MECHANISM OF THE SELECTIVE SURGE OF FOLLICLE-STIMULATING HORMONE IN DIOESTROUS RATS DURING THE INDUCTION OF OVULATION BY HUMAN CHORIONIC GONADOTROPHIN

1980 ◽  
Vol 86 (3) ◽  
pp. 489-495 ◽  
Author(s):  
SHUJI SASAMOTO ◽  
KAZUYOSHI TAYA
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Time Of Day ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Normal Cycle ◽  
Luteinizing Hormone Releasing Hormone ◽  
Immature Rats ◽  
Lh Release ◽  
Lh Rh

A selective surge of FSH with a small concomitant rise in LH occurred invariably in rats when ovulation was induced by injecting human chorionic gonadotrophin (HCG) at various reproductive stages such as day 15 of lactation and in 29-day-old immature rats as well as in dioestrous animals. No FSH surge occurred on day 3 of lactation or in 26-day-old immature rats in which ovulation could not be induced by HCG. The FSH surge occurred 6–18 h after HCG treatment regardless of the time of day of injection of HCG. Ovulation began by 12 h and was completed by 18 h after injection of HCG. Pituitary responsiveness to luteinizing hormone releasing hormone (LH-RH) with respect to FSH release strikingly increased at 01.00 h on day 1 after HCG injection at 17.00 h of dioestrus (day 0) to levels similar to those of the group at 01.00 h of oestrus, when the greatest response was noted during the normal cycle. With regard to LH release pituitary responsiveness to LH-RH at 01·00 h on day 1 markedly increased but the response was only about half of the response at 01·00 h of oestrus and one third of the response at 17.00 h of pro-oestrus when the greatest response was noted during the normal oestrous cycle. These results indicate that during ovulation the pituitary gland of the rat is highly responsive to LH-RH with respect to the release of FSH, for which secretory changes in the ovary after an ovulating dose of HCG may be responsible.

INHIBITION BY MELATONIN OF THE PITUITARY RESPONSE TO LUTEINIZING HORMONE RELEASING HORMONE IN VIVO

1978 ◽  
Vol 76 (3) ◽  
pp. 487-491 ◽  
Author(s):  
K. YAMASHITA ◽  
M. MIENO ◽  
T. SHIMIZU ◽  
ER. YAMASHITA
Keyword(s):  
Luteinizing Hormone ◽  
Carotid Artery ◽  
Anterior Pituitary ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Lh Rh ◽  
Lh Secretion

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.

RESTORATION OF OESTROGEN POSITIVE FEEDBACK EFFECT ON LH RELEASE BY BROMOCRIPTINE IN HYPERPROLACTINAEMIC PATIENTS WITH GALACTORRHOEA-AMENORRHOEA

1979 ◽  
Vol 91 (3) ◽  
pp. 591-600 ◽  
Author(s):  
Toshihiro Aono ◽  
Akira Miyake ◽  
Takenori Shioji Motoi Yasuda ◽  
Koji Koike ◽  
Keiichi Kurachi
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Serum Prolactin ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
Lh Release ◽  
The Mean ◽  
Lh Rh ◽  
Lh Releasing Hormone ◽  
Positive Feedback Effect

ABSTRACT Five mg of bromocriptine was administered for 3 weeks to 8 hyperprolactinaemic women with galactorrhoea-amernorrhoea, in whom the response of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) to 100 μg of iv LH-releasing hormone (LH-RH) had been evaluated. Twenty mg of conjugated oestrogen (Premarin®) was injected iv any day between the 10th and 12th day from the initiation of the treatment, and serum LH levels were serially determined for 120 h. Hyperresponse of LH with normal FSH response to LH-RH was observed in most patients. Bromocriptine treatment for 10 to 12 days significantly suppressed mean (± se) serum prolactin (PRL) levels from 65.1 ± 23.0 to 10.4 ± 2.0 ng/ml, while LH (12.6 ± 2.1 to 24.8 ± 5.9 mIU/ml) and oestradiol (40.1 ± 7.6 to 111.4 ± 20.8 pg/ml) levels increased significantly. Patients on bromocriptine treatment showed LH release with a peak at 48 h after the injection of Premarin. The mean per cent increases in LH were significantly higher than those in untreated patients with galactorrhoea-amenorrhoea between 32 and 96 h after the injection. The present results seem to suggest that the restoration of LH-releasing response to oestrogen following suppression of PRL by bromocriptine may play an important role in induction of ovulation in hyperprolactinaemic patients with galactorrhoea-amenorrhoea.

ANTIGONADOTROPHIC PROFILE OF ANTISERA AGAINST HUMAN GONADOTROPHIN PREPARATIONS

1971 ◽  
Vol 67 (2) ◽  
pp. 262-276 ◽  
Author(s):  
P. Petrusz ◽  
C. Robyn ◽  
E. Diczfalusy
Keyword(s):  
Biological Activity ◽  
Luteinizing Hormone ◽  
Total Dose ◽  
Follicle Stimulating Hormone ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Immunological Activity ◽  
Human Menopausal Gonadotrophin ◽  
Stimulating Hormone

ABSTRACT Forty-two antisera were prepared in rabbits against human chorionic gonadotrophin (HCG), human hypophysial gonadotrophin (HHG), human urinary luteinizing hormone (LH) and human menopausal gonadotrophin (HMG) preparations. The gonadotrophic profiles of the antigens were previously characterized by bioassay, immunoassay and bioimmunoassay methods. The 25 most potent antisera were tested in statistically valid bioassays for their HCG and follicle stimulating hormone (FSH) neutralizing activities as well as for their neutralizing potencies against the FSH-like activity present in HCG preparations. The anti-HCG/anti-FSH ratios of the anti-HCG sera tested varied between 6.2 and > 254, while those of the anti-HHG, anti-LH and anti-HMG sera were close to 2. It was found that the total dose of immunological activity (anti-HCG neutralizing and anti-FSH neutralizing potency) rather than that of the biological activity administered to the rabbits was decisive for obtaining antisera with high anti-HCG and anti-FSH titers. Immunization with a highly purified HCG preparation (> 17 000 IU/mg) resulted in antisera exhibiting lower anti-HCG/anti-FSH ratios than did immunization with partially purified preparations. A highly purified urinary LH preparation which did not contain any detectable FSH activity gave rise to antisera exhibiting anti-HCG/anti-FSH ratios of approximately 2.0. These highly purified HCG and LH preparations were shown previously to possess high anti-FSH neutralizing potencies (Petrusz et al. 1971b). Booster injections did not change significantly the quality or the titer of the antigonadotrophic sera studied. The HCG neutralizing potency of anti-HCG sera was approximately 3 times higher when assayed against a highly purified HCG preparation (> 17 000 IU/mg) as compared to potency estimates obtained against the laboratory standard of HCG (about 2000 IU/mg). It is suggested that consideration should be given to the establishment of standard preparations of antigonadotrophic sera. It is concluded that bioimmunoassays are more suitably than conventional bioassay methods for the assessment of the antigenic purity of human gonadotrophin preparations.

Sensitivity of rat adenohypophyseal cells to estradiol and LHRH during long-term culture

1981 ◽  
Vol 240 (6) ◽  
pp. E602-E608
Author(s):  
L. Lagace ◽  
F. Labrie ◽  
T. Antakly ◽  
G. Pelletier
Keyword(s):  
Luteinizing Hormone ◽  
Cell Types ◽  
Thyroid Stimulating Hormone ◽  
Time Interval ◽  
Pituitary Cells ◽  
Luteinizing Hormone Releasing Hormone ◽  
Lh Release ◽  
Lh Rh ◽  
Stimulating Hormone

To determine possible effects of the time in culture on the responsiveness of the different pituitary cell types to estrogens, rat anterior pituitary cells were incubated up to 20 days in the presence or absence of 10 nM 17 beta-estradiol. Whereas spontaneous luteinizing hormone (LH) and thyroid-stimulating hormone (TSH) release decreased by 85-90%, follicle-stimulating hormone (FSH) and prolactin accumulation in medium were only 50% decreased after 20 days in culture, thus suggesting that the secretion of FSH and prolactin is less dependent on extrinsic stimulatory factors. Estradiol increased spontaneous LH release and its responsiveness to luteinizing hormone-releasing hormone (LH-RH) up to day 16 in culture, whereas the stimulatory effect of the estrogen on FSH secretion was significant only up to day 6. The stimulatory effect of estradiol on basal TSH release was seen up to day 8 in culture, whereas that on spontaneous prolactin release increased progressively after day 8 in culture up to the last time interval studied (20 days). As revealed by immunocytochemistry, the stimulatory effect of estradiol was not due to changes of cell growth.

PRODUCTION OF ANTISERA AGAINST HIGHLY PURIFIED HUMAN FOLLICLE-STIMULATING HORMONE, LUTEINIZING HORMONE AND THYROID-STIMULATING HORMONE

1976 ◽  
Vol 70 (3) ◽  
pp. 335-344 ◽  
Author(s):  
J. I. THORELL ◽  
B. HOLMSTRÖM
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Thyroid Stimulating Hormone ◽  
High Titre ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Antigenic Determinants ◽  
High Avidity ◽  
Cross Reactions ◽  
Stimulating Hormone

SUMMARY Antisera were produced in rabbits against highly purified preparations of human LH (2000 or 10000 i.u./mg), human FSH (5500 i.u./mg), and human TSH (7·5 i.u./mg). Most rabbits produced antisera of high titre and high avidity. Cross-reactions were minimal between human TSH and human chorionic gonadotrophin (HCG) and between human FSH and HCG but marked between human LH and HCG. TSH and FSH also showed a constant but relatively weak cross-reaction. LH cross-reacted with FSH to a higher degree than did HCG. The avidity of the antisera was high. It was concluded that much of the lack of specificity recorded for glycoprotein antisera are effects of impure immunogens. Some of the true cross-reactions are probably explained by shared antigenic determinants of the β-subunits. Unadsorbed antisera could be used for assay of FSH and TSH in plasma from pregnant women.

EFFECTS OF DEXAMETHASONE ON THE RESPONSES OF LUTEINIZING HORMONE AND TESTOSTERONE TO TWO INJECTIONS OF LUTEINIZING HORMONE RELEASING HORMONE IN YOUNG POSTPUBERTAL BULLS

1978 ◽  
Vol 77 (3) ◽  
pp. 389-395 ◽  
Author(s):  
P. CHANTARAPRATEEP ◽  
M. THIBIER
Keyword(s):  
Luteinizing Hormone ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Site Of Action ◽  
Lh Release ◽  
Lh Rh

Six young postpubertal bulls were studied in two experiments, 3 months apart. In experiment 1, three bulls received i.m. injections of dexamethasone (20 mg) and 5 h later these animals plus three control bulls received i.m. injections of luteinizing hormone releasing hormone (LH-RH, 250 μg). In experiment 2, the controls from experiment 1 received dexamethasone and the treated animals from experiment 1 acted as controls for experiment 2. All bulls also received an i.m. injection of 250 μg LH-RH on day 2 of each experiment. The concentrations of LH and testosterone in samples of jugular blood were determined by radioimmunoassay. There were no significant differences in the patterns of testosterone and LH release between the two experiments. On day 1, the response of LH to LH-RH was significantly (P < 0·05) reduced by dexamethasone, but on day 2 values in the control and treated groups were similar although significantly (P<0·05) lower than values on day 1. The response of testosterone to LH-RH was not affected by dexamethasone. These results are discussed in terms of the site of action at which dexamethasone may act to depress the release of LH.

scholarly journals Molar pregnancy and thyroid storm - literature review

2017 ◽  
Vol 23 (3) ◽  
pp. 121-125 ◽  
Author(s):  
G. A. Filipescu ◽  
Oana Alina Solomon ◽  
Nicoleta Clim ◽  
Amelia Milulescu ◽  
Andreea Gratiana Boiangiu ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Literature Review ◽  
Follicle Stimulating Hormone ◽  
Cross Reactivity ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Thyroid Storm ◽  
Unusual Complication ◽  
Molar Pregnancy ◽  
Dilation And Curettage

AbstractMolar pregnancies results from a tainted fertilization process. Trophoblastic thyroidian hyper function is an unusual complication of a molar pregnancy. The degree of thyroid stimulation and the severity of clinical hyperthyroidism is directly proportional to HCG concentration. Human chorionic gonadotrophin is almost identical with TSH, luteinizing hormone (LH) and follicle-stimulating hormone, this analogy in the structure will cause cross-reactivity with their receptors. Hyperthyroid status can vary from asymptomatic hyper function to thyroid storm. Dilation and curettage represents the treatment for hyperthyroidism in molar pregnancy. Awareness of this condition is important for diagnosis and treatment.

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