Impact of hypoxia on dynamics of the post-hypoxia HIF-1α level in neocortex and adaptation forming in rats with different resistance to hypoxia

Abstract

Hypoxic preconditioning induces two-phase increase of HIF-1α expression in the neocortex of low-resistance rats. The first, brief phase appears after each hypoxic episode and rapidly disappears in normoxic conditions. The second increase in of HIF-1α expression occurs in 24 hours after the hypoxic episode. The phase-nature of HIF-1α expression corresponds to the dynamics of urgent and long-term resistance in low-resistance rats, which suggests the HIF-1α involvement in mechanisms of urgent and long-term adaptation. In high-resistance rats, hypoxia preconditioning does not influence the HIF-1α protein expression and the adaptation. Severe hypoxia inhibits the HIF-1a protein expression in the neocortex of both rat phenotypes, depresses the formation of urgent resistance, and abolishes the induction of long-term adaptation.