Naked diggers can breathe like plants

Sergey Sysoev, Naked Science

Small colonial rodents that live in branched burrows and almost never come to the surface have many unusual abilities. Another of them turned out to be a unique way of breathing for animals.

With a lack of oxygen, naked diggers (Heterocephalus glabe) survive by using fructose for metabolism. Understanding how animals manage this maneuver can seriously help in the treatment of patients suffering from lack of oxygen during heart attacks and strokes. An international group of scientists from the USA, Europe and South Africa, who made the discovery, reported about it today on 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 last remarkable discovery from the life of naked diggers – mammals that are unable to maintain a constant body temperature, who live several decades longer than other rodents, very rarely get cancer and do not experience many types of pain," says one of the team leaders, Professor Thomas Park from the University of Illinois at Chicago.

In humans, laboratory mice, and all other known mammals, brain cells die when they run out of oxygen. But the diggers have a backup way of survival: their brain cells begin to "burn" fructose in anaerobic glycolysis, and this process produces enough energy to last until better times. Previously, it was believed that in the living world, this variant of metabolism is available only to plants.

In a new study, biologists forced naked diggers to stay in an atmosphere with a reduced oxygen content for a long time. I must say that this happens regularly in the wild – a colony of diggers is a burrow, practically devoid of communication with the surface and inhabited by several dozen adults. Complete isolation of the burrow can last for years, while its inhabitants never go anywhere. The CO2 content in burrows often reaches 7-10% when its content in atmospheric air is 0.03–0.04%. It is logical to ask how they are experiencing this situation and what helps them in this.

Professor Park talks about naked diggers and their unusual talents.

During the experiment, the researchers found a large amount of fructose in the blood of the diggers. And they found that it is absorbed into brain cells with the help of GLUT5 fructose pumps, which in other mammals are found only in intestinal cells responsible for the absorption of glucose and other monosaccharides.

With 80% carbon dioxide in the air, which will kill a person in a few minutes, naked diggers survive for at least five hours. They fall into suspended animation, reducing motor activity and dramatically slowing down the pulse and respiratory rate in order to conserve energy. In this state, they start using fructose until oxygen appears. The naked digger is the only mammal known to date that uses suspended animation during oxygen starvation.

"The naked digger simply rearranged some of the basic blocks of metabolism to make it super tolerant to low oxygen content," notes Park, who has been studying these strange animals for 18 years.

The naked digger is a small burrowing rodent leading an underground lifestyle. It lives in large, complex colonies-families resembling colonies of collective insects, like ants or wasps. In addition to its characteristic appearance, it stands out for a huge rodent lifespan (more than 32 years with a body length of 8-10 cm), immunity to certain types of pain stimuli and coldness, almost does not suffer from cancer and does not suffer from atherosclerosis and dementia at all.

Portal "Eternal youth" http://vechnayamolodost.ru  21.04.2017