Suspended animation

In the April 22 issue of Science, a group from the Fred Hutchinson Cancer Center reports that a state of suspended animation can be achieved in (nonhibernating) mice when administered hydrogen sulfide (H2S). H2S is a reversible inhibitor of oxidative phosporylation. It is known that this induces hibernation in some animals.

When the mice were exposed to 80 ppm of H2S, their oxygen consumption dropped by 50% in the first 5 minutes. After 6 hours, their metabolic rate dropped by 90% and the core body temperature reached 15 degrees Celsius where the ambient temperature was 13 degrees. When the mice were returned to room air and temperature, their metabolic rate and body temperature returned to normal.

If this works in humans, we may now have a means of reducing metabolic demand after traumatic injury or surgery. H2S may become a standard part of the repertoire of paramedics. I won't bother to dwell on the space travel implications.

Hydrogen sulfide is the gas emitted by volcanos and geysers responsible for the rotten egg smell. It is usually considered toxic but now you know that if you see someone looking lifeless at the edge of a volcano, make sure to pull them out because they may note be dead but just be in a state of suspended animation.