Serum LH-RH and LH patterns in men after pulsatile administration of LH-RH. comparison of different doses and routes of administration

1984 ◽  
Vol 20 (6) ◽  
pp. 1394 ◽  
Author(s):  
J. Happ ◽  
H. Schultheiss ◽  
H. Mölle ◽  
G. Hör
Keyword(s):  
Routes Of Administration ◽  
Serum Lh ◽  
Pulsatile Administration ◽  
Lh Rh ◽  
Different Doses

Serotonin-reinstatement of luteinizing hormone surges after loss of positive feedback in ovariectomized rats bearing subcutaneous capsules containing oestrogen

1983 ◽  
Vol 98 (1) ◽  
pp. 7-17 ◽  
Author(s):  
R. F. Walker
Keyword(s):  
Positive Feedback ◽  
Ovariectomized Rats ◽  
Facilitatory Effect ◽  
Serum Progesterone ◽  
Serotonin Content ◽  
Serum Lh ◽  
Serotonin Turnover ◽  
Lh Rh ◽  
Lh Releasing Hormone ◽  
Feedback Responses

In ovariectomized rats treated chronically with oestrogen there is a loss of positive feedback effects on LH secretion. This was not due to depletion of pituitary LH since injection of LH releasing hormone (LH-RH; 50 ng/100 g body wt) caused a significant (P < 0·01) rise in serum LH even after the loss of spontaneous LH surges. However, the magnitude of the increase in serum LH in response to LH-RH was greater (412 ± 41 μg/l) before than after (291 ± 29 μg/l) loss of the LH surges. Excessive blood sampling was also not responsible, since positive feedback responses declined comparably in rats bled daily or once every 3–4 days. Progesterone (0·5 mg s.c.), administered for 5 consecutive days, failed to restore LH surges indicating that deficiency of this steroid after ovariectomy does not cause positive feedback responses to disappear in rats exposed chronically to oestrogen. Moreover regular daily fluctuations in serum progesterone, probably of adrenal origin, occurred before as well as after daily LH surges were lost. Serotonin content and turnover were depressed (P < 0·05) when ovariectomized rats first received the subcutaneous capsules containing oestrogen. This change correlated temporally with the onset of daily LH surges and was eventually lost. After 30 days exposure to oestrogen, serotonin turnover increased (P < 0·01) and positive feedback responses were absent. Catecholamine levels and turnover did not show differential responses to oestrogen and were depressed after acute as well as chronic steroid treatment. p-Chlorophenylalanine (pCPA; 250 mg/kg)+ l-dihydroxyphenylalanine (l-DOPA; 200 mg/kg), which depress serotonin and enhance catecholamine synthesis respectively, failed to reinstate LH surges, but these were restored in 22% of the rats receiving l-DOPA alone. pCPA, followed 2 days later by 5-hydroxytryptophan (5-HTP) at 11.00 h, reinstated LH surges in 88% of rats, and a dose–response curve showed that as little as 4 mg 5-HTP/kg stimulated repetitive LH surges when given with pCPA according to this schedule. However, the administration of α-methyl-p-tyrosine + l-DOPA, an analogous treatment involving catecholamines, was only marginally effective (15%). These findings suggest that perturbations of monoamine metabolism occurring in ovariectomized rats exposed to oestrogen for several weeks contribute to loss of daily LH surges. Since pCPA + 5-HTP restored LH surges most effectively, then positive feedback may disappear as the facilitatory effect of serotonin is lost after chronic oestrogen administration.

ENDOCRINE STUDIES AND SUCCESSFUL TREATMENT IN A PATIENT WITH TRUE HERMAPHRODITISM

1979 ◽  
Vol 91 (1) ◽  
pp. 184-192
Author(s):  
Evangelina Valdés ◽  
Carlos Fernández del Castillo ◽  
Raul Gutiérrez ◽  
Fernando Larrea ◽  
Martha Medina ◽  
...  
Keyword(s):  
Chromosome Complement ◽  
Reproductive Function ◽  
External Genitalia ◽  
Serum Testosterone ◽  
Serum Levels ◽  
Normal Children ◽  
Serum Lh ◽  
Genital Ambiguity ◽  
And Gender ◽  
Lh Rh

ABSTRACT A 12-year old, 46 XX true hermaphrodite born with genital ambiguity was studied and successfully treated. The serum LH and FSH profile resembled that of a pubertal normal individual, and LH-RH administration induced a normal LH response. Baseline testosterone serum levels were within the range for normal children. Exogenous HCG stimulation induced a significant serum testosterone increase up to values similar to those observed in normal post-pubertal males. Surgical examination disclosed the presence of bilateral ovotestis, normal Mullerian derivatives, epididymis, and vas deferens. A complete ovotestis with testicular predominance and the testicular portion of the contralateral ovotestis as well as the Wolffian derivatives, were removed. A further HCG stimulation 3 months after surgery, failed to induce serum testosterone increase. Spontaneous menarche was observed 6 months after surgery and ovulation was well documented. At present the patient has several characteristics of female sex including those of chromosome complement, gonad, internal and external genitalia, hormone levels and gender identity, thus demonstrating that treatment was successful and that reproductive function could be obtained. The finding of spontaneous ovulation following removal of the testicular portion suggests normal cyclic gonadotrophic release implying a difference between animal models and man in regard to hypothalamic virilization.

scholarly journals Pharmacokinetics and pharmacodynamics of GH: dependence on route and dosage of administration

2007 ◽  
Vol 156 (6) ◽  
pp. 647-653 ◽  
Author(s):  
Alexandra Keller ◽  
Zida Wu ◽  
Juergen Kratzsch ◽  
Eberhard Keller ◽  
Werner F Blum ◽  
...  
Keyword(s):  
Pharmacokinetic Parameters ◽  
High Dose ◽  
Open Label ◽  
Igf Binding Proteins ◽  
Trained Subjects ◽  
Routes Of Administration ◽  
Igf Binding ◽  
Serum Gh ◽  
Different Doses ◽  
Igfbp 3

Objective: Pharmacokinetic and pharmacodynamic data after recombinant human GH (rhGH) administration in adults are scarce, but necessary to optimize replacement therapy and to detect doping. We examined pharmacokinetics, pharmacodynamics, and 20 kDa GH after injection of rhGH at different doses and routes of administration. Design: Open-label crossover study with single boluses of rhGH. Methods: Healthy trained subjects (10 males, 10 females) received bolus injections of rhGH on three occasions: 0.033 mg/kg s.c., 0.083 mg/kg s.c., and 0.033 mg/kg i.m. Concentrations of 22 and 20 kDa GH, IGF-I, and IGF-binding proteins (IGFBP)-3 were measured repeatedly before and up to 36 h after injection. Results: Serum GH maximal concentration (Cmax) and area under the time-concentration curve (AUC) were higher after i.m. than s.c. administration of 0.033 mg/kg (Cmax 35.5 and 12.0 μ g/l; AUC 196.2 and 123.8). Cmax and AUC were higher in males than in females (P < 0.01) and pharmacodynamic changes were more pronounced. IGFBP-3 concentrations showed no dose dependency. In response to rhGH administration, 20 kDa GH decreased in females and remained suppressed for 14–18 h (low dose) and 30 h (high dose). In males, 20 kDa GH was undetectable at baseline and throughout the study. Conclusions: After rhGH administration, pharmacokinetic parameters are mainly influenced by route of administration, whereas pharmacodynamic variables and 20 kDa GH concentrations are determined mainly by gender. These differences need to be considered for therapeutic use and for detection of rhGH doping.

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.

Serum LH and FSH Responses to Synthetic LH-RH in Normal Infants, Children and Patients With Turner's Syndrome

PEDIATRICS ◽  
1974 ◽  
Vol 54 (4) ◽  
pp. 470-475
Author(s):  
Selzo Suwa ◽  
Hatae Maesaka ◽  
Ichiro Matsui
Keyword(s):  
Normal Subjects ◽  
Serum Levels ◽  
Young Female ◽  
Normal Female ◽  
Turner's Syndrome ◽  
Turner’S Syndrome ◽  
Normal Children ◽  
Serum Lh ◽  
Female Children ◽  
Lh Rh

Effects of LH-RH on LH and FSH release were studied in 26 normal children and six patients with Turner's syndrome (two of them showed 45 x karyotype and the others were mosaics). Synthetic LH-RH (2µg/kg of body weight) was given intramuscularly after an overnight fast. The increase of serum FSH level was significantly greater in normal female infants than male infants. A similar tendency was observed in normal female children aged 2 to 9 years. No sex difference was observed in the LH response to LH-RH in all the normal subjects Studied. The response of FSH release to LH-RH was significantly greater than that of LH in female infants and young female children. The responsiveness of LH to LH-RH gradually increased with advancing age. Basal serum levels of FSH rather than LH were high in the patients with Turner's syndrome. Again a much greater increase of serum FSH than of LH was noted after the administration of LH-RH to patients with Turner's syndrome.

SERUM LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE CONCENTRATIONS IN IMMATURE FEMALE RATS TREATED WITH MULTIPLE INJECTIONS AND VARIOUS AMOUNTS OF LUTEINIZING HORMONE RELEASING HORMONE

1975 ◽  
Vol 66 (1) ◽  
pp. 13-20 ◽  
Author(s):  
D. C. JOHNSON ◽  
R. S. MALLAMPATI
Keyword(s):  
Luteinizing Hormone ◽  
Constant Stimulus ◽  
Female Rats ◽  
Intact Female ◽  
Immature Female ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
Lh Rh

SUMMARY Release of immunoreactive LH and FSH was induced in immature intact female rats by repeated injections of synthetic luteinizing hormone releasing hormone (LH-RH). Altering the dose of LH-RH (5, 10, 20, 50 ng) and the frequency of administration (every 10, 20, 30 or 60 min) over a period of 2 h produced a variety of serum LH and FSH concentrations and ratios. When the dose was a constant 20 ng but the frequency of injections was either 20 or 30 min, a steady state in serum gonadotrophin concentrations was reached within 1 h and the level remained the same during the second hour. When given every 10 min, 20 ng LH-RH produced a much higher concentration of both LH and FSH during the second hour of stimulation. Examination of the gonadotrophin levels after each injection of LH-RH showed that the pituitary response was variable in spite of a constant stimulus.

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