- Experiments show yeast and worms deprived of oxygen can survive extreme cold.
- The research widens possibilities for suspending metabolism, then resuming life without ill effects.
- Scientists hope to parlay the work into techniques to buy time for trauma patients.
One-year-old Erika Nordby was found frozen outside her house in Canada in 2001 and was then resuscitated. New studies on animals suggest deprivation of oxygen prior to exposure to cold temperatures may aid survival in such conditions. Click to enlarge this image.
AP Photo/Ian Jackson
New studies show that critters severely deprived of oxygen prior to exposure to near-freezing temperatures enter a state of suspended animation and can resume their lives, apparently unscathed, when their bodies are re-warmed.
Experiments conducted on yeast and garden worms show neither can survive extreme cold, with 99 percent dying after spending 24 hours in temperatures just above freezing. But if first deprived of oxygen, 66 percent of the yeast and 97 percent of the worms lived to see another day once temperature and oxygen levels were returned to normal.. What's more, the creatures actually lived regular lifespans, not just a curtailed amount of time.
"If you take animals that are just ripping along and make them cold, they drop dead. But if you lower the amount of oxygen they can consume so that they appear dead, then make them cold, they survive," cell biologist Mark Roth, with the Fred Hutchinson Cancer Research Center in Seattle, told Discovery News.
"It was pretty shocking to me that we could do this," added Roth, who has been working for about a decade on suspended animation, in hopes of developing techniques to buy time for people in medical emergencies.
"Similar things might be happening in higher mammals, but that remains to be seen," added Fumito Ichinose, associate professor of anaesthesia at Harvard Medical School. "This is a very interesting observation."
Roth's experiments stem from a curiosity about people who had survived extreme cold.
Mitsutaka Uchikoshi, a Japanese man, for example, fell asleep on a snowy mountain in 2006 and was found 23 days later with no heartbeat and a body temperature of 71 degrees Fahrenheit. He was revived. Or a Canadian toddler who during the winter of 2001 wandered outside wearing nothing but a diaper and was found two hours later. Despite a temperature of 61 degrees, she was resuscitated, with no long-term ill effects.
"There might be some agent in us that can regulate our ability to survive the cold," Roth said.
While the idea of suspend animation conjures up science fiction stories of people freezing themselves for later life, Roth says he's more interested in understanding the physiological limits of metabolism and figuring out how to buy small bits of time when minutes and hours can mean the difference between life and death.
"I would love for something from the work to become useful for people," Roth said.
The research will appear in the July 1 issue of Molecular Biology of the Cell.
Tags: Animals, Animation, Death and Dying, Life, Life Science
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