The naked rat develops the survival properties of a plant in the absence of oxygen

In conditions of lack of oxygen, the naked rats can survive by breaking down fructose just like plants do - this finding could lead to treatments for heart attacks and strokes

The naked rat can survive without oxygen using a fructose-based metabolism, just as plants do in a similar situation. This is what researchers report this week in the journal Science.

Understanding how the animals do this can lead to treatments for patients suffering from crises of oxygen deficiency, such as heart attacks and strokes.

"This is the most amazing discovery about the naked rat, a cold-blooded mammal that lives decades longer than other rodents, rarely gets cancer, and does not feel many types of pain," says Thomas Park, professor of biological sciences at the University of Illinois at Chicago, who led an international team of researchers from - UIC, from the Max Delbrück Institute in Berlin and the University of Pretoria in South Africa.
In humans, laboratory mice and all other known mammals, when brain cells are starved of oxygen they run out of energy and begin to die. But the naked rat has a backup: its brain cells start burning fructose, which produces anaerobic energy through a metabolic pathway that until now scientists thought was only used in plants.

In the new study, the researchers exposed rats to low oxygen conditions in the laboratory and found that they released large amounts of fructose into the bloodstream. The fructose, the researchers found, was transported to brain cells by molecular fructose pumps, which in all other mammals are found only in the intestinal cells.

"The naked rat simply rearranged some basic building blocks of the metabolic system to make it extremely tolerant of low-oxygen conditions," said Park, who has studied the strange species for 18 years.

At low oxygen levels enough to kill a person within minutes, the rats can survive for at least five hours, Park said. They go into hibernation. There is a dramatic decrease in mobility, heart rate and breathing rate slow to conserve energy, and they begin using fructose until oxygen is available again.

The naked rat is the only mammal so far that knows how to use hibernation to survive the lack of oxygen.

The scientists also showed that the rats were protected from another deadly aspect of low oxygen - a build-up of fluid in the lungs known as pulmonary edema that high-altitude mountain climbers face.
The scientists think that the naked rat's unusual metabolism is a product of adaptation to life in their oxygen-poor burrows. Unlike other subterranean mammals, the rats live in overcrowded conditions, hundreds of them in each colony. When so many animals live together in poorly ventilated burrows, the oxygen supply quickly depletes.

to the notice of the researchers