X-Message-Number: 15507
Date: Wed, 31 Jan 2001 16:03:14 EST
Subject: Pharmacology

Fred Chamberlain has expressed the hope that, with current or near-future 
vitrification methods, cryopreservation damage might be limited to a 
relatively minor degree of toxicity, and patients might be recovered by 
advanced pharmacology, without the need of a mature nanotechnology. Let's 
explore this a bit further.

First, for a little perspective, we know that there is a large variance in 
fragility or hardiness of patients. On the one hand, children drowned in cold 
water have made full recoveries after about an hour under water with no pulse 
or respiration. On the other hand, old/sick people may succumb to relatively 
minor infections, or fail to respond to emergency treatment. In crude 
language, we might say the patient's "reserves" vary widely. Since virtually 
all cryonics patients are old or/and sick, and have probably suffered 
appreciable post mortem deterioration as well, their reserves will nearly 
always be minimal. 

Now, "pharmacology" essentially refers to administration of drugs or 
chemicals, or possibly also biological agents, through a variety of 
avenues--ingestion by mouth, inhalation, topical application to skin or 
mucosa, injection into the vasculature, injection into specific organs or 
tissues, intestinal lavage, perhaps a few others. But in order for a thawed 
patient to benefit from pharmacology, he must first be "alive"-functioning 
sufficiently to allow utilization of the pharmacologicals. 

As I recall, published reports tell us that, with the rat brain slices, 
specimens that showed 53% function by the K/Na criterion did not recover 
further after hours of culturing or incubation. In other words, today's 
pharmacology could not restore them to normal function. Maybe tomorrow's 
pharmacology will do better, but we don't know. After all, in the absence of 
actual repair of the machinery, all pharmacology can do is offer nutrition or 
medicine, so to speak; if the tissues are not sufficiently functional to 
utilize this nutrition or medication, then it won't help. 

With advanced nanotech, on the other hand, the degree of damage just doesn't 
matter (except possibly from a cost or time perspective), so long as the 
original structure is present or inferable. And housekeeping structures 
(mitochondria, glial cells?) can "simply" be replaced if necessary, since 
they are generic and probably not related to the individuality of the patient.

Again, today's "life support" systems obviously will not suffice to restore 
and maintain enough function in thawed cryo patients to allow uptake and 
utilization of chemical or biological medications, even if those medications 
by themselves could permit self-repair of the tissues. Tomorrow's might--but 
the reports to date on the rat brain slices do not seem encouraging. After 
all, those slices--as far as I know--were already getting the best available 
environment, the right nutrients and oxygen etc. It isn't easy to see how any 
further additions to the nutrient bath could improve matters. I suppose, at 
some point, there could be a kind of hybrid between pharmacology and 
microtech (rather than nanotech), but we'll just have to wait and see.

How much post mortem delay is allowable before viability by the K/Na 
criterion becomes very low? I have tried to find out, and seen estimates from 
a few minutes to about an hour--and that is with originally young and healthy 
specimens, under ideal laboratory conditions. Since cryonics patients are 
almost never young and healthy and cryopreserved under ideal laboratory 
conditions, we can probably estimate that patients will have much less K/Na 
viability than reported with the rat brain slices.

That suggests that it is unlikely that pharmacology alone will suffice, even 
with actual full vitrification. 

Nevertheless, less damage is better than more damage, and all improvements 
are welcome. Once more, we (CI) will test all promising procedures, as our 
resources permit--including some that no one else seems to be trying--and 
make them available to our members when this appears desirable and feasible. 

Robert Ettinger
Cryonics Institute
Immortalist Society

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