When oxygen is scarce, naked mammals (Heterocephalus glabe) survive by using fructose for metabolism. Understanding how the animals manage this maneuver could seriously help in treating patients suffering from oxygen deprivation in heart attacks and strokes. The international team of scientists from the United States, Europe and South Africa that made the discovery reported it today in the pages of the journal Science (Park et al., Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat). “This is a new but not the least remarkable discovery from naked mole-rats, mammals unable to maintain a constant body temperature that live several decades longer than other rodents, very rarely get cancer and are free of many types of pain,” says one of the team’s leaders, Prof. Thomas Park of the University of Illinois at Chicago. In humans, lab mice and all other known mammals, brain cells die when they run out of oxygen. But shrews have a backup way to survive: their brain cells begin to “burn” fructose in anaerobic glycolysis, a process that produces enough energy to last until better times. Previously, it was thought that in the living world, this variant of metabolism was only available to plants. In the new study, biologists forced naked molehills to stay in an atmosphere with reduced oxygen content for a long time. It should be said that in the wild this happens regularly – a colony of diggers is a burrow, virtually devoid of communication with the surface and inhabited by several dozen adults. The complete isolation of a burrow can last for years, and its inhabitants never go anywhere. The CO2 content in burrows often reaches 7-10%, while its content in atmospheric air is 0.03-0.04%. It is logical to ask how they survive this situation and what helps them in this. During the experiment, the researchers found large amounts of fructose in the blood of the diggers. And found that it is absorbed into brain cells with the help of fructose pumps GLUT5, which in other mammals are found only in the intestinal cells responsible for the absorption of glucose and other monosaccharides. At 80% carbon dioxide in the air, which would kill a human in minutes, naked diggers survive for at least five hours. They go into anabiosis, reducing motor activity and dramatically slowing their heart rate and respiratory rate to conserve energy. In this state, they begin to utilize fructose until oxygen is available. The naked shrew is the only mammal known to date to utilize anabiosis during oxygen deprivation. “The naked mole has simply rearranged some of the basic building blocks of its metabolism to make it ultra-tolerant to low oxygen,” notes Park, who has been studying these strange animals for 18 years. The naked digger is a small, swarming rodent that leads an underground lifestyle. It lives in large, complexly organized colonies-families resembling colonies of collective insects like ants or wasps. In addition to its characteristic appearance, it is distinguished by a huge life expectancy for rodents (more than 32 years with a body length of 8-10 cm), immunity to some types of painful stimuli and cold-bloodedness, almost no cancer and does not suffer from atherosclerosis and dementia.