Changes in Metabolic Parameters of Rats in Different Age Periods After Prenatal Stress

INTRODUCTION: Currently, biomedical specialists give special attention to studying the influence of stressogenic factors on an organism of a pregnant woman, the embryonic development of the fetus and the subsequent development of offspring in the early and late ontogenesis. It has been found in a number of studies that prenatal stress can lead to reduction of physical activity and hormonal disorders. The factors leading to disorders in regulation of immune and metabolic homeostasis have been identified. Despite considerable interest in the study of the consequences of prenatal stress, its impact on changes in metabolic intensity in different periods of postnatal ontogenesis in animals of different genders has not been sufficiently studied.

AIM: To study parameters of metabolism intensity in different age periods of postnatal ontogenesis in rats’ offspring of both genders after intrauterine stress load.

MATERIALS AND METHODS: Stress load was modeled in daily forced swimming of pregnant rats at 10–12°C for 5 min. Oxygen consumption, carbon dioxide excretion (ml/h/kg), and heat exchange (kcal/h/kg) in male and female rats were determined using a Phenomaster automated modular unit (TSE Systems GmbH, Germany) on the 21^st, 30^th and 60^th day of the ontogenesis. Statistical significance of differences between the studied parameters was assessed using Mann-Whitney U-test for independent groups.

RESULTS: The study parameters of intact animals practically did not differ in the suckling (the 21^st day) and infantile period (the 30^th day), but significantly decreased in the juvenile period of development (the 60^th day). It was found that the intrauterine stress did not lead to statistically significant changes in the absolute values of metabolic parameters as compared to the control, but affected the period of appearance of age-related variations of these parameters in male rats. In these animals, the volumes of oxygen consumption, carbon dioxide excretion, and the level of heat radiation reduced as early as in the infantile period (as compared to 21-day-old rats) and reached the minimum level by the 60^th day of the postnatal ontogenesis. In female rats subjected to intrauterine stress, changes in the study parameters in different periods of life were similar to those of intact animals.

CONCLUSION: Therefore, prenatal stress modeled by swimming of female parents in cold water, has a modulating effect on age-related dynamics of metabolic parameters of male rats, which was manifested by the decrease in these parameters in the earlier period of development.