X-Message-Number: 15118
Date: Sat, 16 Dec 2000 06:25:13 -0500 (EST)
From: Ben Best <>
Subject: An assist to CPAs and Ice-Blockers

            An assist to CPAs and Ice-Blockers

   CryoProtective Agents (CPAs) and Ice-Blockers can prevent
ice-formation and promote vitrification. But Ice-Blockers
typically do not cross cell membranes. And CPAs are always
challenging to perfuse/diffuse because both their toxicity and
viscosity vary inversely with temperature. 

   Arctic frogs have an adaptation that causes rapid liver
glycogen breakdown and rapid glucose uptake by cells as 
ambient temperatures drop close to freezing. Glucose is 
not only an energy source, but is a non-toxic CPA. If such
a form of insulin sensitivity could be engineered to function
in mammals (notably humans) this could assist efforts to 
achieve cryonic suspended animation. 

   The engineering would most likely take the form of modifying
the insulin receptors -- either directly or through reprogramming
of the genes that code for insulin receptors. The trigger for 
accelerated glucose uptake could be a rare/exotic molecule not
normally found in physiological conditions. 

    A cryonics patient with such modified insulin receptors could 
be perfused with glucose in the very first phases of cryonics
rescue -- along with the trigger molecule. Thus, there could be
rapid perfusion/diffusion/uptake of the glucose into cells at
a temperature high enough to ensure that the process is both
thorough and very rapid -- and without toxic effect. 
   It will probably be at least a decade before such insulin-receptor
modification is feasible (assuming that it will ever be feasible),
but awareness of the possibility gives us something else to look
forward to. 
                                  -- Ben

            Ben Best ()
            ICQ -- http://www.mirabilis.com/20636141

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