The pattern of the expression of hypoxia-inducible factor (HIF-1α) in the neocortex and hippocampus of rats after the presentation of different modes of hypobaric hypoxia

Using the immunohistochemical method, we studied changes in the expression of the hypoxia-inducible factor (HIF-1α) in the neocortex and hippocampus of rats after moderate preconditioning (MH), severe (SH) hypobaric hypoxia, and their combined action. We found that a three time but not a single MH had a pronounced effect on the activity of HIF-1; MH increases its expression in the regulatory oxygen-sensitive alpha subunit in neurons of the neocortex and hippocampus of rats. We also found that a three time (but not a single) hypoxic preconditioning enhances HIF-1α expression in both the hippocampus and neocortex in response to the following SH, whereas in non-preconditioned animals MH substantially decreases the HIF-1α level.