Journal of Reproduction and Development, Vol. 50, No. 1, 2004

JSAR Outstanding Research Award

Studies on the Regulation of Expression of Luteinizing Hormone
Receptor in the Ovary and the Mechanism of Follicular Cyst
Formation in Ruminants
Noritoshi KAWATE1)
1)

Laboratory of Theriogenology, Graduate School of Agriculture and Biological Sciences,
Osaka Prefecture University, Sakai, Osaka 599–8531, Japan
Abstract. In the series of studies, changes of expression and regulation of luteinizing hormone (LH)receptor in the ovary of domestic ruminants were examined. Furthermore, mechanisms of formationof follicular cysts in domestic ruminants, caused by stress and so on, were endocrinologicallyelucidated. Results of the studies provide the following conclusions. (1) The quantity of LH receptor
in the bovine antral follicles increases rapidly in the latter stage of its development. (2) The quantity of
LH receptor and its mRNA in the bovine and caprine corpus luteum increase during theirdevelopments. The increase of the receptor in the caprine luteal development is regulated by LH
through the receptor mRNA level. (3) At least, three splice variants of LH receptor mRNA exist in thebovine luteal tissue and the variant receptors are expressed at different cellular sites according to its
structure. (4) Intracellular consecutive cysteine residues of LH receptor are palmitoylated and thereby
inhibit internalization of the receptor. (5) As a mechanism of the bovine follicular cyst caused bystress, it is suggested that increased secretions of progesterone and cortisol from the adrenal glandexert inhibitory effects on the hypothalamus and follicle, respectively, and subsequently LH and FSH
surges are blocked, then finally ovulation is suppressed and the follicle becomes cystic.
Key words: Luteinizing hormone (LH) receptor, Follicle, Corpus luteum, Follicular cyst, Domestic
ruminant(J. Reprod. Dev. 50: 1–8, 2004)

t has been suggested, in domestic ruminants,that luteinizing hormone (LH) has a pivotal
role in the regulation of ovarian functions [1–5].
The action of LH on the ovarian cell is mediatedthrough its specific receptor located on the plasma
membrane. Based upon the sequences of fulllength cDNA encoding the LH receptor [6–10], it
has been proposed that the LH receptor belongs toa family of guanine nucleotide-binding (G) proteincoupl ed re cep tors that con si st of a l ong
extracellular domain , se ven tra nsmembrane
helices, and a short intracellular carboxyl-terminal
domain. Upon binding to the LH receptor, theAccepted for publication: December 26, 2003
Correspondence: N. Kawate (e-mail: nkawate@vet.osakafu-u.ac.jp)

hormone stimulates adenylyl cyclase activity, cyclic
adenosine 3’, 5’-monophosphate production, andconsequently biological reactions such as
steroidogenesis is enhanced [11]. Thus, the quality
and quantity of LH receptor are important factors
affecting the sensitivity to its ligand.
Adenohypophyseal
andplace ntal
gonadotropins, which possess various degrees of
LH activity, and gonadotropin-releasing hormone(GnRH), which stimulates endogenous LH release,hav e been us ed a s drugs t o treat o varia ndysfunctions and control ovaries artificially incattle, sheep and goats [12–14]. Development andprevalence of estrus and ovulation synchronization
for the artificial insemination and embryo transfer

2

KAWATE

of cows increase the opportunity of using thehormonal drugs [15–17]. The efficaciousness of thetrea tment with G nRH a nd go nado tro pins
possessing LH activity depends partly on thequality and quantity of LH receptor in the ovary.
The present series of studies were carried out toexamine changes of expression and regulation of
LH receptor at the levels of protein and mRNA in
the ovary of domestic ruminants. Furthermore,mechanisms of formation of follicular cysts indomestic ruminants, caused by stress and so on,were elucidated endocrinologically, focusing on
hypothalamus-pituitary-ovarian axis.

Changes of Expression and Regulation of LH
Receptor in the Ovary of Domestic Ruminants
Changes of quantity of LH receptors in thedevelopment of antral follicles and in the cystic
follicles
In order to determine changes of quantity of LH
receptors during the bovine follicular development
and in the ovarian cysts, numbers of LH receptors
in granu losa cells and th eca i nterna andconcentrations of steroids in follicular fluid in
antral follicles at the developing stages and in cystic
follicles were examined [18, 19]. As a result, thenumbers (receptors/cell) of LH receptors in
granulosa cells and theca interna increased rapidly
in the latter stage of antral follicular development

Fig. 1.

concomitantly with augmentation of aromataseactivity [18]. The results also showed that the
number of LH receptor (receptors/cell) is reducedin follicular cysts as compared with that in the large
antral follicles [18]. Total number of LH receptor
per cyst in the theca interna of the luteinized cysts
was comparable to that of the large antral follicles,
while the total n umber was reduced for th efollicular cysts [19]. Thc changes of LH receptor
co nt e n t a n d es t ra dio l s e cre t io n du r ing t h edevelopment of the bovine antral follicle are shown
schematically in Fig. 1.
We also demonstrated that the injections of low
dose hCG after the treatment with an intravaginal
progesterone release device promote follicularmaturation and fertile estrus induction in the goats
during the early postpartum nursing period [20].
In this study, it is plausible that the treatment withlow dose hCG may also increase the LH receptor
content thus allowing the follicles to ovulate andluteinize in response to the LH surge induced by
the increment of estradiol-17β in the goat.

Changes of quantity of LH receptors in thedevelopment of corpus luteum and its regulation
The number of LH receptors in the bovine corpus
luteum during the estrous cycle increased in thecourse of development and maintained high during
the pregnancy [21]. Steady-state level of mRNA
encoding the LH receptor in the bovine corpus
luteu m al so i ncreased durin g the lu te al

Schematic diagram of changes of LH receptor content and estradiol-17β
secretion during the development of the bovine antral follicle and in thecystic follicle, and changes and regulation of LH receptor content during
the development of corpus luteum in cows and goats. LHR, LH receptor;
E2, estradiol-17β; P4, progesterone.

LH RECEPTOR IN RUMINANT OVARY

development [22]. The increments of LH receptor
and its mRNA in the luteal development during the
estrous cycle were also observed in the goat [23].
Such increments were partially inh ibited byadministration of GnRH antagonist, which potently
suppresses the pulsatile LH release in peripheral
blood [5], suggesting that LH up-regulates its
receptor protein through augmentation of theamount of its transcript (Fig. 1)[23].

Expression of splice variants for LH receptor mRNAand protein
The presence of multiple transcripts encoding
LH receptor in the corpus luteum was revealed by
Northern blot analyses for rats [24], pig [7], sheep[25], horse [26] and human [27]. Upon sequencingof the mRNAs, some of multiple forms encoding
the LH receptor were determined to be splicevariants [7, 25–28]. In the present study, wecharacterized splice variants for LH receptor
mRNA in the bovine corpus luteum and examinedt he lev els of th e v aria n ts du ring t h e lu te aldevelopment. The study showed that at least threesplicing variants of LH receptor mRNA including

Fig. 2.

3

F, B and G forms in addition to the full-length A
form exist in the bovine corpus luteum [22]. The F
form shows complete deletion of exon X and is
spliced from the 3’-end of exon IX to the 5’-end ofexon XI, in frame (Fig. 2). The B form is spliced
from the 3’-end of exon X into the coding region ofexon XI, and the splicing generates a frame shift
and a premature stop codon (Fig. 2). The G form is
spliced from the 3’-end of exon IX to the sameacceptor site as the B form in the coding region ofexon XI, and the splicing generates a frame shift
and a premature stop codon (Fig. 2). Thus, the Fform receptor has the complete transmembrane
and intracellular domains while the B and G form
receptors do not have the transmembrane andintracellular domains. Furthermore, all of theforms of LH rece ptor mRNA incre ased in acoordinated manner during the development ofbovine corpus luteum [22].
Complete cDNA sequences of the three splicevariants of bovine LH receptor were cloned in a
mammalian expression vector and transfected into
COS-7 cells [29, 30]. Scatchard analysis of the intact
cells transfected with the A or F form of bovine LH

Schematic diagram indicating numbers of amino acids of a full-length form (A form), andsplice variants (F, B and G forms) of bovine LH receptor. A and F forms consist of an
extracellular domain, a transmembrane domain and an intracellular domain. The
extracellular domain of F form is shorter by 27 amino acids than that of A form because theexon X is completely deleted and spliced from the 3’-end of exon IX to the 5’-end of exon XI,
in frame. B or G form is spliced from the 3’-end of exon X into the coding region of exon XI,
and the splicing generates a frame shift. The frame shift causes a unique 45-amino acidsequence (bar with oblique lines) and a premature stop codon (arrow). The extracellulardomain of G form is shorter by 27 amino acids than that of B form because of complete
deletion of exon X as observed in the F form.

4

KAWATE

Fig. 3.

Proposed diagram indicating palmitoylation of consecutive two cysteines justafter the seventh transmembrane domain of LH receptor. The sites ofpalmitoylation at Cys 621 and 622 residues of rat LH receptor are indicated. IVII, seven transmembrane domains.

receptor cDNA showed high affinity and low
capacity of [125I]-hCG binding sites on the cells. No
binding activities were observed in the intact cells
transfected with the B or G form of bovine LH
receptor cDNA. However, Scatchard analysis ofdetergent-solubilized cells transfected with A, F, B
or G form of bovine LH receptor cDNA showedbinding activity with similar affinity among theforms. These results suggest that the F form ofbovine LH receptor protein is expressed on the cellsurface in the same way as the full-length A form.
Besides, the data demonstrate that the B and G
f o r m s o f t h e re c e p t o r p r o t e i n a r e t r a p p e dintracellularly.

Palmitoylation of LH receptor and its role
It has been suggested that the LH receptor own
not only transducing function of the signal fromLH, but turning-off action of the agonist responsein the face of continuous agonist exposure, namely,
desensitiz atio n o f t he recept or [31 ]. The
desensitization consists of uncoupling of ther e c e p t o r f r o m it s c o g n a t e G p r o t e i n s a n dinternalization of the receptor-ligand complex. The
intracellular domain of the LH receptor is supposedt o b e r e s p o n s i b le f o r t h e u n c o u p l i n g a n dinternalization [31]. An intracellular cysteine
residue present in the juxtamembrane region of the
C- te rm inal ta il of ma ny G- p rot e in c ou p led

receptors including rhodopsin and β 2-adrenergic
receptor has been shown to be palmitoylated [32,33]. The LH receptor has two adjacent cysteines inthis position and these cysteines are conserved
among species [6–10, 29]. Thus, we examinedw h e th e r t h e t w o a d j a c e n t cy s t e in e s i n t h e
in tracellula r domain of th e LH receptor are
palmi toy lated and any function s of th epalmitoylation in regulation of the receptor [34, 35].
The results showed that both cysteine residues ofth e ra t LH re ce pt or (C y s 62 1 an d 6 2 2) wa s
palmitoylated creating a membrane-anchoring siteat the putative cytoplasmic domain (Fig. 3) [34].
This palmitic acid-mediated anchoring decreased
the ligand-induced receptor internalization thereby
prolonging the retention of the ligand-boundreceptor on the cell surface (Fig. 4) [34]. Besides, wedemonstrated that palmitoylation inhibited ligandinduced receptor down-regulation [35].

Mechanism of Follicular Cyst Formationin Ruminants
Follicular cysts are a serious cause of
reproductive failure in cattle because they occur
f re q u e n t ly a n d p r o lo n g t h e i n t e rv a ls f ro m
postpartum to first estrus and conception [36]. The
bovine follicular cysts have been reported sinceLH RECEPTOR IN RUMINANT OVARY

Fig. 4.

5

Schematic diagram of internalization of palmitoylation-deficient mutants (A)and a wild type of LH receptor (B). The rate of internalization of the mutant LH
receptor is faster than that of the wild type receptor.

1831 [37]. However, causes and mechanisms ofoccurrence of the bovine follicular cysts have notbeen elucidated. We have been studying on theendocrinology of hypothalamus-pituitary-ovarian
axis regarding formation mechanisms of follicular
cysts in ruminants.
It has been suggested that stress is a possible
cause for bovine follicular cysts sin ce Garmreported that adrenal gland was enlarged in cows
with ovarian cysts at 1949 [37]. Later, it wasreported that the follicular cystic disease could be
induced by treatment with adrenocorticotropic
hormone (ACTH) in cows by Liptrap et al. [38]. We
demon strated th at, du rin g th e formation offollicular cysts induced by treatments with ACTH,
the preovulatory release of LH and FSH is blocked
and that the suppressed release of FSH and LH
might be caused by increases in secretions ofcortisol and progesterone, and by the decrease in
secretion of estradiol-17β [39]. Furthermore, we
examined direct effects of steroids, those arereleased from adrenal glands when animals arestressed, on hypothalamus, anterior pituitary or
ovarian follicle. The results demonstrate that highconcentration of progesterone act directly on thebovine pituitary stalk-median eminence of the
hypothalamus to inhibit the release of GnRH [40].
Also, it is suggested that the direct inhibitory effectof cortisol on secretion of estradiol-17 β and LH

receptor content in cultured bovine granulosa cells[41]. Th e series of these resu lts suggest thefollowing possible formation mechanism for thebovine follicular cyst caused by stress (Fig. 5) [42].
First, ACTH stimulates releases of progesterone
and cortisol upon the cow is stressed. Then,
increased secretion of progesterone inhibits releaseof GnRH from the hypothalamus. On the other
hand, enhanced secretion of cortisol decreases the
LH receptor contents and estradiol secretion of theantral follicle. Consequently, positive feedback
action of estradiol to hypothalamus and pituitary isdeteriorated and the LH surge is suppressed.
Finally, the ovulation is blocked and the follicle
becomes cystic (Fig. 5).
In naturally occu rring cases of th e bovine
follicular cysts, we demonstrate that the function of
the anterior pituitary is not abnormal [43, 44],suggesting that the disappearance of the LH surge
is p r o b a b ly d u e t o t h e a b no rm a lit y i n th e
hypothalamus [45]. We also showed in an aged
goat with follicular cysts that lack of response to LH
surges may be a cause for the cystic disease [46].

Conclusions
The quantities of LH receptor in follicles andcorpus luteum of the domestic ruminants including

6

KAWATE

increased progesterone and cortisol from theadren al gl and in hib it fun ction s of th e
hypothalamus and follicle, respectively.

Acknowledgments

Fig. 5.

Schematic diagram of a possible mechanism forformation of bovine follicular cysts by stress.
Increased secretion of progesterone (P 4) from adrenal
glands inhibits GnRH release from hypothalamus.
Increased secretion of cortisol (Fk) from adrenal
glands lower LH receptor (LHR) content andsecretion of estradiol-17 β (E 2) in antral follicles.
Consequently, feedback action of estradiol-17 β tohypothalamus-pituitary is weakened and LH surge
is diminished. Then the ovulation is blocked and thefollicle becomes cystic.

cattl e and g oats in crease durin g theirdevelopments. The increase of the receptor during
the caprine luteal development is regulated by, atleast, LH through the receptor mRNA level. Splicevariants of LH receptor are expressed at different
cellular sites according to its structure. The LH
receptor is palmitoylated at its intracellular domain
and thereby the receptor numbers on cell surface
can be regulated. Stress can cause the bovine
follicular cyst through a possible mechanism that

I wish to express my warm thanks to Prof.
Kiyoshi Okuda (Okayama University) for his
recommendation of our research for this honorable
award and his continuous encouragement toresearch. I am very appreciative to Emeritus Prof.
Junichi Mori, Prof. Tsutomu Sawada, Prof. Toshio
Inaba and Dr. Hiromichi Tamada (Osaka Prefecture
University) for their guiding me to work for the
research , continuous encouragement andcollaboration. I wish to express my thanks andrespect to Dr. Tetsuyuki Suga (retired in 1996;
Yamaguchi University) for teaching of a fieldoriented research and his tre mendous
collaboration. During and after my stay in Ann
A r b o r i n M i ch i g a n , tr a in in g f o r m o le c u la r
endocrinology and continuous encouragement toresearch have been provided by Prof. K. M. J.
Menon (University of Michigan). I appreciatemany veterinarians and scientists, who used towork on the research with me and graduated fromthe above universities, for their collaboration. This
work was partially supported by Grant-in-Aid for
Scien tific Research n os. 01480106, 02954112,
04760206, 09760272, 11836009 and 13660324 from
the Ministry of Education, Culture, Sports, Scienceand Tech nolog y of Japan, and by the Ito
Foundation.

References
1. Simmons KR, Hansel W. Nature of the luteotropic
hormone in the bovine. J Anim Sci 1964; 23: 136–141.
2. Kaltenbach CC, Graber JW, Niswender GD,
Nalbandov AV. Luteotrophic properties of some
pituitary hormones in nonpregnant or pregnant
hypophysectomized ewes. Endocrinology 1968; 82:
818–824.
3. Snook RB, Brunner MA, Saatman RR, Hansel W.
The effect of antisera to bovine LH in
hysterectomized and intact heifers. Biol Reprod 1969;
1: 49–58.
4. Baird DT. Luteotrophic control of the corpus
luteum. Anim Reprod Sci 1992; 28: 95–102.
5. Kawate N, Morita N, Tsuji M, Tamada H, Inaba T,

Sawada T. Roles of pulsatile release of LH in thedevelopment and maintenance of corpus luteum
function in the goat. Theriogenology 2000; 54: 1133–
1143.
6. McFarland KC, Sprengel R, Phillips HS, Kohler M,
Rosemblit N, Nikolics K, Segaloff DL, Seeburg
PH. Lutropin-choriogonadotropin receptor: An
unusual member of the G protein-coupled receptor
family. Science 1989; 245: 494–499.
7. Loosfelt H, Misrahi M, Atger M, Salesse R, Vu
Hai-Luu Thi MT, Jolivet A, Guiochon-Mantel A,
Sar S, Jallal B, Garnier J, Milgrom E. Cloning andsequencing of porcine LH-hCG receptor cDNA:
Variants lacking transmembrane domain. ScienceLH RECEPTOR IN RUMINANT OVARY

1989; 245: 525–528.
8. Minegishi T, Nakamura K, Takakura Y, Miyamoto
K, Hasegawa Y, Ibuki Y, Igarashi M. Cloning andsequencing of human LH/hCG receptor cDNA.
Biochem Biophys Res Commun 1990; 172: 1049–1054.
9. Jia XC, Oikawa M, Bo M, Tanaka T, Ny T, Boime I,
Hsueh AJW. Expression of human luteinizing
hormone (LH) receptor: Interaction with LH andchorionic gonadotropin from human but not equine,rat, and ovine species. Mol Endocrinol 1991; 5: 759–
768.
10. Gudermann T, Birnbaumer M, Birnbaumer L.
Evidence for dual coupling of the murine
luteinizing hormone receptor to adenylyl cyclase
and phosphoinositide breakdown and Ca 2+
mobilization. Studies with the cloned murine
luteinizing hormone receptor expressed in L cells. J
Biol Chem 1992; 267: 4479–4488.
11. Davis JS, May JV, Keel BA. Mechanisms ofhormone and growth factor action in the bovine
corpus luteum. Theriogenology 1996; 45: 1351–1380.
12. Youngquist RS. Cystic follicular degeneration in thecow. In: Morrow DA (ed.), Current Therapy in
Theriogenology 2. Philadelphia: W.B. Saunders
Company; 1986: 243–246.
13. McDonald MF. Estrous synchronization andcontrol of the estrous cycle. In: Morrow DA (ed.),Current Therapy in Theriogenology 2. Philadelphia:
W.B. Saunders Company; 1986: 887–889.
14. Smith MC. Synchronization of estrus and the use of
implants and vaginal sponges. In: Morrow DA (ed.),Current Therapy in Theriogenology 2. Philadelphia:
W.B. Saunders Company; 1986: 582–583.
15. Pursley
JR,
Mee
MO,
Wiltbank
MC.
Synchronization of ovulation in dairy cows using
PGF2α and GnRH. Theriogenology 1995; 44: 915–923.
16. Al-Katanani YM, Drost M, Monson RL, Rutledge
JJ, Krininger CE 3rd, Block J, Thatcher WW, Hanse
PJ. Pregnancy rates following timed embryotransfer with fresh or vitrified in vitro produced
embryos in lactating dairy cows under heat stressconditions. Theriogenology 2002; 58: 171–182.
17. Kawate N, Itami T, Choushi T, Saitoh T, Wada T,
Matsuoka K, Uenaka K, Tanaka N, Yamanaka A,
Sakase M, Tamada H, Inaba T, Sawada T.
Improved
conception
intimed-artificial
insemination using a progesterone-releasing
intravaginal device and Ovsynch protocol in
postpartum suckled Japanese Black beef cows.
Theriogenology 2004; 61: 399–406.
18. Kawate N, Inaba T, Mori J. Numbers ofgonadotropin receptors and concentrations ofsteroid hormones in bovine follicles. Jpn J Anim
Reprod 1989; 35: 106–112.
19. Kawate N, Inaba T, Mori J. A quantitative
comparison in the bovine of steroids andgonadotropin receptors in normally developing

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

7

follicles and in follicular and luteinized cysts. Anim
Reprod Sci 1990; 23: 273–281.
Kawate N, Yamazaki M, Tamada H, Inaba T,
Sawada T. Effect of low dose of hCG on induction offertile estrus in Shiba goats pretreated intravaginallywith progesterone during the early postpartum
nursing period. J Reprod Dev 2002; 48: 497–504.
Okuda K, Uenoyama Y, Naito C, Sakabe Y, Kawate
N. LH receptors during the estrous cycle andpregnancy in the bovine corpus luteum. Reprod Fertil
Dev 1999; 11: 147–151.
Kawate N, Okuda K. Coordinated expression of
splice variants for luteinizing hormone receptor
messenger RNA during the development of bovine
corpora lutea. Mol Reprod Dev 1998; 51: 66–75.
Kawate N, Tsuji M, Tamada H, Inaba T, Sawada T.
Inhibition of luteinizing hormone receptor
expression during the development of caprine
corpora lutea by administration of gonadotropinreleasing hormone antagonist. Mol Reprod Dev 2002;
63: 444–450.
Hoffman YM, Peegel H, Sprock MJ, Zhang QY,
Menon KM. Evidence that human chorionicgonadotropin/luteinizing hormone receptor downregulation involves decreased levels of receptor
messenger ribonucleic acid. Endocrinology 1991; 128:
388–393.
Bacich DJ, Rohan RM, Norman RJ, Rodgers RJ.
Characterization and relative abundance ofalternatively spliced luteinizing hormone receptor
messenger ribonucleic acid in the ovine ovary.
Endocrinology 1994; 135: 735–744.
Saint-Dizier M, Chopineau M, Dupont J, Daels PF,
Combarnous Y. Expression and binding activity ofluteinizing
hormone/chorionicgonadotropin
receptors in the primary corpus luteum during earlypregnancy in the mare. Biol Reprod 2003; 69: 1743–
1749.
Nishimori K, Dunkel L, Hsueh AJ, Yamoto M,
Nakano R. Expression of luteinizing hormone andchorionic
gonadotropin receptor
messenger
ribonucleic acid in human corpora lutea during
menstrual cycle and pregnancy. J Clin Endocrinol
Metab 1995; 80: 1444–1448.
Bernard MP, Myers RV, Moyle WR. Cloning of rat
lutropin (LH) receptor analogs lacking the soybean
lectin domain. Mol Cell Endocrinol 1990; 71: R19–23.
Kawate N, Tamada H, Inaba T, Sawada T.
Expression of a cloned full-length cDNA encoding
bovine luteinizing hormone receptor in COS-7 Cells.
J Reprod Dev 2002; 48: 531–538.
Kawate N, Tamada H, Inaba T, Sawada T. Cloningof full-length cDNAs encoding the bovine
luteinizing hormone receptor splice variants andexpression in cultured cells. J Reprod Dev 2001; 47
Suppl: a24.
Ascoli M, Fanelli F, Segaloff DL. The lutropin/

8

32.

33.

34.

35.

36.
37.
38.

39.

KAWATE

choriogonadotropin receptor, a 2002 perspective.
Endocr Rev 2002; 23: 141–174.
Ovchinnikov YA, Abdulaev NG, Bogachuk AS.
Two adjacent cysteine residues in the C-terminal
cytoplasmic fragment of bovine rhodopsin are
palmitylated. FEBS Lett 1988; 230: 1–5.
O’Dowd BF, Hnatowich M, Caron MG, Lefkowitz
RJ, Bouvier M. Palmitoylation of the human beta 2adrenergic receptor. Mutation of Cys341 in the
carboxyl
tail
leads
to
an
uncoupled
nonpalmitoylated form of the receptor. J Biol Chem
1989; 264: 7564–7569.
Kawate N, Menon KMJ. Palmitoylation ofluteinizing
hormone/humanchorionic
gonadotropin receptors in transfected cells. J Biol
Chem 1994; 269: 30651–30658.
Kawate N, Peegel H, Menon KMJ. Role ofpalmitoylation of conserved cysteine residues ofluteinizing hormone/human choriogonadotropin
receptors in receptor down-regulation. Mol Cell
Endocrinol 1997; 127: 211–219.
Kesler DJ, Garverick HA. Ovarian cysts in dairy
cattle: a review. J Anim Sci 1982; 55: 1147–1159.
Garm O. A study on bovine nymphomania. Acta
Endocrinol 1949; Suppl 3 (III): 1–144.
Liptrap RM, McNally PJ. Steroid concentrations incows with corticotropin-induced cystic ovarianfollicles and the effect of prostaglandin F2alpha andindomethacin given by intrauterine injection. Am J
Vet Res 1976; 37: 369–375.
Kawate N, Inaba T, Mori J. Changes in plasma
concentrations of gonadotropins and steroid
hormones during the formation of bovine follicular

40.

41.

42.
43.

44.

45.

46.

cysts induced by the administration of ACTH. J Vet
Med Sci 1996; 58: 141–144.
Kawate N, Inaba T, Mori J. Effects of progesterone
and cortisol on the release of gonadotropinreleasing hormone from the perifused pituitary
stalk-median eminence and on luteinizing hormone
release from the pituitary of cows. Anim Reprod Sci
1993; 34: 93–100.
Kawate N, Inaba T, Mori J. Effects of cortisol on theamounts of estradiol-17β and progesterone secreted
and the numbers of luteinizing hormone receptors
in cultured bovine granulosa cells. Anim Reprod Sci
1993; 32: 15–25.
Kawate N. Mechanism of ovarian cyst formation inruminants. J Jpn Vet Med Assoc 2001; 54: 79–84.
Kawate N, Inaba T, Mori J. Gonadotropin-releasing
hormone receptors in anterior pituitaries of cattle
during the estrous cycle. Anim Reprod Sci 1991; 24:
185–191.
Kawate N, Yamada H, Suga T, Inaba T, Mori J.
Induction of luteinizing hormone surge by pulsatileadministration of gonadotropin-releasing hormone
analogue in cows with follicular cysts. J Vet Med Sci
1997; 59: 463–466.
Kawate N, Tsuji M, Tamada H, Inaba T, Sawada T.
Reduced sensitivity to hypothalamic estrogen in acase of recurring bovine follicular cyst. J Jpn Vet med
Assoc 2000; 53: 195–199.
Kawate N, Morita N, Tsuji M, Tamada H, Inaba T,
Sawada T. Anovulation to a luteinising hormone
surge in one aged goat with follicular cysts. Vet Rec
2000; 147: 272–274.