Suspended Animation In Mice Without Freezing

Predictions Market writes "Low doses of hydrogen sulfide, the toxic gas responsible for the unpleasant odor of rotten eggs, can safely and reversibly depress both metabolism and aspects of cardiovascular function in mice, producing a suspended-animation-like state that does not depend on a reduction in body temperature and include a substantial decrease in heart rate without a drop in blood pressure. The researchers measured factors such as heart rate, blood pressure, body temperature, respiration, and physical activity in normal mice exposed to low-dose (80 ppm) hydrogen sulfide for several hours. In all the mice, metabolic measurements such as consumption of oxygen and production of carbon dioxide dropped in as little as 10 minutes after they began inhaling hydrogen sulfide, remained low as long as the gas was administered, and returned to normal within 30 minutes of the resumption of a normal air supply. 'Producing a reversible hypometabolic state could allow organ function to be preserved when oxygen supply is limited, such as after a traumatic injury,' says the lead author of the study. 'We don't know yet if these results will be transferable to humans, so our next step will be to study the use of hydrogen sulfide in larger mammals.' The full report is available online."

Yeah but...

after inhaling hydrogen sulfide for 30 minutes, trust me, you'll wish you were dead.

True but...

many things that can save our lives (major surgery, chemotherapy) also leaves us wanting to die. Just because something is horribly painful doesn't mean we should avoid it.

Re:True but...

I'm suddenly beginning to realize why married men live longer...

Re:Yeah but...

Actually, no. Your nose will be almost completely anaesthetized after several breaths.

That's actually a dangerous feature of hydrogen sulfide - it's quite poisonous and you can breath a fatal dose of it without even realizing that you're breathing a poison.

Re:Yeah but...

The safe level to work in for 8 hours per day (MAC value), 5 days per week has recently been dropped from 10 ppm to 2 ppm.
80 ppm of H2S is going to be lethal after 8 -24 hrs of exposure, much earlier you will be suffering bleeding and other very unpleasant effects.
At 500 ppm you're dead in 30 to 60 minutes and at 800 ppm you will not survive 2 minutes.
The kicker is at 1000 ppm, you're immediately unconscious and will die within seconds.

You'll start smelling it at about 0.1 ppm but at otherwise not lethal concentrations it will desensitise your nose and you will eventually not realise it's still around or getting stronger.

As a side effect it has a much wider range of explosiveness than regular hydrocarbon gasses and because it's heavier than air it will concentrate at low places.

I declare this year of the mouse!

We can clone mice. We can cure mice cancer. We can put them into suspended animation, allowing them to live on into future generations (meaning they will probably be the first organic space pets). Something tells me that the rats of NIMH are already in the execution phase of some higher level plans with all the work we've managed to accomplish on their genetics.

Re:I declare this year of the mouse!

"We can clone mice. We can cure mice cancer. We can put them into suspended animation"

Looks like we can do more for mice, than for humans ... Its not just the rats of NIMH, Douglas Adams was right about the mice!

Re:I declare this year of the mouse!

Sure mice are making strides in the educational and scientific markets, but while you mouse people have been declaring it the "year of the mouse" for the last 10 years, squirrels have continued their predatory and monopolistic domination of both business and home rodent segments.

Re:I declare this year of the mouse!

Chopping up mice is old school -- this [milk.com] is how a real man prepares his mice.

Remember this next time you buy a curry..

Premature pressure loss can result in a whole room full of people in suspended animation.

"All I can remember was this overpowering stink" .. :-)

No, that isn't the next step

'We don't know yet if these results will be transferable to humans, so our next step will be to study the use of hydrogen sulfide in larger mammals.'

Uhh, no. The next step is to determine if this is the kind of suspended animation that is good for anything. If the mice enter a reduced metabolic state and then, after 3 days, die, well that's not terribly useful for anything. If, however, the mice managed to live 10 times the usual rodent lifetime then that's something... not terribly great.. but something. Try to make it so the mice are recoverable after 1000x the usual lifespan and you might have something useful.

I think that's not what they had in mind

While that's insightful in its own right, from reading the summary, I get the impression that they're not aiming for the kind of suspended animation where you freeze someone for 1000 years and wake them up later. Doing that at room temperature would be kinda dangerous anyway, since if you slowed their immune system 10 times they'll rot alive sooner or later anyway.

I'm getting the impression that this is more for rushing you to a hospital when they picked you up half-dead and bled half-dry off the side of the road.

If you're in serious shock for example, if the other mechanisms still work, the body will try to keep the brain alive, even at the cost of cutting off oxygen supply to the other internal organs. Which decay very fast. (Muscles have their own oxygen reserves, so they tend to survive, your liver doesn't.) Cells run out of oxygen and essentially commit suicide in an orderly fashion, i.e., apoptosis [wikipedia.org].

If it doesn't have enough even for the brain, which is often the case, the damage is irreversible and often fatal. Very fast.

So if they can slow your metabolism a lot, that might just give them extra time to haul you into ER. It might just turn that 5 minute rush before your brain starts getting massive damage, into, say, 50 minutes. Which might just do the trick.

I.e., briefly: it's not for colonizing Alpha Centauri, mate, it's just while they haul you to ER.

Herbert West, Reanimator

I read recently (on /. I think) that it was discovered the tissue damage was done when RISING o2 levels triggered apoptosis. Meaning there is actually a period as long as 2hrs where little or no tissue damage has occurred. If the o2 levels can be brought up in a way that keeps the trigger from thinking a massive o2 spike is about to mutate all the DNA we might realize the dream of Herbert West. I also read about this a while back and they didn't think it would scale to humans, but if it did, it might stack nicely to allow delaying reanimation even longer.

Re:No, that isn't the next step

There are always places where harmful chemicals can be useful. Even if this causes damage/death after a few days/weeks/months, there are situations where it will prevent death that would occur in minutes.

Just off the top of my head, mines. Mandatory pressurized bottle w/ masks at every junction in a mine, in case of collapse (I'm thinking it *has* to be less explosive than storing bottles of pure oxygen). If it slows oxygen consumption to 25% (pulled out of my ass, because examples need numbers!) of normal, that gives rescue workers 4 times a long to dig out live bodies.

Once they are out, the hospitals/trained medical professionals can go about treating them for Crush Syndrome and for the poison that kept them alive by killing them slowly.

thats great!

Thats great, now all we need is a heuristic computer with a suitable monitoring alogrithm to look after them whilst they are sleeping/hibernating. Still, good luck looking for volunteers for those trials.

Re:thats great!

Thats OK. Large scale software projects never have conflicting requirements.

Old News

Can we get an update? There have already been tests involving pigs (lifted straight from the wikipedia [wikipedia.org] entry)

Induced hibernation

In 2005 it was shown that mice can be put into a state of suspended animation-like hypothermia by applying a low dosage of hydrogen sulfide (80 ppm H2S) in the air. The breathing rate of the animals sank from 120 to 10 breaths per minute and their temperature fell from 37 C to just 2 C above ambient temperature (in effect, they had become cold-blooded). The mice survived this procedure for 6 hours and afterwards showed no negative health consequences.[6] In 2006 it was shown that the blood pressure of mice treated in this fashion with hydrogen sulfide did not significantly decrease.[7]

Such a hibernation occurs naturally in many mammals and also in toads, but not in mice. (Mice can fall into a state called clinical torpor when food shortage occurs). If the H2S-induced hibernation can be made to work in humans, it could be useful in the emergency management of severely injured patients, and in the conservation of donated organs.

As mentioned above, hydrogen sulfide binds to cytochrome oxidase and thereby prevents oxygen from binding, which leads to the dramatic slowdown of metabolism. Animals and humans naturally produce some hydrogen sulfide in their body; researchers have proposed that the gas is used to regulate metabolic activity and body temperature, which would explain the above findings.[8]

However, a 2008 study failed to reproduce the effect in pigs, concluding that the effects seen in mice were not present in larger mammals. [9] [pccmjournal.com]

Re:Old News

However, a 2008 study failed to reproduce the effect in pigs, concluding that the effects seen in mice were not present in larger mammals. [9] [pccmjournal.com]

Maybe pigs are just used to smelling bad? :D

Send people to Mars or Alpha Centauri

You can also enable long term space travels with such a finding!

Linux

They can suspend a mice, but making Ubuntu suspend on my laptop and work afterwards; that they can't do. It's a strange world

So does this mean...

...I am doing something good to people when I fart [wikipedia.org] in a room ?

prrrrtttttttttttttttt......
"Ok, who left the fart ?"
"It was me ! I wanted to prolong your lives !"
"That's a kind of frank boldness I haven't seen before...."

Just wondering...

... some towns around the planet have quite a reputation for having a high sulphur rate in their atmosphere (Rotorua [wikipedia.org] in NZ is nicknamed "Sulphur City" because of that -- you can actually smell it when you're getting close to the town, and it takes a little while to get used to breathing that air !). Why don't they conduct a survey on the metabolism of the people naturally exposed to those gases ?

Enough!

Enough of this fake "science" funded by corporations like Taco Bell.

Maybe it wasn't the sermons

At the Lutheran church I attended as a child, the well water came up through a sulferous layer of rock. Every time the water ran, the place reeked of rotten eggs. Maybe it wasn't the sermons that put us to sleep all those years...

Quit getting in the way of science...

Wow, this is really new [slashdot.org] and interesting stuff. I can't quite put my finger on it, but reading it gives me the strangest sense of deja vu [slashdot.org].

Obviously, those articles were in suspended animation, and were just reawakened today. Jeesh...Don't you realize that they need experiments like this to see what will and will not work?