RESPONSE OF MOUSE OVARIES IN VIVO AND IN ORGAN CULTURE TO PREGNANT MARE'S SERUM GONADOTROPHIN AND HUMAN CHORIONIC GONADOTROPHIN

The rate of secretion of 17-oxosteroids by the testes of anaesthetized dogs in vivo was used as an index of LH secretion. Intracarotid injection of luteinizing hormone releasing hormone (LH-RH, 1, 5 or 10 μg/kg body wt) resulted in an increase in the testicular 17-oxosteroid secretion which was roughly proportional to the dose administered and which reached a maximum 60 min after the injection. Testicular output of 17-oxosteroids was unaffected by administration of melatonin (10 or 100 μg/kg body wt) into the carotid artery. When LH-RH (5 μg/kg) was injected into the carotid artery 3 h after intracarotid injection of melatonin (10 or 100 μg/kg), the testicular response to LH-RH was considerably diminished. Pretreatment with melatonin (100 μg/kg) did not alter the testicular response to human chorionic gonadotrophin (20 i.u./kg body wt) given i.v. It is concluded that melatonin may act directly on the anterior pituitary gland in dogs to inhibit the LH-RH-induced release of LH.

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Immunochemical analysis of the human chorionic gonadotrophin-like material secreted by 'normal' and neoplastic urothelial cells

Journal of Molecular Endocrinology ◽

10.1677/jme.0.0020107 ◽

1989 ◽

Vol 2 (2) ◽

pp. 107-112 ◽

Cited By ~ 17

Author(s):

R. K. Iles ◽

T. Chard

Keyword(s):

Bladder Tumour ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Sds Page ◽

Β Hcg ◽

Bladder Carcinomas ◽

Immunochemical Characteristics ◽

Normal Urothelium

ABSTRACT Material with the immunochemical characteristics of human chorionic gonadotrophin (hCG) is produced by bladder tumour cells in vitro and in vivo. In order to characterize this material further, media were collected from 17 cell cultures (three choriocarcinomas, seven bladder carcinomas and seven 'normal' urothelium). The hCG-like material was compared with pregnancy hCG and purified α- and β-subunits by specific radioimmunoassays. Media were also submitted to affinity chromatography and the fractions further analysed by SDS-PAGE and Western blotting. It was shown that both the neoplastic and normal urothelium produced only free β-subunit-like material. This urothelial 'β-hCG' has the same molecular weight and electrophoretic mobility as that present in the intact hCG of pregnancy.

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Internalization of receptor-bound human chorionic gonadotrophin in preovulatory rat granulosa cells in vivo

Acta Endocrinologica ◽

10.1530/acta.0.1030406 ◽

1983 ◽

Vol 103 (3) ◽

pp. 406-412 ◽

Cited By ~ 8

Author(s):

Kalle Jääkeläinen ◽

Seppo Markkanen ◽

Hannu Rajaniemi

Keyword(s):

Plasma Membrane ◽

Granulosa Cells ◽

Subcellular Distribution ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Female Rats ◽

Electron Microscope Autoradiography ◽

Silver Grains ◽

Pregnant Mare Serum Gonadotrophin

Abstract. The subcellular distribution of 125I-labelled human chorionic gonadotrophin (hCG) in preovulatory rat granulosa cells was studied in vivo. Pregnant mare serum gonadotrophin-pretreated immature female rats received an iv injection of [125I]hCG a few hours before the endogenous preovulatory gonadotrophin surge. The animals were killed at 2 or 6 h after the [125I]hCG injections. Light microscope autoradiographs showed that the mural granulosa cells of large follicles were the most highly labelled cells in the ovaries. Electron microscope autoradiography was used to study the subcellular distribution of radioactivity in the mural granulosa cells. At 2 h 45% of the counted silver grains were associated with the plasma membrane and 10% with the lysosomes, at 6 h the values were 51% and 9%, respectively. The distribution of the observed silver grains was compared with the generated expected source to grain pairs by computerized linear multiple regression analysis. The magnitudes of the regression coefficients revealed that the plasma membrane and the lysosomes were the only specifically 125I-labelled organelles, that a few radioactive molecules were located diffusely over the cytoplasm at 2 h and that the 125I-radioactivity of the nuclei was negligible. The present results suggest that preovulatory rat granulosa cells are in vivo able to internalize into lysosomes [125I]hCG initially bound to LH/hCG receptors of the plasma membrane.

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INTERNATIONAL REFERENCE PREPARATION OF HUMAN CHORIONIC GONADOTROPHIN FOR IMMUNOASSAY: POTENCY ESTIMATES IN VARIOUS BIOASSAY AND PROTEIN BINDING ASSAY SYSTEMS; AND INTERNATIONAL REFERENCE PREPARATIONS OF THE α AND β SUBUNITS OF HUMAN CHORIONIC GONADOTROPHIN FOR IMMUNOASSAY

Journal of Endocrinology ◽

10.1677/joe.0.0840295 ◽

1980 ◽

Vol 84 (2) ◽

pp. 295-310 ◽

Cited By ~ 73

Author(s):

P. L. STORRING ◽

ROSE E. GAINES-DAS ◽

D. R. BANGHAM

Keyword(s):

Geometric Mean ◽

Collaborative Study ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Considerable Heterogeneity ◽

International Reference ◽

Reference Preparation ◽

Α And Β Subunits

The preparation and nature of the International Reference Preparation of Human Chorionic Gonadotrophin (HCG) for Immunoassay (IRP), as well as that of a second batch of ampoules (HCG 75/589) prepared identically from the same HCG preparation, are described. A collaborative study of these materials was carried out by 11 laboratories in eight countries, using different bioassay and immunoassay methods. Using the various in-vivo and in-vitro bioassays and receptor assays, the mean log potency estimates for each method within each laboratory of the HCG content of ampoules of the IRP, in terms of the Second International Standard of Human Chorionic Gonadotrophin for Bioassay (IS), were homogeneous and gave an overall weighted geometric mean (95% confidence limits) of 650 (632–669) International Units (i.u.)/ampoule. There was considerable heterogeneity of potency estimates of the IRP in terms of the IS both within and between many of the immunoassay systems (reflecting the impurity of the IS), and hence attempts to calibrate the IRP with immunoassay systems of different specificities were invalid. Immunoassay estimates of the HCG content of preparations of serum and urine, in terms of the IRP, showed considerable heterogeneity between assay systems (although the degree of this heterogeneity was no greater than that observed using the IS as standard), but the ranking order between preparations was consistent. Confirmation was obtained that contamination of the IRP with HCG-α and HCG-β subunits was insignificant. Accelerated degradation studies of the IRP stored at increased temperatures suggested that its stability under normal storage conditions would be satisfactory. It was agreed that the IRP was suitable to serve as an international reference preparation for immunoassay, and it was assigned a unitage of 650 i.u./ampoule on the basis of bioassay calibration. Since the ampoules of HCG (75/589) did not differ significantly from the IRP in any of the assay systems studied, it appeared to be equally suitable as a reference preparation. The International Reference Preparations of the α and β Subunits of Human Chorionic Gonadotrophin for Immunoassay are also described.

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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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Nitric oxide mediates human chorionic gonadotrophin-induced prostaglandin E generation in rat oocyte - cumulus complexes

Reproduction Fertility and Development ◽

10.1071/r96043 ◽

1997 ◽

Vol 9 (4) ◽

pp. 391 ◽

Cited By ~ 4

Author(s):

Alicia Jawerbaum ◽

Elida T. Gonzalez ◽

Alicia Faletti ◽

Virginia Novaro ◽

Martha A. F. Gimeno

Keyword(s):

Nitric Oxide ◽

Methyl Ester ◽

No Synthase ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Prostaglandin E ◽

No Donors ◽

Nos Inhibitors ◽

Preovulatory Follicles

To determine whether nitric oxide (NO) generation mediates human chorionic gonadotrophin (hCG)-induced prostaglandin E (PGE) secretion by oocyte–cumulus complexes (OCC), the secretion of PGE by cultured rat OCC in the presence of NO donors and NO synthase (NOS) inhibitors was characterized. NO donors (sodium nitroprusside and 3-morpholino-sydnonimine- hydrochloride) increased PGE accumulation in OCC to values similar to those obtained in the presence of hCG. The three NOS inhibitors tested (N G -nitro-L-arginine methyl ester, NG -monomethyl-L-arginine and aminoguanidine) prevented the hCG-induced PGE accumulation in cultured OCC. This effect appears to be specific since D-enantiomers NG -nitro-D-arginine methyl ester and NG -monomethyl-D-arginine had no effect. The present results suggest that NO mediates the hCG-induced accumulation of PGE in rat OCC, a process which may occur in vivo in preovulatory follicles prior to ovulation.

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Fate of receptor-bound human chorionic gonadotrophin in pseudopregnant rat ovaries perfused in vitro

Acta Endocrinologica ◽

10.1530/acta.0.1090115 ◽

1985 ◽

Vol 109 (1) ◽

pp. 115-121

Author(s):

Hannu Rajaniemi ◽

Jan Sogn ◽

Paul Holmes ◽

Björn Källfelt ◽

Per Olof Janson

Keyword(s):

Molecular Weight ◽

Histological Examination ◽

Gel Filtration ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Cell Periphery ◽

Small Molecular Weight ◽

Immunohistochemical Studies

Abstract. Pseudopregnant rats were injected with [125I] hCG, anaesthesized 1 h later and after cannulation of the aorta the ovaries were isolated and perfused with Gey & Gey buffer containing 0.2% BSA. The release of radioactivity was monitored for 2 h and analyzed by gel filtration. Five to ten per cent of the radioactivity was released within 2 h and represented small molecular weight peptides and iodotyrosine and [125I]hCG. Analysis of the ovarian radioactivity prior to and after perfusion revealed that virtually all hCG was receptor-bound. Loading the medium with unlabelled hCG displaced [125I]hCG from the receptor but did not enhance its degradation. Histological examination showed that the ovarian tissues were still intact after the 2 h perfusion. Immunohistochemical studies revealed a localization of the hCG at the cell periphery both prior to and after perfusion. These results provide evidence showing that the rate of internalization of receptor-hCG complexes in rat luteal cells is slow in vivo.

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The effect of human chorionic gonadotrophin on the expression of progesterone receptors in human luteal cells in vivo and in vitro

Reproduction ◽

10.1530/rep.1.00216 ◽

2005 ◽

Vol 130 (1) ◽

pp. 83-93 ◽

Cited By ~ 20

Author(s):

W Colin Duncan ◽

Eva Gay ◽

Jacqueline A Maybin

Keyword(s):

Granulosa Cells ◽

Luteal Phase ◽

Progesterone Receptors ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Progesterone Secretion ◽

Late Luteal Phase ◽

Lutein Cell

The human corpus luteum expresses genomic progesterone receptors (PRs) suggesting that progesterone may have an autocrine or paracrine role in luteal function. We hypothesised that the reduction in luteal PR reported in the late-luteal phase augmented progesterone withdrawal and had a role in luteolysis. We therefore tested the hypothesis that luteal rescue with human chorionic gonadotrophin (hCG) would maintain PR expression. PR was immunolocalised to different cell types in human corpora lutea (n = 35) from different stages of the luteal phase and after luteal rescue with exogenous hCG. There was no change in the staining intensity of theca-lutein cell or stromal cell PR throughout the luteal phase or after luteal rescue. In the late-luteal phase, granulosa-lutein cell PR immunostaining was reduced (P < 0.05) but the trend to reduction was also seen after luteal rescue with hCG (P = 0.055). To further investigate the effect of hCG on granulosa-lutein cell PR expression, an in vitro model system of cultured human luteinised granulosa cells was studied. Cells were cultured for 12–13 days exposed to different patterns of hCG and aminoglutethamide to manipulate progesterone secretion (P < 0.0001). Expression of PR A/B and PR B isoforms was examined by quantitative real-time RT-PCR. PR A/B mRNA was lower (P < 0.05) after 11–13 days of culture than after 7 days of culture. This reduction could not be prevented by hCG in the presence (P < 0.05) or absence (P < 0.05) of stimulated progesterone secretion. The expression of PR B mRNA showed a similar pattern (P = 0.054). Simulated early pregnancy in vivo and hCG treatment of luteinised granulosa cells in vitro did not appear to prevent the down-regulation of PR seen during luteolysis.

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