Response of lutropin (LH) and follitropin (FSH) to the administration of gonadoliberin (GnRH) in pregnant and post-partum cattle including experiments with prolactin suppression

THERIOGENOLOGY OF LUTROPIN

~SP~NSE

ADMINISTRATION POST-PARTUM

(LH) AND

FOLLITROPIN

OF GONADOLIBERIN

CATTLE

INCLUDING

TO THE

(FSH)

(GnRH) IN PREGNANT

EXPERIMENTS

AND

WITH PROLACTIN

SUPPRESSION

E. SCHALLENBERGER, Institut

D. SCHAMS

fiir Physiologie

und Forschungsanstalt Technischen 8050 Freising

and K. ZOTTMEIER

der Siidd. Versuchs-

fiir Milchwirtschaft

Universitat

- Weihenstephan,

Received for Publication:

der

Miinchen Germany

March 3, 1978

ABSTRACT

GnRH

(250 )Ig) was administered

total of 121 experiments the period

from

180 days ante

turn (pp). Additionally secretion

under

after parturition

injections

in a

(ap) to 50 days post parprolactin

by means

of 150 mg Bromocryptine

1, 4 and 7 pp. LH response

the dose response

intravenously

out on 21 cows during

in one group of animals

was inhibited

intramuscular on days

carried

(peak height,

curve) was about

of 3

(CB-154) area

the same from

ACKNOWLEDGMENTS We are grateful to the following for generous gifts: Farbwerke Hoe&St, Frankfurt/Main,GFR (GnEU-I); Sandoz Ltd., Basle, Switzerland (CB-154);National Institutesof Health, Bethesda, USA (NIH-PB3, NIH-FSH-B,);Dr. H. Papkoff, San Francisco, USA (bovineLH III17-BP). This project was supported by the Deutsche Forschungsgemeinschaft.

JULY

1978 VOL. 10 NO. 1

35

THERIOGENOLOGY 150

to 60

days ap, then decreased

parturition partum.

significantly

and was lowest during

At a later time the LH response

than during pregnancy. cantly during

nificant

influence

values

was more pronounced

The FSH response

decreased

the last 9 days ap, remained

first 6 days pp and increased

thereafter.

of prolactin

in all GnRH treated

gonadotropin the period response

responsiveness

animals

pp was much higher

some indication this hormone

on LH and FSH

on day- 50 pp).

pronounced

for the individuality cycle post partum

pituitary

(except during

the variation

of the LH

than ap. The LH results

of the wide range of response

after parturition

the

There was no sig-

was measurable

around parturition),

siqnifi-

low during

inhibition

(except for the total FSH released

Whereas

towards

the first 6 days post

gave

pattern

for

which might be one reason

in the initiation

of a new estrous

in cattle.

INTRODUCTION

In contrast

to the exact timing of hormonal

tion occurring during post-partum variation.

period

or a decreased

responsiveness

of the pituitary

that enhanced

prolactin we

(2,

inhibition post partum

3)

of CB-154

be due to a lower and/

data on this in cattle, changes

in the

to GnRH injections

of pregnancy,

dur-

around parturition

and

Since it is known

suppress

also investigated

by means

to considerable

possible

to respond

levels

the

of the hypothalamo-hypo-

the first 50 days post partum.

in men

requla-

events during

in the pituitary

system. As there is limited

ing the last trimester during

might

of gonadotropins

(I) we have tried to demonstrate ability

cycle,

in cattle are subject

This high variability

rate of synthesis

physeal

the estrous

gonadotropin

values

the effect of prolactin

administration

immediately

to see if there was any improvement

in LH and

FSH responsiveness.

36

JULY

1978 VOL. 10 NO. 1

THERIOGENOLOGY MATERIALS AND METHODS Preparation and administration of GnRH: The synthetGnRH decapeptide preparation LRH-Hoe 471 (Geiger et iC al. (4)) was dissolved and diluted with saline and administered intravenously in a constant concentration of 250 pg/ 4.0 ml final volume. Preparation and administration of Bromocryptine: The synthetic ergot alkaloid, 2-Br-a-ergocryptine-sulfonate, CB-154 (Sandoz, Basle) was dissolved in 40 % ethanol and administered intramuscularly in a concentration of 150 mg/ 4.0 ml final volume on days 1, 4 and 7 post partum. Experimental animals:

The experiments were carried

out with 29 female animals (aged 2.5 to 10 years) of the local Brown Swiss breed at our experimental station Veitshof. Experimental design:

Repeated injections of GnRH

were given to groups of 6 - 12 animals from 180 days ante to 50 days post partum in intervals as shown in Tables I and II. To exclude any seasonal effect, the animals were selected according to their time of parturition either from June to August or from November to January. Within this study 7 animals additionally received CB-154 injections im on days 1, 4 and 7 post partum. Blood sampling: Blood was collected from the jugular vein by means of indwelling catheters at 15 min intervals from 30 min before until 5 h after the administration of the releasing hormone. Serum samples were kept frozen at - 18O C until assayed. Hormone determination: The LH, FSH and prolactin concentrations were determined radioimmunologically (5, 6,

JULY

1978 VOL. 10 NO. 1

37

THERIOGENOLOGY 7). The reference pituitary

standard

preparation

for FSH was a crude bovine

NIH-FSH-Blhavinq

ty of 0.4 times the international NIH-FSH-S, BP having

and for LH bovine a biological

As reference

(biol. activity

reference

pituitary

activity

preparation

a biological

activi-

preparation

preparation

111-17-

of 0.9 times NIH-LH-S.,.

for bovine

prolactin

NIH-P-B3

24.1 IU/mq) was used.

RESULTS

The following

parameters

the LH and FSH response and post partum

after injection

between

and the area under the plotted tal hormone

parturition

and reach

could be measured

significantly

for to-

during

of LH peak value

pregnancy.

Similar

the following the curve

significantly

(p
concentrations

40 days. LH peak

(see Fig.

1) decrease

between

(~~0.05)

injection

10 days post

hormone

5 h but was reduced

The quotient pattern.

peak value

is

and is significantly

the whole of the post-partum

The shortest

ly after parturition.

and maximum

during pregnancy

(p < 0.05) during examined.

again

than during pregnancy.

and base level gave a similar

constant

of increased

constant highly

the last 9 days before

10 days pp higher values

during

to higher values

The interval

decrease

(~~0.05) from 150-150 days ap to 9 - 1 days

ap and increase

period

and peak,

I) are relatively

during

levels and the area under

reduced

(ap)

the resulting

injection

of pregnancy,

(pcO.005)

than ever observed

relatively

of GnRH ante

curve as indicator

(see Table

the last 4 months

significantly

partum

to characterize

response.

LH base levels during

choosen

(pp): peak and base values,

the time interval

quotient,

were

interval

As indicated concentration

was found immediate-

in Fig.

1 the duration

was on an average

around parturition.

about

The variability JULY

of

1978 VOL. 10 NO. 1

THERIOGENOLOGY the measured standard

LH-concentrations

deviations)

was much higher indicates

during

(as expressed

the whole

than ever evaluated

a range of relatively

in the

post-partum

period

ante partum.

This

low to very high response

patterns.

There was a reduction

of the FSH base concentration

from 60 days ap until parturition to the levels peak values

in the periods

decreased

last 9 days before that. The maximum

before

parturition

Fig.

2). The quotient

than during

injection

and peak value was about

(see also

of the interval

slight-

25 minutes

between shorter

post

showed no

10 days ap, then values

diminished

On day 10 pp there was an obvious

(p(O.05).

(p(O.05)

period

around par-

Total FSH response

change until

significantly rise

duration

than ante partum.

significant

pregnancy

and reduced

The average

the

again after

peak to base level increased

the end of gestation

FSH

during

in the post-partum

turition.

partum

(~(0.05)

and increased

concentrations

lower on the average

II) compared

and thereafter.

significantly

were

ly towards

(see Table

and a further

tendency

to increase

on days

30 and 50 pp.

In the group of animals partum

prolactin

depressed

on day

ter as indicated reached

control

the same level.

values

were

with CB-154 significantly

10 pp both during in Table values

were not significantly of reduction

area under JULY

compared

3). FSH peak values

are quite

win-

the FSH curve

cows, LH base and total hormone

altered,

but there was a

to controls

(see Table

and base concentrations

diminished

comparable

1978 VOL. 10 NO. 1

treated

LH peak values

tendency

quotients

and during

concentrations

on day 20 pp and remain at about

response

were not significantly

post

(pCO.0005)

summer

III. Prolactin

In these CB-154

levels were unaffected.

‘IV and Fig.

treatment

and the resulting

to control

is slightly

animals.

smaller

during

The the 39

experiments

with CB-154

treatment

50 pp there is a significant released

post partum.

(~(0.05)

Only on day

reduction

FSH; at the same time FSH base values

of total

increase.

DISCUSSION

The present responsiveness

The response

as there were

pituitary

secretion

comparable

formed during winter in cows, Jenkin

demonstrated

post partum.

Contrary

to conditions

measured

in this study beginning LH response

cycle in cattle

was observed increased

post partum

in dairy cows differ cows in which

could be near term and

there was some

patterns

with day

during

10 pp quite

as reported

report

for the estrous

(11). LH base levels

earlier

(12; 13; 14).

the early post-partum

from those in post-partum

duced up to 20 days pp

was

in ewes and also in women we

as described

pituitary

O-5 con-

(IO) a minor LH responsiveness

in an earlier

our LH results

reduction

with advancing

late gestation,

reported

40

a progressive

6 weeks after delivery

(9). In women

per-

to our observations

sensitivity

increase

increase

Similar

responsiveness

in sheep during

3 weeks post partum;

However

can be excluded

Flirtheron little or no LH response

tinuously.

influence

in the experiments

(8) described

days pp and after that period,

comparable

from 9 days be-

after GnRH treatment

in ewes. Lowest

in the

to GnRH ante

A seasonal

pattern

results

and summer.

et al.

in the LH response

variations

was lowest

6 days after parturition.

on this gonadotropin

gestation

demonstrate

of the maternal

and post partum. fore until

experiments

LH responsiveness

period

suckled

to GnRH was re-

(1).

JULY

1978VOL. 10 NO. 1

THERIOGENOLOGY We conclude responsiveness

from our experiments

to GnRH pp seem to be not the main

for the variabilities cycles

commencing

variability nection

estrous

between

given during

cycle

may be partly

day 9 and 50 pp. So far injections

different

compared

Pituitary

stages of the estrous earlier

measured

in peripheral

increase

of pituitary

lar amounts

blood

significant

LH content

in peripheral

(15) estimated

change

in sheep

partum.

In women

gestation

plasma)

pituitary

FSH content

up to

the content

decreased.

FSH response

to GnRH was de-

by peripheral

GnRH until

constant

until

conditions

were

turn,,the FSH basal

levels

to our earlier

estrous

cycles

JULY

found during increased during

IO days ap. This means

depleted

day 10 ap. Beginning

parable

FSH levels

and 3 - 6 weeks post

but 8 - IO days pp the response

was neither

(based

on sheep and cows.

19). In our dairy cows, the FSH response was almost

(16). The

showed very simi-

reports

of pregnancy

similar

preg-

in ewes that there was no

(17) as assessed

in the last trimester

during

post partum

and thereafter

A very low pituitary tected

of LH

curve in our study

in mean pituitary

135 days of gestation

amounts

(8; 15). In cows there is an

as in the mentioned

Charnley et al.

smaller

to the total LH concentration

the LH dose response

on measurements

It

17 - 18 of the cycle.

in sheep decreases

related

were

cycle.

(11) that during mid-

to days

LH content

and is closely

area under

in con-

in the cows could be

(day 11 - 12) significantly

nancy

The high

of the onset of cyclicity.

symptoms

could be shown already

are released

reason

of new estrous

IO days after parturition.

the variability

First visible observed

in the initiation

in the responsiveness

with

that a decreased

(18,

pregnancy that the

of FSH nor refractory

to

with day IO post par-

and response

data obtained

to GnRH were com-

during

the normal

(11).

1978VOL.lONO.l

41

THERIOGENOLOGY The progressive

decrease

nancy might be explained tinuously

high progesterone

plasma placental pregnancy

estrogens

especially

This feedback

Separate

during

control mechanisms

pregnancy

indicates

and its reduction

fusions

seem

to exist for FSH

of the placental

stimulated.

patterns

period

estrogen

There was a marked

of estrogen, change during slightly

during

during

and after

after

in-

h in heifers,

LH and FSH could be

rise of the FSH values

decrease

at the higher

at

dose

LH levels did not

this time. LH base concentrations later

the

source. After

and after infusion.

10 - 12 hours

be

until day 6 post partum

between

the lower dose and a marked

in

might

a few days before

The low response

reaction

blood

FSH responsiveness

of 1.6 - 8.0 mg estradiol-17R/4

different

in the response

of estrogens

a short period of recovery

termination

LH responsiveness

in peripheral

feedback

for the increasing

parturition.

by daily administration

differences

for the gonadotropins

cattle. A dose related responsible

of

parturition.

(20).

and LH as there are distinct pattern

of con-

the last trimester

during the few days before

to sheep and diminished rate

during preg-

feedback

levels and the increasing

action was simulated

of progesterone and synthesis

in LH response

by the negative

(Schallenberger

rose

and Schams,

unpublished).

There were no indications lactin

significantly

in our experiments

influences

the pituitary

ness to GnRH. We do not see any importance cal significant treated

difference

and CB-154

of the importance function

period

responsive-

in the statisti-

of total released

FSH of un-

cows on day 50 pp. The question

of prolactin

post partum

the anestrous extended

treated

that pro-

remains.

for the recovery It was reported

in post-partum

when they are suckled.

lactating

Nilked

of ovarian (21) that

cows is

cows usually JULY

ovulate

1978 VOL. 10 NO. 1

THERIOCENOLOCY earlier partum

after calving prolactin

gonadotropin

cycle

levels

in women

concentrations

In these cases of CB-154

than suckled

is restored

(22). High post

are responsible

and amenorrhea

inhibition

increases

ones

of prolactin

for low

during

lactation.

secretion

by means

LH and FSH levels and the menstrual (23; 2).

REFERENCES

1.

Webb,

R., Lamming,

G.E., Haynes,

J.G. Response

Manns,

cows to injections -50: 203-210 2.

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luteinizing

(Kbh.) 2:

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on serum follicle hormone

25-33

E.S., Forsbach,

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Geiger,

R., Kbnig, F.

capeptide Biophys.

Schams, mung

stimulating in women

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Acta

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G., Soria,

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Enzmann,

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LH-RH.

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THERIOGENOLOGY 6.

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gonadotropin-releasing

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LH-RH and pituitary

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response

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the oestrous

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117: 75-79

JULY

(1973)

1978 VOL. 10 NO. I

THERIOGENOLOGY

ng LH

ngLH

1 ml serum

119-90 dayso

/ml

serum

ngLH

/ml

serum

P

~~L~i~

501 89-60 days a P

0

1

2

3

L

1 25Opg GnRHlv

Fig.

1.

LH

5

0 1

1234501

250,ugGnRH IV

response (mean +

2

3

t

SD)

after

c 5 hours

25Opg G>>Rti IV

injection of 250/1g GnRH iv

to female cattle durinq 8 consecutiveperiods ante m (180 - 1 days ap) and 5 periods postprtm(l0

- 50 days pp)

n:nmbe.rof~iments

JULY

1978VOL.lONO.l

47

THERIOGENOLOCY

ng FSHlml

600

serum

J

ng FSH/mt

MO-15Odays (I p in:6

serum

ng FSH I ml serum

59-30days

I

10th

a p

in=12)

day pp In.9 I

I

t------L------L-r----

2

3

L

5

3

0

L

5

t

0

hours 250&g

GnRH

iv

250/g

GnRH

i v

25O$g

GnRH

i v

Fig. 2. FSH response (mean+SD)after injectionof 25Opg GnRH iv to female cattleduring 8 omsecutivepericds antepartum (180-Idays ap) and 5 periods post partun (O-50 days pp). n: number of experiments

48

JULY

1978 VOL. lONO.

1

THERIOGENOLOGY

ng LH /ml

serum

ng FSH / ml serum

T

lo"'day pp In=71

40

10th day pp

400

30

300

200 100

I, 20th

, , , ,

(

daypp

3o’h daypp t n=7 I

30th

daypp

ln=71

pp I

sothdoy II-l-61

,

400

In=61

300

, , , ,

I,, 1 P 25Oyg

2

3

L

GnRH i v

0

1

2

3

t 250,ug GnRH i v

4 5 hours

Fig. 3. UI and FSH response (mean+SD)after injection of 25Opg GnRH iv to 03~s on days 10, 20, 30 and 50 post partum after treatment with a prolactin inhibitor (150 nq CI3-154 im) on days 1,4,and7pp. n:numkrofexperiments

JULY

1978 VOL. 10 NO. 1

49

50

JULY

1978 VOL. 10 NO. 1

c

113241

53+21

Areaunderthe 9 hmitd x 2 SD

2.3

3132152

135+71

6

l&-150

Interval injec&ion peak (nin) x+SD

QuotientpeW base level

FsHrmx.peak v;itue (fig/ml) x+SD

FSH baselevel (n&l) G+ SD

Nunberofexprimts (n)

Day

79+18

105+19

3.1

4201185

137+_87

6

119-90

partm

91239

115224

2.8

4362131

157290

6

89-60

83235

110+_17

3.5

403tl57

116272

12

59-30

1: statistical significant(pCO.05)

71231

109222

2.5

4672158

184+102 _

7

149-120

Iulte

snd the first 50 days post piirhr

8

9-l

x

I

43213

Y

lm_21

2.2

I

31510

82219

1.9

292248

againstpreviousvalue

77+49

114221

3.9

4122157 242+66

9

o-6

1156253

I

!

5&t24

%

91+30

2.2

3492159

1 16e61

9

10

I

1

46218

m-42

1.9

me147

16355

9

20

Post pax-turn

thelasttrimssterofpregnanCy

107256 1108234

8

29-10

TableII. FSH respmse afteriv injectionof250~GnRHdurbg

62222

81225

2.4

3192113

134274

7

30

96223

50

I

4

tinter

mmr

zasdn

X

2

2

30

50 44

38

42

42

80

170

110

110

2.9

6.8

2.7

0.3 x

17.3

21.5

15.2

1.0 x

2.5

3.2

1.2

0.1

16.4

15.6

8.7

0.6

statisticalsignificant (p <0.0X5) against amtmls

2

4

50

20

5

30

2

5

20

IO

5

nmber of aximls

10

day @St pzrtm

-_ Prolactinconcen_trations (ns/ml) n SD X --

CT3-154treatrwnt

T

3

3

4

5

3

3

4

4

nvmberof aniwals

60

54

77

96

66

66

88

80

4.2

4.8

3.1

3.6

22.7

19.4

15.8

23.4

Prolactin cmcentr. r: x

Controls

Table 111. Prolactin concentrationsin peripherab blood post partum after treatmnt with a prolactin inh%itor on days 1, 4 and 7 pp in cxm-parison to untreated contro:s

1.2

2.4

1.2

1.3

14.2

10.6

10.7

13.7

(n9A-U SD

I

ut w

5 L

z

7 F

10

1

23.2212.2

79228

interval injectionheak x + SD (min)

areaunder the c-qe (units) X 2 SD

11.8

14.127.2

1.25.2

quotient peak/ base level

pc+ value h-q/ml)x -+ SD

jmx.

base-level (ng/ Iml)x+SD

nuker of eXpri-7 mnts (n)

day post partum

30.1L22.1

81227

13.6

19.4216.0

1.45.7

7

20

L H.

26.2214.1,

66230

12.2

13.429.4

1.15.4

7

30 -

36.z17.2

88.246

14.6

19.e10.7

1.33.7

6

50

52.2228.7

105236

2.7

329+144

12 1240

7

4111~25.7

116239

2.1

2a_56

97240

7

20

FSH

46.1+19.0

99245

2.1

226242

1 le52

7

30

Table IV. LH andFSH response after ivinjectionof 25Opg GnRH during the post-partum period after treatmentwithaprolactin inhibitor on days 1, 4 and 7 pp

39.126.2

105L28

1.7

241+51

141249

6

50

A