When Oxygen Runs Low, the Naked Mole-Rat Finds a Way
These unique mammals may teach humans tricks to lessen effects of stroke, heart attack, scientists say
THURSDAY, April 20, 2017 (HealthDay News) -- When brain cells are starved of oxygen, people and all other mammals run out of energy and begin to die.
Not so for a hairless, underground rodent called the naked mole-rat. It survives low-oxygen conditions because its brain cells switch from using glucose as fuel to fructose -- a process that is typically found in plants, not animals.
Scientists believe their new findings could someday lead to new treatments for people who have a heart attack or stroke.
"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 the study's leader, Thomas Park. He is a professor of biological sciences at the University of Illinois at Chicago.
The naked mole-rat is native to Africa and lives in extensive underground burrows. In the latest research on these remarkable creatures, Park and his colleagues found that naked mole-rats can survive for at least five hours at low-oxygen conditions that would kill people within minutes.
The animals do this by releasing large amounts of fructose into their bloodstream if they become deprived of oxygen. Molecular fructose "pumps" -- which are typically only found in the intestines, not the brains, of other mammals -- carry this fructose to their brain cells.
In essence, "the naked mole-rat has simply rearranged some basic building-blocks of metabolism to make it super-tolerant to low-oxygen conditions," Park explained in a university news release.
The mole-rats also conserve energy by moving less, and slowing their pulse and breathing rate, the study showed.
And when oxygen levels run low in their burrows, the mole-rats use fructose until oxygen levels rise again -- a back-up plan that isn't used by any other known mammals, the researchers said.
Mole-rats are also protected from pulmonary edema, a dangerous buildup of fluid in the lungs that occurs when people are deprived of oxygen at high altitudes. Scientists speculate these mammals adapted to living in overcrowded, low-oxygen underground burrows.
All of this might have implications for human health, added study co-researcher Gary Lewin, a researcher at the Max Delbruck Center for Molecular Medicine in the Helmholtz Association, in Berlin, Germany.
"Patients who suffer [heart attack] or stroke experience irreparable damage after just a few minutes of oxygen deprivation," Lewin noted in a Helmholtz news release.
In the future, by tweaking some genes, it theoretically might be possible for humans to gain the "back-up" plan already employed by the naked mole-rat in periods when oxygen runs low, Lewin said.
The report was published April 20 in Science.
The U.S. National Library of Medicine has more about oxygen deprivation.
-- Mary Elizabeth Dallas
SOURCES: Helmholtz Association and University of Illinois at Chicago, news releases, April 20, 2017
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