The developing brain as an object of study of the formation of oxidant and antioxidant systems

Background. Differentiation of structures, tissues and systems of the brain occurs gradually. The values of individual biochemical constants vary depending on the timing of the embryonic, early and late postnatal period of development. In this respect, of interest are oxidation/antioxidation systems that are multicomponent and therefore do not mature at the same time. The aim is to study the processes of lipid peroxidation by the level of malonic dialdehyde and antioxidant protection (superoxide dismutase, catalase, reduced glutathione) in the brain of embryos and offspring of rats at different periods of pre- and postnatal development of rats. Methods. 39 pregnant female Wistar rats weighing 220-250 g were selected, from which 176 embryos and rat pups of different sex and age were obtained, including embryos of the 3rd trimester of pregnancy (13-17 days of gestation) and rat pups aged from 1 to 14 weeks. The concentration of malonic dialdehyde (indicator of lipid peroxidation) was determined in the brain tissue, as well as the activity of superoxide dismutase, catalase, and the level of reduced glutathione as indicators of antioxidant defense systems. Results. It was found that the brain of embryos is characterized by low levels of malonic dialdehyde, the concentration of which sharply increases immediately after the birth of rat pups. A similar, but less pronounced pattern is also recorded for indicators of antioxidant protection (superoxide dismutase activity and the level of reduced glutathione). The opposite reaction was observed in the case of catalase, whose activity in the brain in the prenatal period was high, and after birth it was significantly decreased. In the period of further postnatal development up to sexual maturity (14 weeks, or 3 months of age), there was no significant change in the activity of superoxide dismutase, catalase, and the concentration of reduced glutathione, but a 2-fold drop in the level of malonic dialdehyde in brain. Conclusion. It is concluded that already in the first months of life in rats, a quite stable status of lipid peroxidation and antioxidant defense systems of the brain tissue develops.