BIOLOGY

OF

12, 335-345

REPRODUCTION

Circulating

Levels

During

of Steroids

Pregnancy

Attention L.

(1975)

in the

to the

E. ATKINSON,2

Rescue

G.

University

Circulating

levels

those

of progesterone

of the nonpregnant

chorionic

gonadotropin

levels

(the

a peak

corpus

at

(RhCG)

Iuteum

about

throughout

RhCG

in early

secretion

(largely

early

and

fall

the

estradiol)

School

while

increase

in circulating

rise

concentration

again

only

levels

of estrogens

suggest

that

the order

10-I

I days

after

ovulation,

prior

to

progesterone

day

levels,

23

and

at the outset levels and

fall.

of

pregnancy

lastly,

estradiol

and

estrone

and

35

15261

at

estradiol

reach

a high

prior

to parturition.

of RhCG

secretion,

levels

which

and

rise

and

fall

placental

whose

this

plateau

at about levels

rise rapidly

in

RhCG

causes

a sharp

of pregnancy. is RhCG. secretion

time

with

estrogen

progesterone

23 of pregnancy

to

remains

fall in the face of waxing

on day

at

=

35,

and variable

by the placenta

ovariectomy

2 days)

time

day

Serum

rise in

in progesterone

before

of the continuation

progesterone,

significant

elevation (doubling

estrogens

Ovariectomy

the first

levels gestation

estrone.

are indistinguishable

rapidly

of

by

since

NEILL,4

monkey

an abrupt

rises

production

followed

J. D.

Pennsylvania

when

undetectable

no compromise

of hormone

SURVE,3

Pittsburgh,

rhesus peak,

with

on day

the day

on

as RhCG

data

Serum

Circulating

abruptly

to

a nadir

maxima

about

initiated

falls

of gestation.

H.

in Early

1974

the LH

then

These at

after

RhCG

reaching

A.

in the pregnant

12 days

Serum

to

rising

estrogen

pregnancy, rest

Special

Luteum

of Medicine, 3,

concomitant

supervenes.

and

pregnancy,

titers

of

FRITZ,

is noted

pregnancy,

80 of pregnancy

day

23

Corpus

October

until

levels

rescue).

day

undetectable titers

and

animal

With

KNOBIL

of Pittsburgh Accepted

from

R.

E.

Gonadotropin

Monkey,

of the Pregnancy’

J. HOTCHKISS,

of Physiology,

Chorionic

Rhesus

AND Department

and

first by

causes

no

fall

in peripheral

discernable

the

placenta

is

in circulating

serum

after

day 35

of pregnancy. These

data

corpus

luteum

failure

of

support

the

in early

pregnancy

Iuteal

expression

hypothesis

progesterone

of

the

that

secretion

luteolytic

the

is caused

effect

to

of the

shortlived

stimulation

by the initiation be

maintained

increased

of progesterone

of placental in

luteal

the

face

RhCG

of

estrogen

secretion

secretion

rising

RhCG

titers

also

stimulated

production

by the

and

that

may

the

be an by this

gonadotropin.

Astute

observation

skin coloration, ogy in pregnant

of the similarities

endometrial monkeys,

of sex

monkeys

and luteal histoland in nonpregnant

pose be

‘Some form

(Proc.

5, 95,

this

2

and

from

York.

Ford

Division, New

Hanover. Present Department

by

from

The

8,246. HD

USPHS.

03969, and

Population

by

Sandoz

Pharmaceutical

address: of

Division

Physiology,

of Emory

Basic

Health

University,

which sence

Sciences.

335 All

rights

©

1975

by The

of reproduction

Society

for

in any

form

Study

of Reproduction.

reserved.

aegis

of

by the

maintain

monkey

of the corpus

pregnancy gland

can The

with

the

menstrual cycle, period is charac-

chorionic newly

goto pro-

periods.

is identical

The remainder by the secretions

of the pituitary

the ovary and Corner,

Atlanta,

30322

Copyright

by a renaissance the

Co..

07936.

period

under

secreted

(1944)

distinct

phase of the nonfertile the second gestational

trophoblast. dominated

chorionic

Hisaw

in the rhesus three

gestational

New

10021.

gestation into

human

led

terized (CG)

Bio-

Council.

University.

that

luteal while

Reproduction

grants

NIH.

Rockefeller

address: N.J.

Biol.

Reproduction

with

(hCG),

divided

first

in abstract

Foundation.

The

York

presented

1970: (Biol.

supported

00298

address:

Present

Ga.

RR

the

been

Society,

was

and

Present

medical

have

in a review

work

05654

a grant

data

Endocrine

1971)

1973); AM

of these

treated

nadotropin

luteum

gonadotropin formed

syncytial

of gestation is of the placenta in

both

(Smith,

the

ab-

1954)

and

(Hartman, 1939, 1941; Hartman 1947; Tullner and Hertz, 1966a).

336

ATKINSON

This study was detail the hormonal time

initiated events

of implantation

the “rescue” distinguishes tile

first which

with

special

of the corpus the fertile cycle

cycle,

and

in circulating

estradiol

throughout

attention

to

luteum, which from the nonfer-

secondly,

changes

to define in occur at the

to

describe

levels

AL.

chromatographic data

and

in the rhesus

monkey.

purification

are expressed by

estradiol

levels

method

utilizing

the

chromatographic

separation

residue

ether

LH-20

Animals The

general

menstrual tion

cycle,

of

serum

monkeys from

day

samples

have

from

expected

8 of these

parturition

Daily

blood

pregnant

animal

ovariectomy

on

separated

and

The

day

serum

to

day

23

of

other

blood

samples

and

was

the

resumed.

were

estimated

(Johansson

subsequent

in the 4-9

ml fraction, able

the

et al.,

in

1968) of

The

LH

peak

which

was

designated

pregnancy.

of

the

The

time

of ovulation

in this

from

hours

13-37

so that

after

the actual

pregnancy

day

by our

the

(392-5

peak.

The

that sample

by

of rhesus

aborted

delivered

varies

etal.,

1973)

(Weick falls

on day

term,

1 or 2 of

6 delivered

normal

days

the

2 (SE)

±

in this group

Van

after

agrees

Wagenen

(1972)

One

of the remaining

monkeys.

a macerated

other

to

at 167

of gestation

published

peak

of conception

followed

18 gm)

time

LH

0 of

species

designation.

Of the 8 animals young

the

as day

fetus

on

a nonviable

day

well

for

LH

animals

infant

on

the 139

day

of pregnancy.

100

Assays

Mass.)

initially

measured

by

method

described

by

authentic tion

This

of the

say method in which pl serum

the

progesterone

matography.

highly

the dry was

et

was

isolated

method

was

residue

assayed

of diethyl for

progesterone

in

out

The

mean

were

blank

for 200 M1 water

mized

monkeys

(±0.4,

n

munoassay, 53)

ies

in

with

both

the

same

of

Corp.,

estrone

Boston,

and

of

the

estradiol

assays

was et a!,,

(Hotchkiss

as

45.0-49.6

or

from

5) and

=

the

estrone

2.9

pg

radioim-

6) and 2.5 pg (±0.3,

=

added

to

n

The

recover-

serum

ranged

corrected

for

procedural

losses

recovery

of

“C-estrone

and

the extraction and purificadata, corrected for blank

values

are expressed

and

procedural

or estradiol/mI C.

losses,

Biological

assay

gonadotropin prepared

by

purification

from

urine

side

of of

biologic

el a!. (1971) in rabbits

(LER

pregnant (RhCG-LA-I’)

I056-C2) monkeys

by the 1961)

and

was

to

40.6

IU

method

uses ovine

as a trace. and

exhibited

our

an antiserum

in

RhCG inhibition

the

by

Nis-

(GDN-I5)

iodinated

Dilutions

standard parallel

RhLH.

well

described and

(1964).

and

extremely

LI-I

ovarian

of Finney

RhCG

react

which

1969)

(RhCG-

activity

system

against

Tullner,

(Parlow,

for cross

was during

standard

equivalent

by the

Radioimmunoassays

raised LH

CG

activity

as calculated

wender

and This

method

chorionic standard

accumulated

(Peckham

for

depletion

monkey RhCG

monkeys.

bioassayed

have

rhesus crude fractions

RhCG

pregnant

acid

hCG/mg

A

pooling

was to

for

(RhCG).

the

as pg estrone

serum.

radioimmunoassay

of 20-50

observaovariecto-

‘4C-estradiol carried through tion procedures. The final

RhLH

(1972)

n

estradiol

the

chro-

by a modifica-

n

in

of

from

radioimmunoassay.

pg when

determined

number

pg (±0.9.

2.3 pg (±0.6,

estradiol

layer

radioimmunoas-

(±SE,

3.9

50 pg estrone

of

from

and

in the

by thin

without

the

respectively

preparations

content

pg)

(estradiol-2,4,6.7-3H,

200 zl serum

and

were 46),

=

D.

extracts

react

described

values

tions)

RhCG

Stone

under

(5-200

use

remainder

previously

in dispos-

in similar tubes been evaporated.

Nuclear

both

The

as

which

and ether

used

the

in the 9-18

estrone

cross

trace

England

to being from

to dryness

the

steroid

New

binding

replaced

by Thorneycroft

tritiated

be

to

to been

(heptane:

prior

collected

for

permitted

had

estradiol

were

antibody

in

protein

a!.

progesterone

levels

the

serum

which

evaporated curves

the

zl

is eluted

and

eluates and

estradiol

(1967a)

competitive

Neill

specific

described

progesterone

of

to

found Serum

Standard

and

LA-I’)

Progesterone.

of air.

Cl/mM,

ascorbic

A.

tubes

and

antibody

with

a larger

125 of pregnancy;

premature

column

applying

mixture

Estrone

ml fraction,

The

ability

estrone

=

day

x 6 cm) solvent

buret.

this

1971).

fall

determination

ml

culture

glass

of

for

brief,

100-200

and estradiol (5-100 pg) were prepared which the eluting solvent had previously

were

performed.

by

column

of

eluting

radioimmunoassays.

bilateral sera

into

carried

Out on all samples.

concentration by

to

additional

The

assays

for were

was after

pregnancy. the

day prior

one

37 days

for

of

ovulation

confirmed

from

of

daily

weeks

sampling

taken

carried

11-14

taken

and every 2-4

consists (0.9

of this

In

500:500:75:3)

a 25

poured

a stream

rhesus

on days were

until

the

previously

cycle

daily

until

were

progestin

and

prior

prepara-

weekly

were

frozen

all assays

bred

animals

when

samples

and cycling

samples

Twice

of

described

normally

were

Blood

days.

dating

technique, been

mulatta)

of the fertile

30

monkeys,

Twenty

cycle.

7-30

obtained

Not

sampling

(Macaca

next

rhesus

1968).

menstrual

the

of

blood

eta!.,

(Johansson

the

care

the

deand

chromatography

estrogens.

extracts

columns

with

method

estrone

by a modification

two

The

concentrations

Serum

LH-20

these

of diethyl

estrogen

determined

Sephadex of

1973).

serum.

(1971).

chloroform:methanol:water,

METHODS

et a!..

radioimmunoassay

et a!.

were

isolation

equilibrated

AND

total

the

Hotchkiss

Sephadex

MATERIALS

Serum

measured

by

(Karsch

as ng progesterone/mI

B. Estrogens. were

scribed

the

of estrone

pregnancy

ET

of

ovine

sera

from

preparation curves

in

STEROIDS

this

radioimmunoassay

tency

of

rhesus

system

circulating

RhCG

monkeys

potency

averaged

in terms

RhCG

radioimmunoassay employs

sensitivity

of

Because

we reasoned

RhLH

and

each

serum

ability

of these

systems.

increase the

in

assay

concomittant panel).

activity

in

Patterns

nant and significantly the LH terone

levels

increased. serum lived,

by

peak

serum panel).

41

4.

The

Os

a clear

ID

0-I

0

00

000

in

without

FIG.

a

3, lower

2.

Dose-response

the GP-RhLH I for

34) provoked

curves

radioimmunoassay.

additional

of RhLH See

and

RhCG

Legend

to

in

Figure

details.

radioimmunologic system.

_1-

#341

Pregnancy

levels

in

when

preg-

animals

abruptly surge

concentration, al.

et

in

(1969),

was

CD C-,

previously

at 20 days

rising

10

proges-

gestational

to a nadir

before

when 4, lower

monkeys were not until the 12th day after

first

Neill

indisgesta-

by both

(Fig.

Early

in the pregnant

falling

in a 3.

panel)

4, top panel),

progesterone

described LH

During

This

progesterone rose (Fig.

100

progesterone

(Fig.

also

were first

01

observed

(day

in

levels

of the

of

LTS

nonpregnant different

peak

was

radioimmunoassay

RESU

serum

Figure

activity

elevation

rise in serum

day

discriminating

of the cycle,

activity

the

0

assaying

detected

3. upper

RhLH

in the GP-RhLH

Mean

12 was activity

RhCG

in

procedures

21-23

(Fig.

discernable

Hormonal

The

until

in pregnant

likewise

to

levels by

concentrations animals

pigs

systems

in

on day days

of

guinea differences

in circulating

illustrated

system

levels

a scarcely

in large

systems.

peak

change

Peak

estrogen

raised

radioimmunologic

RhCG

tional

be differentiated

is

Between

tinguishable

(1970)

radioimmunoassay

RhLH

preovulatory

assay

two

bio-

estrogen

nonpregnant

RhLH

of the

both

setting

of their

and

et a!.

changes

in

pregnant

in the

that

sample

Serum

immunopofive

337

PREGNANCY

poorly

radioimmunoassay

could

RHESUS

Monroe

two

RhCG

physiological

by

antiserum

RhCG.

The

SE)

reacts

2).

these

from

IN

equivalents.

cross

an Fig.

I).

sera (±8%,

described

(GP-RhLH,

(Fig.

76%

of hCG

In contrast. which

in

CG

AND

short-

after

the

1.0

again.

00 0

ni

0

60

4#{176} 4.

20

50 40 0.1

0

0

,‘

FIG. pooled monkey

RhCG IU

I.

Dose-response

serum

hCG/mg.

a relative assay. hormone

1:100)

the GDN-15

in

The potency

Counts =

has

from

and

of

x

absence

in the

I0

The of

0

40.6

(WDP-X-47-BC)

NIH-LH-5I in the

potency

-J

20

rhesus

radioimmunoassay.

standard

1.9

RhCG.

a pregnant

a biologic

RhLH

precipitated 100%.

30 of RhLH,

RhCG

(LA-I’)

000

0,,ssI

curves

(diluted

standard

00

10

has

20

OAAD

of unlabelled

FIG. from

3. Serum

days

7-60

RhLH of a fertile

30 40 DAYS and cycle.

RhCG See text

50 concentrations for

details.

60

338

ATKINSON

ET

AL.

secretion.

Estrone

tially

and

rose

pattern

as

fashion,

achieving

at two (Table edly

and fell

RhCG,

at 25 days

The

but

in

RhLH 7-60

the corpus

FIG.

4.

Mean

centrations

5 0 15 20 25 30 35 404550 DAYS FROM LH PEAK serum progesterone and estrogen con-

(±SE)

in the rhesus depicted. keys

0

of serum

and RhCG of the fertile

concentrations cycle of four

animals

are depicted

during

monkey.

Progesterone

and estrogen

shown ized

for

data

at day

from

from

6 nonpregnant

day

of the corpus

In

contrast

LH

after

and

25 nonpregnant The

of

the

radioim-

employed.

is

100

mon-

monkeys data

levels

early period of attesting to the

cycle

monkeys

are

are

normal-

peak

(day

0). The

vertical

line

LH

peak

indicates

the

mean

the

luteum

nonfertile

17 pregnant

purposes.

of the II

fertile

from

data

comparative

to the day

drawn

the

Data

pro-

in Figure

RhLH

abilities

munoassays

rescue

relationships

immunoreactive

discriminatory -5

luteum

to fall.

did not change during the rapidly rising RhCG titers, ‘0

modest only

6.

that

a more

rescue mark-

representative Note

ini-

temporal

the corpus luteum levels rose again

continued

temporal

levels

same

significance

after

titers

gesterone, from day

the

statistical

days after I). Estradiol

as RhCG

estradiol

with

E 0’

rescue. 0.)

gen levels

to progesterone, were

maintained

nancy. During progesterone, reaching

during

early

corpus after

are

the

LH

gestational progesterone cantly

rescue peak),

rise

corpus luteum continued to about

two

to (11

the

the day

on

in serum monkey.

0

the

day

for two

throughout

the remainder

not shown).

As observed

gestational

surge

during

the days

the

Li IU, Li 5

0

a-

RhCG and were signififollowing

weeks,

before

the

300 250 200

,

a.

150 100 50

two serum (data

4, the early

of maximal

35

falling

of pregnancy in Figure

of progesterone period

z

to the first

to undetectable levels in an additional weeks. No RhCG was detectable in

tained

of

(SE)

prior

C

rescue (Table 1). RhCG levels rise, with a doubling time of

days,

0’ Li

day

0.3

±

of progesterone. concentrations

elevated

E

estrone,

the progesterone,

normalized

luteum

in fell,

at day 34 of pregnancy.

5 depicts

data

pregrise

estradiol and RhCG concentrations during early pregnancy in the rhesus The

estro-

the second gestational estrogen concentrations

a minimum

Figure

however,

is not

sus-

RhCG

-5 DAYS FIG.

5.

estradiol

5

10

FROM Mean

serum

monkeys.

corpus

luteum

15

20

CORPUS

concentrations

20 rhesus of the

0

CG, (±SE)

The

data

rescue.

25 LUTEUM

progesterone. during are

early

normalized

See text

for

30

35

40

RESCUE estrone pregnancy

and in

to the day discussion.

STEROIDS

CG

AND

IN

RHESUS

TABLE CIRCULATING

HORMONE

LEVELS

AROUNO

TIME

TI-IF

339

PREGNANCY

I OF

LUTEUM

CORPUS

RESCUE

0)

(DAY

IN

THE

RHESUS

MONKEY

Day

Progesterone.

zg/ml

ng/ml

Estradiol,

pg/mI

Estrone,

pg/mI

I

0.284

±

0.023(19)0

4.65

±

0.86(16)

59

±

8(9)

49

±

9(6)

0

0.272

±

0.025(19)

2.50

±

0.43(l6)

63

±

11(9)

52

±

13(6)

+1

0.380

±

0.024(19)r

8.37

±

l.06(l6y’

76

±

15(9)

87

±

18(6)

+2

0.661

±

0.047(19)”

8.43

±

0.79(16)

97

±

11(1 l)

131

±

24(7

-

0

RhCG.

(number

of animals).

OSignificantly

Mean

SE,

different

from

the

preceding

day.

p