4 replies to this topic

[manofsan]

Apparently, mice have been put into suspended animation by exposure to Hydrogen Sulphide gas:

http://www.newscient...le.ns?id=dn7294

The mice supposedly later recovered without any ill effects.

They're citing some impressive figures, such as drop in metabolic rate of 90%, drop in core body temperature, and radically reducing the breathing rate. Potential applications may be in keeping emergency victims alive, or reducing stroke damage.

Interestingly, they were talking about H2S buildup being a regulator of metabolic rate, and how it can reduce oxygen demand. Since we're always talking about mitochondrially-generated ROS, couldn't this be a way to slow the aging process? Just send all the old people to Mars under suspended animation, then they age slowly along the way, and wake up in a low-gravity environment.

I'd seriously wonder though how long you could keep a person under that suspended animation without causing harmful effects. After all, if high concentrations of H2S are lethal, then I'd imagine that even low concentrations can gradually cause damage over enough time. If Nature meant us to inhale H2S, then it would have positioned our lower orifice closer to our upper ones.

Comments?

[bgwowk]

They're citing some impressive figures, such as drop in metabolic rate of 90%, drop in core body temperature, and radically reducing the breathing rate. Potential applications may be in keeping emergency victims alive, or reducing stroke damage.

We've been through this in another thread. They key point is that drop in metabolic rate and drop in core body tempertature naturally go hand-in-hand. If you drop core body temperature (already done in medicine for various purposes), you naturally get a drop in metabolic rate. These guys did it backwards: drop metabolic rate with H2S, and get a drop in core temperature. But is the end result any better than if you just cool the old fashioned way? It's not clear to me that it is.

---BrianW

[manofsan]

Well, it shows that there are various choke points in our metabolism that can be squeezed on to slow the metabolic chain. Maybe there are other choke points besides H2S levels and body temp. If you applied the choke from multiple points instead of just one, perhaps it would be less stressful on the body.

Suppose you could selectively introduce H2S into certain cells and not others, then it might permit you to selectively slow some cells down and not others. You can't do that with core body temp.

Heh, somebody tell me, if a team used this suspended animation technique to make a mouse live 5 times longer, could they win the Methuselah Mouse Prize? Or would it be considered cheating because your mice was unconscious throughout its lifespan? After all, what's the point in living 5 times longer if you're comatose and not able to experience and enjoy life?

[bgwowk]

Well, it shows that there are various choke points in our metabolism that can be squeezed on to slow the metabolic chain. Maybe there are other choke points besides H2S levels and body temp. If you applied the choke from multiple points instead of just one, perhaps it would be less stressful on the body.

Exactly. With respect to the current research, the question is whether the combination of H2S and hypothermia allows an organism to survive longer than just hypothermia alone. The media reports aren't really clear on that.

---BrianW

[John Schloendorn]

Would anyone be so kind to post the actual science article? Apparently, my uni does not deem Science important enough to be included in their library...