The rapid development of technology has a significant impact on the daily life of a person. Light, sound, information pollution leads to sleep disturbance, which has a negative impact on the physical condition. Even short-term sleep disturbance caused by dark deprivation Leads to a decrease in serum testosterone LeveLs. The imbaLance of maLe sex hormones, the synthesis of which is under the controL of the hypothaLamic-pituitary system, negativeLy affects the morphofunctionaL state of the testes. The effect of exogenous meLatonin on the morphoLogicaL and functionaL state of the spermatogenic epitheLium of the testes, Leydig cells in white outbred male rats of 4 months of age was studied on the model of premature aging caused by 30-day dark deprivation, and the KLotho protein LeveL in bLood serum was assessed by enzyme immunoassay. It was found that the morphoLogicaL changes in the testes were characterized by a decrease in the thickness of the spermatogenic epithelium by 30 days after dark deprivation and a decrease in the LeveL of the KLotho protein, which is a marker of premature aging. The introduction of exogenous meLatonin had a protective effect on the morphoLogicaL and functionaL status of the testes of animaLs, accompanied by the restoration of the spermatogenic epitheLium, an increase in the KLotho protein to the LeveL of the negative controL group.

The effect of 30-day dark deprivation (light-dark cycle 24/0 h, artificial illumination 300 Lux) on the morphofunctional state of the testes was studied using morphological and morphometric analysis of histological preparations of white mongrel male rats 4 months of age. The level of follicle-stimulating hormone in blood serum was assessed by enzyme immunoassay. It was found that 30-day dark deprivation increases the level of follicle-stimulating hormone in the blood serum. Morphological changes in the testes were characterized by a decrease in the area of Sertoli cells and their nuclei, the thickness of the spermatogenic epithelium. The hormonal background and morphofunctional state of the testes were corrected by the administration of exogenous melatonin for 14 days.

On the model of premature aging induced by 30-day dark deprivation (light-dark cycle 24/0 h, artificial illumination 300 Lux), the effect of exogenous melatonin (0.3 mg/kg, 14 days after the cancellation of dark deprivation, intragastric daily in 2 % starch mucus) on the dynamics of body weight and the level of Klotho protein in the blood was studied in outbred white male rats of 4 months of age. It has been shown that prolonged dark deprivation is accompanied by a statistically significant decrease in the content of the Klotho protein in the blood serum, which is a marker of premature aging. Metabolic disorders associated with a statistically significant decrease in the level of melatonin and Klotho protein in the blood were expressed in fLuctuations in the dynamics and rate of body weight gain in animaLs. At the same time, exogenous meLatonin had a protective effect on the condition of animals - it contributed to an increase in the content of Klotho protein in the blood serum and restored the level of melatonin to the values of the negative control indicator.

The study revealed pathomorphological changes in the placenta in late preterm birth from 34 weeks to 36 weeks and 6 days. Late preterm birth is accompanied by morphostructural changes in the placental tissue, manifested by involutive-dystrophic changes, impaired maturation of chorionic villi as well as the presence of compensatory-adaptive reactions.

Studies of the influence of chronic soft, hard immobilization and immersion stress on the early stages of postnatal ontogenesis (the breast period, the period of transition to independent nutrition and the pre-juvenile period) are presented.