By Taylor Ha ’18
Naked mole-rats are pink, wrinkly, and big-toothed. Deep underground in hypoxic, or low oxygen, and high carbon dioxide conditions, these strange creatures live in colonies of up to 280 members. And, according to a recent study published on April 21, 2017, they also have the ability to metabolize fructose, just like plants, and survive without oxygen for 18 minutes without any physiological harm.
By contrasting how naked mole-rats and mice responded to different levels of oxygen, Dr. Thomas J. Park, who researches the neurobiology of sensory systems at the University of Illinois at Chicago, and his colleagues examined the molecular mechanisms behind the naked mole-rat’s ability to tolerate low-oxygen environments. Members of the two species were placed in atmospheric chambers with controlled hypoxia conditions, and exposed to oxygen levels ranging from 0 to 5 percent for different amounts of time. Naked mole-rats recovered from 10-minute and 18-minute exposures to zero percent oxygen, but not from 30-minute exposures, while mice stopped breathing after approximately 6 minutes.
The researchers then analyzed changes in the naked mole-rats’ metabolite concentration during anoxia, or a complete absence of oxygen, and unexpectedly discovered high fructose and sucrose concentrations in anoxic tissues – up to 240 μM and 1.47 mM at 30 minutes in the blood, respectively – signifying that these sugars could power metabolism under low oxygen conditions. By analyzing mole-rat and mice brain tissue, the scientists also concluded that in the mole-rat’s brain and heart, fructose could substitute glucose as a viable energy source.
Scientists now know more about the biological adaptations behind the naked mole rat’s subterranean lifestyle. But more importantly, the study results can help researchers create strategies to prevent hypoxic damage in people who suffer from oxygen deficiency in bodily tissues – a condition associated with heart disease and stroke that can permanently damage the brain, liver and other organs.
- T.J. Park, et al., Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat. Science 356, 307-311 (2017). doi: 10.1126/science.aab3896.
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