LH- and FSH-secreting pituitary adenoma in a postmenopausal woman.

Gonadotropin secreting pituitary adenomas have been reported with increasing frequency in men, but they are still rarely recognized in women. We report a 52-year-old postmenopausal woman with LH- and FSH-secreting pituitary adenoma. She had increased LH (37.0 +/- 13.7 IU/l) (mean +/- SD) and FSH (109.9 +/- 26.7 IU/l) but these concentrations were within normal ranges in 80 postmenopausal women (LH: 29.7 +/- 18.3 IU/l, FSH: 104.0 +/- 43.9 IU/l). The administration of GnRH and conjugated estrogen resulted in normal response of LH and FSH. No abnormal response of gonadotropin to TRH and bromocriptine was observed. After transsphenoidal adenomectomy both LH and FSH decreased (LH: 11.1 +/- 4.2 IU/l, FSH: 37.0 +/- 9.6 IU/l). An immunocytochemical study revealed that the adenoma cells synthesize both LH and FSH. The rarity of gonadotropin secreting pituitary adenomas in women could be the result of greater difficulty in recognition due to an increase in serum gonadotropin in postmenopausal women.     

Changes in plasma inhibin levels following pulsatile gonadotrophin-releasing hormone therapy in a man with idiopathic hypogonadotrophic hypogonadism

Changes in circulating inhibin levels were related to changes in testosterone (T) and the gonadotrophins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in a hypogonadotrophic hypogonadal man before and during pulsatile gonadotrophin-releasing hormone therapy which resulted in normal spermatogenesis. Before treatment, the plasma inhibin levels in the patient (210 +/- 50 U/l; mean +/- SD of four samples) were lower than in normal controls (552 +/- 150 U/l; p less than 0.01), as were T (1.1 nmol/l) and gonadotrophin (less than 1.0 IU/l) levels. Within 1 week of gonadotrophin-releasing hormone treatment, plasma LH (14.1 +/- 0.7 IU/l) and FSH (14.4 +/- 0.6 IU/l) reached supraphysiological levels. In response, T and inhibin concentrations increased progressively to reach high normal levels (27.7 +/- 1.6 nmol/l and 609 +/- 140 U/l) at 4 weeks, by which time the gonadotrophin levels stared to decline and gradually returned to the normal range between 12 and 24 weeks of treatment. There was a concomitant decrease in T and inhibin levels which remained within the normal range. The decline in the FSH level following the rise in testicular hormones was earlier and steeper than that of LH (37.5% decrease at 4 weeks vs. 30.4% at 12 weeks), suggesting that T and inhibin may act together to inhibit pituitary FSH secretion as opposed to LH secretion which is primarily controlled by T. It is concluded that, in man, during maturation of the pituitary-testicular axis, changes in circulating inhibin parallel those of T, and quantitatively normal inhibin secretion is dependent on gonadotrophin stimulation. FSH secretion may be regulated through negative feedback control, by both T and inhibin.     

Reproductive endocrine functions in men with primary hypothyroidism: effect of thyroxine replacement

Reproductive endocrine functions were studied in men with primary hypothyroidism during the hypothyroid phase and after achieving euthyroid status with thyroxine substitution therapy. Hypergonadotropism [luteinising hormone (LH), 18.7 +/- 7.3 IU/l; follicle-stimulating hormone (FSH), 6.3 +/- 2.0 IU/l], low serum testosterone (6.1 +/- 2.8 nmol/l), low serum sex-hormone-binding globulin (SHBG; 13.2 +/- 2.0 nmol/l) and subnormal testosterone response to human chorionic gonadotropin hCG; (30% increase in serum testosterone following hCG) observed during the hypothyroid phase were restored to normal (LH, 7.2 +/- 2.0 IU/l; FSH, 2.7 +/- 0.9 IU/l; testosterone, 12.9 +/- 2.7 nmol/l; SHBG, 26.5 +/- 8.4 nmol/l, and 2-fold increase in serum testosterone following hCG) with thyroxine substitution therapy. Some improvement in sperm count and motility was also observed.     

Inhibin B,follicle stimulating hormone,luteinizing hormone,and estradiol and their relationship to the regulation of follicle development in girls during childhood and puberty

Inhibin B, produced by granulosa cells in the ovary, is a heterodimeric glycoprotein suppressing synthesis and secretion of the follicle stimulating hormone (FSH). The aim of the present study was to determine hormone profiles of inhibin B, FSH, luteinizing hormone (LH), and estradiol in girls during childhood and puberty and to evaluate whether inhibin B is a marker of follicle development. We examined the correlation between inhibin B and gonadotropins and estradiol during the first two years and across the pubertal development. Using a specific two-side enzyme-linked immunosorbent assay (ELISA), inhibin B levels were measured in the serum of 53 healthy girls divided into 8 groups according to age. In addition, serum FSH, LH, and estradiol were measured by chemiluminescent immunoassay in all serum samples. A rise in serum levels of inhibin B (55.2+/-7.3 ng/l, mean +/- S.E.M.) and FSH (1.78+/-0.26 UI/l), concomitant with a moderate increment of serum LH (0.36+/-0.09 UI/l) and estradiol (45.8+/-12.2 pmol/l) concentrations was observed during the first three months of life and declined to prepubertal concentrations thereafter. A strong positive correlation between inhibin B and FSH (r = 0.48, p<0.05), LH (r = 0.68, p<0.001) and estradiol (r = 0.59, p<0.01) was demonstrated during the first 2 years of life. A rise in serum levels of inhibin B, FSH, LH, and estradiol was found throughout puberty. Inhibin B had a strong positive correlation with FSH (stage I of puberty: r = 0.64, p<0.05; stage II of puberty: r = 0.86, p<0.01), LH (I: r = 0.61, p<0.05; II: r = 0.67, p<0.05), and estradiol (II: r = 0.62, p<0.05) in early puberty. From pubertal stage II, inhibin B lost this relationship to gonadotropins and estradiol. Serum inhibin B and FSH levels increased significantly during pubertal development, with the highest peak found in stage III of puberty (133.5+/-14.3 ng/l), and decreased thereafter. In conclusion, inhibin B is produced in a specific pattern in response to gonadotropin stimulation and plays an important role in the regulation of the hypothalamic-pituitary-gonadal axis during childhood and puberty in girls. Inhibin B is involved in regulatory functions in developing follicles and seems to be a sensitive marker of ovarian follicle development.     

Prolonged suppression of gonadotropin secretion after weight recovery in an anorectic patient with Turner's syndrome: reduced gonadal function in anorexia nervosa is independent in part on nutrition

Two hypotheses have been postulated as to the pathogenesis of hypogonadotropinemia in anorexia nervosa; one is starvation and weight loss and the other is a psychological factor to influence gonadotropin secretion. Our patient suffered from very rare concurrence of Turner's syndrome and anorexia nervosa and a study of this experiment in nature provided important evidences concerning decreased secretion of gonadotropins in the eating disorder. The patient was diagnosed as Turner's syndrome when she was 6 years old. Her gonadotropin levels were elevated to the castrated ranges (LH 61.8 IU/l; FSH 175.8 IU/l) after 8 years of age. She was noticed to be anorectic at the age of 13 years. Serum levels of the pituitary gonadotropins were lowered (LH 2.9 IU/l; FSH 3.0 IU/l) and their responses to luteinizing hormone-releasing hormone were decreased beneath the normal prepubertal limits. After one year of the anorectic period, she recovered the weight though her gonadotropin levels remained in the very low ranges (LH 2.7 IU/l; FSH 2.5 IU/l). The results suggest that hypogonadism in anorexia nervosa is not solely caused by nutritional deficiency but rather by other factors such as psychological abnormalities.     

Immunoactive inhibin as a marker of Sertoli cell function following cytotoxic damage to the human testis

Sertoli and Leydig cell functions were evaluated in men with testicular damage due either to cytotoxic chemotherapy (CCT) or radiotherapy (XRT). Serum immunoactive inhibin, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone concentrations were measured in 15 men (19-50 years) who had received 6-10 courses of combination CCT (mustine, vinblastine, procarbazine and prednisolone) for Hodgkin's disease 1-8 years earlier and 18 men (21-49 years) who had undergone unilateral orchidectomy for testicular seminoma followed by XRT (30 Gy) to the remaining testis, 1-4 years earlier. Normal men (n = 16, 19-36 years) acted as controls. Median inhibin (422 U/l) and testosterone (16.0 nmol/l) levels in the CCT-treated group were not significantly different from controls, whereas median FSH (14.5 IU/l) and LH (10.0 IU/l) levels were higher (p less than 0.0001 and p less than 0.001) than normal (2.9 and 5.5 IU/l). The median inhibin/FSH (I/FSH) ratio in the patients was lower (p less than 0.0001) than in the controls (33.8 vs. 187.0) as was the testosterone/LH (T/LH) ratio (1.7 vs. 3.8, p less than 0.001). In the XRT-treated group, both median inhibin (194.5 U/l) and testosterone (12.7 nmol/l) levels were lower (p less than 0.0001 and p less than 0.01) than normal (532.8 U/l and 20.0 nmol/l) in the presence of greatly elevated FSH (26.0 IU/l) and LH (14.5 IU/l) levels. In conclusion, CCT-induced testicular damage is associated with subtle Sertoli and Leydig cell dysfunction demonstrated by the reduced I/FSH and T/LH ratios; however, compensatory mechanisms maintain normal testosterone and inhibin levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Alterations in sex steroids and gonadotropins in post-menopausal women subsequent to long-term mifepristone administration

Long-term administration of progesterone antagonists (PAs) and progesterone receptor modulators (PRMs) has been proposed as a novel hormonal therapy for various hormone dependent maladies. We studied the long-term endocrine effects of mifepristone on the kinetics of estradiol (E(2)) and its precursors, and on gonadotropin levels in five postmenopausal women treated for unresectable meningioma with mifepristone [200 mg/day] for at least 15 months. Serum samples were analyzed for LH, FSH and SHBG with fluoroimmunoassay; androstenedione (A), testosterone (T), estrone (E(1)) and E(2) were measured with radioimmunoassay (RIA). Serum levels of mifepristone were measured using both RIA and high performance-liquid chromatography (HPLC). Serum levels (mean +/- SD) of LH and FSH were suppressed from pretreatment values of 32 +/- 16 and 65 +/- 30 IU/l to 13 +/- 7 and 33 +/- 16 IU/l at 6 months (P < 0.05), respectively. Serum (mean +/- SD) A, T, E(1), and E(2) were increased from initial values of 6.9 +/- 0.9 nmol/l, 1.2 +/- 0.3 nmol/l, 77 +/- 25 pmol/l, and 29 +/- 14 pmol/l to 6 month values of 13.1 +/- 5.6 nmol/l, 1.8 +/- 0.6 nmol/l, 178 +/- 60 pmol/l, and 45 +/- 22 pmol/l (n.s.). The correlation coefficients between the levels of A, T, E(1), and E(2) were statistically significant, whereas the ratios of T/A, E(1)/A, E(2)/E(1), and E(2)/T remained unchanged. The levels of SHBG remained stable, and ranged from 48 +/- 10 to 65 +/- 9 nmol/l (mean +/- SD). Thus, prolonged mifepristone treatment marginally increased the serum levels of A, T, E(1) and E(2). These effects of mifepristone are likely due to its antiglucocorticoid effect and thus increased secretion of adrenal A. Serum levels of LH and FSH declined. The serum levels of gonadotropins and those of T, E(1) and E(2) were inversely, yet significantly, correlated. Therefore the decrease in LH and FSH might reflect the slightly increased levels of T, E(1) and E(2). However, the lack of change in SHBG and the low E(2) levels suggest that enhanced systemic estrogen effects are unlikely during long-term mifepristone treatment.     

Long-term results of long-acting luteinizing-hormone-releasing hormone agonist in central precocious puberty.

Thirty children with precocious puberty (24 girls aged 6.5 +/- 2.3 years and 6 boys aged 7 +/- 2.9 years) were treated over 5 years with Decapeptyl. In girls, the menses disappeared, breast enlargement regressed, and uterus and ovary sizes returned to prepubertal values. In boys, a significant decrease of testicular size was observed. Plasma levels of estradiol and testosterone, and basal and post-luteinizing hormone (LH)-releasing hormone (LHRH) LH and follicle-stimulating hormone (FSH) remained in the prepubertal range. Growth velocity decreased after 1 year from 9.7 +/- 3.5 to 5.5 +/- 1.3 cm/year, while the height age/bone age ratio was normalized in both sexes after 3 years. In 15 girls, Decapeptyl was interrupted after 2.3 years. During those 2.3 years, bone age increased from 11.6 +/- 0.8 to 12.5 +/- 0.7 years with a growth velocity of 5.3 +/- 1.8 cm/year. During the year following interruption, height increased from 152.2 +/- 4.9 to 157.7 +/- 4.9 cm (growth velocity 5.5 cm/year) and bone age from 12.5 +/- 0.7 to 13.5 +/- 0.6 years. One year after treatment, plasma levels of estradiol were 106.7 +/- 84.7 pg/ml, of LH, 25.5 +/- 17.6 mIU/ml, and of FSH, 10.8 +/- 5.9 mIU/ml. Menses appeared in 13 girls. Moreover, 18 months after interruption, bone age was 13.9 +/- 0.6 years and height 159.5 +/- 5.2 cm, being significantly superior to the final height of a historical control group: 151.5 +/- 4.8 cm (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Gonadotropin pulsatile secretion in girls with premature menarche

Five prepubertal girls (2.3-8.1 years old) were studied for isolated or recurrent vaginal bleeding in the absence of other signs of precocious puberty (premature menarche). Four of these girls with recurrent vaginal bleeding were studied for pulsatile gonadotropin secretory patterns. During sleep 3 girls showed luteinizing hormone (LH) pulses with low amplitude and a pubertal pattern of frequency whereas follicle-stimulating hormone (FSH) increased without demonstrable episodic secretion. Luteinizing hormone-releasing hormone (LHRH) tests demonstrated that FSH responses are greater than the LH responses, as in prepuberty. In 3 cases estradiol levels had augmented above normal prepubertal range. The menses spontaneously stopped during the follow-up. A reevaluation of the gonadotropin pattern, having the menses stopped for 6 months, in one of the girls with pulsatile LH secretion showed an apulsatile prepubertal LH pattern. Also estradiol levels returned to prepubertal range. A follow-up of 10-66 months of these patients did not show any growth and bone acceleration or signs of precocious puberty. Our data suggest that in premature menarche a partial and transient activation of hypothalamo-pituitary axis could be present. Premature menarche seems to be a benign and self-limiting condition and one of the girls had a normal onset of puberty during follow-up.     

Inhibin B levels in adolescents and young adults with type 1 diabetes

OBJECTIVE/METHODS: To assess exocrine and endocrine testicular function in subjects with diabetes, we evaluated serum inhibin B, gonadotrophins and testosterone levels in 33 male adolescent and young adult patients affected by type-1 diabetes (age 21.0 +/- 5 years; range 14.2-33.3), with a mean disease duration of 12.7 +/- 5.8 years (range 1.5-25.3) and various metabolic control (HbA1c 7.8 +/- 1.5%; range 5.5-13.2) and compared them with those of an age-matched group of 36 healthy control subjects (age 19.5 +/- 4.1 years; range 13.6-28.1). Both patients and controls had a testicular volume >or=15 ml. Inhibin B was measured by ELISA method. RESULTS/CONCLUSION: Diabetics and controls had comparable inhibin B (203 +/- 74 vs. 221 +/- 69 pg/ml, respectively) and follicle-stimulating hormone (FSH) levels, while luteinizing hormone (LH) and testosterone levels were significantly higher in the diabetic group. Inhibin B was negatively correlated both in patients and controls with FSH, while a negative correlation with LH was found only in the diabetic group. We conclude that our young diabetic males, after a mean disease duration of 12 years and various metabolic control, had inhibin B and FSH levels comparable to those of normal subjects. Therefore, they seem to have a regular testicular function and in particular a normal seminiferous tubule/Sertoli cell activity despite sustained hyperglycemia.     

Sex difference in the effect of obesity on 24-hour mean serum gonadotropin levels.

To determine the effect of obesity on serum gonadotropin levels and any possible sex difference in the effect, we measured the 24-hour mean serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) concentrations in 62 healthy men with Body Mass Index (BMI) ranging from 20 - 94 and 61 healthy, regularly cycling women with BMIs ranging from 19 - 76. We also measured free testosterone (T) and estradiol (E2) in these subjects. There was a significant negative correlation between serum FSH and BMI in men: FSH(IU/L) = 49.9 x BMI -0.567; r = - 0.376, p = 0.0026; but a significant positive correlation between serum FSH and BMI in women: FSH(IU/L) =7.66 +/- 0.071 x BMI; r = 0.302, p = 0.018. Serum LH was weight-invariant in both sexes. In men, free T was negatively correlated with BMI: Free T (nmol/L) = 0.74 - 0.0068 x BMI; r = 0.585, p = 0.0381; and free E2 was positively correlated with BMI: Free E2 (pmol/L) = - 1.03 +/- 0.057 x BMI; r = 0.50, p = 0.0014. In obese women as a group, free T was higher than in lean women (33 +/- 6.8 S.E.M. vs. 17.4 +/- 2.0 pmol/L; p < 0.0001), and free E2 was also higher than in lean women: (6.90 +/- 0.80 vs. 4.84 +/- 0.55 pmol/L; p = 0.046). Of the many cases of hypothalamic-pituitary hormonal dysregulation that have been reported in obesity, none has been studied for sex differences. Our results mandate that possible sex differences be investigated in all cases of dysregulation.     

The FSH-inhibin axis in Prader-Willi Syndrome: heterogeneity of gonadal dysfunction

ABSTRACT: BACKGROUND: We characterized the spectrum and etiology of hypogonadism in a cohort of Prader-Willi syndrome (PWS) adolescents and adults. METHODS: Reproductive hormonal profiles and physical examination were performed on 19 males and 16 females ages 16-34 years with PWS. Gonadotropins, sex-steroids, inhibin B (INB) and anti-Mullerian hormone (AMH) were measured. We defined 4 groups according to the relative contribution of central and gonadal dysfunction based on FSH and INB levels: Group A: primary hypogonadism (FSH >15 IU/l and undetectable INB (<10 pg/ml); Group B: central hypogonadism (FSH <0.5 IU/l, INB <10pg/ml); Group C: partial gonadal & central dysfunction (FSH 1.5-15 IU/l, INB >20 pg/ml); Group D: mild central and severe gonadal dysfunction (FSH 1.5-15 IU/l, INB < 10 pg/ml. RESULTS: There were 10, 8, 9 and 8 individuals in Groups A-D respectively; significantly more males in group A (9, 4, 4 and 2; P=0.04). Significant differences between the groups were found in mean testosterone (P=0.04), AMH (P=0.003) and pubic hair (P=0.04) in males and mean LH (P=0.003) and breast development (P=0.04) in females. Mean age, height, weight, BMI and the distribution of genetic subtypes were similar within the groups. CONCLUSIONS: Analysis of FSH and inhibin B revealed four distinct phenotypes ranging from primary gonadal to central hypogonadism. Primary gonadal dysfunction was common, while severe gonadotropin deficiency was rare. Longitudinal studies are needed to verify whether the individual phenotypes are consistent.     

Amino-terminal leucine-rich repeats in gonadotropin receptors determine hormone selectivity.

Recombinant expression of truncated receptors for luteinizing hormone/chorionic gonadotropin (LH/CG) revealed that the amino-terminal leucine-rich repeats 1-8 of the extracellular receptor domain bind human chorionic gonadotropin (hCG) with an affinity (Kd = 0.72 +/- 0.2 nM) similar to that of the native LH/CG receptor (Kd = 0.48 +/- 0.05 nM). LH/CG receptor leucine-rich repeats 1-8 were used to replace homologous sequences in the closely related receptor for follicle stimulating hormone (FSH). Cells expressing such chimeric LH/CG-FSH receptors bind hCG and show elevated cylic AMP levels when stimulated by hCG but not by recombinant human FSH (rhFSH). Similarly, a chimeric LH/CG receptor in which leucine-rich repeats 1-11 originated from the FSH receptor is activated by rhFSH but not by hCG. For this chimera, no residual [125I] hCG binding was observed in a range of 2 pM to 10 nM. Our results demonstrate that specificity of gonadotropin receptors is determined by a high affinity hormone binding site formed by the amino-terminal leucine-rich receptor repeats.     

Changes in circulating levels of immunoreactive follicle stimulating hormone, luteinizing hormone, and testosterone during sexual development in the rhesus monkey, Macaca mulatta

Basal serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T) and the responsiveness of these hormones to a challenge dose of luteinizing hormone releasing hormone (LHRH), were determined in juvenile, pubertal, and adult rhesus monkeys. The monkey gonadotrophins were analyzed using RIA reagents supplied by the World Health Organization (WHO) Special Programme of Human Reproduction. The FSH levels which were near the assay sensitivity in immature monkeys (2.4 +/- 0.8 ng/ml) showed a discernible increase in pubertal animals (6.4 +/- 1.8 ng/ml). Compared to other two age groups, the serum FSH concentration was markedly higher (16.1 +/- 1.8 ng/ml) in adults. Serum LH levels were below the detectable limits of the assay in juvenile monkeys but rose to 16.2 +/- 3.1 ng/ml in pubertal animals. When compared to pubertal animals, a two-fold increase in LH levels paralleled changes in serum LH during the three developmental stages. Response of serum gonadotrophins and T levels to a challenge dose of LHRH (2.5 micrograms; i.v.) was variable in the different age groups. The present data suggest: an asynchronous rise of FSH and LH during the pubertal period and a temporal correlation between the testicular size and FSH concentrations; the challenge dose of LHRH, which induces a significant rise in serum LH and T levels, fails to elicit an FSH response in all the three age groups; and the pubertal as compared to adult monkeys release significantly larger quantities of LH in response to exogenous LHRH.     

Presence of positive feedback in males with Klinefelter's syndrome

This study examined the effect of 17 beta-estradiol (E2) on basal and luteinizing hormone (LH)-releasing hormone (LHRH)-stimulated gonadotropin secretion in 9 patients with Klinefelter's syndrome. Intramuscular injection of E2 (10 micrograms/kg/day during 5 days) induced a rapid decrease in follicle-stimulating hormone (FSH) and LH levels. The maximum suppression was observed on day 7 (D7) for FSH [median 9.7 mIU/ml (range 4.6-37.8) vs. 21.7 mIU/ml (range 12.2-56.9)] and on D2 for LH [median 13.6 mIU/ml (range 6.8-25.2) vs. 21.2 mIU/ml (range 13-54.7)]. E2 concentrations rose and reached their peak values on D3 [median 723 pmol/l (range 517-1,247.8) vs. 110.1 pmol/l (range 68.6-227.5) on D0]. These changes were followed by a subsequent rise in LH on D4 [36.7 mIU/ml (range 19.4-77.7)]. LH response to LHRH was higher during E2 treatment: median value of absolute peaks: 156.3 mIU/ml (range 56.7-188.6) on D4 vs. 64 mIU/ml (range 38.9-131) on DO. These results demonstrate the presence of a positive feedback in patients with Klinefelter's syndrome.     

Concentrations of steroids and gonadotropins in follicular fluid from normal heifers and heifers primed for superovulation

The concentrations of six steroids and of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured in follicular fluid from preovulatory and large atretic follicles of normal Holstein heifers and from preovulatory follicles of heifers treated with a hormonal regimen that induces superovulation. Follicular fluid from preovulatory follicles of normal animals obtained prior to the LH surge contained extremely high concentrations of estradiol (1.1 +/- 0.06 micrograms/ml), with estrone concentrations about 20-fold less. Androstenedione was the predominant aromatizable androgen (278 +/- 44 ng/ml; testosterone = 150 +/- 39 ng/ml). Pregnenolone (40 +/- 3 ng/ml) was consistently higher than progesterone (25 +/- 3 ng/ml). In fluid obtained at 15 and 24 h after the onset of estrus, estradiol concentrations had declined 6- and 12-fold, respectively; androgen concentrations had decreased 10- to 20-fold; and progesterone concentrations were increased, whereas pregnenolone concentrations had declined. Concentrations of LH and FSH in these follicles were similar to plasma levels of these hormones before and after the gonadotropin surges. The most striking difference between mean steroid levels in large atretic follicles (greater than 1 cm in diameter) and preovulatory follicles obtained before the LH surge was that estradiol concentrations were about 150 times lower in atretic follicles. Atretic follicles also had much lower concentrations of LH and slightly lower concentrations of FSH than preovulatory follicles. Hormone concentrations in follicles obtained at 12 h after the onset of estrus from heifers primed for superovulation were similar to those observed in normal preovulatory follicles at estrus + 15 h, except that estrogen concentrations were about 6-40 times lower and there was more variability among animals for both steroid and gonadotropin concentrations. Variability in the concentrations of reproductive hormones in fluid from heifers primed for superovulation suggests that the variations in numbers of normal embryos obtained with this treatment may be due, at least in part, to abnormal follicular steroidogenesis.     

Gonadotropins at menopause: the influence of obesity, insulin resistance, and estrogens

Obese, postmenopausal women have lower FSH levels. To determine whether this is due to higher estrogen exposure, we compared feedback gonadotropin sensitivity and its relation to insulin resistance in four groups of obese and lean, postmenopausal women. Group one was treated with 400 mg troglitazone (TG) daily for two weeks; 150 clomiphene citrate (CC) was added daily for the second week. Group two received 150 mg CC daily for a week. Group three received 1000 mg metformin (MET) daily for two weeks, with 120 mg raloxifene (RAL) added during the second week. Group four received 120 mg RAL for a week. Before and after each period, a serum pool was obtained from samples taken every minute during a 10 ml interval. The women recruited for this study were categorized as obese or lean based on BMI >/= 29 or BMI < 29, respectively. Obese, menopausal women had lower FSH (45.5 IU/l) and LH (16.2 IU/l) values than those of lean (64.1 IU/l and 23.0 IU/l), but the obese menopausal women had higher leptin, DHEAS, glucose, insulin, and HOMA-IR levels. Log [FSH] was associated with BMI (r = -0.53, P < 0.000001) and number of pregnancies (r = -0.37, P = 0.0009). TG treatment did not change HOMA-IR or gonadotropin levels, but DHEAS and androstenedione levels decreased significantly. CC alone or together with TG, diminished FSH (-7.9 and -9.2) and LH (-2.5 and -3.6) concentrations, with a greater reduction in lean women. MET reduced glucose and the HOMA-IR index without affecting gonadotropin or steroid levels. Conclusions: obese, menopausal women have lower FSH levels due to greater estrogen exposure, by mechanisms unrelated to insulin resistance.     

Serum 5-androstene-3 beta,17 beta-diol sulphate and 5 alpha-androstane-3 alpha,17 beta-diol sulphate in hirsute females with polycystic ovarian disease

Serum sulphates of 5-androstene-3 beta,17 beta-diol (5-ADIOL-S), 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-DIOL-S) and dehydroepiandrosterone (DHEA-S), unconjugated androstene-dione (AD) and testosterone (T), sex hormone binding globulin (SHBG), free androgen index (FAI), 17 alpha-hydroxyprogesterone (17OHP), luteinising hormone (LH) and follicle stimulating hormone (FSH) were measured by specific radioimmunoassay in 28 hirsute women with polycystic ovarian disease (PCO) and in normal women (n = 73). Mean levels of steroids measured were significantly elevated, and SHBG significantly depressed, in the women with PCO with values (mean +/- SE) for 5-ADIOL-S (516 +/- 51 vs 267 +/- 10 nmol/l), 3 alpha-DIOL-S (130 +/- 9 vs 52 +/- 2 nmol/l), DHEA-S (7.3 +/- 0.5 vs 4.4 +/- 0.2 mumol/l), AD (11.3 +/- 1.1 vs 3.4 +/- 0.2 nmol/l), T (3.3 +/- 0.2 vs 1.5 +/- 0.1 nmol/l) and 17OHP (5.1 +/- 0.8 vs 2.8 +/- 0.2 nmol/l). SHBG levels were 31 +/- 2.9 vs 65 +/- 2.5 nmol/l, and the free androgen index [100 x T (nmol/l) divided by (SHBG nmol/l)] was 12.5 +/- 1.4 vs 2.4 +/- 0.1. The mean LH to FSH ratio was also elevated at 2.8 +/- 0.3. These studies suggest that the measurement of 5-ADIOL-S and DHEA-S may indicate adrenal gland involvement in PCO while 3 alpha-DIOL-S appears to be a reflection of peripheral androgen metabolism. A comprehensive biochemical profile of PCO should thus include the analysis of these sulphoconjugates as well as unconjugated steroids.     

Effect of inhibin from primate Sertoli cells and GnRH on gonadotropin subunit mRNA in rat pituitary cell cultures

Partially purified inhibin from primate Sertoli cell culture medium (pSCl) suppresses both LH and FSH secretion from cultured rat pituitary cells stimulated with GnRH. To examine the mechanism of action of pSCl, we have measured steady state levels of mRNAs for the gonadotropin subunits in pituitary cell cultures exposed to 10 nM GnRH for 6 h in control or pSCl-containing medium (short term) and after 72-h pretreatment with pSCl or control medium (long term). Messenger RNA levels were determined by Northern analysis using specific cDNA probes for rat FSH beta, LH beta, and the common alpha-subunit. In the long term experiments, pSCl inhibited GnRH-stimulated release of FSH (47.4 +/- 3.3% of control), LH (69.2 +/- 2.3%), and free glycoprotein alpha-subunit (74.2 +/- 4.5%), and intracellular FSH declined to 88.4 +/- 3.5% of control. Concentrations of the subunit mRNAs were all decreased: FSH beta to 54.4 +/- 5.0%, LH beta to 79.6 +/- 9.4%, and alpha to 70.8 +/- 8.7% of control. In the short-term experiments, pSCl also suppressed FSH, LH, and alpha-subunit secretion to 75.9 +/- 3.6%, 79.5 +/- 2.1%, and 90.9 +/- 1.8% of control, respectively. Intracellular LH and alpha-subunit levels were significantly increased in cells treated for 6 h with GnRH and pSCl (155 +/- 18%, 145 +/- 14% of control), while FSH was comparable to control. After 6 h, pSCl selectively reduced the level of mRNA for FSH beta (56.5 +/- 5.8% of control).(ABSTRACT TRUNCATED AT 250 WORDS)     

17beta-estradiol regulation of human growth hormone (hGH), insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) axis in hypoestrogenic, hypergonadotropic women

OBJECTIVE: Ovarian hormonal function may be as important contributing factor to hGH-IGF-I-IGFBP-3 axis as age. AIM: To examine plasma hGH, IGF-1 and IGFBP-3 levels in women with premature ovarian failure compared to healthy normal controls and postmenopausal ones. PATIENTS: Group A-15 women with premature ovarian failure (POF) (mean: age 38.9+/-5.2 years, FSH 101.4+/-29.0 IU/l; 17beta-estradiol 22.5+/-14.6 ng/l). Group B consisted of 15 menopausal women (mean: age 54.7+/-2.7 years; FSH 81.9+/-32.1 IU/l; 17beta-estradiol 17.1+/- 8.0 ng/l). Group C - controls - 15 normally menstruating women (mean: age 37.1+/-9.0 years; FSH 6.2+/-1.0 IU/l; 17beta-estradiol 144.8+/-117.1 ng/l). METHODS: Body mass and BMI were measured. Basic fasting plasma hGH, IGF-I, IGFBP-3, insulin, testosterone and LH as well as prolactin (PRL), FSH and estradiol were assessed by RIA kits. Statistical analysis. Shapiro-Wilk test, Mann-Whitney u-test, Spearman rang correlation coefficient, stepwise multiple regression. RESULTS: Mean serum IGF-I level was the lowest (p<0.005) in group B (172.0+/-54.6 microg/l) and the highest in group C (273.6+/-109.0 microg/l). The mean plasma IGF-I level in group A was similar (NS) (208.3+/-66.5 microg/l) to that found in group B and lower (p<0.02) compared with that in group C. The lowest (p<0.005) serum IGFBP-3 level was found in group B (3.1+/-0.7 microg/l) compared to group C (4.4+/-0.3 microg/l). The mean plasma IGFBP-3 level (3.1+/-1.0 microg/l) in group A was lower than in group C (p<0.005) but identical as in group B. No statistically significant differences between groups were observed in mean hGH levels. Women in group A and C were younger (p<0.001) than those in group B. The lowest mean estradiol level was found in groups A and B. The highest was in group C (p<0.001). Mean plasma LH and FSH levels were higher (p<0.001) in groups A and B vs group C. In group C there were links between IGF-I and age (r=-0.60; p=0.014) The IGF-I/age relation disappeared in the groups A and B (rA=-0.26; rB=0.10; NS). The same regards IGFBP-3/ age link (rA=-0.44, NS; rB=0,31;NS). Estradiol level was related to hGH levels in group C (r=-0.54; p<0.05). In none of groups hGH/IGF-1 as well as IGFBP-3/hGH relations were found. Prolactin accounted for 69% of the variance in IGF-I level in the group B (p=0.003) and for 24% in group A (NS). Testosterone accounted for 88% (p=0.004) of the variance in IGF-I level in group B and IGFBP-3 was responsible for 86% (p=0.038) of the variance in IGF-I level in group C. Again IGFBP-3 was responsible for 47% (p=0.023) in group A and for 49% (p=0.04) in group B of the hGH variance. CONCLUSIONS: 17b-estradiol may be as important contributor to insulin-like growth factor-I (IGF-I) plasma level as age in hypoestrogenic, hypogonadotropic women.