RAT HEARTS REVIVED FROM LIQUID
NITROGEN--this milestone in cryobiology has
been confirmed at the Alcor facility during
the week of Aug. 30-Sep. 4, 1996.
The achievement was reported last year from
the University of Pretoria, South Africa, by
Michelle Olga Visser, who used a new
cryoprotective agent (CPA). She also
reported submitting a paper on the
experiment to CRYOBIOLOGY, with three
co-authors at her university, in December
1995.
Mrs. Visser is Head of Research, Department
of Thoracic Surgery, Faculty of Medicine,
University of Pretoria. She is a
perfusionist by training and practice,
working for the University hospital and also
as an independent contractor. She is a Ph.D.
candidate in cryobiology, whose studies
include physiology and pharmacology.
She has been doing research in organ
cryopreservation for the last three years,
after having started the first homograft
bank in Pretoria eight years ago at her
department. She set up this bank to store
heart valves harvested for re-implantation,
using standard cryo procedures (DMSO), and
developed an interest in developing a method
for organs.
Her original report was met with general
skepticism or indifference, and publication
has apparently been delayed by requests for
revisions. But Anatole Dolinoff, president
of the Cryonics Society of France, suggested
that Mrs. Visser get in touch with Robert
Ettinger, and extensive discussions by
e-mail followed. CI and Alcor invited her
and her husband Siegfried to come to Arizona
as our guests and demonstrate the Visser
method with rat hearts. This was finally
done, and we have seen first-hand the
confirmation of this
accomplishment--arguably the most important
since 1948, when Jean Rostand froze frog
sperm with glycerol.
The Vissers were assisted in the Alcor
building, in a lab used and lent by
CryoSearch Inc., by biochemist Hugh Hixon
and by other Alcor people including Rhonda
Iacuzzo and Tanya Jones. Witnesses included
Steve Bridge, Mike Perry, Robert and Mae
Ettinger, Fred and Linda Chamberlain, David
Pizer, Paul Garfield, Ralph Whelan, Brian
Shock, Derek Ryan, and Mathew Sullivan. Fred
and Linda also helped with some of the
chores, including videotaping.
BRIEF DESCRIPTION OF RESULTS: It wasn't
smooth going. The equipment was different
than the Vissers were accustomed to, and
some of it was not compatible; and human
error is easy with small animal organs.
There were several failures during several
long days of work. But there were also two
hearts that showed weak beating and one that
showed strong beating, after rewarming from
liquid nitrogen temperature. This is
unequivocal proof that the Visser technique
(at least as applied to rat hearts) is far
superior to anything previously reported.
Control hearts--immersed in liquid nitrogen
in the same manner but not perfused--showed
gross damage, including cracking, and no
signs of life.
Because of limitations of equipment, the
hearts were kept in liquid nitrogen for only
a half minute to a minute--but the
temperature probe showed core temperature
within a few degrees of that of liquid
nitrogen, - 196 C or - 320 F. Once such a
temperature is reached, it is generally
agreed that the length of time of storage
does not matter. Mrs. Visser reports that
the longest she has kept hearts in liquid
nitrogen is 45 minutes, and these were
successfully revived. Alcor personnel will
be working to establish a reliable, routine
experimental protocol, and will be storing
rat hearts for longer periods. Cryonics
Institute also plans to test longer term
storage of various organs.
BRAINS: For cryonics, results with brains
are the most important. There are
experimental and theoretical reasons to
think the Visser method will work well with
brains also. The CPA penetrates the
blood-brain barrier. Preliminary experiments
at Alcor with rat brains show normal
appearance to the naked eye and under the
light microscope (but we do not yet have
micrographs).
LIMITATIONS OF THIS REPORT: Pending journal
publication of their paper, the authors do
not want to publicize the identity of the
CPA or other details of the procedure, or to
discuss the mechanism of cryoprotection.
Patents have been applied for, or soon will
be, in South Africa and several other
countries, by Cryopreservation Technologies
cc, the South African corporation in which
Mr. and Mrs. Visser are majority
shareholders.
CRYONICS LICENSING AGREEMENT: In return for
help in funding their further research, the
Vissers have given CI and Alcor exclusive
license to use their present and future
technology for cryonics purposes. This
includes the right to sub-license.
PERSONAL NOTES: The Vissers formed an
excellent working relationship with Hugh
Hixon--who impressed everyone with his
resourcefulness in adapting equipment--as
well as with other Alcor people including
Rhonda Iacuzzo and Tanya Jones. The Vissers
stayed with Mae and Bob Ettinger, and were
pleasant, considerate, and extremely
interesting guests. There were many long
conversations on a variety of topics-
especially between the Vissers and Mae,
since Bob was often tied up with other
duties. Mr. Visser, a consulting engineer,
understands the Visser method thoroughly and
acts as lab partner; he is also the main
business person in the Vissers' company.
Mrs. Visser, despite her amazing energy,
drive, and perfectionism, is also kind and
understanding.
NON-CRYONICS RESEARCH: A priority of the
Visser group is to pursue research with
large animal organs, in preparation for
transplant experiments, leading up to human
cryogenic organ banking. There are reasons
to believe there is a very large potential
market for such technology--not only
including such traditional transplant
candidates as kidney, heart, liver,
pancreas, corneas etc., but also limbs or
digits, glands such as thyroid, and others.
TIME HORIZONS: When Mrs. Visser has funding,
she estimates 8 months to a year to prove
pig organ transplants. After that, the time
required to get permission for human
clinical trials, and to run those trials,
and then to get regulatory approval, depends
on the country or countries of choice and
other factors. All told, perhaps 3 to 5
years. The demand for transplants, and the
life-saving nature of the technology, might
expedite matters, compared to customary
procedures.
For 100% proof of reversible
cryopreservation of the human brain, we know
of no reliable way to make even a rough
guess. It will take as long as it takes. But
with the Visser method we have a running
start--and it seems very possible that our
cryonics patients will very soon have much
better suspensions than any previously
available.
Robert C.W. Ettinger, President, Cryonics
Institute
Stephen W. Bridge, President, Alcor Life
Extension Foundation