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Some estrogenic effects of endometrial extract

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Some estrogenic effects of endometrial extract

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Content SOME ESTROGENIC EFFECTS OF
ENDOMETRIAL EXTRACT
A Thesis
Presented to
the Faculty of the Department of Zoology
University of Southern California
In Partial Fulfillment
of the Requirements for the Degree
Master of Arts
by
Morton Shomstein
May 1941
UMI Number: EP67150
All rights reserved
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a note will indicate the deletion.
DisscNrtatbin RuUishing
UMI EP67150
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This thesis, written by
..........M0RT0IL.5H g # T E .............
under the direction of h..%§ Faculty Committee,
and approved by a ll its members, has been
presented to and accepted by the Council on
Graduate Study and Research in partial fulfilT
ment of the requirem ents fo r the degree of
MASTER OF ARTS
''Dean
Secretary
Date.
Faculty Committee
Chairman
TABLE OF CONTENTS
CHAPTER PAGE
I. INTRODUCTION AND REVIEW OF LITERATURE .......... 1
II. MATERIALS AND METHODS......................... 11
III. RESULTS .......... 16
IV. DISCUSSION.................................. 29
V. SUMMARY .................................... 40
BIBLIOGRAPHY ..................................... 42
LIST OF TABLES
TABLE PAGE
I. Qualitative Assay of Endometrial Extract in
Mature Ovariectomized Rats • ............ 17
II. Quantitative Assay of Endometrial Extract in
Mature Ovariectomized Rats ......... 18
III. The Effects of Endometrial Extract on
Immature Female Rats .................. 20
LIST OF FIGURES
FIGURE PAGE
1. Photomicrograph of the Uterus of a Mature
Ovariectomized Control Rat................... 21
2. Photomicrograph of the Uterus of a Mature
Ovariectomized Experimental Rat ...... 22
3. Photomicrograph of the Vagina of a Mature
Ovariectomized Experimental Rat.............. 23
4. Photomicrograph of the Vagina of a Mature
Ovariectomized Control R a t .................. 24
5. Photomicrograph of the Uterus of an Immature
Experimental Rat .............. 25
6. Photomicrograph of the Uterus of an Immature
Control Rat .......................... 26
7. Photomicrograph of the Vagina of an Immature
Experimental Rat ........ ............ 27
CHAPTER I
INTRODUCTION AND REVIEW OF LITERATURE
A question that has often arisen in endocrinological
literature is whether the ovary is the sole source of estro
genic hormone, or is there some other possible site of ori
gin. With the discovery of estrogenic substances in various
tissues of the body other than the ovary, many investigatiors
have been initiated to ascertain whether or not these tissues,
besides being the site of location, might also possibly be
the site of their productions
A possible means, not indeed of actually localizing
the origin of the estrogen in the tissue where it is found,
but at least of ruling out the ovary, is afforded by those
species in which total castration during pregnancy does not
necessarily result in the termination of gestation. This has
been authenticated in many species.
Herrick (1928), working with guinea pigs, observed
that pregnancy could continue in some cases if the ovaries
were removed even before the middle of the gestation period.
Hart and Cole (1934) ovariectomized a mare at about
the 200th djiy of pregnancy. Gestation proceeded normally to
term in the absence of the ovaries. The mare gave birth to
a normal foal and lactated normally.
Hauterius (1956) reduced the litter size of rats by
removing all but one fetus. The rats were then ovariecto
mized. He found that gestation continued to term, with nor
mal delivery of the lone remaining rat,
Hartman (1958) castrated two rhesus monkeys on the
l9th day of gestation, and each carried its fetus to full
term.
In human beings, the occurrence and necessary removal
of bilaterally cystic ovaries during pregnancy has given sev
eral opportunities for the study of hormone output after cas
tration.
Amati (1928) was the first to examine and record such
a patient for the presence of hormone after castration, but,
unfortunately, the results are not conclusive. The patient
had both ovaries removed at about the 105th day of pregnancy.
Three days after birth (which took place 165 days after oper
ation) the blood serum was tested on immature guinea pigs and
found to produce changes of the uterus and vagina attributed
to hormone action. Since the test animals were not castrated,
it cannot be known whether or not the active substance was
estrogenic or gonadotropic in nature*
Five cases, however, have been studied by more speci
fic tests. Waldstein (1929) reported a patient bilaterally
castrated at the 34th day of pregnancy. Delivery occurred
normally at 270 days, with normal lactation. During the last
month of pregnancy the blood serum contained about 1000 mouse
units of estrogenic substance per liter and the urine 400 to
500 mouse units per liter.
Szarka (1930) studied a case in which bilateral ovari
ectomy was done in the 3rd month, the pregnancy continuing to
term followed by normal lactation. Ten hours before birth
the urine contained 1000 mouse units per liter.
The patient studied by von Probstner (1931) was castrated
about the 50th day, and gave birth at about 280 days, with nor
mal lactation. Genital atrophy was observed four months after
parturition. In this case the urinary estrogen Content was
tested every three to four weeks throughout pregnancy, and
that of the blood near term and during the puerperium. After
a preliminary drop the estrogen output returned to normal,
reaching 8000 mouse units in the last few months.
Allan and Dodds (1935) studied a pregnant patient cas
trated at about 3§ months. The estrogen in the urine was as
sayed at 2000 mouse units per liter before operation. Fifty-
four days after operation the yield was 1300 mouse units per
liter. This was a drop of 40 per cent, but the output was,
of course, very much higher than that found in non-pregnant
subjects.
Guldberg (1936) reported a case in which double ovari
ectomy occurred on the 113th day. Premature delivery took
place on the 214th day. During the 100 days before delivery.
there were five examinations made of estrogenic substance
and gonadotropic hormones in the blood and morning urine.
The yield of estrin was high, reaching more than 17,000 mouse
units per liter in the morning urine and 900. mouse units in
the blood plasma.
From such observations as these it is certain that
there is an extra-oyarian source of estrogenic substance.
Of the many tissues, that have been tested for estro
genic properties, one, the endometrium of the uterus, has al
ready been dealt with, but not to any appreciable extent.
With the possibility in mind that the endometrium might be
the extra-ovarian source of estrogenic substance, a series of
experiments were instituted to determine the estrogenic proper
ties, if any, of this tissue. Also all the data that might
have a bearing on the problem was gathered, so that the burden
of proof would not rest solely on the experimental results
of this work, and w^ould, therefore, be more conclusive.
There has been very little experimental v/ork done to
determine whether or not any estrogenic substances are present
in the uterus. A few reports deal with attempts that have
been made to assay various uterine extracts for estrogenic
activity.
In 1904 Schuking prepared a saline extract of uterine
tissue which, when injected into rabbits stated to be non-
pregnant, prevented the occurrence of pregnancy, ostensibly
through the inhibition of ovulation.
On the other hand, Blair-Bell (1906) presented a the
ory, without any experimental evidence in support of it, that
a hypothetical hormone which he called ^^uterin" might be the
cause of ovulation. He based his theory on the very close
relationship of the ovary and uterus in pregnancy,
Parkes and Bellerby (1927) made alcohol extracts from
the whole uterus of a pregnant cow and two sheep, the stage
of pregnancy not being known, which, when injected into ovari
ectomized mature female rats, induced a definite estrogenic
reaction.
Cathpole and Cole (1954) made a preliminary estrogenic
assay of the endometrium of a pregnant mare. Injections of
an olive oil extract of this tissue into ovariectomized mature
female rats gave a positive estrus reaction.
Cheval (1935) reported that a saline extract of uterine
tissues of various animals, including the dog, was prepared
which stimulated proliferation of the granulosa cells of the
follicles in ovarian grafts. He also obtained a white, water-
soluble powder which exerted a similar effect v/hen administered
in five daily injections of 200 milligrams each in rats. The
nature of the substance has yet to be determined.
Although the work on uterine extracts has been insig
nificant, there has been no dearth of material on estrogenic
substances in general. A tremendous amount of research has
been carried out to determine what constitutes estrogenic
activity. As the purpose of this paper is to investigate
the presence or absence of an estrogenic substance in the
endometrium, it might be well to give some space to a con
sideration of what criteria signify the estrogenic activity
of a substance and how these criteria were determined.
Early work on ovarian hormones had been retarded by
the lack of a clear-cut, short, workable test for activity.
Uterine changes as a criterion are difficult to follow be
cause of the internal location of the organ.
With the discovery of the striking changes of the vag
inal epithelium occurring during the estrus period in various
rodents^-in the guinea pig by Stockard and Papanicolaou (19X7),
in the rat by Long and Evans (1922), and in the mouse by E,
Allen (1922)— and the possibility of accurately following
these changes in the living animal by the cellular contents
of vaginal smears. (Kalint and Doisy, 1928), a new criterion
for the activity of injected extracts became available.
In ovariectomized animals the effect of estrogenic hor
mones is studied by noting the growth of the accessory genital
organs following hormone administration as compared with the
castrate state following ovariectomy. The castrate condition
of the epithelial wall of the vagina of the rat is well ad
vanced in 4 to 6 days after removal of the ovaries,(Long and
Evans, 1922). At this time the epithelium is only two or
three layers of cells in thickness. Growth of this tissue is
7
extremely slow, for mitotic figures are either absent or very
rare. Leucocytes may be found under and in this epithelium
and their migration through it to the lumen furnishes the
typical control smear composed almost entirely of leucocytes.
A considerable amount of growth can be noted in the
vaginal wall of the rat 24 hours after the first of a series
of injections of estrogenic substance (Allen, et al, 1924).
This wave of growth is accentuated at 36 hours, at which time
the epithelium has usually grown to twelve or fifteen layers
in thickness. This new tissue is distinct from the old vag
inal vfall. The cells from the old vaginal wall constitute the
large nucleated cells characteristic of the proestrous smear
(Long and Evans, 1922).
Then in the outer layers of the old vaginal wall, a
typical granular layer forms. This is later transformed into
a cornified layer, which is at first not superficial but lies
underneath the two or three layers of the old vaginal wall.
Then the old vaginal wall is desquamated into the lumen and
the cornified cells become superficial. WitE a gradual de-
tatchment of these cornified cells a smear typical of the
estrus period is obtained. This is made up entirely of large,
flat, non-nucleated, cornified cells. At this time the vag
inal wall may contain from twelve to sixteen layers beneath
the cornified layer (Allen, et al, 1924).
As the effect of the hormone stimulation wears off.
8
the cornified layers are sloughed off into the lumen, the
epithelium then becomes infiltrated with enormous numbers
of leucocytes which completely remove the outer nucleated
layers and invade and destroy the desquamated masses in the
lumen. This degenerative phase (metaestrum) returns the vag
inal wall to the thin control condition of the ovariectomized
animal.
Although the changes in the vaginal walls of rodents
are easily followed in the living animal by the vaginal
smear technique, the changes occurring in the uterus are
equally as prominent and, were it not for the internal loca
tion of the organ, might prove as valuable a criterion of
hormone function. In from 4 to 6 days after removal of the
ovaries the uterus is found to be small and anemic, and its
lumen slit-shaped in cross-section. Leucocytes are present
in the epithelium and underlying connective tissue, and the
glands are collapsed and atrophic. After several injections
of estrogenic substance a rapid recovery from this castrate
condition is apparent. The leucocytes disappear from the
uterine mucosa and the whole organ is hyperemic. In brief,
these uterine chahges consist of rapid growth followed by
secretion as a definite reaction to injected hormone (Allen, E.
et al, 1924).
That injections of estrogenic substances can effective
ly substitute for the normal internal secretions of the ovary
in ovariectomized animals has been confirmed by a number of
investigators. Allen, Francis and Robertson (1924) found
that injections of estrogenic substance into various spayed
animals, including the rat and the rabbit, induced the accel
erated growth, hyperemia, and sécrétion in the genital tract
characteristic of the period of estrus. These results have
been further verified by Halpern and D’Amour (1934), and by
Asdell and Seidenstein (1935). Similar results have been ob
tained in monkeys by Robertson, Maddux and Allen (1950).
In immature animals there are other criteria used to
determine the estrogenic activity of a substance. In the
immature female rat the vagina does not open until the attain
ment of puberty. Until maturity it is a solid cord of cells,
at least in the outer one-half of its extent (Long and Evans,
1922). A lumen may appear at the uterine end where the vagi
nal epithelium is very thin, being composed of only two or
three layers of cells. Injections of estrogenic substance re
sult in rapid growth of this tissue. This induces a thicken
ing of the vaginal epithelium and the formation of a corni
fied layer, thus opening the vaginal orifice.
The changes in the uterus resulting from injections of
estrogenic substance are also very pronounced. The tiny, in
fantile uterus begins rapid growth and differentiation. The
superficial epithelium and glands are transformed from a
typical embryonic type of cell to a well-differentiated, low.
10
columnar type. The muscle layers are rapidly differentiated.
Enough secretion is formed to greatly distend the uterus
(Allen and Doisy, 1924).
These changes in immature animals following adminis
tration of estrogenic compounds have been verified by a num
ber of investigators, especially in the case of the albino
rat. Allen et al, (1924), Allen and Doisy (1924), and Frank,
Kingery and Gustavs on (1925) all found that Injections of es
trogenic material would cause the premature opening of the
vagina in immature rats, both normal and spayed, in from 4 to
6 days after the first of a series of injections. Similar
effects have been noted in the guinea pig by Loeb and Kountz
(1928).
I
CHAPTER II
MATERIALS AND METHODS
The animals used in these experiments were white fe
male rats from the colonies maintained by the University of
Southern California School of Medicine and the Department of
Zoology. Two groups were employed— immature and mature fe
males.
The material for injection was prepared in the follow
ing manner from the endometrium of a pregnant mare. The uter
us from which the endometrium was obtained was from a pregnant
mare containing a fetus 5 inches to 6 inches, crown rump mea
surement. The entire endometrium was removed immediately
after the animal was killed and placed in 350 cc. of acetone
while still v;arm. A fetus of this size is estimated, accord
ing to a table given in Chauveau (1891), as being 10 weeks old
The endometrial tissue weighed 45 gms.. This endometrial
tissue was kept in the acetone for approximately seven months
for extraction of its hormonal contents. At the end of this
period this acetone solution v/as then evaporated by means of
ah aerating apparatus and the residue redissolved in 175 cc.
of sesame oil, or one-half the original amount of acetone
used, so that each cc. of sesame oil contained the hormonal
equivalent of 2 cc. of acetone. The impurities in this oily
12
solution were removed by centrifugation and it was then
placed in 30 cc. sterile vaccine bottles.
The experimental work was divided into two parts: in
one, a series of six adult ovariectomized females were used;
in the other, a series of ten, 21 day old females, were em
ployed. Adult ovariectomized females were used in order to
determine whether or not the activity of the endometrial ex
tract was estrogenic or gonadotropic in nature.
These mature females were ovariectomized in the follow
ing manner; Anesthesia was induced by an intraperitoneal in
jection of nembutal. The abdomen was then shaved and an inci
sion made along the mid-line of the abdomen. The abdominal
wall was then retracted and the ovary on one side exposed.
This was then removed, together with the anterior portion of
the oviduct. The other ovary was exposed through the same
incision and removed in the same manner. The fimbriated por
tion of the oviduct was also removed, to insure the complete
removal of all ovarian tissue. The incision was closed with
surgical sutures. Aseptic procedure was maintained as nearly
as possible under the conditions. The rats were then placed
in clean cages and in 2 to 3 days had recovered from.the
effects of the operation.
At the end of this time daily vaginal smears were made
from each rat for a period of 10 days, in order to verify the
success of the operation and to make sure that no fragment of
13
functional ovarian tissue had inadvertently been left behind.
The vaginal smears were made with a curved glass rod and the
material removed by the rod was placed on a glass slide and
examined under the microscope without benefit of any stain.
Each of the rats was in a continued state of diestrus for the
entire 10 day period during which the smears were made. From
this evidence it was concluded that all the ovarian tissue had
been completely extirpated; otherwise, a state of estrus would
have been manifested.
Following this preliminary treatment the ovariectomized
mature females were started on a course of injections to de
termine whether or not any estrogenic substance was present
in the endometrial extract. The six rats were divided into
two groups: one group consisted of four experimental animals,
the other consisted of two controls. The experimental rats
V» ■
were injected with 2 cc. of the endometrial extract daily, in
1 cc. doses, spaced 5 to 6 hours apart. In the control group,
one rat received 2 cc. of sesame oil daily, in 1 cc. doses,
while the other rat received no injections at all. All injec
tions were given subdutaneously in the dorsal portion of the
neck. Injections were-made subcutaneously to allow for great
er and longer absorption. Vaginal smears were made daily
from all of the ovariectomized rats to determine whether or
not estrus had been induced.
A second series of injections was then instituted to
14
determine the hormonal concentration of the endometrial ex
tract in terms of rat units: i.e., to find the least amount
of the extract containing one rat unit. A rat unit is defined
as the least amount of estrogenic substance necessary to give
an estrus reaction in three out of four ovariectomized mature
rats 48 to 52 hours after the first of a series of injections.
1939) iStarting with 2 cc.. injection^, as mentioned
above, the amount was reduced J cc. each time until the low
est amount was reached whereby estrus could be brought about
in the rats. After the assay had been completed, the rats
were brought into estrus once more and were then killed by
means of a sharp blow on the back of the head. The vagina
and uterus were removed and placed immediately in Bouin*s
fluid.
The immature female rats were also divided into two
groups: eight rats were placed in the experimental group
while two were used as controls. All eight experimental ani
mals were given injections of the endometrial extract, while,
in the control group, one rat received injections of sesame
oil and the other rat no injections at all, the same as in
the first group.
The endometrial extract was injected in 1 cc. doses
twice daily, 5 to 6 hours elapsing between injections. The
same procedure was followed in injecting the sesame oil into
the control rat. All injections were given subcutaneously
15
in the dorsal portion of the neck. The injections were con
tinued until an external opening had appeared in the vagina.
When the vaginal orifice became apparent, the animals were
killed by giving them a sharp blow on the back of the head.
The uterus and vagina were removed and immediately placed in
Bouin*s fluid.
Slides were then made from the uteri and vaginas of
the mature ovariectomized rats and the immature rats. The
procedure used was as follows:
55 per cent alcohol — wash 3 or 4 times
50
n tT
" — 45 minutes
70
tt ft TT : ' __ TT TT
80
ti n
" — 12 or more
90
n
T T 45
minutés
95
1 ! n
TT ___ 45
minutes
Absolute " — 45 ”
Xylene - — until clear
Paraffin — ij- to 2i hours
imbed in paraffin and bayberry
Section at 8 micra
Stain vd.th Delafield* s hematoxylin and eosin
CHAPTER III
RESULTS
The results obtained in the series of §ix mature ovar
iectomized female rats were quite uniform. Each of the four
rats which received injections of the endometrial extract was
brought into a state of estrus, as indicated by a microscop
ical examination of the cellular contents of the vagina.
Both controls remained in the diestrus state.
The qualitative assay of the endometrial extract is
given in Table I. It can be seen that 4 cc. of the extract
was sufficient to induce estrus in each of the experimental
animais.
The second series of experiments was carried out on
the mature ovariectomized female rats to determine the approx
imate concentration of estrogenic substance in the endometri
um.
The results from this series of experiments are given
in Table II. It can be seen that injections of 2 cc., 1 3/4 cc.
and 1 l/g cc. of endometrial extract gave a positive estrus
reaction in each of the four experimental animals. Three of
the four rats returned,a positive reaction with 1 1/4 cc.,
while only two of the rats responded to 1 cc. of the extract.
In the series of ten immature female rats, where an
17
TABLE I
QUALITATIVE ASSAY OF ENDOMETRIAL EXTRACT
IN MATURE OVARIECTOMIZED RATS
Rat
No.
Inj.
With
No. of
Injec
tions
Am»t,
Inj.
In Full
Estrus
I Endometrial
Extract
4 4 cc. Yes
II
t!
4 4 cc. Yes
III
IT
4 4 cc. Yes
IV
TT
4 4 cc. Yes
Control Sesame
Oil
4 4 cc. No
Control Nothing
No
18
TABLE II
QUANTITATIVE ASSAY OF ENDOMETRIAL EXTRACT
IN MATURE OVARIECTOMIZED RATS
Rat
No
Am*t.
Inj.
In
Estrus
Am*t.
Inj.
In
Estrus
Am’t. In
Inj. Estrus
Ain’t. In
Inj. Estrus
Am’t.
Inj.
In
Estrus
I
2 cc. Yes 1^3/4
cc.
Yes ii cc. Yes ij cc. Yes 1 cc. Yes
II 2 cc. Yes 1-3/4
cc.
Yes ij cc. Yes li cc. No 1 cc. No
III
2 cc. Yes 1-3/4
cc.
Yes li cc. Yes If cc. Yes 1 cc. Yes
IV 2 cc. Yes 1-3/4
cc.
Yes
ij cc. Yes li cc; Yes 1 ÇC . No
19
attempt was made to bring about a premature opening of the
vagina, the results were also quite uniform, although there
were slight individual differences in the amount of endome
trial extract necessary to induce this change.
The results of this series of experiments is given in
Table III. Each of the eight experimental rats responded pos
itively. Two of the immature rats; only required 10 cc. of
the extract, while five required 11 cc., and one 18 cc. be
fore an external opening of the vagina became established.
The control rats remained the same, no apparent external
change being manifested in them.
Histological examination of the uteri and vagina of
the mature ovariectomized and the immature rats, both experi
mental and control, revealed some very striking differences.
The uteri of the mature ovariectomized controls (Figure 1,
page 21) were small and atrophic in comparison with those of
the mature ovariectomized experimental rats (Figure 2, page
22). The vaginal epithelium of the mature experimental rats
was very well developed, reaching some 14 or 15 layers in
thickness in spots (Figure 3, page 23), while that of the
controls was but poorly, developed-, (Figure 4, page -24) . The
vaginal lumen of the experimental animals was larger than that
of the controls. There were great numbers of leucocytes pre
sent in the vaglriai lumen of the' controls, while none were
present in the experimental rats.
so
TABLE III
THE EFFECTS OF ENDOMETRIAL EXTRACT
ON IMMATURE FEMALE RATS
Rat
No,
Inj.
With
No. of
Injec
tions
Am*t.
Inj.
Vagina
Opened
Days
after 1st
Injection
I Endometrial
Extract
11 11 cc. Yes 6
II
tT
10 10 cc. Yes 6
III 11 11 cc. Yes 6
IV
tT
11 11 cc. Yes 6
V
t!
IS IS cc. Yes 7
VI
TT
11 11 cc. Yes 6
VII
TT
10 10 cc. Yes 6
VIII
TT
11 11 cc. Yes 6
Control Sesame Oil IS IS cc. No 7
Control Nothing No 7
FIGURE 1.
Photomicrograph of the Uterus of a Mature Ovariectomized
Control Rat, Showing the Atrophic Lumen Characteristic of
This State. X50

FIGURE 2.
Photomicrograph Through the Uterine Wall of a Mature Ovari
ectomized Experimental Rat Shov/ing the Marked Thickening
Characteristic of Estrus. X50
22
mm,
FIGURE 5.
Photomicrograph of the Vagina of a Mature Ovariectomized
Experimental Rat Showing the Thick Epithelium Characteristic
of Estrus, X450

FIGURE 4.
Photomicrograph of the Vagina of a Mature Ovariectomized
Control Rat Showing the Atrophic Epithelium Characteristic
of Anoestrus. X450
P/L
FIGURE 5.
Photomicrograph of the Uterus of an Immature Experimental
Rat Showing a Well Developed Lumen and Differentiation of
the Uterine Wall. X50
25
mm
FIGURE 6
Photomicrograph of the Uterus of an Immature Control Rat
Showing the Slit-like Lumen and Poor Differentiation
Characteristic of the Infantile State. X50
>6
FIGURE 7.
Photomicrograph of the Vagina of an Immature Experimental
Rat Showing Thickening of the Epithelium and a Well Estab
lished Lumen, XlOO

28
In the immature group, shown in Table III, page 20,
similar differences were manifested. The uteri of the exper
imental rats (Figure 5, page 25) were larger than those of
the controls (Figure 6, page 26), and they showed a much more
distinct differentiation of the various layers of the uterine
wall. In the experimental animals, the vaginal epithelium was
of great thickness, and the vaginal lumen v;as well established
(Figure 7, page 27).
CHAPTER IV
DISCUSSION
From the data given in Table I, page 17, wherein the
qualitative effects of the endometrial extract are presented,
it is apparent that an estrus-inducing substance is contained
in the endometrium. Furthermorethe proof that this sub
stance is estrogenic, rather than gonadotropic, in nature is
clearly shown ly the fact that its potency has been demon
strated in adult ovariectomized rats. Were it gonadotropic
in nature, it would have had no effect upon ovariectomized
animals, for gonadotropic hormones only possess the power of
stimulating the gonad to produce its own secretion; they can
not substitute for the hormones of the gonad.
The quantitative assay of this endometrial extract, as
given in Table II, page 18, was a method employed to deter
mine the approximate concentration, in rat units, of the endo
metrial tissue employed in this work. As previously stated,
a rat unit is the least amount of estrogenic substance which
will produce a state of estrus in three out of four ovariecto
mized rats after the first of a series of injections. From
the data presented in Table II, the amount of endometrial ex
tract most closely meeting this requirement is seen to be 1^ cc
Thus ij cc. of the oily endometrial extract constitutes approx
50
imately one rat unit. The total amount of sesame oil used was
175 CO.; by dividing ij into this amount the quotient 140 is
obtained, which is the total number of rat units present in
this solution. Since this sesame oil contained the entire
estrogenic substance extracted from the endometrium, the
tissue used in this work, therefore, contains approximately
140 rat units of estrogenic substance.
Further evidence of the presence of an estrogenic sub
stance in the endometrium is given in Table III, page 20,
wherein the effects of injection of endometrial extract into
immature female rats are given. This table shows that in
each of the rats receiving the extract there was induced a
precocious opening of the vagina. This, as has previously
been brought forth, is one of the classical criteria of estro
genic activity. The slight fluctuation in the amounts neces
sary to produce this result can be explained on the basis of
individual differences; some rats respond much more strongly
than others to similar amounts of estrogenic substance.
Still further evidence is given by histological exam
ination of the uterus and vagina of these experimental and
control rats. All of the changes manifested in these tissues
by injections of estrogenic substance, as stated in the re
view of estrogenic principles, are likewise manifested here.
The experimental evidence previously brought forth and
discussed indicates that the endometrium contains an estro
31
genic substance. However, the experimental results cannot
show or prove whether or not the estrogenic substance was
secreted by the endometrium, or if it merely was stored there.
This question can only be discussed by the bringing in of
other. relevant evidence. There are two main fields from
which this evidence may be taken: clinical and experimental.
The clinical findings will be presented as is, with no attempt
being made to enlarge or interpret them. In the experimental
evidence, an attempt will be made to discuss and interpret
the findings, and, where possible, to correlate them with
those of the author.
Clinical. In 1898, Abel advanced the idea, on the
basis of his experiences, that the effects of panhysterec-
tony in women could be mitigated by the conservation of a por
tion of the mucous membrane of the cervix sufficient for the
continuation of menstruation. This view has been affirmed by
more recent clinicians.(Graves, 1917, and Hawks, 1921).
However, the view that the removal of the uterus had
no direct effect upon the ovary also had a number of adherents.
The first of these was Keitler (1904), who based his conclu
sion upon a thorough-going review of every case reported in
the literature up to 1904 with additional ones from his own
practice. Keitler believed that the reason for the adverse
effects of panhysterectomy, when such effects occurred, was
the fact that in the process of removing the uterus, some of
32
the blood vessels to the ovaries were injured. When subtotal
hysterectomy was employed, the chance of interfering with
these was minimized. Two years later, Holzbach (1906) sug
gested that the ovarian changes were the result of injury to
the ovarian nerves, a view widely attributed to Vineburg
(1915), who reached the same conclusion some nine years later.
According to these views, the only benefit resulting from
partial hysterectomy was the psychic one of the effect of
menstruation upon the patient. The belief that hysterectomy
has no effect upon the ovary is the conservative one of to-day,
Experimental. On the experimental side there are a
number of reports stating that panhysterectomy in the dog
(Unterberger, 1930), opossum.(Hartman, 1925), rat (Durant,
1926), mouse (Westman, 1929), rabbit (Unterberger, 1930),
and ferret (Deansley and Parkes, 1933) is without effect upon
the function of the ovary. The tests of ovarian function in
cluded the periodic occurrence of vaginal estrus cycles, the
periodic increase of bodily activity that occurs at estrus,
and mating behaviour. Some investigators have also remarked
upon the lack of degenerative changes in the ovary.
On the other hand, we have the effects upon the ovary
which have been attributed to total removal of the uterus.
These changes are not sudden in their outset, nor do they,/
appear soon after the operation. The morphological changes
that have been described are usually said to consist of a
35
marked increase of interstitial cells, the frequent occur
rence of follicular cysts, depending upon the species and
age at time of operation, and follicular atresia (Reynolds,
1939). In some cases prolongation of the life of the corpora
lutea is the most pronounced effect of hysterectomy. Hechter,
Fraenkel, Levi, and Soskin (f940) observed that hysterectomy
in the pregnant rat markedly prolonged the life of the corpus
luteum. Loeb (1923) reported that hysterectomy performed in
the guinea pig a few days following ovulation might preserve
the life of the cyclic corpora lutea for several months.
Loeb and Smith (1936), working with rabbits, observed that
hysterectomy caused the corpora lutea to persist for much
longer times than normal, in some instances over fifty days.
In the opinion of the author, a definite corollary
exists between the prolongation of the life of the corpus
luteum by hysterectomy and the effect of estrin on the cor
pus luteum or its product, progesterone.
Deanesly (1931) reported that injections of 3-10
mouse units of estrin in pseudo-pregnant mice caused vaginal
cornification and copulation. The corpora lutea were
.shrunken and there was vascular collapse.
Allen (1932) found that progestin extracts lost their
ability to produce progestational proliferation in the cas
trated rabbit*5 uterus when they are given simultaneously
with sufficient amounts of estrin.
34
Robson (1935) injected large doses of estrin into
pseudo-pregnant rabbits. This had an inhibitory effect upon
the action of the corpus luteum, for the luteal reaction
commonly observed in the endometrium was lacking. In 1^6,
Robson further demonstrated that, whereas 0^75 mg. of pro
gesterone usually produced a degree of progestational pro
liferation equivalent to that observed at the height of pseudo-
pregnancy, the effect of this amount of progesterone could
be completely inhibited by the simultaneous injection of 1/75
of its weight of estrin. Some inhibition was obtained with
l/300th of its weight of estrin.
From these facts it can be reasonably assumed that
there is some substance present in the uterus which exerts a
somewhat similar effect on the corpus luteum as does estrin.
In view of the finding of an estrogenic substance in the endo
metrium, this relation is still further strengthened.
It is interesting to note that in the reports setting
forth the negative effects of hysterectomy upon the ovary,
no stress is placed upon the interval elapsing from the time
of operation to the time of removal and histological examina
tion of the ovaries, although the structural changes that fol
low total removal of the uterus are not pronounced until some
three or four months have passed.
There is a body of experimental evidence which shows
that the effect of hysterectomy upon the ovaries is blood-
35
borne. The idea that the uterus elaborates a hormone was
suggested more than twenty-five years ago, although there
was no real shred of evidence at the time to substantiate
the idea (Bond, 1906). In 1924, however, Takakusa described
the degenerative changes in the ovary follpwing hysterectomy
and he added the important fact that these ovarian changes
may be prevented in either of two ways; by transplanting
uterine tissue into the hysterectomized animals, or Iqy para
biosis with a normal female whose uterus and gonads are in
tact.
These observations stood alone until 1928, when they
were confirmed as regards the effect of uterine transplants.
A series of papers from a number of laboratories showed that
certain degenerative ovarian changes could be prevented if
uterine tissue were transplanted at the time of hysterectomy.
Zimmerman (1928) transplanted pieces of endometrium
into the abdominal wall of hysterectomized rabbits and found
that regressive changes in the retained ovary were inhibited
as long as sufficient uterine tissue remained viable.
Parpenoff (1931), using mice, found that hysterectomy
without endometrial transplantations produced follicular
atrophy. With the use of endometrial transplants into the
abdominal wall, he was able to stimulate the growth of new
follicles and fresh corpora lutea.
Seesums and Murphy (1933) reported that hysterectomy
56
in the rabbit inhibits the development of estrus, and brings
about changes in the microscopic structure of the remaining
ovaries, which tend to be both inhibitory and degenerative in
nature. Autotransplantation of the endometrium has a tendency
to limit the extent of the inhibitory and degenerative changes
which result from hysterectomy. Seesums and Murphy believe
that the endometrium elaborates a hormone which influences
the ovary.
Hechter, et al (1940) reported that corpora lutea,
whose life had been prolonged try hysterectomy, would regress
in a short time if uterus tissue were transplanted.
The most convincing work seems to be that of Cheval
(1934), who carried out three sets of experiments in dogs
along the following lines: (a) double ovariecton^r with auto
transplantation of some of the ovarian tissue; (b) pan
hysterectomy with ovarian transplantation; and (c) ovarian
transplantation with hysterectomy and transplantation of some
of the uterine tissues. The tissues were removed at various
times in the different experiments and examined microscopi
cally. The times were eighteen days, one month, three months,
four months, and in some cases later. It was found that only
the ovarian transplants in the hysterectomized animals with
out uterine transplants (b) showed the follicular atresia and
the increase of interstitial tissue characteristic of hyster
ectomy of long standing. In (c) the transplants of uterine
37
tissue prevented the appearance of such changes and main
tained the ovarian structure essentially like that of (a),
which merely had ovarian transplants.
Similar results were claimed by Watrin and Brabant
(1932), who used rabbits in their experiments. Cheval also
advanced the view that the viability of ovarian grafts is
enhanced by hormones of the uterine mucosa.
Two important facts were established by these experi
ments. First, the action of the uterus on the ovary is
blood-borne, and second, the ovarian changes in the hyster
ectomized animals occurred in transplanted tissues, where
trauma to the original blood vessels and nerves could not
possibly be a disturbing factor. Moreover, the work of
others (Zimmerman, Papernoff, Seesums, etc.) showed that the
ovary in situ may be protected from the effects of hysterec
tomy by uterine transplants. In all three of the experiments,
the endometrium was sufficient to prevent the ovarian changes.
Although all the above facts point to the likelihood
of the endometrium being the source of estrogenic substance
in women castrated during pregnancy, there is still a consid
erable body of opinion which Holds that the placenta should
best be regarded as this extra-ovarian source. They base
their contention on the followii^ facts:
(a) The high yield of estrin in the placenta of
various animals. Corner (1928) has given a number
of examples of this. The human placenta contained
38
from 400 to 700 rat units of estrogenic substance,
that of the chimpanzee about 200 rat units, The
mare placenta also gave a positive result.
(b) The higher estrogenic content of the blood
and urine during pregnancy. The theory as regards
this is that, since the placenta is an organ of
pregnancy, it is logical to suppose that any changes
occurring during pregnancy are due to the placenta
rather than, for example, to the endometrium, which
is always present.
In answer to (a), it can be shown that there are a
number of cases where placental assays revealed no estrogen
content. Allen (1927) reported that the placentae of pigs,
dogs, cats, and rats contained no active estrogenic substance
As regards (b), there is no reason to believe that
just because the placenta is an organ of pregnancy it neces
sarily follows that the changes occurring during pregnancy
are due to it. Although the endometrium is a permanent
structure, it, too, undergoes extensive changes preparatory
to the implantation of the embryo. Especially prominent
among these changes is the increase in the number of glands.
Thus it can also be reasoned that the increase in the endo
metrial glands brings about an increase in the amount of se
cretion, which would account for the greater estrogen output
during gestation.
There are other factors which tend to negate the
theory regarding the placenta as the extra-ovarian source of
estrogen.
Frank, Goldberg, and Salmon (1936) found that the
59
estrogenic factor continues to be excreted after surgical
removal of the ovaries, as well as after the physiological
menopause and functional destruction of the ovaries by
x-rays. As this excretion of estrogenic substance continued
in non-pregnant subjects, it wovHd further tend to eliminate
the placenta as the source.
Another factor which might throw some light on the
subject has been brought forth by Selye, Collip and Thomson
(1935). They observed that the epithelial cells found in the
uterine wall remained in a fully developed condition several
days after the placentae had been removed in rats. These
cells also seemed to be largely independent of the gonads,
since ovariectomy did not cause their immediate involution.
It was observed that they disappeared immediately after de
livery.
The best explanation for the presence of an estro
genic substance in the placenta seems to be that of Parkes
and Bellerby (1927), who advanced the idea that the estro
genic substance was merely stored there, in order to pre
vent it from reaching the fetus. In view of the fact that
large doses of estrin cause absorption of the fetus (Newton,
1935), the above idea seems still more logical, for it
doesnit seem plausible that the placenta would secrete some-.
thing inimical to itself.
CHAPTER V
SUMMARY
In this work, extracts of the endometrium were tested
for estrogenic activity. Sesame oil extracts of the endome
trium of a pregnant mare were injected into adult ovariecto-
mized and immature rats. The results obtained throughout the
entire series of injections were quite uniform, only slight
individual differences being manifested. It was found:
(1) That the endometrium used in this experiment
contained approximately 140 rat units of estrogen sub
stance.
(2) That this extract could induce estrus in the
ovariectomized rats, and bring about a premature open
ing of the vagina in the immature rats.
These results were further confirmed by histological examina
tion of the uteri and vaginae of both groups of rats. The
uteri of the ovariectomized mature rats were larger than
those of the controls, while the vaginal epithelium was much
better developed. The same differences were found in the
immature group.
Also, an attempt was made to correlate the experimental
findings of this work with other, related investigations, in
order to indicate the likelihood of the endometrium being
the extra-ovarian source of estrogenic : substance.
The above evidence indicates that the endometrium does
41
contain an estrogenic substance, and, moreover, the evidence
indicates that the endometrium is the source of that estrogen
ic substance.
BIBLIOGRAPHY
42
BIBLIOGRAPHY
Abel, G., 1898, ^^Dauerfolge der Zweifel’schen Myomectomie’ ^,
Archivs fur Gynokologie. 58:261.
Allan, H. and Dodds, E.G., 1935, "Hormones in the Urine
Following Oophorectomy During Pregnancy", Biochemical
Journal, 29:285.
Allen, E., 1922, "The Oestrous Cycle of the Mouse", American
Journal of Anatomy. 30:297.
1927, "Hormone Content of the Placenta of the
Chorionic Membranes", Proceedings of the Society for
Experimental Biology and Medicine. 24:608.
, Sex and Internal Secretions. Baltimore, Williams
and Wilkins Company, 1939 •
Allen, E. and Doisy, E.A., 1924, "The Induction of a Sexu
ally Mature Condition in Immature Females by the Injec
tion of the Ovarian Follicular Hormone", American
Journal of Physiology. 69:577.
Allen, E., Francis, B.F., Robertson, L.L., Colgage, G.E.,
and Johnston, C.G., 1924, "The Hormone of the Ovarian
Follicle; its Localization and Action in Test Animals,
and Additional Points Bearing Upon the Internal Secre
tion of the Ovary", American Journal of Anatomy. 34:133.
Allen, W.M., 1932, Physiology of the Corpus Luteum, VIII,
Interrelationships of Oestrin and the Corpus Luteum as
determined by their Effects on the Adult Rabbit. American
Journal of Physiology, 100:650.
Amati, G., 1928, "Placenta and Ovarialhormen", Zentralbildung
fur Gynakologie. 52:2639.
Asdell, S.A. and Seidenstein, H.R., 1935, "Theelin and Pro-,
jestin Injections on Uterus and Mammary Glands of Ovariec
tomized and Hypophysectomized Rabbits", iProdeedlngs of the
Society for Experimental Biology and Medicine, 32:391.
Blair-Bell, W., 1906, "Preliminary Note on a New Theory of
Female Genital Activity", Liverpool Medical Chirurgical
Journal. 26: 234.
45
Bond, G.J., 1906, "Some Points in Uterine and Ovarian
Physiology and Pathology in Rabbits", British Medical
Journal. 2:121.
Catchpole, H.R. and Cole, H.H., 1954, "The Distribution and
Source of Oestrin in the Pregnant Mare", Anatomical
Record. 59:335.
Chauveau, M., The Comparative Anatomy of Domesticated Animals.
D. Appleton & Company, New York, 1891.
Cheval, M., 1934, "Ovarian and Uterine Grafts", Proceedings of
the Royal Societ?/ of Medicine. : 27:1395.
1935, "L’Uterus Exerce-t-il une Action Lutein-
sante sur l’Ovaire?", Bulletin Académique Royale de
Belgique. 15:283.
Corner, G.W., 1938, "The Sites of Formation of Estrogenic
Substance in the Animal Body", Physiological Reviews.
18:154.
Deanesly, R., 1931, "The Effects of Oestrin on the Pseudo
Pregnant Mouse", American Journal of Physiology. 72:62.
Deanesley, R. and Parkes, A.S., 1933, "The Effect of Hyster
ectomy on the Estrous Cycle of the Ferret", American
Journal of Physiology. 78:80.
Durant, E.P., 1926, "The Effect, of Hysterectomy on the
Oestrous Cycle of the White Rat", American Journal of
Physiology. 76:234.
Frank, R.T., Kingery, H.M. and Gustavson, R.G., 1925, "The
Female Sex Hormone", J ournal of the American Medical
Association. 85:1558.
Frank, R.T., Goldberger, M.A. and Salmon, Y.J., 1936, "Estro
genic Substances in the Blood and Urine After Castration
and the Menopause", Proceedings of the Society for Experi
mental Biology and Medicine. 33:615.
Golding, G.T. and "Ramire, F.T., 1928, "Ovarian and Placental
Hormone Effects in Normal Immature Albino Rats",
Endocrinology. 12:804.
Graves, Vf.P., 1917, "Retention of Ovarian Tissue After Hyster
ectomy", Surgery. Gynecology and Obstetrics. 25:315.
44
Giildberg, E., 1956, "Die Produktionstatten der Sexualhor-
mone im Normalen Graviden Weiblichen Organismus in
Lichte der Hormonanalyse des Ovariopriven Graviden
Zustandes", Acta Qbstetrlca et Gynécologie Scandinavia.
15%345.
Halpern, S.R. and D’Amour, F.E., 1934, "Effect of Estrin
Upon Gonads, Mammary Glands and Hypophysis of the Rat",
Proceedings of the Society for Experimental Biology
and Medicine, 52:108.
Hart, G.H. and Cole, H.H., 1954, "Source of Estrin in the
Pregnant Mare", American Journal of Physiology, 109:320.
Hartman, C.G., 1925, "Hysterectomy and the Oestrus Cycle in
the Opossum, American Journal of Anatomy, 35:25.
1938, "Pregnancy in the Monkey Continues After Cas
tration’ ) Anatomical Record, 70:35.
Hawks, E.M., 1921, "The Ovary After Hysterectomy for Fibroids",
American Journal of Obstetrics and Gynecology, 1;959.
Hauterlus, H.O., 1936, "Reduction of Litter Size and Main
tenance of Pregnancy in the Oophorectomized Rat: Evi
dence Concerning the Endocrine Role of the Placenta",
American J ournal of Physiology, 114:399.
Hechter, 0., Fraenkel, M., Levi, M. and Soskin, S., 1940,
"Influence of the Uterus on the Corpus Luteum",
Endocrinology, 26:680.
Herrick, E.H., 1928, "The Duration of Pregnancy in Guinea
Pigs After Removal and also after Transplantation of
the Ovaries", Anatomical Record, 39;193.
Holzbach, E., 1906, "Ueber die Funktion der nach total
Extirpation des Uterus Zuruck Gelassenen Ovarien und
Ihre Beziehung zu den Postoperativen Erscheinungen",
Archivs fur Gynokologie, 99:231.
Kalint, L.C. and Doisy, E.A., 1928, "The Vaginal Smear
Method of Assay of the Ovarian Hormone", Endocrinology,
12:760.
Keitler, H., 1904, "Uber Anatomisehe und Funktionelle
Verhalten der Belassen Ovarien nach Extirpation des
Uterus", Monatschrift fur Geburtsh und Gynakologie,
20: 686.
45
Loeb, L., 1925, "The Effect of Extirpation of the Uterus on
the Life and Function of the Corpus Luteum in the Guinea
Pig", Proceedings of the Society for Experimental Biology
and Medicine, 20;441.
Loeb, L. and Kountz, W.B., 1928, "The Effect of Injection of
Follicular Extract on the Sex Organs in the Guinea Pig
and the Interaction between the Follicular Substance and
Substance Given off by the Corpus Luteum", American
Journal of Physiology, 84:283.
Loeb, L. and Smith, M.G., 1936, "The Effect of Hysterectomy
on the Duration of Life and Retrogression of the Corpora
Lutea and on Secondary Sex Organs in the Rabbit", American
Journal of Anatomy, 58:1.
Long, V.A. and Evans, H.M., 1922, "The Oestrous Cycle in the
Rat and Its Associated Phenomena", Memoirs of the Univer
sity of California, Volume 6.
Nev/ton, W.H., 1955, "Pseudo-parturition in the Mouse and the
Relation of the Placenta to Post-partum Oestrous",
American Journal of Physiology, 84:196.
Parfenoff, N., 1931, "Zur Frage uber die Wechselwirkung
Zwischen Uterus und Eierstoechen", Monatschrift fur Geburtsh
und Gynakologie, 88:423.
Parkes, A.S. and Bellerby, C.W., 1927, The Significance of
the Occurrence of Oestrin in the Placenta IV, Studies on
the Internal Secretion of the Ovary, American Journal of
Physiology, 62:385.
von Probstner, A., 1931, "Zur Frage der Innersekretorischen
Tatigkeit der Plazenta", Endokrinologie, 8:161.
Reynolds, S.R.M., Physiology of the Uterus', Paul B. Hoehner,
Inc., New York, 1939.
Robertson, D.C., Maddux, W.P., and Allen, E., 1930, "Ovarian
Hormone Effects in Ovariectomized Monkeys", Endocrinology,
14:77.
Robson, J.M., 1935, "The Action of Oestrin on the Uterus of
the Hypophysectomized and ofthe Pregnant Rabbit", Journal
of Physiology, 84:148.
1936, "The Action of Progesterone on the Uterus of the
Rabbit and Its Antagonism by Oestrone", Journal of
Physiology, 88:100.
46
Schuking, A., 1904, "Uber Innere Sekretion der Uterus-
chlelmheit und uber Bildung von Metrotoxin", Zentral
bildung fur Gynakologie, 28:455.
Selye, H., Collip, J.B., and Thomson D.L., 1935, "Endocrine
Interrelations During Pregnancy", Endocrinology, 19:159.
Sessums, J.V. and Murphy, D.P., 1933, "The Influence of the
Endometrium Upon the Rabbit Ovary After Hysterectomy",
Surgery, Gynecology and Obstetrics, 56:600.
Stockard, C.R. and Papanicolaou, G.N., 1917, "The Existence
of a Typical Oestrous Cycle in the Guinea Pig with a
Study of its Hystological and Physiological Changes",
American Journal of Anatomy, 22:225.
Szarka, A., 1930, "Hormonale Verhaltnisse der Schwanger-
schaft bei Fehlen der Eierstocke", Zentralbildung fur
Gynakologie, 54,2211.
Takakusu, S., 1924, "Untersuchengen uber die Gegenseitige
Be inf lus s ung des Ovar i urns und des Uterus", Archivs fur
Mikroskopishe Anatomie und Entwicklung, 102:1.
Unterberger, F., 1930, "Experimentalle Untersuchengen uber
die Tatigkeit der Eierstocke nach Uterus extirpât ion",
Zentralbildung fur Gynakologie; 54:655.
Vineburg, N.H., 1915, "What is the Fate of the Ovaries Left
in Situ After Hysterectomy?", Surgery, Gynecology and
Obstetrics, 21:559.
Waldstein, E., 1929, "Fruhkastration in der Schwangerschaft
Zur Genese der Ovarialhormons", Zentralbildung fur
Gynakologie, 53:1305.
Vv^atrin, M, and Brabant, H., 1932, "Les Repercussions de
1’Hysterectomie sur I’Histophysiologie Ovarienne",
Archives de Biologie, 43:153.
Westman, A., 1929, "Untersuchengen uber die Ovarialfumktion
nach Uterusextripation", Zentralbildung fur Gynakologie,
53:2578.
Zimmerman, R., 1928, "Hat der Uterus Innersekretorische
Bedeuting’ ) Archivs fur Gynokologie, 134:328.

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Creator Shomstein, Morton (author)

Core Title Some estrogenic effects of endometrial extract

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