When Oxygen Runs Low, the Naked Mole-Rat Finds a Way

Even tougher than we thought

Even tougher than we thought

Researchers from the University of IL in Chicago were amazed to find yet another incredible feat from the small rodent.

Certain prejudices have prevented us from learning more about these creatures, mainly because some consider them mind-numbingly ugly. Seriously, what the hell, nature?

When they are cut off from a regular oxygen supply, naked mole-rats survive by metabolizing fructose in the same manner as plants tend to do so.

When the oxygen was completely removed and replaced with nitrogen, the mice died after 45 seconds.

The naked mole-rat is the only known mammal to use suspended animation to survive oxygen deprivation.

The scientists think that the naked mole-rats' unusual metabolism is an adaptation for living in their oxygen-poor burrows.

PARK: They had more stamina than the researchers.

Researchers believe that naked mole rats can accomplish this by changing their primary source of energy, allowing them to rely on fructose rather than oxygen. But the process of taking that sugar and turning it into energy requires oxygen.

"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", said Thomas Park, professor of biological sciences at the University of IL at Chicago, who led the study.

Even more surprising is the fact that the necessary genetic pathways for the heart and brain to burn fructose are present in all mammalian cells-including ours. Individuals of this species are used to living jam-packed with hundreds of their kin in small, poorly-ventilated burrows - where the oxygen-o-meter often falls below breathable levels. Thus the naked mole-rat seems to have made such an arrangement in its body that it shows super-tolerance to a low oxygen situation.

Researchers found that the rodents could stay alive for hours under low oxygen conditions that would kill most mammals within minutes. Molecular fructose "pumps" - which are typically only found in the intestines, not the brains, of other mammals - carry this fructose to their brain cells. Using a technique called mass spectrometry, Park and his colleagues analysed tissue from the mole-rats' vital organs, including their brains and hearts.

They also detected a fructose metabolite in anoxic brains, but not in brains supplied with oxygen.

The study is important not just because it reveals the true biology of these curious creatures.

But it remains to be seen if human cells could be coaxed into behaving this way.

"Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat" (science.aab3896) co-authors are Bethany L. Peterson, Gregory Blass, Brigitte M. Browe, Daniel T. Applegate, Victoria Gavaghan, Vince G. Amoroso and Vidya Govind of UIC's Laboratory of Integrative Neuroscience; Richard D. Minshall and John Larson of the UIC College of Medicine; Gary R. Lewin, Jane Reznick, Damir Omerbaši?, Tetiana Kosten, Ole Eigenbrod, Valérie Bégay, P. Henning J.L. Kuich, Christin Zasada, Stefan Kempa, Wiebke Hamann, Michael H. Radke and Michael Gotthardt of the Max Delbru?ck Center for Molecular Medicine and Ewan St. J. Smith, now at the University of Cambridge; and Nigel C. Bennett and Heike Lutermann of the University of Pretoria.

If human cells could rearrange their metabolism in this way, critical organs could be saved when a stroke or infraction occurs.

When this happens, naked mole-rats lose consciousness, slowing their heart rate and stopping their breathing.