[Hypoxic preconditioning modifies the activity of pro- and antioxidant systems in rat hippocampus].

The effects of repetitive mild hypobaric hypoxic preconditioning upon pro- and antioxidant systems in rat hippocampus were studied. It was found that three-trial preconditioning by mild hypobaric hypoxia (360 mm Hg, 2 h) induced moderate oxidative stress immediately after the last preconditioning trial. In addition, it down-regualted the levels of peptide antioxidants (Trx-1, Trx-2, Cu,Zn-SOD) and several lipid peroxidation products 24 h later.

[Effects of the prenatal hypoxia on the hypothalamic-pituitary-adrenal axis function and working memory in rats].

A comparative analysis of the effects of severe hypobaric hypoxia in different prenatal periods on expression profiles of glucocorticoid receptors (GR) in dorsal (CA1) and ventral (dental gyrus) hippocampus and neocortex of rats, their stress reactivity and working memory has been performed in the present study for the first time. According to the data obtained, severe hypoxia in the prenatal period induces remarkable disturbances of GR expression in the neurons of neocortex of adult males but not females, that correlates to the disruption of working memory in adult males exposed to hypoxia on the prenatal 14-16th days. Elevation of stress plasma corticosterone levels have been observed only in the females subjected to hypoxia on the prenatal 17-19th days.

[Changes in Mn-superoxide dismutase expression in rat hippocampus induced by single and triple exposure to moderate hypobaric hypoxia].

The purpose of this work was to study the dynamics of expression of mitochondrial Mn-dependent superoxide dismutase (Mn-SOD) 3 and 24 hours after single and triple exposure to mild hypoxia. The investigation was conducted in 18 male Wistar rats using immunocytochemical method. It was shown that in various hippocampal areas the effects of single and triple hypoxia exposure on the Mn-SOD expression could be different or largely similar.

[Comparison of effects of a single and thrice-repeated moderate hypobaric hypoxia upon expression of thioredoxine-1 in the rat hippocampus].

We have previously shown that severe acute hypobaric hypoxia (SH) increases the expression of several endogenous antioxidants including thioredoxin-1 (Trx-1) in hippocampal neurons of rats. Preconditioning by three sessions of mild hypobaric hypoxia (MH) significantly augments this increase at the early period after subsequent SH, but MH itself without subsequent SH, in contrast, decreases expression of Trx-1. The dynamics of Trx-1 expression between the first and the last (third) sessions of preconditioning remains, however, unclear.

[Dynamics of lipid peroxidation of membranes in cells and mitochondrial fraction of neocortex in non- and preconditioned rats after severe hypobaric hypoxia].

There was studied effect of severe hypobaric hypoxia and subsequent reoxygenation on level and dynamics of lipid peroxidation in membranes of neocortex cells and in mitochondria-enriched neocortex fraction of non-preconditioned rats and of rats preconditioned thrice with a moderate hypobaric hypoxia. The threefold hypoxic preconditioning increasing brain resistance has been shown to significantly prevent disturbance of lipid peroxidation processes in neocortex--one of the most hypoxia-sensitive brain structures--and to modify development of these processes in mitochondria.