The role of oestrogens on gonadotrophin secretion in the testicular feminization syndrome1

1980 ◽  
Vol 95 (3) ◽  
pp. 314-318 ◽  
Author(s):  
Martha Medina ◽  
Alfredo Ulloa-Aguirre ◽  
Maria A. Fernández ◽  
Gregorio Pérez-palacios
Keyword(s):  
Clomiphene Citrate ◽  
Poor Response ◽  
Testicular Feminization ◽  
Normal Response ◽  
Serum Lh ◽  
Gonadotrophin Secretion ◽  
Before And After ◽  
Complete Form ◽  
Lh Secretion

Abstract. The role of oestrogens on gonadotrophin secretion was assessed in three related patients with the complete form of testicular feminization syndrome. Serum LH and FSH levels were measured before and after I.RH stimulation as well as before, during and after chronic clomiphene citrate administration. Moderately elevated LH basal levels with a significant LH rise following I.RH were observed. Normal or even low FSH level with poor response to LRH were found in all subjects. Administration of clomiphene citrate resulted in a significant serum LH increase without any change of FSH. Following castration both LH and FSH rose and a normal response to LRH was observed. These results were interpreted as demonstrating that, while endogenous oestrogens modulate LH secretion in patients with androgen unresponsiveness, it plays no role in regulating FSH secretion and suggested that a factor of testicular origin without androgenic or oestrogenic activity is responsible for FSH regulation.

THE METABOLISM OF TESTOSTERONE, ANDROSTENEDIONE AND OESTRONE BY TESTES FROM A CASE OF TESTICULAR FEMINIZATION

1968 ◽  
Vol 42 (3) ◽  
pp. 391-403 ◽  
Author(s):  
A. P. WADE ◽  
G. S. WILKINSON ◽  
J. C. DAVIS ◽  
T. N. A. JEFFCOATE
Keyword(s):  
Testicular Tissue ◽  
Major Metabolite ◽  
Testicular Feminization ◽  
Phenolic Fraction ◽  
Enzyme Systems ◽  
Before And After ◽  
Complete Form ◽  
Urinary Steroid ◽  
Chromatographic Evidence

SUMMARY [4-14C]Testosterone, [4-14C]androstenedione and [4-14C]oestrone were incubated with testicular tissue obtained from an 18-yr.-old patient with the complete form of the testicular feminization syndrome. Considerable biosynthesis of testosterone from androstenedione occurred, but metabolism of testosterone by the tissue was minimal. The small phenolic fraction from these incubations did not contain any recognizable oestrogens. Metabolism of oestrone was almost complete, less than 4% being recovered as unchanged oestrone. Of eight areas of radioactivity found during chromatography, five were shown to be associated with oestrone, 2-methoxyoestrone, oestradiol-17β, 2-hydroxyoestradiol-17β, and 2-methoxy-oestradiol-17β. Chromatographic evidence suggested that an oxo-oestrone and a compound more polar than oestriol were present. No oestriol was found. The results confirm those of other workers to the effect that testosterone is the major metabolite of androstenedione in feminizing testes. Incubation of the testes with oestrone showed them also to possess the enzyme systems necessary for hydroxylation at position 2 and the subsequent methylation of this group. Urinary steroid measurements before and after removal of the testes showed these organs to be actively secreting. Attempts to demonstrate oestrogenic activity in the urine additional to that accounted for by chemical estimation were unsuccessful.

Non-responsiveness of serum gonadotropins and testosterone to pulsatile GnRH in hemochromatosis suggesting a pituitary defect

1993 ◽  
Vol 128 (4) ◽  
pp. 351-354 ◽  
Author(s):  
Lise Duranteau ◽  
Philippe Chanson ◽  
Joelle Blumberg-Tick ◽  
Guy Thomas ◽  
Sylvie Brailly ◽  
...  
Keyword(s):  
Single Pulse ◽  
Serum Testosterone ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Gonadotropin Secretion ◽  
Pulsatile Gnrh ◽  
Serum Lh ◽  
Before And After ◽  
Gnrh Therapy ◽  
Lh Secretion

We investigated the potential pituitary origin of gonadal insufficiency in hemochromatosis. Gonadotropin secretion was studied in seven patients with hemochromatosis and hypogonadism, before and after chronic pulsatile GnRH therapy. Pulsatile LH secretion was studied before (sampling every 10 min for 6 h) and after 15-30 days of chronic pulsatile GnRH therapy (10-12 μg per pulse). Prior to GnRH therapy, all the patients had low serum testosterone, FSH and LH levels. LH secretion was non-pulsatile in four patients, while a single pulse was detected in the remaining three. Chronic pulsatile GnRH administration did not increase serum testosterone levels; similarly, serum LH levels remained low: neither pulse frequency nor pulse amplitude was modified. We conclude that hypogonadism in hemochromatosis is due to pituitary lesions.

Role of aromatase inhibitor in ovulation induction in patients with poor response to clomiphene citrate

2006 ◽  
Vol 32 (5) ◽  
pp. 502-506 ◽  
Author(s):  
Mosammat R. Begum ◽  
Ehsan Quadir ◽  
Anowara Begum ◽  
Rowsan A. Begum ◽  
Momtaz Begum
Keyword(s):  
Aromatase Inhibitor ◽  
Ovulation Induction ◽  
Clomiphene Citrate ◽  
Poor Response

Adrenal progesterone facilitates the negative feedback of oestrogen on LH release in ovariectomized rats

1993 ◽  
Vol 139 (2) ◽  
pp. 253-258 ◽  
Author(s):  
A. M. Salicioni ◽  
R. W. Carón ◽  
R. P. Deis
Keyword(s):  
Ovariectomized Rats ◽  
Adrenal Steroids ◽  
Serum Progesterone ◽  
Oestrogen Treatment ◽  
Ovx Rats ◽  
Serum Lh ◽  
Oestradiol Benzoate ◽  
Lh Release ◽  
Lh Secretion

ABSTRACT There is evidence that the adrenals play a role in the regulation of the synthesis and release of gonadotrophins in various vertebrates. The aim of this study was to determine the part played by adrenal steroids, with special reference to progesterone, on the concentration of LH in ovariectomized (OVX) and oestrogen-primed rats. OVX rats received a single s.c. injection of vehicle or oestradiol benzoate (OB, 20 μg/rat). This day was designated as day 0. Three or four days later (day 3–day 4), the rats were treated with mifepristone (10 mg/kg) or with two doses of progesterone antiserum and blood samples were obtained at 13.00 and 18.00 h. OB treatment of OVX rats reduced serum LH at 13.00 h and 18.00 h on day 3 but only at 13.00 h on day 4. The administration of mifepristone at 08.00 h to OVX and oestrogen-treated rats induced a significant increase in serum LH at 18.00 h on days 3 and 4, without modifying the values at 13.00 h. When mifepristone was given at 13.00 h a much larger increase in serum LH was obtained at 18.00 h. In OVX and oestrogen-treated rats, adrenalectomy on day 2 (08.00–09.00 h) induced an increase in serum LH at 18.00 h similar to that observed in the OVX and oestrogen-primed rats after mifepristone treatment. In order to determine the specificity of the effect of mifepristone, a group of OVX and oestrogentreated rats was injected with progesterone antiserum at 08.00 and 13.00 h on day 3. Serum LH concentrations at 13.00 and 18.00 h on day 3 were similar to values obtained in OVX rats treated with oestrogen and mifepristone. Serum progesterone was measured at 08.00 and 13.00 h in OVX and OVX and oestrogenprimed rats. At both times, values were similar in OVX rats but oestrogen treatment significantly increased serum progesterone levels. The important role of adrenal progesterone on the regulation of LH secretion in OVX and oestrogen-primed rats is evident from these results. Blocking progesterone action at the receptor level, we showed that OB significantly increased LH values at 18.00 h. On the basis of these studies it is tempting to speculate on the possibility of an inhibitory or stimulatory effect of oestrogen on serum LH concentration in OVX rats, according to the presence or absence of adrenal progesterone action. Journal of Endocrinology (1993) 139, 253–258

The N-methyl-d-aspartate receptor antagonist MK-801 delays the onset of puberty and may acutely block the first spontaneous LH surge and ovulation in the rat

1991 ◽  
Vol 131 (3) ◽  
pp. 435-441 ◽  
Author(s):  
H. M. A. Meijs-Roelofs ◽  
P. Kramer ◽  
E. C. M. van Leeuwen
Keyword(s):  
Nmda Receptors ◽  
Receptor Antagonist ◽  
Acute Treatment ◽  
Physiological Role ◽  
Female Rat ◽  
Mk 801 ◽  
Aspartate Receptor ◽  
Serum Lh ◽  
Lh Secretion

ABSTRACT The physiological role of activated hypothalamic N-methyl-d-aspartate (NMDA) receptors during the final phase of female sexual maturation was explored in the rat. The effects of administration of the specific non-competitive receptor antagonist MK-801 on the occurrence of first ovulation and on LH secretion were studied. Injections of MK-801 (0·1–0·2 mg/kg body wt, s.c.) were given once or twice daily, starting at 28 or 35 days of age and continuing up to the day of first ovulation, resulted in a significant delay of this ovulation. Rats that were treated daily with 0·2 mg MK-801/kg, starting on days 30 or 34 and continuing up to day 38, but not including the day of first pro-oestrus, also showed retarded first ovulation. No decrease in serum LH concentration, compared with control rats, could be detected in these rats. Acute treatment with MK-801 (one or two injections of 0·2, or one injection of 0·5 mg/kg) given at 11.30 h (and 16.00 h) on the day of first pro-oestrus produced partial (1 × 0·2 mg/kg) or complete (2×0·2 and 1 × 0·5 mg/kg) blockade of first ovulation; blocked rats ovulated 1 day later. Serum LH concentrations at 16.00 h on the day of pro-oestrus were significantly decreased in all MK-801-treated groups compared with saline-injected control rats. At 19.00 and 22.00 h LH concentrations remained low in all non-ovulating MK-801-treated rats, but increased in the MK-801-treated rats that ovulated. Thus chronic blockade of the NMDA receptors by the antagonist MK-801 delays but does not prevent first ovulation, whereas acute treatment blocks the pro-oestrous LH peak. It was concluded that activation of NMDA receptors plays an important role both in tonic and preovulatory LH secretion during the onset of puberty in the female rat. Journal of Endocrinology (1991) 131, 435–441

Role of the organum vasculosum laminae terminalis in the control of gonadotrophin secretion in rats

1982 ◽  
Vol 93 (3) ◽  
pp. 355-NP ◽  
Author(s):  
F. Piva ◽  
P. Limonta ◽  
L. Martini
Keyword(s):  
Ovariectomized Rats ◽  
Adult Rats ◽  
Organum Vasculosum Laminae Terminalis ◽  
Serum Lh ◽  
Parallel Increase ◽  
Gonadotrophin Secretion ◽  
Radiofrequency Lesions ◽  
Organum Vasculosum

The organum vasculosum laminae terminalis (OVLT) was destroyed by radiofrequency lesions in regularly cycling and in long-term ovariectomized adult rats. After OVLT lesion practically all cyclic females (16 out of 22) became dioestrous, as indicated by vaginal smears. At the time of killing these animals (8 days after the lesion) serum LH levels were undetectable, while serum FSH was as low as in cyclic animals in dioestrus. In the few OVLT-lesioned animals which exhibited some sort of oestrous cyclicity, serum LH showed a small subphysiological increase at pro-oestrus: this was not accompanied by a parallel increase in serum FSH and in these animals a delayed peak of FSH occurred on the day of oestrus. Ovariectomized rats bearing OVLT lesions had serum titres of LH and FSH as high as those of ovariectomized control rats. It is suggested that the OVLT may play a role in the control of the cyclic release of gonadotrophins but is not involved in the tonic regulation of gonadotrophin secretion.

INHIBITION OF MID-CYCLE GONADOTROPHIN RELEASE IN HEALTHY WOMEN BY PIMOZIDE AND FUSARIC ACID

1976 ◽  
Vol 81 (2) ◽  
pp. 455-460 ◽  
Author(s):  
J. Leppäluoto ◽  
P. Männistö ◽  
T. Ranta ◽  
M. Linnoila
Keyword(s):  
Dopamine Receptors ◽  
Fusaric Acid ◽  
Control Level ◽  
Normal Cycle ◽  
Lh Surge ◽  
Healthy Women ◽  
Serum Lh ◽  
Gonadotrophin Secretion ◽  
Before And After ◽  
Menstrual History

ABSTRACT The effects of pimozide, a drug blocking dopamine receptors, and fusaric acid, an inhibitor of dopamine β-hydroxylase, on mid-cycle release of FSH and LH were studied in 8 healthy women 20–25 years of age. None had used contraceptive drugs for the preceding 10 months. From the menstrual history and serum LH determinations during the normal cycle, mid-cycle gonadotrophin bursts were predicted for the following three cycles. Two days before and after the expected gonadotrophin surge were regarded as sufficient for the drug tests. Pimozide (initially 2 mg, then 1 mg/day) and fusaric acid (600 mg/day) were administered in a randomized cross-over study. The mid-cycle LH values were reduced from the control level of 56 ± 10 mIU/ml (mean ± se) to 22 ± 4 mIU/ml by pimozide (P < 0.001) and to 17 ± 5 mIU/ml by fusaric acid (P < 0.001). The serum FSH level was 9 ± 2 mIU/ml on the day of the LH surge and did not change significantly during treatment with either drug. The LH and FSH responses to synthetic LRF (100 μg iv) were not changed by pimozide or fusaric acid. The rise of basal temperature associated with ovulation was not affected by the drugs. These results suggest that suprapituitary noradrenergic and dopaminergic neurotransmitters are involved in the regulation of mid-cycle gonadotrophin secretion in women.

A possible role of clomiphene citrate in the control of pre-ovulatory LH surge during induction of ovulation

1985 ◽  
Vol 109 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Naoki Terakawa ◽  
Ikuya Shimizu ◽  
Hirohisa Tsutsumi ◽  
Toshihiro Aono ◽  
Keishi Matsumoto
Keyword(s):  
Nuclear Receptor ◽  
Clomiphene Citrate ◽  
Ovariectomized Rats ◽  
Receptor Complex ◽  
Oestrogen Receptors ◽  
Lh Surge ◽  
Serum Lh ◽  
Lh Release

Abstract. A possible role of clomiphene citrate (clomiphene) in the control of ovulation in anovulatory women was investigated. Since a single ip administration of 5 μg oestradiol-17β (E2) to long-term ovariectomized rats did not induce LH surge, the following studies were designed to determine whether pretreatment with clomiphene followed by administration of E2 could induce LH surge in the ovariectomized rats. Changes in cytoplasmic and nuclear oestrogen receptors (ER) were also examined in the pituitaries of these animals. An ip injection of 200 μg clomiphene suppressed serum LH levels significantly for 72 h. The clomiphene injection rapidly caused an elevation of nuclear ER with a concomitant depletion of cytoplasmic ER level in the pituitary and the ER levels remained almost unchaged for 72 h. An administration of E2 12 or 24 h after the clomiphene injection had no significant effects on either the serum LH levels or the cytoplasmic and nuclear ER levels, compared with those induced by clomiphene alone. However, LH surge and the depletion of nuclear ER in the pituitary occurred 24 h later when E2 was injected 48 h after the clomiphene administration. The E2-induced LH release seems to be induced by a replacement of clomiphene by E2 on the nuclear receptor complex. These results suggest that clomiphene may exert actions directly on the pituitary gland to augment oestrogeninduced LH release.

Suppression of LH secretion by oestradiol, dihydrotestosterone and trenbolone acetate in the acutely castrated bull

1984 ◽  
Vol 100 (1) ◽  
pp. 107-112 ◽  
Author(s):  
T. W. Gettys ◽  
M. J. D'Occhio ◽  
D. M. Henricks ◽  
B. D. Schanbacher
Keyword(s):  
Feedback Control ◽  
Pituitary Gland ◽  
Treated Group ◽  
Primary Site ◽  
Trenbolone Acetate ◽  
Releasing Hormone ◽  
Serum Lh ◽  
Lh Releasing Hormone ◽  
Lh Secretion

ABSTRACT Twenty acutely castrated bulls were used to investigate the role of androgenic and oestrogenic steroids in the feedback control of LH secretion. The effects of 5α-dihydrotestosterone (DHT) or the growth stimulants trenbolone acetate (TBA) or oestradiol-17β (OE2) on serum LH secretory profiles were measured. In addition, pituitary LH responses to exogenous LH releasing hormone (LHRH) were determined to differentiate between hypothalamic and pituitary sites of steroid action. At the time of castration, two groups of animals were given implants of either 45 mg OE2 or 200 mg TBA. Another group received equivalent to 30 mg daily injections of DHT. Control steers showed an increase in LH from 2·4 ± 0·5 (s.e.m.) μg/l to 7·0 ± 0·5 μg/l during the week after castration. Treatment with DHT and TBA prevented the post-castration rise in serum LH. In contrast, steers given implants of OE2 showed a significantly greater increase in LH than controls 1 day after castration, but by day 5 LH declined in the OE2-treated group to precastration values. Five weeks after castration control steers secreted LH in pulses at intervals of 40–50 min and with an amplitude of 4·2± 0·4 μg/l. Pulses were not detected in the LH profiles of the steroid-treated steers. Dihydrotestosterone and TBA significantly reduced pituitary LH responses to exogenous LHRH, whereas steers receiving OE2 showed LH responses to LHRH which were similar to those observed in castrated controls. These results support the hypothesis that androgenic and oestrogenic components participate separately in the feedback control of LH secretion in the bull. A similar LH response to exogenous LHRH in control and OE2-treated animals suggests that the primary site of oestrogen feedback is at the level of the hypothalamus. Conversely, the small LH response to LHRH in androgen-treated animals suggests that androgen feedback is, in part, imposed at the level of the pituitary gland. Interestingly, LH secretion is regulated by dosages of androgenic and oestrogenic steroids which are available commercially as growth stimulants for cattle. J. Endocr. (1984) 100, 107–112

ABSENCE OF POSITIVE FEEDBACK EFFECT OF OESTROGEN ON LH RELEASE IN PATIENTS WITH TESTICULAR FEMINIZATION SYNDROME

1978 ◽  
Vol 87 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Toshihiro Aono ◽  
Akira Miyake ◽  
Takayuki Kinugasa ◽  
Keiichi Kurachi ◽  
Keishi Matsumoto
Keyword(s):  
Sex Differentiation ◽  
Serum Testosterone ◽  
Normal Male ◽  
Testicular Feminization ◽  
Serum Lh ◽  
Exogenous Oestrogen ◽  
Lh Release ◽  
Normal Males ◽  
Lh Rh

ABSTRACT The response of serum LH to exogenous oestrogen administration was studied in 5 patients with testicular feminization syndrome (TFS). The serum LH levels were elevated in all the patients, while serum testosterone levels were within the normal male range. Serum FSH levels were elevated in 4 patients and normal in one patient. Intravenous administration of 100 μg of LH-RH provoked a further increase in both LH and FSH. Following intravenous injection of 20 mg of conjugated oestrogen (Premarin®), the LH levels were serially determined until 120 h in TFS patients, 5 normal males, and 10 normal females during the mid-follocular phase (D7-9). Both TFS patients and normal males showed no LH release following oestrogen injection in contrast to normal females who displayed a significant increase in LH with a peak at 48 to 56 h after the injection. These results seem to suggest that the insensitivity of the hypothalamus to androgen in TFS patients do not affect the sex differentiation of the hypothalamus. The possible role of oestradiol conversion from testosterone in the hypothalamus is discussed.

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