Alteration of the lipid phase transition during mouse embryos freezing after in vitro culture with linoleic acid.

Lipids significantly affect embryo cryopreservation in some mammalian species depending on the cell lipidome quantity and composition. One of the ways to study the relationship between lipid content and cryotolerance of cells is to study the effect of lipidome modification on laboratory mice. The objective of this research was to study how in vitro culture of mouse embryos with linoleic acid (LA) will affect lipid phase transition (LPT) during cooling and subsequent embryo development after cryopreservation. Embryos obtained in vivo at the 2-cell stage were cultured with 200 µM LA for 46 h up to the morula/blastocyst stage. Thereafter, one portion of embryos was slowly frozen to reveal the effect of LA on survival after cryopreservation, another portion was used to characterize the lipid composition and to determine the temperature of the LPT onset. Confocal fluorescence microscopy of Nile Red stained embryos showed a significant increase in lipid content of the LA treated group compared to the controls. Raman measurements showed that the onset of LPT in LA treated embryos is lower than in untreated ones: -5 °C vs +2 °C. However, these changes in the LPT onset did not affect the survival rates of embryos after cryopreservation. In summary, in vitro culture with LA changes the biophysical characteristics of embryos' lipidome and is realized in lower LPT onset, but this does not affect embryo survival after cryopreservation.

[Effects of a high-fat diet on the lipid profile of oocytes in mice]. / Влияние диеты с повышенным содержанием жира на липидный профиль ооцитов мышей.

There are evidences that obese women exhibit a detrimental oocyte quality. However, it remains unclear how this change is associated with obesity, indirectly - or directly through a change in the content and/or composition of lipids in oocytes. The aim of this work was to study effects of a high-fat diet applied to female donor mice on the amount and qualitative composition of lipids of immature and in vivo matured oocytes. A high-fat diet caused larger body weight in female mice compared with the control ( p < 0.001; 44.77 ± 1.46 and 35.22 ± 1.57, respectively), and increased the blood levels of cholesterol ( p < 0.05; 2.06 ± 0.10 and 1.78 ± 0.10, respectively) and triglycerides ( p < 0.05; 2.13 ± 0.23 and 1.49 ± 0.21, respectively). At the same time, this diet does not affect the level of unsaturation of lipids in immature (0.207 ± 0.004 in the experiment and 0.206 ± 0.002 in the control) and matured oocytes (0.212 ± 0.005 in the experiment and 0.211 ± 0.003 in the control). Total lipid content increased during in vivo maturation of mouse oocytes. The amount of lipids was greater in mature oocytes in the experimental group compared to the control ( p < 0.01; 8.15 ± 0.37 and 5.83 ± 0.14, respectively). An increase in intracellular lipid amount during oocyte maturation was revealed both after a standard diet ( p < 0.05; 4.72 ± 0.48 and 5.83 ± 0.14, respectively) and after a fat-rich diet ( p < 0.001; 3.45 ± 0.62 and 8.15 ± 0.37, respectively). Thus, during in vivo oocyte maturation in mice the content of intracellular lipids enhanced, the high-fat diet aggravated this dynamics of lipid increase during in vivo maturation of oocytes.

[Developmental Aspects of Senescence].

Different types of senescence and major theories of aging are reviewed, and mechanisms of this complex biological phenomenon are discussed. Emphasis is placed on changes in the nervous systems of mammals and humans with age. Experimental animal models for studying aging and modern approaches to the correction of age-related deterioration are considered. Chemicals and other factors that may alleviate age-related disorders and slow down senescence are critically reviewed.

[EFFECTS OF IN VITRO CULTURE AND EMBRYO TRANSFER ON THE ARTERIAL BLOOD PRESSURE, BODY WEIGHT AND BEHAVIOUR IN ISIAH RATS].

This study was the first to investigate long-term effects of in vitro culturing of embryos combined with their cryopreservation and transfer on arterial blood pressure, body weight and behavior in hypertensive rats. No differences in body weight and arterial blood pressure levels were found between the naturally born rats and those born with the help of ART (assisted reproductive technologies). However, ART-born rats spent more time on rearing, as was revealed by the open-field test. The results of the elevated plus maze test indicated that these rats spent more time in the open arms and demonstrated a longer duration of head dips. Moreover, the light-dark box test showed a longer total leaning-out time in this group. Taken together, the results of the three behavioral tests demonstrate a greater exploratory activity and lower anxiety in ART-born ISIAH rats than in natural born ones.

[Assisted reproductive technologies and arterial hypertension].

The effects of assisted reproductive technologies on the development of hypertensive phenotype were reviewed. A special emphasis is made on the effects of embryo culture and subsequent transfer on the blood pressure in the offspring. The analysis of studies with the laboratory models, mostly hypertensive strains of rats, is performed. These data are discussed in the context of the use theassisted reproductive technologies in medicine.