The morphological changes in myocardial tissue in spontaneously hypertensive rat (SHR) occurring after administration of propylthiouracil (PTU) were assessed in the project. PTU at a concentration of 0.1% was given to the animals with drinking water for 47 days. After the end of the experiment, the morphological parameters of cardiomyocytes, the density of cardiomyocytes and fibroblasts in the myocardium, and the average area of the lumen of veins were examined. The progressive development of dystrophic processes in the myocardium was established against the background of PTU intake, which was characterized by a decrease in the cardiomyocyte density and an increase in the volume of connective tissue, venous congestion, and expansion of the lumen of veins.

Goal. The goal was to study the effect of the dorsal root ganglia cryoextract (DRGCE) as a composition containing neurotrophic factors on the structural and functional characteristics of rat ovaries of different ages. Methods. The experiments were performed on female white rats of 6 and 14 months of age that corresponds to the reproductive and late reproductive age of this species of animals. DRGCE was made from dorsal root ganglia of neonatal piglets. Before the DRGCE was used, it was mixed with the physiological saline (PS) so that the concentration of the protein was 0.3 mg/ml. DRGCE was intraperitoneally injected for 9 days (0.2 ml/animal). In the control group, PS was used instead of DRGCE. The injection of DRGCE and PS started in the estrous. To assess the progression of the estrous cycle, vaginal smears were taken daily at 10 a.m. for two weeks before administration, during administration, and for 20 days after administration of DRGCE. The duration of the estrous cycle, relative number of estrous and diestrus phases as well as irregular estrous cycles were studied. 28-29 days after the start of DRGCE administration, animals were killed. Histological analyse of ovarian follicles of different stages of development were carried out. Results. DRGCE administration in rats of reproductive age increased the duration of estrous cycle due to diestrus phase and the number of irregular estrous cycles. Similar changes in the estrous cycle of late reproductive age animals were observed regardless of the administration of DRGCE. The quantitative analysis did not show statistically significant differences between the total numbers of follicles in all animal groups. DRGCE administration led to a decrease the number of primordial follicles and an increase the number of atretic follicles in the ovaries of animals of both reproductive ages. In rats of reproductive age, the number of antral follicles decreased after application of DRGCE. Conclusions. Administration of DRGCE stimulates the growth and development of primordial follicles, but at the same time increases process of follicular atresia, especially at the antral stage. This effect does not depend on the age of the experimental animals.

Background. The main clinical manifestations of thyroid gland (TG) diseases are associated with the influence of thyroid hormones on the cardiovascular system. At the same time, hypothyroidism as well as hyperthyroidism increase the risk of arterial hypertension. Based on this, the development of an experimental model that combines thyroid pathology and hypertension is relevant. From this point of view, the hypertensive SHR rats is a valuable object of study, since the course of arterial hypertension in these animals corresponds to the signs of human hypertension. Objective. Study of the dynamics of the morphological parameters of the thyroid gland in SHR rats with prolonged administration of propylthiouracil (PTU). Methods. Female SHR rats were used in the experiments; drinking water contained a 0.1% solution of PTU. TG was taken on the 17th, 25th, 31st, 39th and 47th days of the experiment, subjected to histological examination and staining with hematoxylin / eosin according to standard methods. We analyzed the average height of the follicular epithelium, the average follicle area, the nuclear cytoplasmic ratio (NCR) of thyrocytes, the ratio of the number of thyrocytes to fibroblasts per 50 μm2 (T/FB). Results. It was established that the height of the epithelium, NCR, and the area of the follicles change irregularly during the intake of PTU: at first, fluctuations of indicators are observed, and starting from 31st day they are stabilized. In general, after 47 days of receiving PTU, the average height of the follicular epithelium increased by 0.7 μm, the average area of the follicles – by 182 μm2, and NCR – by 0.11. In the stroma of the gland, activation of fibroblast proliferation was observed as evidenced by a decrease in the T/FB ratio from 2.87 to 0.54. Conclusion. When using a solution for drinking with 0.1% PTU for 47 days characteristic changes of hypertrophy and hyperplasia are observed in the thyroid tissue of hypertensive SHR rats. Stabilization of morphological parameters is observed after 30 days of taking PTU.

A comparative analysis of parental age-associated changes in the reproductive function and embryonic development has been performed for offspring of D. melanogaster imagoes of mutant (w(CS)(1) and w(Or)(1)) and wild-type (Canton-S and Oregon-R) lines. Fruit fly imagoes from three age groups (3-, 10-, and 20-day-old) were used in the experiment. Reciprocal crossings of young (3-day-old) imagoes to individuals from each age group were performed in order to identify the effects of maternal and/or paternal age on reproductive function parameters in the offspring. The effects of maternal and paternal ages on various reproductive function parameters in F-1 offspring were shown to vary between wild-type lines and mutant lines w(CS)(1)and w(Or)(1), which is apparently due to genetic differences between the lines. The white mutation alone or combined with advanced parental age had a negative effect on fertility and viability characteristics in F-1 offspring and caused a predisposition to the development of dominant lethal mutations and death at the pupal stage, such that the emergence of less adapted and viable offspring in the population was prevented.

Since the discovery, neonicotinoids have been considered as the most promising compounds with insecticidal activity due to the specific effect on nicotinic acetylcholine receptors of insects and low toxicity for mammals in the applied concentration ranges, and also because of the lack of resistance formation to them in insects. Neonicotinoids introduction into agricultural practice has resulted in significant increase of different crops yields. However, with the active widespread use of this class of insecticides, a number of negative consequences have been identified, in particular for pollinating insects. The detection of these effects led to a significant restriction or ban on these compounds use in agricultural practices in a number of countries. Ukraine is not among them. Considering that insecticides of this class are freely sold and their use is uncontrolled, the corresponding active substances are constantly present in agroecosystems, and their residual (non-lethal) concentrations can affect the viability and reproduction of insects, both harmful and useful or neutral. This study is an experimental comparative analysis of the effect of residual concentrations of neonicotinoid insecticides and nicotinic acid on Drosophila reproduction. The results of the study have shown that nicotinic acid has a similar (inhibition), but less strong (in comparison with the insecticides used) effect on the fertility and viability of genetically different Drosophila stocks. The genotype-dependent effects of the studied compounds on the lethality at pupa stage have been revealed. It has also been established that among the offspring of individuals who survived under the effect of neonicotinoids and niacin, the proportion of those who survive to the larval stage increases in comparison with the control group. Therefore, depending on the genotype, the long-term (in ontogenesis) effects of neonicotinoids and nicotinic acid at low concentrations may shift the selection in the offspring of exposed individuals from the early embryonic stage towards the parents (i.e., affect gametogenesis and viability of gametes).

At present, little is known of what happens to bone-marrow cells under caloric restriction or periodic starvation. The aim of the study was to investigate the influence of periodic starvation on the proliferative potential and cell morphology of the heterogeneous bone-marrow pool of young and old rats. Periodic starvation reduced the number of bone-marrow cells independently of the animal age, but did not affect cell viability and morphology. In young rats, periodic starvation increased the proportion of differentiated cells in the bone-marrow population; in old animals, it increased the number of undifferentiated blasts and blood-cell precursors. Bone-marrow cell cultivation was accompanied with reduced cell heterogeneity. Periodic starvation increased proliferative potential of bone-marrow cells from old rats. This suggests that periodic starvation at late stages of ontogenesis has an antiaging effect on bone-marrow cells in vivo and in vitro.

Indices of carbohydrate metabolism and histological structure endocrine tissue of the pancreas in rabbits with experimental diabetes after intrasplenic allo- and xenotransplantation of pancreatic islets of neonatal animals has been studied. It was found that intrasplenic transplantation of islets restores and maintains the long-term within the physiological norm of carbohydrate metabolism without hypoglycemic episodes. Intrasplenic transplantation pancreatic islets activates of the autoregeneration in endocrine pancreatic tissue of recipient animals, leading to the pool restoration of insulin-producing β-cells.

Influence of age of parents and duration of starvation on egg production and demonstration of embryonic mortality at different stages of egg development has been studied. It is shown that, with increasing age of organisms, the overall egg production reduces and the percentage of embryonic mortality increases at 0–5.5 and 5.5–17 h of development. An increase in the duration of starvation also promotes a reduction in egg production in 3- and 10-day-old adult D. melanogaster compared with short-term starvation. A statistically significant effect of factors, such as the allelic state of the white locus, the genetic background, the age of the parents, and the duration of starvation, on all studied parameters was established.