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Publication
Journal: Journal of Clinical Endocrinology and Metabolism
October/13/1993
Abstract
We used the aromatase inhibitor testolactone (<em>4</em>0 mg/kg.day) to treat 12 girls with precocious puberty due to the McCune-Albright syndrome for periods of 0.5-5 yr. In the 7 girls who received testolactone for at least 3 yr, the mean +/- SD serum estradiol level was 618 +/- 268 pmol/L at the start of therapy and fell to 156 +/- 8<em>4</em> pmol/L at 1 yr, 116 +/- <em>4</em>8 pmol/L at 2 yr, and 2<em>4</em>1 +/- 260 pmol/L at 3 yr (P < 0.05 compared to the start of therapy), with recurrent ovarian cysts at 3 yr in 2 patients. These 7 girls averaged 8 menses/yr before therapy. The average frequency of menses decreased to 2 episodes/yr during the first year of treatment, 3/yr during the second year, and <em>4</em>/yr during the third year. The mean +/- SD testosterone levels were slightly above the normal prepubertal range (0.51 +/- 0.2 nmol/L) before treatment and did not change significantly during treatment. The mean +/- SD <em>androstenedione</em> levels rose from 1.1 +/- 0.6 nmol/L before treatment to 2.1 +/- 0.1 nmol/L at 2 yr and 2.8 +/- 0.1 nmol/L after 3 yr of treatment (P < 0.05 compared to before treatment) and were consistent with normal adrenarche. The mean predicted adult stature was 1<em>4</em>3.0 +/- 7.8 cm before treatment and 1<em>4</em>7.3 +/- 11.5 cm at 3 yr (P = NS). In 3 of 12 girls, all with bone age greater than 12 yr, the gonadotropin responses to LHRH indicated early central precocious puberty after 1-<em>4</em> yr of treatment. The adverse effects of testolactone were transient abdominal pain, headache, and diarrhea in 3 girls and elevated hepatic enzymes in 1 girl who had abnormal liver function before treatment. Six families acknowledged difficulty in adhering to the daily dosing schedule. We conclude that testolactone can be effective in the treatment of LHRH-independent precocious puberty in girls with McCune-Albright syndrome, but that some patients exhibit an escape from the effects of treatment after 1-3 yr.
Publication
Journal: Journal of Clinical Investigation
May/25/1981
Abstract
The plasma concentrations of dehydroepiandrosterone, <em>androstenedione</em>, and dehydroepiandrosterone sulfate decrease during the first year of life, remain low during childhood, and then increase during adrenarche. To determine whether alterations in adrenal enzyme activity might explain the changing secretory pattern of the adrenal androgens, we measured human adrenal microsomal 3 beta-hydroxysteroid dehydrogenase-isomerase, 17,20-desmolase, 17-hydroxylase, and 21-hydroxylase activities. 12 adrenals from individuals aged 3 mo to 60 yr were studied. The patients were divided into three groups based upon the age of the patient when the adrenal glands were obtained: group 1, infants aged 3--8 mo (n = 3); group 2, preadrenarchal or early adrenarchal children aged 2--9 yr (n = <em>4</em>); and group 3, adults aged 20--60 yr (n = 5). The mean activity of the 17,20-desmolase, 17-hydroxylase, and 21-hydroxylase fell by 50% and that of 3 beta-hydroxysteroid dehydrogenase-isomerase activity rose 80% from group 1 to 2. A fourfold increase in 17,20-desmolase (P less than 0.002) and 17-hydroxylase (P less than 0.001) activity and a doubling in 21-hydroxylase activity (P less than 0.005) occurred between groups 2 and 3. We conclude that the decline in plasma adrenal androgens after birth appears to be associated with a rise in 3 beta-hydroxysteroid dehydrogenase-isomerase and a fall in 17,20-desmolase and 17-hydroxylase activity. The subsequent increase in plasma adrenal androgen concentration during adrenarche is coincident with a rise in 17,20-desmolase and 17-hydroxylase activity.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
June/29/1989
Abstract
Persistent suppression of gonadotropin and ovarian steroid production can be achieved in women with polycystic ovarian disease (PCO) by daily administration of a long-acting GnRH agonist (GnRHa). This study was designed to determine the patterns of recovery of clinical responses and hormonal secretion after chronic GnRHa administration in women with PCO. Six women with PCO were treated with daily sc injections of [D-His6(imBzl),Pro9-NEt]GnRHa (100 micrograms) for 6 months. Blood samples were obtained at the time of and three times weakly for 90 days after discontinuation of agonist therapy. In five women who did not ovulate, the suppressed serum FSH levels rose to pretreatment values within 10 days. In contrast, a gradual and progressive increase in serum LH (as measured by bioassay and immunoassay) was apparent by day 18. The LH increase coincided with progressive increases in serum estrone (E1), <em>androstenedione</em>, and testosterone. Serum estradiol (E2) began to rise on day 28. All hormones returned to their pretreatment baseline values within the 90-day recovery interval, with the exception of E2. Trend analysis of the slopes of recovery revealed that the incremental secretion patterns of E1, E2, <em>androstenedione</em>, and testosterone differed significantly from that of FSH, but not from those of bioactive or immunoactive LH. Serum progesterone, dehydroepiandrosterone sulfate, and cortisol did not change after withdrawal of GnRHa. One woman ovulated spontaneously on day 52 before which her hormone secretion patterns were indistinguishable from those of the other women. In summary, 1) during recovery after discontinuation of chronic GnRH agonist therapy the patterns of FSH and LH release suggested resumption of endogenous GnRH action on the pituitary with greater release of FSH than LH, a pattern that would be expected in the absence of ovarian steroid influence; 2) the lack of early estrogen production despite the increase in serum FSH concentrations suggests inadequate FSH secretion, abnormal ovarian responsiveness to FSH, or impaired FSH bioactivity; 3) androgen secretion was provoked by the increase in LH secretion; <em>4</em>) per unit LH measured by bioassay, greater ovarian androgen secretion was stimulated in PCO than ovulatory women; and 5) the likelihood of spontaneous ovulation during recovery was minimal.
Publication
Journal: Journal of Steroid Biochemistry and Molecular Biology
February/24/2013
Abstract
Endogenous androgens play a role in the development and progression of prostate cancer (PC), thus androgen suppression may offer an effective therapeutic strategy for this disease. Orteronel (TAK-700), 6-[(7S)-7-hydroxy-6,7-dihydro-5H-pyrrolo[1,2-c]imidazol-7-yl]-N-methyl-2-naphthamide, is a novel, non-steroidal, selective inhibitor of the 17,20-lyase activity of CYP17A--a key enzyme in the production of steroidal hormones--and is being developed as a therapy for PC. The purpose of this study was to elucidate the inhibitory activity of orteronel, in particular its specificity for androgen synthesis enzymes, in male rats--an androgen-synthesis model that largely reflects this pathway in humans. Orteronel inhibited 17,20-lyase activity in rats with an IC(50) of 1200 nM but did not inhibit 17α-hydroxylase or 11β-hydroxylase (CYP11B1) activity in rats at concentrations up to 10 μM. In cellular steroidogenesis assays using rat testicular cells, orteronel suppressed testosterone and <em>androstenedione</em> production with an IC(50) of 6<em>4</em>0 nM and 210 nM, respectively, but did not suppress either corticosterone or aldosterone production in rat adrenal cells at concentrations up to 30 μM. In addition, serum testosterone and <em>androstenedione</em> levels in human chorionic gonadotropin-injected hypophysectomized rats were significantly reduced by single oral administration of orteronel at a dose of 30 mg/kg (both p ≤ 0.01); serum corticosterone and aldosterone levels in ACTH-injected hypophysectomized rats did not result in significant differences compared with controls, following orteronel administration at doses up to 300 mg/kg. Serum testosterone levels in intact male rats were significantly reduced by orteronel <em>4</em>h after dosing at 100mg/kg (p ≤ 0.01); testosterone levels showed a tendency to recover afterward. In intact male rats, the weight of the prostate glands and seminal vesicles was decreased in a dose-dependent manner following multiple doses of orteronel at 37.5, 150, and 600 mg/kg, TID for <em>4</em> days. The reversibility of orteronel was further confirmed using a human adrenocortical tumor cell line. In summary, orteronel is a selective and reversible 17,20-lyase inhibitor, and decreases the weight of androgen-dependent organs in male rats. Our data suggests that orteronel would therefore be effective for androgen-dependent disorders such as PC.
Publication
Journal: Cancer Research
October/13/1981
Abstract
Obesity is a physiological state associated with alterations in hormone production and metabolism. These hormonal changes may bear on the increased risk for selected neoplastic disorders. Obesity is associated with increased estrone production in young and older women as well as in men. The source of this increased estrogen appears to be extragonadal metabolism of the prehormone <em>androstenedione</em>, which increases 3- to <em>4</em>-fold in proportion to the obesity. In severe obesity, <em>androstenedione</em> production itself may be increased, providing extra prehormone for conversion to estrogens. In addition, obesity appears to shift peripheral metabolism of estradiol, resulting in decreased excretion of catechol estrogens which in turn may influence target organ stimulation. Testosterone production is unchanged in obesity; however, there are decreased levels of sex hormone-binding beta-globulin leading to increased clearance rates and spuriously low levels of circulating testosterone in both obese men and obese women. Alterations in sex hormone-binding beta-globulin may further lead to changes in "free" estradiol, which may play a role in target organ stimulation. Other changes noted in obesity include: (a) increased excretion of corticoid metabolites; (b) increased secretion of insulin but decreased insulin effectiveness; (c) blunted growth hormone responses to various challenges; and (d) possibly blunted prolactin responsiveness. There are no reasons at present to suspect that these changes influence cancer risk. With weight loss, sex hormone-binding beta-globulin changes are restored toward normal as are the elevated plasma estrogens and decreased testosterone levels. BEcause weight loss and dieting per se are associated with many physiological changes, hormonal measurements during these times are difficult to interpret. Few studies to date have been performed in formerly obese patients stabilized at their new weight.
Publication
Journal: Clinical Endocrinology
March/29/1998
Abstract
OBJECTIVE
Patients with Laron syndrome (LS) can now be treated with recombinant IGF-I. We describe the development of androgenization during IGF-I treatment of female LS patients.
METHODS
Six female patients with LS--two clinically prepubertal (11.6 and 13.8 years of age) and four young adults (30 to 39 years old)--underwent long-term replacement treatment with recombinant IGF-I. The daily doses were 150 micrograms/kg/day by subcutaneous (s.c.) injection in the girls and 120 micrograms/kg/day in the adult women.
METHODS
Testosterone, delta <em>4</em>-<em>androstenedione</em>, LH, FSH, insulin and IGF-I were determined by radioimmunoassay. Blood samples were obtained after an overnight fast before the IGF-I injection. Serum IGF-I was also determined <em>4</em> hours after the s.c. injections.
RESULTS
During IGF-I treatment, four out of the six patients (two girls and two adults) developed progressive clinical symptoms and signs of hyperandrogenism (oligo/amenorrhoea and acne). Laboratory determinations showed a significant elevation in serum testosterone, delta <em>4</em>-<em>androstenedione</em> and LH/FSH ratio. The hyperandrogenism occurred concomitantly with an increase in IGF-I serum and a decrease in serum insulin concentrations. Reduction in IGF-I dose or interruption in IGF-I treatment restored androgen levels to normal values. At the same time, the acne and oligomenorrhoea resolved.
CONCLUSIONS
Overdosage of IGF-I can lead to androgenization, a previously undescribed undesirable effect of IGF-I. Long-term IGF-I treatment necessitates progressive adjustment of the IGF-I dose to avoid overtreatment.
Publication
Journal: ISRN endocrinology
August/22/2012
Abstract
The polycystic ovary syndrome (PCOS) is one of the most frequent endocrinopathies in women. Its incidence is assessed at 6-8% of the female population in the reproductive age. It is characterised by oligomenorrhea (Oligo), hyperandrogenism (HA), and the presence of polycystic ovaries (PCOs). Carbohydrate and lipid metabolism is being disturbed in many women with PCOS. The pathogenesis of PCOS is still unexplained. Following the main criteria of diagnosis (Rotterdam Consensus 2003), Dewailly, Welt and Pehlivanov divided the patients with PCOS into <em>4</em> phenotype groups: A, B, C, and D. In our studies of 93 patients with PCOS, we found (1) the most frequent appearance (60,2%) of the phenotype A [Oligo + HA + PCO]; (2) an increased <em>androstenedione</em> concentration in a group with HA (A, B, C); (3) an increased HOMA-β and insulin concentration after 30 min an oral 75 g glucose tolerance test (OGTT) in a group of obese women with BMI>> 30 kg/m(2); (<em>4</em>) high levels of total testosterone, total cholesterol, and LDL cholesterol concentrations in a group A with classic phenotype of PCOS: Oligo + HA + PCO-increasing the risk of development of cardiovascular diseases, type 2 diabetes, or metabolic syndrome. The average <em>androstenedione</em> concentrations could be a good diagnostic and prognostic parameter.
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Publication
Journal: Biochemistry
June/8/2006
Abstract
Specific substrate-induced structural changes in the heme pocket are proposed for human cytochrome P<em>4</em>50 aromatase (P<em>4</em>50arom) which undergoes three consecutive oxygen activation steps. We have experimentally investigated this heme environment by resonance Raman spectra of both substrate-free and substrate-bound forms of the purified enzyme. The Fe-CO stretching mode (nu(Fe)(-)(CO)) of the CO complex and Fe(3+)-S stretching mode (nu(Fe)(-)(S)) of the oxidized form were monitored as a structural marker of the distal and proximal sides of the heme, respectively. The nu(Fe)(-)(CO) mode was upshifted from <em>4</em>77 to <em>4</em>85 and to <em>4</em>90 cm(-)(1) by the binding of <em>androstenedione</em> and 19-aldehyde-<em>androstenedione</em>, substrates for the first and third steps, respectively, whereas nu(Fe)(-)(CO) was not observed for P<em>4</em>50arom with 19-hydroxy<em>androstenedione</em>, a substrate for the second step, indicating that the heme distal site is very flexible and changes its structure depending on the substrate. The 19-aldehyde-<em>androstenedione</em> binding could reduce the electron donation from the axial thiolate, which was evident from the low-frequency shift of nu(Fe)(-)(S) by 5 cm(-)(1) compared to that of <em>androstenedione</em>-bound P<em>4</em>50arom. Changes in the environment in the heme distal site and the reduced electron donation from the axial thiolate upon 19-aldehyde-<em>androstenedione</em> binding might stabilize the ferric peroxo species, an active intermediate for the third step, with the suppression of the formation of compound I (Fe(<em>4</em>+)=O porphyrin(+)(*)) that is the active species for the first and second steps. We, therefore, propose that the substrates can regulate the formation of alternative reaction intermediates by modulating the structure on both the heme distal and proximal sites in P<em>4</em>50arom.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
May/14/1986
Abstract
To determine the adrenal contribution to elevated plasma androgens in 31 young hyperandrogenemic women with acne and/or hirsutism, we compared their responses to ACTH with those of 1<em>4</em> normal women. Each subject was given a low dose (10 micrograms/m2) of synthetic ACTH-(1-2<em>4</em>) (Cortrosyn) after administration of 1.5 mg dexamethasone the night before the test. Thirty and 60 min responses of plasma 17 alpha-hydroxypregnenolone (17-Preg), 17 alpha-hydroxyprogesterone, (17-prog), dehydroepiandrosterone (DHEA), <em>androstenedione</em>, 11-deoxycortisol, and cortisol were measured. Eighteen (58%) patients had increased responses of at least one 17-ketosteroid or adrenal androgen precursor. All patients had cortisol responses within the range of those of the 1<em>4</em> normal subjects. Nine patients (29%) had evidence of steroid biosynthetic enzyme deficiencies, either mild congenital adrenal hyperplasia or the heterozygote state; after ACTH, <em>4</em> of these patients had elevated 17-prog in the range of values in heterozygote carriers of 21-hydroxylase deficiency, 2 had elevated levels of 11-deoxycortisol compatible with 11 beta-hydroxylase deficiency, and 3 had elevated levels of 17-Preg and DHEA, suggestive of 3 beta-hydroxysteroid dehydrogenase deficiency. Another 9 subjects (29%) had 17-ketosteroid (DHEA and/or <em>androstenedione</em>) hyperresponsiveness to ACTH with associated elevated 17-Preg responses. As a group, their patterns suggested relatively deficient 3 beta-hydroxysteroid dehydrogenase and relatively hyperactive C lyase without impairment of cortisol secretion. This pattern resembles exaggerated adrenarche, and we postulate that these 9 patients have hyperplasia of the zona reticularis. Neither basal levels of plasma androgens (free testosterone and DHEA sulfate) nor menstrual history predicted which patients would have abnormal ACTH responses. Although 5 of 11 (<em>4</em>5%) patients with acne alone had abnormal responses to ACTH, 10 of 1<em>4</em> patients with acne and hirsutism (71%) had abnormal responses to ACTH. We conclude that an adrenal contribution is found in about half of hyperandrogenemic women with acne and/or hirsutism. This adrenal androgen hyperresponsiveness is heterogeneous. Some patients may have mild forms of congenital adrenal hyperplasia. However, functional androgenic hyperresponsiveness to ACTH, which resembles an exaggeration of adrenarche, is the most common abnormality found. Such findings may provide an explanation for the clinical observation of exacerbations of acne with stress.
Publication
Journal: Neuroendocrinology
July/20/2015
Abstract
3,<em>4</em>-Methylenedioxymethamphetamine (MDMA, 'ecstasy') and methylphenidate are widely used psychoactive substances. MDMA primarily enhances serotonergic neurotransmission, and methylphenidate increases dopamine but has no serotonergic effects. Both drugs also increase norepinephrine, resulting in sympathomimetic properties. Here we studied the effects of MDMA and methylphenidate on 2<em>4</em>-hour plasma steroid profiles. 16 healthy subjects (8 men, 8 women) were treated with single doses of MDMA (125 mg), methylphenidate (60 mg), MDMA + methylphenidate, and placebo on <em>4</em> separate days using a cross-over study design. Cortisol, cortisone, corticosterone, 11-dehydrocorticosterone, aldosterone, 11-deoxycorticosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), <em>androstenedione</em>, and testosterone were repeatedly measured up to 2<em>4</em> h using liquid chromatography-tandem mass spectroscopy. MDMA significantly increased the plasma concentrations of cortisol, corticosterone, 11-dehydrocorticosterone, and 11-deoxycorticosterone and also tended to moderately increase aldosterone levels compared with placebo. MDMA also increased the sum of cortisol + cortisone and the cortisol/cortisone ratio, consistent with an increase in glucocorticoid production. MDMA did not alter the levels of cortisone, DHEA, DHEAS, <em>androstenedione</em>, or testosterone. Methylphenidate did not affect any of the steroid concentrations, and it did not change the effects of MDMA on circulating steroids. In summary, the serotonin releaser MDMA has acute effects on circulating steroids. These effects are not observed after stimulation of the dopamine and norepinephrine systems with methylphenidate. The present findings support the view that serotonin rather than dopamine and norepinephrine mediates the acute pharmacologically induced stimulation of the hypothalamic-pituitary-adrenal axis in the absence of other stressors.
Publication
Journal: Endocrinology
July/30/1984
Abstract
The effects of estrogens on cAMP-induced FSH and LH receptor expression were studied in granulosa cells isolated from immature diethylstilbestrol-implanted rats. Although estradiol alone had negligible effects on granulosa cell maturation, estradiol concentrations from 10(-11)-10(-8) M progressively enhanced cAMP production and gonadotropin receptor formation in choleragen-stimulated cells. During <em>4</em>8 h of culture, estradiol augmented cAMP levels by 2-fold, LH receptors by <em>4</em>- to 6-fold, and FSH receptors by 20-<em>4</em>0%. Estradiol also enhanced the extent of LH and FSH receptor formation by other cAMP-inducing ligands, including FSH, prostaglandin E2, and forskolin. The stimulatory action of 8-bromo-cAMP on gonadotropin receptors was also increased by estradiol, indicating that part of the estrogenic effect was exerted on cAMP-activated processes. Scatchard analyses indicated that estradiol increased the number of choleragen-induced FSH receptors from 2,600 to 3,200/cell and of LH receptors from 13,000 to 86,000/cell with no changes in receptor binding affinity. Choleragen-stimulated cAMP accumulation was enhanced by estradiol during the later stages of culture (after 30 h), while increased LH receptors were detected by 30 h and FSH receptors by <em>4</em>3 h. The stimulatory effects of estradiol were not due to increased cellular proliferation and were also exerted by other estrogens, including estrone and diethylstilbestrol. Androgens, including testosterone and <em>androstenedione</em>, also amplified choleragen action. This effect was largely through conversion to estrogens, since dihydrotestosterone, a nonaromatizable androgen, did not markedly enhance LH receptor formation by choleragen. In contrast, progestins and pregnenelone had no facilitative effect on choleragen-induced responses. Although cortisol and dexamethasone increased choleragen-induced cAMP accumulation, only cortisol elevated LH receptors, and dexamethasone inhibited FSH receptor formation. These results demonstrate that estrogens enhance both ligand-induced cAMP production and cAMP-activated responses during granulosa cell differentiation. In particular, estrogens exert a major effect on the levels of gonadotropin receptors expressed in response to FSH and other cAMP-inducing ligands.
Publication
Journal: Biology of Reproduction
November/15/1987
Abstract
Hamster ovarian follicles at Stages 1 to 10 (Stages 1-<em>4</em>: follicles with 1-<em>4</em> layers of granulosa cells (GC); Stages 5-7: 5-10 layers GC plus theca; Stages 8-10: antral follicles) were isolated on the morning of proestrus or estrus and incubated for 2 h in the absence or presence of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (Prl), progesterone (P<em>4</em>), 17 alpha-hydroxyprogesterone (17OHP), or <em>androstenedione</em> (A). Steroid accumulations in the media were measured by radioimmunoassay (RIA). On proestrus, without any hormonal stimulus, consistent accumulation of P<em>4</em> through estradiol-17 beta (E2) occurred in low amounts only from Stage 6 and on; both FSH (5-25 ng) and LH (1-25 ng) significantly stimulated steroidogenesis by Stage 6-10 follicles, and the effects of FSH, except for Stage 10, were largely attributable to LH contamination. However, 25 ng FSH significantly stimulated A production by Stages 1-<em>4</em>, whereas 1-25 ng LH was ineffective. On estrus, follicles at all stages, especially 1-6, showed significant and dose-dependent increases in P<em>4</em> production in response to FSH; both FSH and LH significantly stimulated P<em>4</em> and 17OHP accumulation from Stage 5 onwards; however, there was no increase in A and E2 compared to controls. Even the smallest estrous follicles showed a shift to predominance of P<em>4</em> accumulation. On proestrus, Prl had a negative influence on LH-induced accumulation of P<em>4</em> and 17OHP by Stages 7-9 and 6-8, respectively, without affecting A or E2.(ABSTRACT TRUNCATED AT 250 WORDS)
Publication
Journal: Toxicology and Applied Pharmacology
June/24/2012
Abstract
The persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an ovarian toxicant. These studies were designed to characterize the actions of TCDD on steroidogenesis and growth of intact mouse antral follicles in vitro. Specifically, these studies tested the hypothesis that TCDD exposure leads to decreased sex hormone production/secretion by antral follicles as well as decreased growth of antral follicles in vitro. Since TCDD acts through binding to the aryl hydrocarbon receptor (AHR), and the AHR has been identified as an important factor in ovarian function, we also conducted experiments to confirm the presence and activation of the AHR in our tissue culture system. To do so, we exposed mouse antral follicles for 96 h to a series of TCDD doses previously shown to have effects on ovarian tissues and cells in culture, which also encompass environmentally relevant and pharmacological exposures (0.1-100 nM), to determine a dose response for TCDD in our culture system for growth, hormone production, and expression of the Ahr and Cyp1b1. The results indicate that TCDD decreases progesterone, <em>androstenedione</em>, testosterone, and estradiol levels in a non-monotonic dose response manner without altering growth of antral follicles. The addition of pregnenolone substrate (10 μM) restores hormone levels to control levels. Additionally, Cyp1b1 levels were increased by 3-<em>4</em> fold regardless of the dose of TCDD exposure, evidence of AHR activation. Overall, these data indicate that TCDD may act prior to pregnenolone formation and through AHR transcriptional control of Cyp1b1, leading to decreased hormone levels without affecting growth of antral follicles.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
January/16/2003
Abstract
In previous studies we established that human bone and human osteoblast-like cells (hOB cells) cultured from bone express 5alpha-reductase (5alpha-R) activity, as demonstrated by the conversion of testosterone and <em>androstenedione</em> to their corresponding 5alpha-reduced metabolites, 5alpha-dihydrotestosterone (DHT) and 5alpha-androstanedione. Two 5alpha-R isozymes (types 1 and 2) have been identified in various tissues. As their nature in bone is unknown, we investigated which isozymes were expressed in first passage hOB cells cultured from bone specimens obtained from six donors (five women and one man). For comparison, 5alpha-reductase isozyme expression in genital skin fibroblasts cultured from foreskin of three males was determined. Pharmacological and biochemical studies using selective inhibitors of the 5alpha-R isozymes were performed, and gene expression was assessed by RT-PCR. In hOB cells, LY19170<em>4</em>, a potent nonsteroidal selective inhibitor of 5alpha-R type 1, and the <em>4</em>-azasteroid 17beta-(N,N,-diethyl-carbamoyl)-<em>4</em>-methyl-<em>4</em>-aza-5alpha-androstan-3-one (a dual inhibitor of 5alpha-R types 1 and 2) inhibited 5alpha-R activity with a 50% inhibitory concentration (IC(50)) of approximately <em>4</em> nM. Finasteride, a selective inhibitor of 5alpha-R type 2, blocked 5alpha-R activity with an IC(50) of approximately 60 nM. The IC(50) of progesterone, a physiological substrate for 5alpha-R, was approximately 200 nM. In genital skin fibroblasts, LY19170<em>4</em> inhibited 5alpha-R with an IC(50) of more than 5000 nM, whereas finasteride and 17beta-(N,N,-diethyl-carbamoyl)-<em>4</em>-methyl-<em>4</em>-aza-5alpha-androstan-3-one effectively inhibited 5alpha-R with IC(50) of approximately <em>4</em> nM. Experiments to determine 5alpha-reductase activity in homogenates of hOB cells as a function of pH showed very low activity at pH 5.5, but a broad shoulder of activity from pH 6.0-9.0, which was not inhibited by finasteride, but was nearly completely blocked by LY19170<em>4</em>. RT-PCR revealed that 5alpha-R type 1 and 2 mRNAs were expressed in both bone and genital skin fibroblasts. Based on our pharmacological and biochemical studies, it appears that 5alpha-R activity in hOB cells is catalyzed predominantly by the type 1 rather than the type 2 isozyme. This expression pattern is in contrast to that in genital skin fibroblasts, where the activity of the type 2 isozyme prevails. As in most androgen target tissues DHT is biologically more active as an androgen than testosterone, DHT is formed in bone by 5alpha-R type 1 action from circulating testosterone, and bone cells also express the androgen receptor, local DHT production may play a physiological role in human bone homeostasis.
Publication
Journal: Journal of Investigative Dermatology
November/2/1992
Abstract
Three beta-hydroxysteroid dehydrogenase/delta 5-delta <em>4</em> isomerase (3 beta-HSD) catalyses an obligatory step in the biosynthesis of all classes of hormonal steroids, namely, the oxidation/isomerization of 3 beta-hydroxy-5-ene steroids into the corresponding 3-keto-<em>4</em>-ene steroids in gonadal as well as in peripheral tissues. Because humans are unique with some primates in having adrenals that secrete large amounts of the steroid precursors dehydropiandrosterone (DHEA) and its sulfate (DHEA-S) and its exceptionally large volume makes the skin an important site of steroid biosynthesis, we have isolated and characterized cDNA clones encoding 3 beta-hydroxysteroid dehydrogenase/delta 5-delta <em>4</em> isomerase from a human skin lambda gt11 library. The longest clone obtained contains the entire coding sequence for type I 3 beta-HSD (372 amino acids) as well as an additional 131 nucleotides in the 5'-untranslated region. The insert of 16<em>4</em>7 bp containing the entire coding region has been inserted in a pCMV expression vector and transfected into human cervical carcinoma cells (HeLa). The expressed enzyme efficiently catalyzes the transformation of pregnenolone, DHEA, and dihydrotestosterone into progesterone, <em>4</em>-<em>androstenedione</em>, and 5 alpha-androstane-3 beta, 17 beta-diol, respectively. Using the enzyme expressed in HeLa cells, we have shown cyproterone acetate, a progestin used in the treatment of acne and hirsutism, as well as norgestrel and norethindrone, two steroids widely used as oral contraceptives, to be relatively potent inhibitors, with Ki values of 0.38 microM, 1.3 microM, and 1.2 microM, respectively. Immunohistochemical localization of 3 beta-HSD, illustrated by using an antibody raised against human placental 3 beta-HSD, shows that the enzyme is localized in sebaceous glands.
Publication
Journal: Clinical Endocrinology
February/4/1987
Abstract
Transient hypogonadotrophic hypogonadism commonly occurs after major medical insults. Because data on testosterone precursors are sparse and because little is known about the aetiology of these changes, we studied the interactions of traumatic brain injury with gonadal steroidogenesis and with sympathetic nervous system activation. Patients were divided into two groups based upon the severity of neurological dysfunction using the Glasgow Coma Score (GCS); Group 1 less than 8, Group 2 greater than or equal to 8. Group 1 was further divided into those patients treated (Group 1b) and those not treated with dexamethasone (Group 1a). Plasma levels of testosterone, <em>androstenedione</em>, 17-hydroxyprogesterone, DHEA sulphate, cortisol, LH, FSH, and the catecholamines noradrenaline (NE), adrenaline (EPI) and dopamine were measured in 31 acutely brain injured men, aged 18-95, shortly after their accident and <em>4</em> days later. In all patients, NE and EPI were elevated on admission (NE: 8<em>4</em>1 +/- 105 (SEM) pg/ml; EPI: 191 +/- 32 pg/ml and there were highly significant inverse correlations between admission NE (r = -0.52, P less than 0.003) and EPI (r = 0.<em>4</em><em>4</em>, P less than 0.02) levels and day <em>4</em> testosterone concentrations. Testosterone fell 53% (P less than 0.001) in 13 Group 1a men, but only 25% (P = NS) in the less severely injured. Similar reductions occurred in cortisol and the steroid precursors. However, only testosterone, 17-hydroxyprogesterone, and DHEA sulphate levels were significantly lower than normal on day <em>4</em>. LH and FSH levels were also significantly reduced from elevated admission levels. In the eight men treated with dexamethasone (8-<em>4</em>0 mg/ml) (Group 1b), the decrease in testosterone, LH and FSH concentrations were similar to those present in Group 1a. Thus, severe traumatic brain injury leads to hypogonadotrophic hypogonadism which affects testosterone and its precursors. The magnitude of the hormonal dysfunction is dependent upon the severity of the neurological insult. Finally, the decrease in testosterone is significantly correlated with admission catecholamine levels, which may suggest a role for the sympathetic nervous system (SNS) in mediating this response in men.
Publication
Journal: Alcohol and Alcoholism
May/8/2000
Abstract
The aim of the present study was to investigate the effect of alcohol on androgen levels among premenopausal women. Eighty-seven women in the mid-cycle phase of the menstrual cycle, <em>4</em>7 of whom used oral contraceptives (OC+), were included in the study. The range for reported alcohol consumption was 0-<em>4</em> drinks/day. The total testosterone levels were significantly higher after alcohol intake (0.5 g/kg) than after placebo at <em>4</em>5 min and 90 min from the start of drinking among both OC- and OC+ subjects. This effect was also seen in the free testosterone fraction. The effect on testosterone was more prominent among OC+ subjects. <em>Androstenedione</em> levels were significantly lowered and the testosterone:<em>androstenedione</em> ratio significantly elevated by alcohol among both OC- and OC+ subjects. No effect of alcohol on dehydroepiandrosterone or dihydrotestosterone levels was observed. A positive correlation was observed between the change in testosterone levels and the change in <em>androstenedione</em> levels during placebo conditions. The correlation was significantly reduced during alcohol conditions among OC+ subjects, indicating an increased <em>androstenedione</em> to testosterone conversion. No significant dose (0.3<em>4</em>, 0.68 and 1.02 g/kg) or time (<em>4</em>5, 90 and 150 min) effects on total testosterone were observed in a substudy involving 10 OC+ subjects. The present results suggest that the testosterone effect is related to the zero-order mechanism of ethanol oxidation. The observed testosterone and <em>androstenedione</em> effects are suggested to be the result of an increased <em>androstenedione</em> to testosterone conversion in the liver caused by the alcohol-mediated elevation in the [NADH]:[NAD(+)] ratio. The present findings may be relevant in the development of hyperandrogenism and loss of female sexual characteristics associated with heavy alcohol consumption.
Publication
Journal: European Journal of Internal Medicine
February/2/2009
Abstract
BACKGROUND
The present study was designed to measure plasma visfatin levels in normal weight women with polycystic ovary syndrome (PCOS) and to assess possible correlations between visfatin and the hormonal or metabolic parameters of the syndrome.
METHODS
Twenty-five normal weight [body mass index (BMI)<25 kg/m(2)] women with PCOS, 2<em>4</em> obese and overweight (BMI>25 kg/m(2)) controls (ovulating women without clinical or biochemical hyperandrogenism), and 2<em>4</em> normal weight controls were studied. Blood samples were collected between the 3rd and the 7th days of a menstrual cycle in the control groups and during a spontaneous bleeding episode in the PCOS groups at 9:00 A.M., after an overnight fast. Circulating levels of LH, FSH, prolactin (PRL), testosterone (T), Delta(<em>4</em>)-<em>androstenedione</em> (Delta(<em>4</em>)-Alpha), dehydroepiandrosterone sulfate (DHEA-S), 17alpha-OH-progesterone (17OH-P), sex hormone-binding globulin (SHBG), insulin, glucose, and visfatin were measured.
RESULTS
Plasma visfatin levels and the visfatin-to-insulin ratio were significantly lower in normal weight controls than in both normal weight women with PCOS and overweight or obese controls. The visfatin-to-insulin ratio was significantly higher in normal weight women with PCOS than in overweight or obese controls. Plasma visfatin levels were found to be positively correlated with LH and Delta(<em>4</em>)A levels, as well as with free androgen index (FAI) values, and negatively correlated with SHBG. LH and SHBG levels were found to be the only independent significant determinants of circulating visfatin. In the control groups, plasma visfatin levels were significantly correlated with BMI, waist (W) measurement, and waist-to-hip ratio (WHR).
CONCLUSIONS
Visfatin levels are positively associated with obesity in healthy women of reproductive age. Moreover, the present study indicates, for the first time, a possible involvement of increased visfatin levels in PCOS-associated metabolic and hormonal disturbances.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
April/11/2005
Abstract
Congenital adrenal hyperplasia due to 3beta-hydroxysteroid dehydrogenase/Delta(5)-Delta(<em>4</em>)-isomerase (3betaHSD), a rare autosomal recessive disorder that affects both sexes, has a heterogeneous clinical presentation ranging from the severe salt-wasting to the non-salt-wasting forms and results from mutations in the HSD3B2 gene. The hormonal criteria for diagnosing the mild variant of 3betaHSD deficiency have been controversial because the initial studies were not based on genetic evidence. We investigated the relationship between the hormonal phenotype and HSD3B2 genotype in 22 patients with clinical and/or biochemical features suggestive of 3betaHSD2 deficiency, including nine female children with premature pubarche, 12 hirsute females, and one boy with salt-wasting and ambiguous genitalia. Serum 17-hydroxypregnenolone (Delta5-17P), cortisol (F), 17-hydroxyprogesterone, dehydroepiandrosterone, and <em>androstenedione</em> levels were determined by RIA and were compared with Tanner pubic hair stage-matched control groups. The genomic DNA was extracted, and the entire HSD3B2 gene was amplified by PCR followed by automatic sequencing. Besides two different mutations previously observed in three patients (T259M and G129R/P222Q mutations), we observed the P222Q mutation in the male patient with salt-wasting form of 3betaHSD2 deficiency. Basal and ACTH-stimulated Delta5-17P levels (nanomoles per liter) ranged from <em>4</em>-<em>4</em>1 (-0.2 to 1<em>4</em> sd) and 36-97 (3.5-15.5 sd), respectively, in patients without mutation in HSD3B2 and from 69-153 (25-57 sd) and 201-351 (36-65 sd), respectively, in patients with mutation in HSD3B2. Basal and ACTH-stimulated Delta5-17P to F ratios ranged from 11-159 (0.5-25 sd) and <em>4</em>2-122 (2.<em>4</em>-11.3 sd), respectively, in patients without mutation in HSD3B2 and from 181-1700 (29-282 sd) and <em>4</em>87-1523 (52-167 sd), respectively, in patients with mutation in HSD3B2. The hormone findings in the genotype-proven patients suggest that the following hormonal criteria are compatible with 3betaHSD2 deficiency in children with premature pubarche: ACTH-stimulated Delta5-17P and Delta5-17P to F ratios at or greater than 201 and <em>4</em>87 nmol/liter, respectively, equivalent to or greater than 36 and 52 sd above matched control mean. Basal and ACTH-stimulated Delta5-17P and Delta5-17P to F ratios in all genotype-proven patients in childhood were unequivocally higher than the levels of either genotype-normal patients. All the other parameters overlapped between the patients with and without mutations in the HSD3B2 gene. In conclusion, genotyping more patients in the present study, we confirm that patients with mutations in the HSD3B2 gene have extremely elevated basal and ACTH-stimulated Delta5-17P levels and Delta5-17P to F ratios. Therefore, these data refine the hormonal criteria proposed to predict more accurately 3betaHSD2 deficiency.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
December/8/2003
Abstract
In PCOS women with insulin resistance, hyperinsulinemia may contribute to inappropriate gonadotropin secretion. To determine whether insulin influences gonadotropin release in PCOS, pulsatile LH secretion and gonadotropin responses to GnRH were evaluated before (phase 1) and during (phase 2) insulin infusion. In phase 1, 11 PCOS and 9 normal women on separate days underwent 1) frequent blood sampling (q 10 min) for 12 h and 2) gonadotropin stimulation by successive doses of GnRH, 2 microg, 10 microg, and 20 microg, administered i.v. at <em>4</em> h intervals over a continuous 12 h. In phase 2, studies were repeated 2 h after initiation of a 12-h hyperinsulinemic-euglycemic clamp (80 mU/m(2).min). Administration of insulin to both groups failed to alter mean serum gonadotropin concentrations, LH pulse frequency, or LH pulse amplitude. Moreover, gonadotropin responses to GnRH were unchanged by insulin infusion. In PCOS and normal women, a significant reduction of serum <em>androstenedione</em> was associated with insulin administration, whereas no differences were noted for the remaining androgens and estrogens measured. These findings demonstrated that in PCOS women, LH secretion and gonadotropin responses to GnRH were not influenced by insulin administration. Insulin infusion had little effect on steroid hormone production with the possible exception of <em>androstenedione</em>. These results suggest that inappropriate LH secretion in PCOS is not a direct consequence of insulin resistance and compensatory hyperinsulinemia.
Publication
Journal: Journal of Cellular Biochemistry
October/24/2001
Abstract
Previously we found that the increased plasma testosterone levels in male rats during exercise partially resulted from a direct and luteinizing hormone (LH)-independent stimulatory effect of lactate on the secretion of testosterone. In the present study, the acute and direct effects of lactate on testosterone production by rat Leydig cells were investigated. Leydig cells from rats were purified by Percoll density gradient centrifugation subsequent to enzymatic isolation of testicular interstitial cells. Purified rat Leydig cells (1 x 10(5) cells/ml) were in vitro incubated with human chorionic gonadotropin (hCG, 0.05 IU/ml), forskolin (an adenylyl cyclase activator, 10(-5) M), or 8-bromo-adenosine-3':5'-cyclic monophosphate (8-Br-cAMP, 10(-<em>4</em>) M), SQ22536 (an adenylyl cyclase inhibitor, 10(-6)-10(-5) M), steroidogenic precursors (25-hydroxy-cholesterol, pregnenolone, progesterone, and <em>androstenedione</em>, 10(-5) M each), nifedipine (a L-type Ca(2+) channel blocker, 10(-5)-10(-<em>4</em>) M), or nimodipine (a potent L-type Ca(2+) channel antagonist, 10(-5)-10(-<em>4</em>) M) in the presence or absence of lactate at 3<em>4</em> degrees C for 1 h. The concentration of medium testosterone was measured by radioimmunoassay. Administration of lactate at 5-20 mM dose-dependently increased the basal testosterone production by 63-187% but did not alter forskolin- and 8-Br-cAMP-stimulated testosterone release in rat Leydig cells. Lactate at 10 mM enhanced the stimulation of testosterone production induced by 25-hydroxy-cholesterol in rat Leydig cells but not other steroidogenic precursors. Lactate (10 mM) affected neither 30- nor 60-min expressions of cytochrome P<em>4</em>50 side chain cleavage enzyme (P<em>4</em>50scc) and steroidogenic acute regulatory (StAR) protein. The lactate-stimulated testosterone production was decreased by administration of nifedipine or nimodipine. These results suggested that the physiological level of lactate stimulated testosterone production in rat Leydig cells through a mechanism involving the increased activities of adenylyl cyclase, cytochrome P<em>4</em>50scc, and L-type Ca(2+) channel.
Publication
Journal: Molecular and Cellular Endocrinology
July/22/1991
Abstract
Effects of inhibin (recombinant human inhibin-A) on ovarian androgen synthesis were tested in vitro using serum-free monolayer cultures of human thecal cells. Treatment for <em>4</em> days with inhibin alone at doses between 10 and 100 ng/ml caused modest (approximately 2-fold) increases in production of androgen (<em>androstenedione</em> and dehydroepiandrosterone): similar to the maximal level of stimulation caused by luteinizing hormone (LH) (10 ng/ml) alone but only about one-third of that caused by insulin-like growth factor I (IGF-I) (30 ng/ml) alone. Combined treatment with LH and inhibin elicited additive effects on androgen production whereas LH and IGF-I were synergistic, giving rise to androgen production rates at least <em>4</em>0 times greater than control. Additional presence of inhibin caused up to 10-fold augmentation of the response to LH + IGF-I. Activin (recombinant human activin-A) was previously shown to inhibit LH + IGF-I-induced androgen synthesis in this human thecal cell culture system. In the present study we found that the additional presence of inhibin (greater than 1 ng/ml) completely neutralized this inhibitory action of activin (10 ng/ml). These effects of inhibin were dose-dependent (ED50 1-10 ng/ml) and maximal at approximately 100 ng/ml. Inhibin stimulation of androgen synthesis occurred in the absence of measurable effects on progesterone production, and cell numbers in cultured cell monolayers were unaltered by the protein. It is concluded that inhibin exerts potent and selective stimulation of human thecal cell androgen synthesis in vitro. These results a paracrine role for inhibin(s) in modulating follicular androgen biosynthesis in the human ovary.
Publication
Journal: Journal of steroid biochemistry
August/31/1988
Abstract
The aim of the present study was to investigate the effectiveness of several imidazole drugs to inhibit human placental aromatase compared with the known inhibitors of aromatase, <em>4</em>-hydroxy<em>androstenedione</em> (<em>4</em>-OHA) and aminoglutethimide (AG). Inhibition was similar with both <em>androstenedione</em> and testosterone as substrates. The order of decreasing inhibitory effect (determined from ID50 values) was: <em>4</em>-OHA greater than tioconazole greater than econazole greater than bifonazole greater than clotrimazole greater than micomazole greater than isoconazole greater than ketoconazole greater than AG greater than nimorazole. The imidazole drugs and AG were reversible inhibitors of aromatase activity, in contrast <em>4</em>-OHA was an irreversible inhibitor. Astemizole inhibited less than <em>4</em>0% whereas metronidazole, carbimazole, mebendazole, tinidazole and thiabendazole inhibited less than 20% of aromatase activity at 100 mumol/l. The imidazole drugs and AG were without effect on 3 beta-hydroxysteroid dehydrogenase-isomerase (3 beta-HSD-I) and 17 beta-hydroxysteroid oxidoreductase activity. In contrast <em>4</em>-OHA was found to be a potent, reversible inhibitor of 3 beta-HSD-I with an ID50 value of 2.15 mumol/l. A common structural feature of the imidazole drugs having an inhibitory effect was the presence of one or more aromatic rings on the N-1 substituent. In contrast, the imidazole drugs having the imidazole ring fused to a benzene ring, i.e. benzimidazoles (astemizole, mebendazole, thiabendazole) and those having an aliphatic side chain on the N-1 of the imidazole ring (carbimazole, metronidazole, nimorazole, tinidazole) were only weak inhibitors of aromatase.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
June/5/1991
Abstract
In search of a more physiological testosterone (T) replacement therapy for hypogonadal states, we evaluated an inclusion complex of T with 2-hydroxypropyl-beta-cyclodextrin (HPBCD). HPBCD enhances T solubility and absorption, but HPBCD is not absorbed. Five hypogonadal men (mean age, 32.<em>4</em> +/- 2.3 yr) with serum T levels below the normal range were treated in two separate experimental phases with either a 2.5- or 5.0-mg tablet of sublingual (SL) T-HPBCD three times daily for 7 days. Acute pharmacodynamic changes were monitored at baseline and 10, 20, and <em>4</em>0 min and 1, 1.5, 2, 3, <em>4</em>, and 8 h after administration of the first dose. At the 5-mg dose, a maximal concentration (Cmax) of T (85.<em>4</em> +/- 11.0 nmol/L) was achieved in 20 min (63 +/- 2<em>4</em>-fold increase), followed by a rapid decline to below the normal range (less than 12 nmol/L) at 2 h, with an estimated half-life of decline of 1.87 +/- 0.19 h. The dihydrotestosterone (DHT) Cmax (<em>4</em>.1 +/- 0.5 nmol/L) occurred at 32 +/- 5 min (8.9 +/- 1.3-fold increase) and declined to below the normal range (less than 1.2 nmol/L) after 3 h. The integrated 8 h value for the ratio of T/DHT was 10.0 +/- 1.1, which fell within the normal range. The increment in <em>androstenedione</em> paralleled that in T, and the Cmax (6.8 +/- 0.9 nmol/L) was reached in 2<em>4</em> +/- <em>4</em> min (2.3 +/- 0.6-fold increase). Compared to baseline, the Cmax was significantly greater for T (P less than 0.005), DHT (P less than 0.0005), and <em>androstenedione</em> (P less than 0.005). Both estradiol (E2) and estrone (E1) remained in the normal range (less than 200 pmol/L), although the Cmax for E1 was significantly greater than baseline (P less than 0.05). Serum LH levels were suppressed (19.0 +/- 2.6%) at 2 h (P less than 0.05), without a significant change in FSH. During 7 days of treatment, there was no cumulative increase in basal T, DHT, and E2 levels or further decline in LH or FSH levels. There was no change in sex hormone-binding globulin levels. Similar results were observed with the 2.5-mg dose, suggesting that the capacity of SL absorption may be limited to a certain dose of T-HPBCD. The fluctuations in T after SL administration of T-HPBCD resemble endogenous episodic secretion. We conclude that T, complexed with HPBCD, is rapidly absorbed by the SL route and quickly metabolized without sustained elevations of DHT or E2.
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