Structural and functional differences in cardiac and brain mitochondria in animals with different tolerance to oxygen deficiency

Depending on the individual resistance to hypoxia, many cell-adaptive reactions are formed, but the mechanisms of their occurrence are still not clear. Hypoxia is associated with many biological processes, including pathogenic microbial infection, cancer, acute and chronic diseases, and more other. Hypoxia-inducible factors (HIFs) regulate the expression of a number of genes involved in cellular metabolism, cell growth/death, cell proliferation, glycolysis, immune response, tumorigenesis, and metastasis. The brain and the heart are the organs most sensitive to oxygen deficiency, and their mitochondria, as the primary consumers of cellular oxygen, help tune cellular and organismal responses to hypoxia through structural or functional modifications. To date, there have been no comparative studies of the ultrastructural features of brain and cardiac mitochondria in animals demonstrating different tolerance types to oxygen deficiency: low-resistance (LR) and high resistance (HR) to hypoxia, which influence the general resistance of the body to oxygen deficiency.