Evening star., 1935-12-14
HORMONE ISFOUND
FOR MOTHER LOVE
Carnegie Researchers Say
ProIactin Injection Stirs
Emotions.
BY THOMAS r. HENEY.

stance winch seems 10 pe Responsible
for mother love was announced today
in the 1885 year book of the Carnegie
Institution of Washington.
II is prolactin, one of the hormones
secreted by the anterior pituitary
gland.
Small but repeated injections Of
this substance will make females with
out babies and physiologically in
capable Of giving birth, adopt mother
less little ones and care for them as
If they were their own.
Injections Of the same substance
will make male rats as "motherly''
as the most solicitous female.
The discovery was made by Drs.
Oscar Riddle, r. w. Bates and E. L.
Lahr Of the institutions genetic lab
oratory. 1t goes far to explain one
Of the most vital forces in the history
of life-the devotion shown by fe-
males to their helpless young without
which the higher forms of life would
be inconceivable. 1t also explains why
some females are more motherly than
others and possibly why some fathers
will show more than paternal devo-
ton to their families.
All Prolactin Same.
The results, of course, apply only
to rats, in so far as the experiments
90. But prolactin is the same through
out the animal kingdom. the substance
in man is identical with that in the
rat, and presumably it has similar
affects. The outstanding difference
probably is that among human beings
so much of institutionalism and ira
dition enter into motherhood and
family life that the reaction is less
direct than among animals, who have
no moral" traditions to uphold.
That is, the human mother will pre-
tend to love her children-even If she
really does not because Of a deficient
prolactin secretion.
Previous experiments had shown
that prolactin played an important
part in feminine physiological proc
eSses-although the secretion was
common to both sexes. Last year the
Carnegie biologists found that it was
possible to induce broodineSs in lay
ing hens by prolactin injections, and
this result led directly to the expert
ments reported today.
Says the Carnegie report: "The
criterion for presence of the maternal
instinct is that rat shall persistently
respond to the presence of q young
rat dropped in front of her cage by
taking it in her mouth, carrying 1t
to her nest, and there covering or
caring for it. Most virgin rats, 46
out Of 81, begin to give this maternal
care with from three to fifteen daily
injections Of prolactin. A few carry
young to the nest but give no further
care. Curiously, three out of the
81 gave the reaction only after
stopping the injections and seven
failed to show the maternal response
after period Of 80 or 40 days. -Four
virgins that did not develop the in
Stinct under prolactin later devel-
oped it after series Of whole pit
uitary extract rich in prolactin. Pro-
lactin apparently developed the in
stinct in two of eight normal male
rats.
Many Tissues Affected.
THE injection Of other pituitary
hormoneS is so rarely followed by q
positive response as to indicate that
none of them induces maternal be-
havior. This demonstration OF the
dependence Of an instinct on q hor-
none contributes to our understand
ing Of animal behavior and psychology
A hormone has been found to act upon
a variety of tissues and processes, such
as lactation, germfnal tissue and CO.
operation with nerve tissue in devel-
opment Of an instinct and at the same
time it maintains an underlying unity
Of the several responses it evokes In
this case, despite the varying kinds OF
tissue involved, all the responses are
concerned with feeding and care OF
the young. Again, it indicates the
periodic release, at least in adult life,
Of this hormone, and the basis of a
particular type Of cyclic behavior is
thus made comprehensive.
Although the mechanism by which
the hormone affects the neural state
or function Is wholly unexplored, this
case provides superior instance OF
somatic or extra neural participation
in a normal psychic state. The ad-
ministration Of this hormone to an
otherwise adequately developed rat
obviously endows the animal with q
quite new normal and necessary psy-
Geological experience. The appar-
emily legitimate and necessary infer
ence from the induced behavior is
that we have thus temporarily added
to such q rat new element of con-
sciousness.
Although prolactin thus appears tc
be the mother-love substance in ma
ture, tests reported three years age
before the National Academy of Sci
ences from John Hopkins University
indicate that it is insufficient of itseli
to maintain the instinct it has started
without adequae dietary help. These
tests showed that mother rats ne
elected, and even devoured, their or
SRAAlk NLlCu LI1CIC was IOIhl lACk
Of the element magnesium In Their
food.
Protection Against Tumors.
Another apparent function Of pro-
lactin, reported by DR.. Riddle, is thai
of protection against ovarian tumors
which often become malignant anc
cause death. The Carnegie expert.
menters gathered evidence, still from
the rats, that such tumors are stim-
ulated, and may even be started, BY
the action of another hormone from
the anterior pituitary, which acts with
prolactin in various physiological proc
esses. These tumors appear to thrive
when there is deficiency Of prolactin
in the blood stream. and their growth
is checked when, through injections
this is brought to or above normal.
This finding, which might have i'm
portant medical implications, ad.
mittedly is not yet supported by ade-
quate evidence, DIR. Riddle says in his