Antioxidant defense system in hibernating mammals

Hibernation is one of the most striking examples of mammals' phenotypic flexibility, allowing them to survive at low temperatures and in the conditions of insufficient food and water. During the torpor there is a decrease in both body temperature and metabolic rate that is accompanied by slowing respiration, significant drop of oxygen consumption as well as by the reduction of cerebral blood circulation and heart rate. In spite of a number of physiological adaptations to hibernation, the arousal from torpor is accompanied by the oxidative stress caused by the enormous rise of oxygen consumption. In these conditions, the antioxidant defense system which provides harmless transfer from torpor to arousal and vice versa, i.e., without any tissues' oxidative damage, becomes especially important. Up to date, it is not fully elucidated how the antioxidant system acts during the periods of hibernation, but it deserves careful attention. In the review the information about the use of different strategies of antioxidant protection during hibernation in small mammals was collected