Deprived of oxygen, mole rats ‘become’ plants.
Naked mole-rats ‘turn into’ plants when they are deprived of oxygen, shows a new study published in the journal Science.
We all absolutely need oxygen to live. But, not naked mole-rats, apparently, suggests a new study. When a team of researchers from the University of Illinois deprived a group of naked mole-rats from the essential gas, they found that the latter did what plants would do: metabolising fructose to survive. (In case you’re wondering, the animals do not literally change into plants!)
The naked mole-rat, also known as the sand puppy or desert mole rat, is a cold-blooded mammal, explains lead researcher Thomas Park. They live in extremely crowded, unventilated environments which would be characterised by fast oxygen depletion. The little guys were demonstrated to do what other known mammals have never done. The latter would die if their brain cells were to face a critical lack of oxygen. But, naked mole-rats have another way to generate energy: their brain cells use up fructose, thereby releasing energy anaerobically, a metabolic activity that only plants can use.
This discovery was made when Park and his colleagues put a group of naked mole-rats under conditions of low oxygen in laboratory. It was, then, observed that large quantities of fructose were released into their blood, as a consequence. This fructose would be loaded into brain cells via fructose pumps. Interestingly, these pumps are present in all other mammals, but only in intestinal cells. Park summarises this marvellous ability as a simple rearrangement of “some basic building blocks of metabolism” so that they develop a greater tolerance to low oxygen concentrations.
If this was not crazy enough, hear this out. The naked mole-rats could survive on fructose when oxygen was at levels that would have been fatal for humans: we would have died in a matter of minutes while the animals survived for a minimum of 5 hours under those impossible conditions.
When they are using up the fructose, the naked mole-rats transition into a state of suspended animation, whereby their movement is limited, and their pulse and breathing are slowed as a way of conserving energy—this makes the naked mole-rat the only documented mammal to take to suspended animation to deal with oxygen deprivation. Then, they switch back to the normal method of releasing energy when oxygen is made available again.
Another interesting finding is that oxygen deprivation normally causes an accumulation of fluid in the lungs, a condition known as pulmonary edema; this is what happens to mountain climbers as they go higher up. But, this does not happen to the naked mole-rat, which is somehow protected from this consequence of lack of oxygen.
This study is deemed to have implications in the science of the heart: it could help researchers design treatments for heart attacks and strokes, conditions that are characterised by oxygen deprivation.