125 The effects of human chorionic gonadotrophin administered 7 days after induced oestrus on original (ovulatory) and induced (accessory) corpora lutea and on pregnancy rates in seasonally anovular dairy goats

Cell suspensions were prepared from tissue samples of human corpora lutea obtained during the mid- and late-luteal phase of the menstrual cycle. Both oestradiol and progesterone production by dispersed cells were stimulated by similar concentrations of human chorionic gonadotrophin (hCG). As the degree of stimulation of production by hCG was greater for progesterone than for oestradiol (five- to tenfold compared with two- to threefold higher than basal production), the ratio of progesterone to oestradiol produced varied according to the level of trophic stimulation. A comparison of cell suspensions prepared from mid- and late-luteal phase corpora lutea, exposed to the same concentration of hCG (10 i.u./ml) in vitro, did not reveal a shift to oestradiol production in the late-luteal phase. Provision of additional testosterone during incubation raised the level of oestradiol production by dispersed luteal cells. At an optimum concentration of testosterone (1 μmol/l), oestradiol synthesis was not raised further in the presence of hCG or N6, O2-dibutyryl cyclic AMP, suggesting a lack of induction or activation of the aromatase system by gonadotrophin in short-term cultures. Basal and stimulated levels of progesterone production were not significantly impaired in the presence of testosterone.

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

Journal of Endocrinology ◽

10.1677/joe.0.0950065 ◽

1982 ◽

Vol 95 (1) ◽

pp. 65-70 ◽

Cited By ~ 41

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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CONCENTRATIONS OF CYCLIC AMP IN RABBIT OVARIAN TISSUE DURING THE PREOVULATORY PERIOD AND PSEUDOPREGNANCY AFTER INDUCTION OF OVULATION BY ADMINISTRATION OF HUMAN CHORIONIC GONADOTROPHIN

Journal of Endocrinology ◽

10.1677/joe.0.0650073 ◽

1975 ◽

Vol 65 (1) ◽

pp. 73-82 ◽

Cited By ~ 8

Author(s):

A. K. GOFF ◽

PATRICIA W. MAJOR

Keyword(s):

Cyclic Amp ◽

Dose Response ◽

Ovarian Tissue ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Corpora Lutea ◽

Response Relationship ◽

Dose Response Relationship ◽

Induction Of Ovulation ◽

Relationship Of

SUMMARY Concentrations of cyclic AMP were measured in rabbit ovaries at various times after injection of an ovulatory dose of human chorionic gonadotrophin (HCG). A biphasic increase in cyclic AMP concentration occurred during the preovulatory period, with peaks 30 min and 3–4 h after HCG injection. Concentrations of cyclic AMP had returned to those observed in ovaries of control oestrous animals before the onset of ovulation 10–12 h after administration of HCG, and remained low throughout the period of pseudopregnancy. Concentrations of cyclic AMP in the newly formed and developing corpora lutea were similar to the concentrations observed in the remainder of the tissue during this period. No significant increase in cyclic AMP concentration was observed 7–9 days after initiation of ovulation. Concentrations of ATP were also investigated during the preovulatory period. The dose– response relationship of HCG to cyclic AMP production in oestrous rabbit ovaries was investigated.

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Induction of selective release of FSH in castrated male rats bearing an ovarian transplant by the administration of human chorionic gonadotrophin

Journal of Endocrinology ◽

10.1677/joe.0.1060031 ◽

1985 ◽

Vol 106 (1) ◽

pp. 31-NP ◽

Cited By ~ 4

Author(s):

G. Watanabe ◽

K. Taya ◽

S. Sasamoto

Keyword(s):

Adult Male ◽

Sex Differentiation ◽

Plasma Concentrations ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Male Rats ◽

Corpora Lutea ◽

Female Rat ◽

Nacl Solution ◽

Abrupt Decrease

ABSTRACT The present study was undertaken to determine whether hypothalamic differentiation is involved in the selective release of FSH during the periovulatory period using adult male rats castrated and implanted with an ovary. Adult male rats (70–90 days old) were castrated and an ovary obtained from a prepubertal female rat (26 days old) was immediately grafted subcutaneously. Four weeks later, human chorionic gonadotrophin (hCG, 10 i.u.) was injected i.v. into the experimentally manipulated rats to induce ovulatory changes in the grafted ovaries. Another group of similarly prepared rats was injected with 0·9% (w/v) NaCl solution as controls. After injection of hCG, plasma concentrations of FSH increased significantly by 6 h, reached peak values at 12 h and declined to control levels at 36 h. On the other hand, plasma concentrations of LH were reduced by 6 h and decreased further during the next 36 h. An abrupt fall in plasma concentrations of oestradiol-17β occurred within 3 h of the administration of hCG. Histological examination revealed that ovulatory changes and luteinization of follicles were induced in grafted ovaries by 18 h after the injection of hCG. Thirty-six hours after treatment with hCG, a set of newly formed corpora lutea was observed in grafted ovaries and plasma concentrations of progesterone were raised. Treatment with oestradiol-17β did not inhibit the selective release of FSH after the administration of hCG, suggesting that the abrupt decrease in secretion of oestradiol-17β from the grafted ovary is not involved in the occurrence of the FSH surge. These results indicate that a selective release of FSH can be induced in castrated male rats bearing an ovarian transplant probably due to decreased secretion of inhibin by the luteinized follicles in the grafted ovaries. Sex differentiation of the hypothalamus is not, therefore, involved in the selective surge of FSH. J. Endocr. (1985) 106, 31–36

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Effects of prolactin on steroid production by human luteal cells in vitro

Journal of Endocrinology ◽

10.1677/joe.0.0960499 ◽

1983 ◽

Vol 96 (3) ◽

pp. 499-503 ◽

Cited By ~ 9

Author(s):

G. J. S. Tan ◽

J. S. G. Biggs

Keyword(s):

Menstrual Cycle ◽

Ovarian Function ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Corpora Lutea ◽

Short Term ◽

Steroid Production ◽

Luteal Cells ◽

Progesterone Production

The effects of prolactin on steroidogenesis were studied in dispersed luteal cells prepared from human corpora lutea of the menstrual cycle. Prolactin, at concentrations of 0·1–1000 ng/ml, had no effect on progesterone production by luteal cells during short-term incubation (3 h). However, in two out of five corpora lutea, higher concentrations of prolactin (100 and 1000 ng/ml) significantly reduced the oestradiol-17β production induced by human chorionic gonadotrophin (hCG; 10 i.u./ml); lower doses of prolactin had little effect. In the remaining corpora lutea, prolactin failed to affect either basal or hCG-induced production of oestradiol-17β. These results are discussed in relation to the mechanism by which prolactin influences human ovarian function.

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ÉTUDE DE L'ACTIVITÉ BIOLOGIQUE IN VITRO DES HORMONES GONADOTROPES

Acta Endocrinologica ◽

10.1530/acta.0.0420509 ◽

1963 ◽

Vol 42 (4) ◽

pp. 509-513 ◽

Cited By ~ 7

Author(s):

D. Gospodarowicz ◽

J. Legault-Démare

Keyword(s):

Incubation Medium ◽

Cholesterol Synthesis ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Corpora Lutea ◽

Lactogenic Hormone ◽

Normal Rat ◽

Stimulation Of

ABSTRACT Human chorionic gonadotrophin (HCG) and lactogenic hormone (LTH or prolactin) were found practically inactive on the incorporation of 14Cacetate into cholesterol of normal rat corpus luteum in vitro. On the contrary, when added simultaneously to the incubation medium, they increased by 90% the labeling of cholesterol. When pseudopregnancy corpora lutea were used, HCG alone stimulated to the same amount, but no stimulation was observed with LTH alone. These results show that the stimulation of cholesterol synthesis is produced by a synergic action of LTH and HCG, LTH being introduced either in vivo (pseudopregnancy) or in vitro.

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103 Effects of administration of human chorionic gonadotrophin at Day 5 post-ovulation on development of the original corpus luteum depend on the locational relationship between the original and accessory corpora lutea

Reproduction Fertility and Development ◽

10.1071/rdv32n2ab103 ◽

2020 ◽

Vol 32 (2) ◽

pp. 177

Author(s):

K. Hazano ◽

S. Haneda ◽

M. Matsui

Keyword(s):

Corpus Luteum ◽

Repeated Measures ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Corpora Lutea ◽

Intrauterine Environment ◽

Prostaglandin F2a ◽

Tissue Area ◽

Luteal Tissue ◽

Relationship Of

In cattle, human chorionic gonadotrophin (hCG) is administered at Day 5 post-ovulation to improve fertility. This treatment can induce ovulation of the first-wave dominant follicle (W1DF), from which an accessory corpus luteum (CL) is generated. In addition, hCG has the effect of promoting CL development. It is possible that the locational relationship between the original and accessary CLs influences the effect of hCG on CL development, because the locational relationship of the CLs affects intraovarian blood flow. The present study aimed to clarify whether the locational relationship between the original and accessory CLs influences the effect of hCG on their development. Cross-bred beef heifers (Holstein×Japanese Black, n=56) were used for the present study. The oestrus cycle was synchronized using oestradiol benzoate (EB) and a controlled internal drug release (CIDR)-based program. Briefly, an administration of EB (2mg) with 9-day CIDR insertion was followed by administration of prostaglandin F2a analogue (PGF2a) on the day of CIDR removal, EB (1mg) 1 day after a PGF2a injection, and GnRH 12h after the second EB injection. At Day 5 post-ovulation, the locational relationship between the original CL and the W1DF was confirmed using transrectal ultrasonography (USG), and two groups were defined: ipsilateral group (IG; n=30), in which the CL and the W1DF are in the same ovary, and contralateral group (CG; n=26), in which the CL and the W1DF are in separate ovaries. Moreover, IG and CG were respectively subdivided into two groups, with or without hCG (1500IU) treatment (IG/hCG, n=15; IG without hCG, n=15, and CG/hCG, n=14; CG without hCG, n=12). The diameter and luteal tissue area (i.e. minus the cavity area) of the original CL and the accessory CL were examined at Days 5, 7, and 14, using USG. Two-way repeated-measures ANOVA was used to compare the diameter and luteal tissue area between IG/hCG and IG without hCG, and between CG/hCG and CG without hCG. In CG, the diameter (P<0.01) and luteal tissue area of the original CL (P<0.001) at Day 7 was increased by receiving hCG, while it did not change in IG. The diameter and luteal tissue area of the original CL at Day 14 were not affected by the administration of hCG in either CG or IG. Moreover, for the accessory CL, no difference of the diameter and luteal tissue area was observed between CG and IG. The present study showed that hCG treatment at Day 5 post-ovulation stimulate the growth of the original CL at Day 7, when the original CL and accessory CL are on contralateral sides. Our results suggest that the effect of administration of the hCG at Day 5 post-ovulation on the original CL development depends on the locational relationship between the original and accessory CL (IG or CG). The function of the CL affects the intrauterine environment for embryonic development. Therefore, it is necessary to investigate the effect of the hCG injection at Day 5 on the function of CL (i.e. plasma P4 concentration) in IG and CG, respectively.

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OESTROGEN BIOSYNTHESIS AND STEROID METABOLISM IN THE PORCINE OVARY

Acta Endocrinologica ◽

10.1530/acta.0.0620449 ◽

1969 ◽

Vol 62 (3) ◽

pp. 449-460 ◽

Cited By ~ 1

Author(s):

P. Preumont ◽

I. D. Cooke ◽

K. J. Ryan

Keyword(s):

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Steroid Metabolism ◽

Corpora Lutea ◽

17 Hydroxyprogesterone ◽

Ovulatory Follicles ◽

Cellular Compartments

ABSTRACT In vitro incubations of isolated porcine pre-ovulatory follicles, corpora lutea, and minced whole pre- and post-ovulatory ovaries were undertaken in an attempt to elucidate the pathways of oestrogen biosynthesis and steroid metabolism in the various cellular compartments of the porcine ovary. The conversion of radioactive acetate to cholesterol, the conversions of pregnenolone and progesterone to 16-hydroxyprogesterone, 17-hydroxyprogesterone, oestrone and oestradiol and the conversion of pregnenolone to 17-hydroxypregnenolone were observed following incubation with pre-ovulatory follicles in vitro. No significant effect of human chorionic gonadotrophin (HCG) added in vitro on steroid metabolism could be demonstrated. The conversions of dehydroepiandrosterone to oestradiol and 16-hydroxydehydroepiandrosterone to 16-hydroxyandrostenedione were obtained with corpora lutea in vitro. Pre-ovulatory whole ovarian mince incubations converted progesterone to 16-hydroxyprogesterone and androstenedione to oestrone. When 16-hydroxyandrostenedione, 16-hydroxyprogesterone and 16-hydroxydehydroepiandrosterone were incubated as substrates and/or formed in these various studies, no evidence for the formation of oestriol or other 16-oxygenated oestrogens could be demonstrated, although non-16 hydroxylated neutral steroids were aromatized in paired experiments.

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