Evening star., 1951-12-19
Mysterious Substance
Increases Span Of Life
Corneeie Institution Study
Opens New Vista of Research

Carnegie Institution Study
Opens New Vista of Research
By Thomas R. Henry
A mysterious substance that increases
the average life span by one-third has
been demonstrated by research workers
of the Carnegie Institution Of Washing
ton.
It is contained in the milk Of elderly
mammals.
Badly stated, this would constitute
a most momentous scientific advance.
Specifically. however, 1t applies to only
one strain Of mice under special circum-
stances, and whether 1t opens up an
enormous new vista for research or only
dlscloses a minor tool in highly spe-
cialized investigation cannot be pre-
dicted.
Carnegie research workers at the De-
partment Of Genetics. at Cold Spring
Harbor, Long Island, have been working
for many years with highly fatal he
reditary leukemia in mice-the mecha-
nismS of its transmission, means Of
modifying and accentuating its effects.
and scores Of other phases Of the prob
lem. The objective, seen only afar of,
Is to get clues on the behavior of leu
kemia In human beings. It must be
made clear, however, that this mouse
leukemia and any form of human leu
kemia are quite different diseases and
findings concerning it are not directly
applicable to anything else.
Mathematical Predictions.
DIR. E. c. MacDowell and his associates
at Cold Spring Harbor work with ex-
tremely pure hereditary strains Of
animals. Some transmit leukenlia.
others do not. When non-leukemic
and a leukemic strain are mated the
number Of offspring that will develop the
disease can be predicted with almost
mathematical precision.
Last year it developed that when
elderly females Of certain non-leukemic
strain were mated with males of a
highly leukemic strain the appearance
OF the fatal blood disease was greatly
delayed. Also the percentage of off,
spring that finally developed leukemia
was considerably lower than expecta.
lions, and lower than that In the off,
spring OF young mothers Of the same
non-leukemic strain and fathers of the
leukemic strain.
Inefe was something old mothers
again, 1t must be emphasized, only Of
LnlS particular strain of mice-trans-
mltted to their offspring which young
mothers Of the same strain did not.
Up to this point it was merely an in
terestlng observation in genetics and
possibly Of some practical value to
RC1Anf1CfS jYfnracfnI iva +Ia LII
clalized subject of leukemia in mice
linen came another observation Of more
generallzed significance. The average
life span Of mice of this strain that did
not develop leukemia but died of other
maladies or plain old age was increased
by approximately one third. Apparent
ly. this was quite independent phe-
nomenon from that of the increased
leukemia resistance
Now 1t has developed, according to
the report, that the same results are
obtained with the offspring of young
mothers who are nursed by old mothers.
Thus the resistance, both to the leuke.
mia and to the whole complex Of causes
which cause the death of mice-aeain
Of this particular strain-appears to be
due to something contained in the milk
Of the old mothers.
The life span was increased from an
average Of 500 up to 800 days. Applied
to human being-there is no such i'm
pllcation in the Carnegie report and
probably 1nSuperable difficulties would
be involved in applying the results to
other types Of animals or even another
strain of mice-this would mean an in
crease in the average span Of life from
around go to around 80 years. ~,
Various Problems Arise.
Various problems arise, and DIR. Mac
Dowell and his associates naturally are
extremely guarded in their statements:
Is this death-resistance factor which
develops only with the aging of mothers
confined to one specific strain of one
species of mice?
Does 1t affect only nursing mice Of
one leukemic strain of one species?
Even aside from the milk, it now has
been found, something of this general
resistance is transmitted by the old
mothers to their offspring who are
nursed by young mothers-but this re-
sistance is weak compared to that OBJ
tanned from the milk.
DR.. Mcdowell and his associates
make only the following highly guarded
statement: ''The discovery of the mech
anism responsible for lengthening life
to the extent Of 80 per cent by a factor
in old nurses milk would have con-
siderably broader implications" than the
discovery of the leukemia resistance
factor alone.
It is as yet by no means clear that
tn d. h. II l.
substance which ever can be isolated.
1t may well be an inseparable complex.
On the other hand, it may be very
significant new factor brought about by
evolution in this obscure corner of the
animal kingdom which exists, or may
be induced to exist in other species and
genuses. If such should prove the case
the finding would have very much
broader Implications"