X-Message-Number: 26065
Date: Thu, 21 Apr 2005 18:51:18 -0400
From: Joseph Bloch <>
Subject: [Fwd: [>Htech] [GRG] Mice sent into hibernation-like state by hydrogen

I saw this posted on the Transhumantech list and thought it might have 
some application to cryonics.

I was thinking (assuming that this effect works in humans as it is 
described to work in mice), might it not benefit the preservation 
process if this low-oxygen-demand state were initiated in a patient 
immediately prior to cryopreservation? It could reduce oxygen-loss 
related damage to the brain.

Just a notion from a layman.


Enhance your body "beyond well" and your mind "beyond normal": 
New Jersey Transhumanist Association: http://www.goldenfuture.net/njta
PostHumanity Rising: http://transhumanist.blogspot.com/ (updated 4/19/05)

-------- Original Message --------
Subject: 	[>Htech] [GRG] Mice sent into hibernation-like state by 
hydrogen sulfide gas (fwd from )
Date: 	Fri, 22 Apr 2005 00:24:10 +0200
From: 	Eugen Leitl <>

The science news outlets are reporting the discovery that mice exposed 
to low concentrations of hydrogen sulfide gas go in to a 
hibernation-like state, with body temperature dropping and breathing and 
heart rate slowing dramatically. Here is a report from Nature.


Published online: 21 April 2005; | doi:10.1038/news050418-13
Eggy smell sends mice into hibernation
Jessica Ebert
Suspended animation technique could prove a boon for surgery.

It seems that mice can be coaxed into a hibernation-like state by a 
whiff of hydrogen sulphide, the gas found in rotten eggs.

The discovery could improve the preservation of organs or tissues for 
transplants, and could lead to more effective treatments for illnesses 
as diverse as cancer and stroke.

Hydrogen sulphide can be deadly in high concentrations, causing burns 
and interfering with respiration. But it is also produced in small 
quantities by animals, in which it is thought to play a vital role in 
controlling body temperature and metabolism.

Mark Roth, a biochemist at the University of Washington, Seattle, and 
his colleagues tried exposing mice to air laced with relatively low 
concentrations of the gas: within minutes, the mice seemed to fall 
unconscious. Their core body temperature dropped by some 20?C, and their 
breathing slowed from about 120 breaths a minute to fewer than 10, the 
team reports in Science1.
When re-exposed to clean air after six hours, the mice bounced back 
without any evident side-effects, says Roth. "This indicates that it's 
possible to decrease metabolic rate on demand," says Roth.

Oxygen delivery

By shutting down metabolism, the body's need for oxygen diminishes, 
which could "revolutionize treatment for a host of human ills", says Roth.

In conditions such as stroke, cardiac arrest and other traumas, healing 
can be limited by the amount of oxygen that can be supplied to damaged 
tissues. This could be helped by reducing the body's overall need for 
oxygen, says Samuel Tisherman, professor of surgery and critical-care 
medicine at the University of Pittsburgh in Pennsylvania.

"Decreasing total oxygen demand during that period of time is of 
interest," Tisherman says. And inducing a state of suspended animation 
would buy doctors more time to address the trauma.

Roth says the gas may also help with cancer treatments. Radiotherapy 
works best when the target cells are well supplied with oxygen, but it 
can be detrimental to healthy cells. Inducing hibernation reduces oxygen 
demand in healthy cells and so should help to protect them.

"A lot of work needs to be done to determine how to use the treatment, 
when to use it, and what kind of benefits you get," cautions Tisherman.

To that end, Roth and colleagues are working to induce a state 
resembling suspended animation in larger animals.


  1. Blackstone E., Morrison M. & Roth M. B. /Science/, *308*. 518 (2005).


Preston (Pete) Estep III, Ph.D.
President and CEO
Longenity, Inc.
1484 Main St.
Waltham, MA 02451

Web: www.longenity.com

Work: 781-209-0249
Fax: 781-209-0175

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