Mechanisms of Protection Against Oxidative Stress During Hibernation

Hibernation-the ability of some animals to enter prolonged winter sleep-is a natural hypometabolic state that allows them to withstand adverse environmental factors (low temperatures, food and water shortages). The ability to hibernate is a consequence of adaptations accumulated over evolution at various physiological levels, among which molecular adaptation to hypoxia plays a key role, which eliminates not only the negative effect of oxygen deficiency on cells, but also the danger of oxidative stress (OS) after awakening. This aspect of hibernation is medically important because understanding the mechanisms underlying the adaptation of hibernating animals to hypoxia and OS can help address a number of important issues related to preventing post-hypoxic complications in people with chronic neurodegenerative and heart disease. The molecular basis of adaptation to hypoxia in hibernating animals is the presence of an effective antioxidant system (AOC) and regulatory mechanisms that provide extraordinary mitochondrial plasticity, which is especially pronounced when animals emerge from hibernation. This review summarizes and systematizes the latest advances in the study of mitochondria and antioxidant defenses during mammalian hibernation, primarily gophers-a common experimental model of hibernation.