The developing brain in the formation of oxidant and antioxidant systems

Abstract

BACKGROUND: The structures, tissues, and systems of the brain differentiate gradually. The values of biochemical constants vary depending on the timing of development, that is, the embryonic, early, and late postnatal periods. In this respect, the multicomponent oxidation and antioxidation systems that do not mature at the same time are of interest.
 AIM: To examine the processes of lipid peroxidation based on the level of malonic dialdehyde and antioxidant protection (superoxide dismutase, catalase, and reduced glutathione) in the brain of rat embryos and offspring at different periods of pre- and postnatal development.
 MATERIALS AND METHODS: Thirty-nine pregnant female Wistar rats weighing 220–250 g were selected, from which 176 embryos and rat pups of different sexes and age were obtained, including embryos in the third trimester of pregnancy (13–17 days of gestation) and rat pups aged 1–14 weeks. The concentration of malonic dialdehyde (indicator of lipid peroxidation) was determined in the brain tissue, and the activity of superoxide dismutase, catalase, and level of reduced glutathione was found as indicators of antioxidant defense systems.
 RESULTS: The brains of the embryos were characterized by low levels of malonic dialdehyde, and its concentration sharply increased immediately after the birth of rat pups. A similar but a less pronounced pattern was also recorded for indicators of antioxidant protection (superoxide dismutase activity and level of reduced glutathione). The opposite reaction was observed in catalase, which demonstrated high activity in the brain in the prenatal period but significantly decreased after birth. With further postnatal development up to sexual maturity (14 weeks, or 3 months of age), no significant changes in the activities of superoxide dismutase, catalase, and concentration of reduced glutathione were noted; however, a twofold drop in the level of malonic dialdehyde in the brain was noted.
 CONCLUSION:Already in the first months of life in rats, a quite stable status of lipid peroxidation and antioxidant defense systems of the brain tissue developed.