THE IMPORTANCE OF PRENATAL PASSIVE SMOKING FOR THE DEVELOPMENT OF CENTRAL RESPIRATORY REGULATION MECHANISM IN NEWBORN RATS IN VITRO

In the prenatal period, neural networks undergo the most significant morphological changes and subsequent functional transformations. The influence of a combination of factors of passive tobacco smoking to the development of the central mechanisms of respiratory control in the prenatal period remains unexplored. The present study was devoted to the study of the prenatal effect of passive smoking factors on the functioning of the central mechanisms of respiratory control in newborn rat. The study was carried out on 107 isolated brain stem-spinal cord preparations of the brain of newborn white outbred rats in vitro. Passive smoking was modeled by fumigating experimental animals with cigarette smoke. To simulate the hypercapnic effect, the bulbospinal preparations were perfused for 10 minutes with a solution of artificial cerebrospinal fluid with a saturated gas mixture, consisting of 10 % CO2 and 90 % O2; to simulate hypoxic exposure, the preparations were irrigated with a solution of artificial cerebrospinal fluid with a saturated gas mixture for 20 minutes 5 % CO2 and 95 % N2. As a result of the study, it was found that in newborn rats that underwent prenatal passive smoking, there is a high frequency of generation of inspiratory discharges, a shift in the spectral power density peaks of respiratory discharges in both ranges towards low frequencies, a decrease in their power, a decrease in the amplitude and a shorter duration of inspiratory discharges. in comparison with intact animals. A feature of the reaction to hypoxia in newborn rats who have undergone prenatal passive smoking is a late formation of the hypoxic depression of respiratory rhythm, reaction to hypercapnia characterized by no reduction in duration respiratory cycle. Thus performed by us research shows that prenatal secondhand smoke affects the mechanism of formation of the respiratory rhythm and pattern and also modifies the respiratory response to change in the partial tension of respiratory gases in cerebrospinal fluid in vitro.