%. This phenomenon is not connected with cytoskeleton restructuring during the cell cycle, but is determined by the increase in intracellular osmotic pressure at late stages of cell cycle. This process results in the increased elasticity of the embryo and, consequently, the penetration of surgical instruments and removal of karyoplast occurs more efficiently. The artificial increase in the intracellular pressure by addition of distilled water to culture medium also increases the efficiency of microsurgical enucleation.

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[The viability of rat amd mouse embryos in low-temperature preservation].

Embryos of the laboratory rats and mice at the two-cell stage were frozen in different media with 1.5 M DMSO at a rate of 0.5-0.7 degrees/min to -40 degrees and the transferred into liquid nitrogen. Temperature of the crystallization initiation was -6 degrees. After thawed embryos were transplanted to foster mothers, these latter gave birth to normal offspring. The best results (38% of the total number of transplanted embryos in mice and 55% in rats) were obtained when using modified Whitten's medium for cryopreservation. Survival of the rat embryos in the NT-6 medium fell to 36% due, supposedly, to changes in pH accompanying the decrease in temperature. These results allow us to recommend modified Whitten's medium and the developed conditions of freezing-thawing for cryopreservation of the rat and mouse embryos.

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PubMedDate not supplied

[Electrostimulated cell fusion in cell engineering].

A survey of studies on reconstructions of animal and plant cells which apply a new physical method--electrostimulated fusion, is presented. Effects of different factors of the medium on the efficiency of electrofusion is discussed. A detailed account is given of the authors' studies on zygotes reconstruction by combined methods of microsurgery and electrostimulated cell fusion. Advantages of the latter as compared to the widely distributed methods of fusion by polyethylenglycol and Sendai virus are considered. This physical method can play an important role in the progress of cellular engineering.

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PubMedDate not supplied

[Nonsurgical embryo transplantation in mice].

Nonsurgical transplantation of the mouse embryos at the blastocyst stage into the uterus was performed using a device of original construction. The use of this device made it possible to exclude the loss of embryos, to reduce the amount of culture medium introduced together with the embryos, to lessen the damage of genital tract and ensured guaranteed "ejection" of embryos into the uterus. The females of the third day of pregnancy were used of recipients. Transplantation was performed between the mice of strains CBA/Lac, C57BL/6 and tetrahybrid CBWA. The level of newborn attained 65% of the number of transplanted blastocysts.

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