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Arctic squirrels may hold key to helping astronauts survive on long missions

Senior biology major Colleen Bue (L) holds an Arctic ground squirrel with professor Kelly Drew in Drew's lab at the University of Alaska in Fairbanks. Photo by Todd Paris/University of Alaska
1 of 5 | Senior biology major Colleen Bue (L) holds an Arctic ground squirrel with professor Kelly Drew in Drew's lab at the University of Alaska in Fairbanks. Photo by Todd Paris/University of Alaska

NEW YORK, Feb. 9 (UPI) -- A University of Alaska researcher is studying the effects of an experimental drug in hibernating Arctic ground squirrels, with the goal of one day helping astronauts survive in space.

Working through a Space Grant from NASA, Kelly Drew, a professor of chemistry and biochemistry at the University of Alaska in Fairbanks, says the drug, if successful, could aid humans during long-term space travel.

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The research could be used to assist crews, "from the extreme of medically induced hibernation for long-term space missions to protecting astronauts from cabin fever, ionizing radiation and much more," according to NASA.

The Arctic squirrels retain muscle and bone mass during extended hibernation, and one goal is to replicate that in humans, the space agency said.

"Of course, the science fiction is that we want people to hibernate for long-term space travel. The European Space Agency has already invested in this, and it is the ultimate dream," Drew said. "My work and the interest in NASA up to this point has not been that grandiose."

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Drew told UPI that the research she leads has focused primarily on the applications of hibernation in critical care and emergency medicine.

"It stems from what they used to call therapeutic hypothermia, and now it's called targeted temperature management. It's a big deal for physicians who take care of brain injury," Drew said, adding that people "usually die because of brain injury."

Improved outcomes

Doctors and emergency care providers have found that cooling victims of traumatic brain injury by even just a few degrees improves the outcome. However, the procedures for cooling the human body have not quite reached advanced levels.

"Right now, what they do initially, is just pack people on ice, and you can imagine what that feels like," Drew said.

"It's easy in somebody after cardiac arrest because they're in a coma, and that's why they get away with it. But when they try to do it to people with stroke or other types of brain injury who are not comatose, it doesn't work. For one, they're just so uncomfortable."

Such emergency care could advance by further understanding how hibernating animals, such as Arctic ground squirrels, reduce their body temperatures, Drew said.

"They do it without any stress. That's just what they're made to do. And they do it by turning down the thermostat. What we've been focused on is short-term cooling from like 24 to 32 hours to three days," Drew said.

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She added that three days of cooling already is standard care for human babies suffering from hypoxic-ischemic encephalopathy, a condition that occurs during labor and delivery that can lead to cerebral palsy.

"Now, they cool the babies for three days and so those are the things that are in the clinic already," Drew said.

"What we're interested in is being able to extend this for remote emergency care, so that applies to Alaska and it also applies to NASA."

Buying time

This could mean that patients -- including astronauts -- who have suffered from a stroke or heart attack could be placed in medically induced hibernation to slow their metabolism until they can receive care, according to the space agency.

Drew said the NASA funding allows her teams to conduct further research on a drug that can induce hibernation in the squirrels.

"One thing we know for sure is that we have a drug that will induce hibernation in ground squirrels, and other people have shown that it induces hibernation in other species that normally hibernate, like hamsters," Drew said.

She said that the experimental drug, BCP-191, named after company, Be Cool Pharmaceutics, also can induce a hibernation-like state called torpor that occurs in mice in which their metabolism is turned down.

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"The problem is this drug has some side effects, and so that's what we're trying to figure out now -- how to manage those side effects so it's safe," Drew said, adding that the drug is more accurately a combination of drugs that induce hibernation and then limit the side effects.

"We're trying to balance the benefit of low blood pressure and low heart rate in what it brings in terms of suppressing your metabolism because humans don't have that tolerance for very, very low blood flow like some of these hibernating species have," Drew said.

Slow progress

She said that progress is being made addressing those side effects and the research is "moving forward a little bit at a time."

Drew said that her goal is that BCP-191 could eventually reach human trials, but that her team recently "hit kind of a bump."

"So we're back to the drawing board, which is a good thing because you really need to understand what's happening," Drew said.

"If we had gotten it before, it would have been just luck and we wouldn't really have known the true relationships between blood levels and effect. And that's really important when you're going to switch to another species."

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Drew noted that her team studies the Arctic ground squirrel because it is the most extreme example of an animal that hibernates.

"If you're going to measure something, the more extreme the example is, the easier it is to get good measurements from it and really understand it because it's such a pronounced effect," she said.

"The Arctic ground squirrel is probably the most famous super-hibernator. It's adapted to the extreme Arctic environment."

These squirrels can stay metabolically suppressed for about three weeks at a time, warming for a day or two before re-entering hibernation.

"The other model that is very appealing for human application is the bear. Obviously, they're a lot harder to work with," Drew said.

"But there is a lot of benefit to the bears and there are people in Fairbanks that are studying bears, and we all kind of work together. It's just harder to do drug development in the bear."

Radiation, cabin fever concerns

Drew added she is working with SpaceWorks Enterprises, which received NASA funding to put together the concept for what hibernation could provide to NASA in meeting its goals of protecting astronauts from radiation and cabin fever.

Denise Thorsen, the director of Space Grant and NASA Established Program to Stimulate Competitive Research at the University of Alaska, said that she believes Drew is "really close" to being able to test the hibernation drugs in humans.

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She said Drew's research can also have ramifications for medical treatment on Earth, such as in rural Alaska, where suffering an injury could mean being flown to Harborview Medical Center in Seattle -- the nearest trauma center.

"You're flying to Seattle, that's a four- or five-hour flight depending on where you come from," Thorsen said.

"If you don't have something to help you not to maintain until you can get there, you're basically dead. So the implication to Alaska is huge."

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