Mammal Or Plant? Oxygen Deprivation Makes Naked Mole-Rats Behave Like Plants

In all mammals, including humans, brain cells run out of energy and begin to die if they are deprived of regular oxygen supply. Unless you happen to be a naked mole-rat, in which case you simply change your metabolism to that of a plant.

An international team of researchers — from universities in the United States, Germany, South Africa and the United Kingdom — placed naked mole-rats in low-oxygen conditions and found the small mammals released large amounts of fructose (a type of sugar) into their bloodstreams, which the brain burns for energy using a metabolic system hitherto known only in plants.

The findings of the team were published Friday in the journal Science, in a paper titled “Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat.”

Naked mole-rats can survive for at least five hours in low-oxygen conditions that would kill an adult human within minutes. They do so by moving into a state of suspended animation, wherein they slow down their pulse rate, reduce breathing and movement, and start using fructose for energy till oxygen becomes plentiful again. Moreover, the study found the animals transported the fructose to the brain using special molecular pumps that are otherwise found only on the intestine walls of all other mammals.

“The naked mole-rat has simply rearranged some basic building-blocks of metabolism to make it super-tolerant to low oxygen conditions. … This is just the latest remarkable discovery about the naked mole-rat — a cold-blooded mammal that lives decades longer than other rodents, rarely gets cancer, and doesn’t feel many types of pain,” Thomas Park, professor of biological sciences at the University of Illinois at Chicago and lead author of the study, said in a statement Thursday.

According to the scientists, the naked mole-rat evolved this unique trait as an adaptation for its natural habitat — they live underground in unventilated tunnels, in colonies of hundreds of individuals. Such living arrangements leave very little fresh oxygen supply.

An understanding of how exactly the change in metabolism occurs could potentially lead to treatment methods for patients who suffer heart attacks and strokes, conditions which cause hypoxia, or oxygen deprivation. Additionally, the researchers showed naked mole-rats are immune to pulmonary edema — a fluid buildup in the lungs seen in mountain climbers at high altitudes.