Luteinizing. Hormone. Surge and Ovulation in the Female Camel. (Came/us dromedarius). M. MARIE1 and A. ANOUASSI. Department of Reproduction and A. I..
BIOLOGY
OF
REPRODUCTION
35,
792-798
(1986)
Mating-Induced Luteinizing in the Female Camel M. MARIE1
Hormone (Came/us and
A. ANOUASSI
Department of Reproduction II Institute of Agronomy and B.P. 6202 Rabat-Instituts,
Hassan
Surge and Ovulation dromedarius)
and
A. I. Medicine
Veterinary
Morocco
ABSTRACT Blood
samples
were
collected
mating
hormone matings, five
secretion occurred,
of progesterone). LH levels at the time the levels increased 1 h after mating A
decrease
in LH
was quantified followed by
from
Luteinizing observed
ng/ml).
(LH) were
after
was
observed
four
in plasma a release of
starting
ment with a coitus-induced mechanism of confirm and extend the observations reported
female
of mating and reached 6 h after
ovulation in the
one-humped
camels
by radioimmunoassay using LH, and three by an ovulation ranged from a maximum
mating
and
one-humped
camel
lasting
in the one-humped bactrian camel (Cam
belong
to
ovulators
servations formation females
of ovarian has been by observing
induced
function. established ovaries
been on
considered
the
basis
(Scaramuzzi cat (Johnson
after
mating ovulators
of
Animals
ob-
1980; Wildt et a!., 1980), and ferret (Carroll et a!., the
only
data
on
this
concern
the
9-12
h.
6 h. These
results
are in agree-
dromedarius).
AND
They
METHODS
Sampling
females
(5-8-yr-old)
and
one
vasec-
male
(8-yr-old) were used in this study. The was conducted from 24 January to 10 a period of sexual activity of the male as
indicated by palate evagination and copious secretions from poll glands. The male was housed apart from the females and introduced 1 h each day and observed. When
complete
mating
was restrainted, vein, and blood for 12 h. In two for 8 and 9.5
1973), et al.,
vole (Charlton et a!., 1975), 1985). In camelids, however,
topic
Blood
adult
tomized experiment February,
described the rabbit
et a!., 1972; Dufy-Barbe et a!., and Gay, 1978, 1981; Concannon
and
Four
Lack of corpus luteum either in nonpregnant obtained post-mortem
has been including
for
LH. Of the seven by a subsequent
to
(Shalash and Nawito, 1964; Musa, 1979), or in nonmated females monitored over a long period by rectal palpation (Nawito et a!., 1968; Musa and Abusineina, 1978) and by progesterone monitoring (Elias eta!., 1984). The pattern of luteinizing hormone (LH) secretion in other induced
for
camel (Camelus elus bactrianus).
MATERIAL
has
10 mm
0.7 to 3 ng/ml. When an LH response in 2-3 h (ranging from 2.9 to 19.1
INTRODUCTION The
every antibovine (indicated
collected samples
two-humped
and
camel, Camelus bactrianus (Xu et a!., 1985). The purpose of this paper is to describe the timecourse of LH secretion after mating in C. dromedarius to gain more precise information about the mechanism of ovulation in this species.
then
in were
was
performed,
a catheter was placed samples were collected animals, blood samples h, respectively. Blood
tubes containing refrigerated until
frozen
until
used
sodium plasma for
assay.
the
female
in the jugular every 10 mm were collected samples were citrate. The was separated After
blood
collection was completed, the mated female was isolated for 10 days before a new presentation to the male. During the experimental period, one blood sample was obtained each day from all females for progesterone assay to assess luteal activity. During the same period of the year (February), 6 females (of which 4 were used in the above experiment) not presented to the male were submitted to frequent
Accepted Received ‘Reprint
January July 9, requests.
29,
1986.
blood sampling trol observations
1985.
792
(8 samples/h for 4 h) to provide for LH fluctuations.
con-
LH TABLE
1. Conditions
Animal
of mating,
characteristics
Duration mating
Observation
of LH
release,
of
and
Beginning LH increase
SURGE
IN CAMEL
occurrence
of
793
of ovulation
End of increase
in four
LH
female
camels.
Beginning of LH decrease
End of LH decrease
Subsequent ovulation
yes no yes yes no no no
(mm) I 2 2 3 3 4 4
A B C D E F C
60 80 70 80 100
190 210 240 240 180
300 360 360 380 410
660 680 840 720 640
5
...
...
...
...
8
...
...
...
...
10 10 10 6
5
curve were 89.3% and 4.5%. Parallelism of the standard curve and serial dilutions of came! plasma is illustrated in Figure 1. Regression coefficients of the logit/log
Assays Camel
LH
was
assay procedure (Golter et a!.,
quantified
by
described for 1973). Nonspecific
total count, absolute relative binding for
binding extreme
the
heterologous
measuring binding
(est) (est)
bovine LH was 4.5% of
for BO was 3 8.4%, and points of the standard
(dose) linear relations spectively. Sensitivity (0.25
ng/ml
coefficients
of plasma). of
12.5
variation
25
were of the
-0.98 assay
The
intraassay
for
and was
-0.97, re25 pg/tube
and
a plasma
interassay
sample
50
100 I
p1
plasma
2
1’
0’ 0
-1’ 4J
0 -J
-2’
-3’ ng U----
0.05 FIG.
1. Binding
inhibition
-U--
-
0.1 of LH ovine
-
0.25 standard
(t=oLH
0.5 24)
and
of serial
-.
I
U
1
2.5
5
dilutions
of camel
plasma
(0).
0LH U
10
con-
794
MARIE
AND
ANOUASSI
A 21
II
2
i
t
3
I
s
$
I
is
ii
12
D 21
II
2
1
2
3
4
1
I
i
I
I
ii
il
12
LH
FIG.
2. Individual
taming (n=7)
13.1 and
observations
ng/ml
9.7%
Progesterone
of
of
LH
LH
evolution
were
after
SURGE
mating.
respectively
Vertical
7.1%
was
axis”LH
(ng/mI),
(mean: 180
(n=5). assayed
by the
method
described
795
IN CAMEL
horizontal
1 h to
were mm). from level.
240
18
axis”time
mi.
mm
(hours
after
Maxima!
after
mating
mating).
values (mean:
were
obtained
3 h 30
mm)
and
maintained for 110 to 230 mm (mean: 2 h 30 During this period, the mean LH values ranged 2.94 to 19.1 ng/m!, or 1.8 to 8.7 times the basal LH values began to decline 300 to 410 mm
for plasma by Marie et al. (1984); the only modification was the use of 2.5 ml of diethyl ether for plasma extraction. Sensitivity of the assay was 0.14 ng/ml. For plasma samples containing respectively 0.47 ng/ml and 3.20 ng/ml, coefficients of variation were 16.0% and 4.0%, respectively, for intraassay, and
after mating (mean: 6 h) and returned to baseline levels 5 h 45 mm later. The decrease of LII in terms of logarithm of the values was in linear relation with
14.4%
time,
and
5.0%
for
interassay.
and
its rate
was
less
than
that
of the
postmating
increase. RESU
Data
are
summarized
time courses of LH in Figure 2. Matings
LTS
in secretion lasted
Table
significantly
cases
(A to between
E), 60
the and
in
individual
patterns are represented from 5 to 10 mm, and
a!! cases, intromission was servations, LII levels remained after mating. This corresponds from 0.68 to 2.95 ng/ml. In five
1 and
in
completed. For all obquite stable at least 1 h to basal levels ranging basal 100
LH mm
level after
increased mating
Control Figure
periodic period; tically ng/ml, 2.
data from 3. These elevations each peak
of LH, is followed
constant, basal which is similar
Moreover,
observed demonstrates patterns
nonmated patterns
LII during that
A to
generally 4 by a return
in the 4-h to a prac-
level, ranging from 0.7 to 2 to patterns F and G in Figure
values the
females are presented are characterized by
are
consistent
first hour fluctuations
E in Figure
2 were
with
levels
after mating. This observed in the not
caused
by
stress
796
MARIE
due to an animal’s struggling sampling, nor from varmatmons in absence of matmng. In three
cases
(A, C, D),
by an ovulation, functional corpus (>0.8 mating of
the
LH
demonstrated luteum. High
ng/ml) were detected to 10 to 11 days after
6.1,
3.8
and
days after progesterone
2.4
ng/ml
mating, secretion
observations four other (