They won't be winning any beauty contests, but naked mole-rats have plenty of weird tricks up their wrinkly pink sleeves. The creatures are incredibly long-lived for their size, they're resistant to cancer, pain doesn't faze them – and according to a new study, they're basically half-plants. When deprived of oxygen, naked mole-rats can survive by going into suspended animation and metabolizing fructose instead, a process that was previously only thought possible in plants.
Cut off the oxygen supply to a human – or any mammal, for that matter – and they'll only have minutes to live, as their brain cells die off. But under similar airless conditions, a naked mole-rat can survive for as long as five hours by entering a state of suspended animation, during which the animal slows its breathing and heart rate.
Fructose is the key to their low-oxygen longevity. When put under pressure, the levels of the sugar in the naked mole-rat's bloodstream shoot through the roof, and molecular pumps push it up to the creatures' brains, where the cells can stay alive by burning fructose instead of oxygen. Until now, scientists thought that this metabolic pathway was only used by plants – in every other mammal species known to science, fructose is only processed in the intestines.
"The naked mole-rat has simply rearranged some basic building-blocks of metabolism to make it super-tolerant to low-oxygen conditions," says Thomas Park, lead researcher on the study.
But low-oxygen environments don't just affect the brain: High-altitude hikers can be struck down with pulmonary edema, when fluid builds up in the lungs. True to their indestructible nature, the unusual metabolism of the naked mole rat seems to protect them from this condition as well.
So why does the animal need this kind of superpower? Another quirk of the creatures is the fact that they live in a strange social structure of queens and colonies, almost like ants. As a result, their burrows are incredibly crowded, containing up to 200 or 300 animals all breathing the same air. A high tolerance to low oxygen is an important skill to develop.
The researchers say that understanding this system could lead to ways to help protect human brain cells from oxygen starvation, in events like heart attacks.
"In a heart attack, we lose a lot of the oxygen going to our brain," says Brigitte Browe, co-author of the study. "If we can figure out how to up-regulate this fructose system and utilize that instead of the glucose system, we will be able to maintain those brain cells at a healthy level."
The researchers discuss their work in the video below. The study was published in the journal Science.
Source: University of Illinois at Chicago