X-Message-Number: 11641
From: "Stephen Bogner, P.Eng." <>
Subject: Nitric Oxide confirmed as a regulator for Cell Death
Date: Thu, 29 Apr 1999 13:25:38 -0600

Researchers at the Howard Hughes Medical Institute (HHMI) at Duke University
in collaboration with scientists at the Dana-Farber Cancer Institute have
now found that nitric oxide (NO), a well-studied molecule implicated in a
host of communication pathways in and between cells, is also a switch that
controls whether cells live or die.
Stamler and his colleagues found that NO molecules occupy a critical site on
the enzyme caspase, a molecular "executioner" within human cells. When
occupying this site, NO effectively plugs a communication pathway that
activates caspase and triggers cell death.
"We showed that nitric oxide sits on the site and keeps the enzyme
inactive," said Stamler. "Conversely, the nitric oxide is removed in cells
programmed to die. Simply put, if you block nitric oxide production within
the cell, you make the cell more susceptible to cell death. And if you add
it back, you prevent cell death."
Apoptosis can be triggered through a biochemical chain of events known as
the Fas pathway. When activated, the Fas pathway initiates a cascade of
signals within the cell that ultimately turns on caspase. When NO occupies
the site on caspase, however, the death message is blocked. Fas somehow
manages to pop the nitric oxide off the cells that are programmed to die.
 "We'd like to think modulation of the nitric oxide system can be used for
therapeutic gain," he said.

The complete article can be found at: http://www.hhmi.org/news/stamler.htm

The reason that I think that this might be of interest to cryonet is because
it may have implications for the medication protocol that might be used to
limit damage prior to or during suspension.  This is not my area of
expertise - so someone knowledgeable may want to comment.

Regards (and long life);


Stephen Bogner, P.Eng.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=11641