Co-operation of progesterone and prostaglandins in ovulation induced by human chorionic gonadotrophin in immature rats primed with pregnant mare serum gonadotrophin

1983 ◽  
Vol 96 (3) ◽  
pp. 387-393 ◽  
Author(s):  
Heigo Kohda ◽  
Takahide Mori ◽  
Toshio Nishimura ◽  
Akira Kambegawa
Keyword(s):  
Inhibitory Action ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Temporary Increase ◽  
Inhibitory Effects ◽  
Concurrent Administration ◽  
Simultaneous Injection ◽  
Induced Ovulation ◽  
Immature Rats ◽  
Pregnant Mare Serum Gonadotrophin

Serial injections of a mixture of prostaglandin (PG) E2 and F2α 0, 2, 4, and 6 h after simultaneous injection of human chorionic gonadotrophin (hCG) and indomethacin incompletely restored the ovulation that would have been blocked by indomethacin in immature rats treated with pregnant mare serum gonadotrophin followed by hCG. Serial injections of another mixture of PGE2 and PGF2α 6, 8, 10 and 12 h after simultaneous injection of hCG and indomethacin similarly reversed, in part, the inhibitory effects of indomethacin on hCG-induced ovulation. In contrast, serial injections of the mixtures of PGE2 and PGF2α 0, 2, 4, 6, 8, 10 and 12 h after simultaneous injection of hCG and indomethacin completely restored the indomethacin-blocked ovulation, suggesting that the prostaglandins mediate the action of hCG on ovulation both in the earlier and later stages of the preovulatory process. Six hours after simultaneous injection of hCG and indomethacin serial injections of a mixture of PGE2 and PGF2α reproduced the acute and temporary increase in concentrations of progesterone and testosterone in plasma which would have been abolished by indomethacin. Progesterone given concurrently with hCG and indomethacin partially antagonized the inhibitory action of indomethacin on ovulation. Serial injections of a' mixture of PGE2 and PGF2α 6, 8, 10 and 12 h after concurrent administration of progesterone with hCG and indomethacin completely restored the indomethacin-blocked ovulation, suggesting that progesterone can substitute the action of prostaglandins injected serially in the first half of the preovulatory process. It was concluded that the co-operation of progesterone in the earlier stage and of prostaglandins in the later stage of the preovulatory interval is required to mediate the action of hCG on ovulation.

INHIBITION BY INDOMETHACIN OF OVULATION INDUCED BY HUMAN CHORIONIC GONADOTROPHIN IN IMMATURE RATS PRIMED WITH PREGNANT MARE SERUM GONADOTROPHIN

1980 ◽  
Vol 84 (3) ◽  
pp. 333-341 ◽  
Author(s):  
TAKAHIDE MORI ◽  
HEIGO KOHDA ◽  
YASUSHI KINOSHITA ◽  
YOJIRO EZAKI ◽  
NORIHIKO MORIMOTO ◽  
...  
Keyword(s):  
Effective Dose ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Temporary Increase ◽  
Dependent Manner ◽  
Minimum Effective Dose ◽  
Immature Rats ◽  
The Mean ◽  
Dose Dependent ◽  
Pregnant Mare Serum Gonadotrophin

Treatment of immature rats with pregnant mare serum gonadotrophin followed by human chorionic gonadotrophin (HCG) caused an acute and temporary increase in concentrations of progesterone, testosterone and oestradiol in plasma with maximum levels 3 h after the administration of HCG. Concurrent injection of indomethacin and HCG reduced, in a dose-dependent manner, the mean number of ova shed and this was accompanied by a dose-dependent decrease in concentrations of plasma progesterone and testosterone but not of oestradiol when they were measured 3 h after the injection of HCG. The minimum effective dose that blocked ovulation completely at 0 h abolished the acute increase of progesterone and testosterone, suggesting that prostaglandins act on ovulation by stimulating steroidogenesis at an early stage in the preovulatory process. The anti-ovulatory action of the minimum effective dose at 0 h became progressively less potent as the time between injection of HCG and administration of indomethacin was increased, although plasma concentrations of progesterone and testosterone measured at autopsy 18 h after treatment with HCG had not changed appreciably. When indomethacin was administered 10 h after HCG, the relationship between the dose of indomethacin and the mean number of ova differed from that observed when simultaneous injections of indomethacin and HCG were given, and the minimum effective dose that prevented ovulation was much higher than that at 0 h, suggesting that prostaglandins act differently on ovulation in the later stage of the preovulatory process. It was concluded that prostaglandins may mediate the action of HCG on ovulation through two mechanisms which operate at different stages of the preovulatory process.

Effects of thymulin on spontaneous puberty and gonadotrophin-induced ovulation in prepubertal normal and hypothymic mice

1999 ◽  
Vol 163 (2) ◽  
pp. 255-260 ◽  
Author(s):  
L Hinojosa ◽  
R Chavira ◽  
R Dominguez ◽  
P Rosas
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Vaginal Opening ◽  
Serum Progesterone ◽  
Thymic Hormone ◽  
Induced Ovulation ◽  
Gonadotrophin Secretion ◽  
Age Dependent ◽  
Neuroendocrine Mechanisms ◽  
Pregnant Mare Serum Gonadotrophin

The effects of thymulin administration beginning on days 19 or 24 of age on spontaneous puberty and gonadotrophin-induced ovulation were analysed in female normal and hypothymic mice. In normal and hypothymic mice, the daily administration of thymulin at 24 days of age resulted in a delay in the age of vaginal opening, with an increase in serum progesterone levels. Normal mice treated with 200 ng thymulin beginning on day 19 of age and injected with pregnant mare serum gonadotrophin (PMSG) 24 h later had an increase in ovulation rate, number of ova shed and weight of the ovaries. None of the hypothymic mice treated with thymulin on day 19 and PMSG on day 20 ovulated. PMSG treatment on day 25 induced ovulation in hypothymic mice. When these animals were injected previously with 200 ng thymulin, the number of ova shed by ovulating animals was lower than in PMSG-treated animals. Administration of thymulin and sequential injection of PMSG and human chorionic gonadotrophin 54 h later resulted in an increase in ovulatory response in comparison with those receiving only PMSG. The results suggest that thymulin plays a role in the regulation of spontaneous puberty through its effects on adrenal and ovarian endocrine functions. The increase in the ovarian PMSG response-treated animals, previously given thymulin, showed that this thymic hormone participates in the regulation of gonadotrophin secretion mechanisms and seems to be dose- and age-dependent. In hypothymic mice, neuroendocrine mechanisms regulating puberty are different from those of normal mice.

STIMULATION BY β2-ADRENERGIC RECEPTORS OF THE PRODUCTION OF CYCLIC AMP AND PROGESTERONE IN RAT OVARIAN TISSUE

1980 ◽  
Vol 87 (1) ◽  
pp. 123-129 ◽  
Author(s):  
ALBERT RATNER ◽  
G. K. WEISS ◽  
CAROLYN R. SANBORN
Keyword(s):  
Cyclic Amp ◽  
Adrenergic Receptors ◽  
Ovarian Tissue ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Adrenergic Stimulation ◽  
Immature Rats ◽  
Luteal Tissue ◽  
Pregnant Mare Serum Gonadotrophin ◽  
Stimulation Of

Ovarian tissue from immature rats treated with pregnant mare serum gonadotrophin (PMSG) or PMSG and human chorionic gonadotrophin was incubated in Medium 199. Stimulation of the formation of cyclic AMP in follicular and luteal tissue by terbutaline (10−5 mol/l), a selective β2-agonist, was blocked by butoxamine (10−5 mol/l), a selective β2-antagonist, whereas practolol (10−5 mol/l), a selective β1-antagonist, was ineffective. Propranolol (10−5 mol/l), a non-selective β-antagonist, butoxamine nor practolol affected the increase in cyclic AMP promoted by the addition of 1 μg LH. Stimulation of the production of progesterone in both follicular and luteal tissue by terbutaline was blocked by butoxamine, but not by practolol. These findings indicated that β-adrenergic stimulation of ovarian cyclic AMP and progesterone is mediated by β2-adrenergic receptors.

A PROGESTERONE-DEPENDENT STEP IN OVULATION INDUCED BY HUMAN CHORIONIC GONADOTROPHIN IN IMMATURE RATS PRIMED WITH PREGNANT MARE SERUM GONADOTROPHIN

1980 ◽  
Vol 87 (1) ◽  
pp. 105-107 ◽  
Author(s):  
HEIGO KOHDA ◽  
TAKAHIDE MORI ◽  
YOJIRO EZAKI ◽  
TOSHIO NISHIMURA ◽  
AKIRA KAMBEGAWA
Keyword(s):  
Experimental System ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Immature Rats ◽  
Ovulatory Process ◽  
Pregnant Mare Serum Gonadotrophin

In immature rats primed with pregnant mare serum gonadotrophin, antiserum to progesterone could prevent or reduce ovulation in response to injected human chorionic gonadotrophin (HCG). To be effective, antiserum treatment had to be within 6 h of gonadotrophin treatment; antiserum given 9 h after HCG was ineffective. Progesterone restored the antiserum blocked ovulation completely or incompletely when administered intravenously within 6 h of treatment with HCG. The first 6 h was shown to be a progesterone-dependent step in the ovulatory process in this experimental system.

CHANGES IN STEROID CONCENTRATION IN THE OVARIES OF IMMATURE RATS TREATED WITH PREGNANT MARE SERUM GONADOTROPHIN AND HUMAN CHORIONIC GONADOTROPHIN

1977 ◽  
Vol 75 (1) ◽  
pp. 43-48 ◽  
Author(s):  
S. BAUMINGER ◽  
B. ECKSTEIN ◽  
H. R. LINDNER
Keyword(s):  
Dehydrogenase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Immature Rat ◽  
Immature Rats ◽  
Rat Ovary ◽  
Pregnant Mare Serum Gonadotrophin

The concentrations of testosterone, progesterone and 20α-hydroxypregn-4-en-3-one (20α-OHP) were measured in the ovaries of immature rats in which ovulation was induced by treatment with pregnant mare serum gonadotrophin (PMSG) and, 48 h later, with human chorionic gonadotrophin (HCG). The concentration of testosterone in the tissue increased significantly 48 h after treatment with PMSG, reached a peak 4 h after the administration of HCG and declined to the basal level 4 h later. Increases in the levels of progesterone and 20α-OHP were observed 4 h after the administration of HCG. Whereas the level of 20α-OHP continued to rise during the subsequent 30 h, progesterone levels declined near the presumed time of ovulation (12 h after administration of HCG). It is concluded that 20α-hydroxysteroid dehydrogenase activity is present in the immature rat ovary before ovulation and that an increase in the production of testosterone in the ovaries of rats treated with PMSG and HCG precedes increased production of progesterone and 20α-OHP in these ovaries.

INDUCTION OF OVULATION BY GONADOTROPHINS IN THE INDIAN FIVE-STRIPED PALM SQUIRREL FUNAMBULUS PENNANTI (WROUGHTON)

1967 ◽  
Vol 39 (3) ◽  
pp. 369-NP ◽  
Author(s):  
PUSHPA SETH ◽  
M. R. N. PRASAD
Keyword(s):  
Breeding Season ◽  
Reproductive Cycle ◽  
Single Injection ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Follicular Growth ◽  
Induction Of Ovulation ◽  
Induced Ovulation ◽  
Follicular Maturation ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY Superovulation was induced in palm squirrels by the administration of gonadotrophins. The regimen of treatment effective in inducing ovulation was 60 i.u. pregnant mare serum gonadotrophin (PMS) administered in three doses of 20 i.u. on days 1, 4 and 7, followed by a single injection of 40 i.u. human chorionic gonadotrophin (HCG) on day 14. The same schedule of PMS and HCG administration induced ovulation in mature and immature squirrels both during the breeding season and the period of sexual quiescence. Ovulation did not occur in PMS-treated females if HCG was not administered. The period required for follicular growth before the follicles responded to the ovulatory stimulus of HCG was 13–14 days; the interval for follicular maturation leading to the release of the ovum was approximately 24 hr. Variations in the numbers of ova shed by different groups of females are related to the phase of the reproductive cycle and the age of the squirrels.

STUDIES ON GONADOTROPHIN-INDUCED OVULATION IN THE IMMATURE RAT

1968 ◽  
Vol 41 (2) ◽  
pp. 171-177 ◽  
Author(s):  
E. T. BELL ◽  
S. F. LUNN
Keyword(s):  
Marked Effect ◽  
Cell Mass ◽  
Hormone Treatment ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Maximum Increase ◽  
Immature Rat ◽  
Immature Rats ◽  
Wet Weight ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY The effect of the administration of 25 i.u. human chorionic gonadotrophin (HCG) on the induction of ovulation in intact immature rats treated with 50 i.u. pregnant mare serum gonadotrophin (PMSG) has been studied. After the administration of HCG a marked increase in ovarian wet weight was observed. The maximum increase, which occurred 10 hr. after hormone treatment, was noted 2 hr. before ova were found in the oviducts. The alteration in ovarian wet weight was associated with a fall in percentage solids. However, it appears likely that an increase both in follicular fluid and in cell mass occurred before ovulation. Possible reasons for the absence of any marked effect on uterine wet weight or percentage solids are discussed.

Oxytocin may play a role in the control of the human corpus luteum

1982 ◽  
Vol 95 (1) ◽  
pp. 65-70 ◽  
Author(s):  
G. J. S. Tan ◽  
R. Tweedale ◽  
J. S. G. Biggs
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
Inhibitory Action ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Progesterone Production ◽  
Human Corpus Luteum

The effects of oxytocin on dispersed luteal cells from human corpora lutea of the menstrual cycle were studied. Oxytocin at a concentration of 4 mi.u./ml produced a slight increase in basal progesterone production. However, higher oxytocin concentrations (400 and 800 mi.u./ml) markedly inhibited both basal and human chorionic gonadotrophin-induced progesterone production. These data provide evidence for an effect of oxytocin on the human corpus luteum. In view of the inhibitory action of oxytocin, increased secretion of this hormone may be important in the demise of the corpus luteum at the end of the menstrual cycle.

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