Citations
All
Search in:AllTitleAbstractAuthor name
Publications
(21K+)
Patents
Grants
Pathways
Clinical trials
Publication
Journal: Clinical Pharmacology and Therapeutics
December/13/2010
Abstract
Kisspeptin is a novel therapeutic target for infertility. A single kisspeptin-54 (KP-54) injection acutely stimulates the release of reproductive hormones in women with hypothalamic amenorrhea (HA), a commonly occurring condition characterized by absence of menstruation; however, twice-daily administration of KP-54 results in tachyphylaxis. We determined the time course of desensitization to twice-daily KP-54 injections, compared the effects of twice-daily and twice-weekly administration regimens of KP-54, and studied the effects of long-term twice-weekly administration of KP-54 on the release of reproductive hormones in women with HA. When KP-54 was administered twice daily, responsiveness to luteinizing hormone (LH) diminished gradually, whereas responsiveness to follicle-stimulating hormone (FSH) was nearly abolished by day 2. Twice-weekly KP-54 administration resulted in only partial desensitization, in contrast to the complete tolerance achieved with twice-daily administration. Women with HA who were treated with twice-weekly KP-54 injections had significantly elevated levels of reproductive hormones after 8 weeks as compared with treatment with saline. No adverse effects were observed. This study provides novel pharmacological data on the effects of KP-54 on the release of reproductive hormones in women with HA.
Publication
Journal: Molecular Endocrinology
December/4/1990
Abstract
Follistatin, a novel, single chain, glycosylated polypeptide bearing no homology with previously characterized inhibins but exhibiting potent and specific pituitary FSH-release inhibition has been structurally characterized by protein microsequencing, cDNA cloning, and DNA sequencing. Two populations of clones differing in their 3'-untranslated sequences were found to encode a 344 amino acid precursor protein and an identical but carboxyl terminal truncated 317 amino acid precursor, respectively. Additionally, one clone, FS18, contained two introns and probably resulted from reverse transcription of heterogeneous nuclear RNA during cDNA library construction. Follistatin is unusually cysteine-rich, containing 36 cysteines in the mature coding sequence of 315 amino acids and an extremely acidic carboxyl terminal region, FS(292-304), comprised of Glu-Asp-Thr-Glu-Glu-Glu-Glu-Glu-Asp-Glu-Asp-Gln-Asp which probably resides outside a tightly cross-linked protein sphere. The heparin-binding ability of follistatin can probably be ascribed to the basic region specified by FS(75-86), Lys-Lys-Cys-Arg-Met-Asn-Lys-Lys-Asn-Lys. Overall, follistatin is organized into three homologous domains, FS(66-135), FS(139-210), and FS(216-287) containing 70, 72, and 72 amino acids, respectively, which show a 52% homology among themselves and a 57% homology with the 56 amino acid human pancreatic secretory trypsin inhibitor protein when aligned for maximum homology.
Publication
Journal: Journal of Cell Biology
May/25/1979
Abstract
Cultured rat ovarian granulosa cells undergo a dramatic morphological change when exposed to follicle-stimulating hormone (FSH). Exposure to FSH causes the flattened epithelioid granulosa cells to assume a nearly spherical shape while retaining cytoplasmic processes which contact the substrate as well as adjacent cells. This effect of FSH is preceded by a dose-dependent increase in intracellular cAMP, is potentiated by cyclic nucleotide phosphodiesterase inhibitors, and is mimicked by dibutyryl cAMP. Prostaglandins E1 or E2 and cholera enterotoxin also cause the cells to change shape. A subpopulation of the cells responds to luteinizing hormone. These morphological changes, which are blocked by 2,4-dinitrophenol, resemble those produced by treating cultures with cytochalasin B. Electron microscopy shows that the unstimulated, flattened cells contain bundles of microfilaments particularly in the cortical and basal regions. After FSH stimulation, microfilament bundles are not found in the rounded granulosa cell bodies but they are present in the thin cytoplasmic processes. These data suggest that the morphological change results from a cAMP-mediated, energy-dependent mechanism that may involve the alteration of microfilaments in these cells.
Publication
Journal: British Journal of Clinical Pharmacology
September/20/2006
Abstract
OBJECTIVE
To assess the pharmacokinetic and pharmacodynamic effects of co-administration of a combined oral contraceptive (ethinyloestradiol plus levonorgestrel) and lamotrigine.
METHODS
Over a period of 130 days, healthy female subjects took lamotrigine (titrated up to 300 mg day(-1)) and the combined oral contraceptive, either individually or as co-therapy. Plasma ethinyloestradiol and levonorgestrel concentrations were measured in the presence and absence of lamotrigine, and serum lamotrigine concentrations were measured in the presence and absence of the combined oral contraceptive. Serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone, oestradiol and sex hormone binding globulin were also determined.
RESULTS
Of the 22 enrolled subjects, 16 had evaluable pharmacokinetic data. The mean (90% CI) ratios of lamotrigine area under the concentration-time curve from 0 to 24 h (AUC(0,24 h)) and maximum observed concentration (C(max)) of lamotrigine when it was given with the combined oral contraceptive and during monotherapy were 0.48 (0.44, 0.53) and 0.61 (0.57, 0.66), respectively. Ethinyloestradiol pharmacokinetics were unchanged by lamotrigine, the mean combined oral contraceptive + lamotrigine : combined oral contraceptive alone ratios (90% CI) of the AUC(0,24 h) and C(max) of levonorgestrel were 0.81 (0.76, 0.86) and 0.88 (0.82, 0.93), respectively. FSH and LH concentrations were increased (by 4.7-fold and 3.4-fold, respectively) in the presence of lamotrigine, but the low serum progesterone concentrations suggested that suppression of ovulation was maintained. Intermenstrual bleeding was reported by 7/22 (32%) of subjects during co-administration of lamotrigine and combined oral contraceptive.
CONCLUSIONS
A clinically relevant pharmacokinetic interaction was observed during co-administration of a combined oral contraceptive and lamotrigine. A dosage adjustment for lamotrigine may need to be considered when these agents are co-administered. A modest decrease in the plasma concentration of levonorgestrel was also observed but there was no corresponding hormonal evidence of ovulation.
Publication
Journal: Biology of Reproduction
May/15/2011
Abstract
Follicle-stimulating hormone (FSH), a pituitary glycoprotein hormone, is an integral component of the endocrine axis that regulates gonadal function and fertility. To transmit its signal, FSH must bind to its receptor (FSHR) located on Sertoli cells of the testis and granulosa cells of the ovary. Thus, both the magnitude and the target of hormone response are controlled by mechanisms that determine FSHR levels and cell-specific expression, which are supported by transcription of its gene. The present review examines the status of FSHR/Fshr gene regulation, emphasizing the importance of distal sequences in FSHR/Fshr transcription, new insights gained from the influx of genomics data and bioinformatics, and emerging trends that offer direction in deciphering the FSHR/Fshr regulatory landscape.
Publication
Journal: Journal of Endocrinology
December/29/1976
Abstract
Plasma levels of LH, FSH, prolactin, oestradiol and progesterone were determined daily during two consecutive menstrual cycles in six women volunteers. During the first (control) cycle no treatment was given and normal secretion of these hormones was observed. Oral administration of tamoxifen (20 mg/day), for either 5 or 10 days of the follicular phase of the second cycle, caused no change in either the overall length of the cycle or the time of occurrence of the mid-cycle gonadotrophin surge. There was little difference in the secretion of LH, FSH and progesterone during the control and test cycles. A two- to eight-fold increase in oestradiol levels was observed during test cycle which was most pronounced at the times of mid-cycle and mid-luteal hormone peaks. There was a significant decrease in plasma prolactin levels at mid-cycle but no real difference could be seen during the remainder of the cycle. The data suggest that tamoxifen may act directly on the ovary to stimulate oestradiol release without intermediary gonadotrophin stimulation. As the drug apparently inhibited prolactin secretion even in the presence of high oestradiol levels, an alternative explanation may be that the reduced prolactin concentration permits augmented ovarian stimulation by normal concentrations of gonadotrophins.
Publication
Journal: Journal of Biological Chemistry
July/6/1993
Abstract
Prostaglandin endoperoxide synthase isoform 2 (PGS-2) mRNA and protein are transiently induced by gonadotropins in granulosa cells of preovulatory follicles prior to ovulation. To better understand the hormonal regulation of the rat PGS-2 (rPGS-2) gene in these cells, genomic clones containing rPGS-2 as well as up to 6 kilobases of 5'-flanking DNA were isolated by screening a rat liver genomic library with a labeled 5'-fragment of the mouse PGS-2 cDNA. Primer extension analysis using ovarian follicular mRNA identified the presence of a single rPGS-2 transcription initiation site located 144 nucleotides upstream of the ATG translation initiation codon. To test for promoter activity within the 5'-flanking region of the rPGS-2 gene, a genomic fragment, -2698/32 (1 = cap site), as well as a series of 5'-deletion mutants, were fused upstream of the chloramphenicol acetyltransferase (CAT) reporter gene and transfected into primary cultures of granulosa cells. Forskolin (7.5 microM), follicle-stimulating hormone (500 ng/ml) and luteinizing hormone (500 ng/ml) induced CAT activity following transfection with the -2698/32PGS.CAT, whereas gonadotropin-releasing hormone (10(-6) M) and interleukin-1 beta (30 ng/ml) had no effect. Deletion mutants delineated the region spanning from -192 to -54 of the transcription start site to be essential for both basal and forskolin-regulated expression of the reporter gene. The same DNA fragment (-192/-54) exhibited specific binding to granulosa cell nuclear extract proteins as analyzed by electrophoretic mobility shift assays. Additional specific bands were observed in extracts prepared from granulosa cells exposed to an ovulatory dose of gonadotropin. Collectively, these results provide the first structural and functional evidence that the transcriptional regulation of the rat PGS-2 gene by gonadotropins and forskolin in granulosa cells involves 5'-flanking DNA sequences, specifically a region between -192 and -54 of the transcription initiation site.
Publication
Journal: Journal of Biological Chemistry
February/14/2008
Abstract
Activin, a member of the transforming growth factor-beta superfamily, is an important modulator of follicle-stimulating hormone synthesis and secretion in the pituitary and plays autocrine/paracrine roles in the regulation of ovarian follicle development. From a microarray study on mouse ovarian granulosa cells, we discovered that the estrogen receptor beta (ERbeta) is inducible by activin. We previously demonstrated that estrogen suppresses activin gene expression, suggesting a feedback relationship between these two follicle-regulating hormones. The purpose of this study was to investigate fully activin A regulation of ER expression. Real time reverse transcription-PCR assays on cultured granulosa cells showed that both ERalpha and ERbeta mRNAs were induced by activin A at 4, 12, and 24 h in a dose-responsive manner. Western blots confirmed an increase in their protein levels. Consistent with increased ERalpha and ERbeta expression, activin A stimulated estradiol-induced estrogen response element promoter activity. Activin A stimulation of ER expression was a direct effect at the level of gene transcription, as it was not abolished by cycloheximide but was abolished by actinomycin D, and in transfected granulosa cells activin A stimulated ERalpha promoter activity. To investigate the effect of activin in vivo and, thus, its biological significance, we examined ER expression in inhibin transgenic mice that have decreased activin expression and discovered that these mice had decreased ERalpha and ERbeta expression in the ovary. We also found that ER mRNA levels were decreased in Müllerian inhibiting substance promoter (MIS)-Smad2 dominant negative mice that have impaired activin signaling through Smad2, and small interfering RNAs targeting Smad2 or Smad3 suppressed ERalpha promoter activation, suggesting that Smad2 and Smad3 are involved in regulating ER levels. Therefore, this study reveals an important role for activin in inducing the expression of ERs in the mouse ovary and suggests important interplay between activin and estrogen signaling.
Publication
Journal: Frontiers in Neuroendocrinology
May/30/2001
Abstract
Intracellular progesterone receptors (PRs) are ligand-inducible transcription factors that mediate the majority of the effects of progesterone (P) on neuroendocrine functions. During the past decade, evidence has accumulated which suggest that PRs can also be activated independently of P, by signals propagated through membrane-bound receptors to the interior of cells. The activation of PRs by this type of "cross-talk" mechanism has been implicated in the physiological regulation of several important neuroendocrine processes, including estrous behavior and periovulatory hormone secretions. We review evidence that both ligand-dependent and ligand-independent activation of PRs occurs in central neurons and in anterior pituitary cells and that the convergence and summation of these signals at the PR serves to integrate neural and endocrine signals which direct several critically important neuroendocrine processes. An integrative function for PRs is reviewed in several physiological contexts, including the display of lordosis behavior in female rodents, the neurosecretion of gonadotropin-releasing hormone surges, secretion of preovulatory gonadotropin surges, and release of periovulatory follicle stimulating hormone surges. The weight of evidence indicates that cross talk at the intracellular PR is an essential component of the integrative mechanisms that direct each of these neuroendocrine events. The recurrence of PR's integrative actions in several different physiological contexts suggests that other intracellular steroid receptors similarly function as integrators of neural and endocrine signals in other neuroendocrine processes.
Publication
Journal: Journal of andrology
June/22/1994
Abstract
In men, administration of exogenous testosterone (T) exerts direct negative feedback effects at the pituitary as well as at the hypothalamic level. This study was undertaken to determine whether T itself causes the inhibitory effects on the pituitary, or whether conversion to estradiol (E2) or dihydrotestosterone (DHT) is required. We assessed the biological activity of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as immunoactivity. Blood samples were drawn before, during, and after a continuous, 72-hour i.v. infusion of T (15 mg/day), E2 (90 micrograms/day), or DHT (500 micrograms/day). Each of these doses is twice the daily production rate of the steroid. Each man received each of the three steroid infusions. We studied four men, ages 23-35, with idiopathic hypothalamic hypogonadism (IHH), who were treated with pulsatile gonadotropin releasing hormone (GnRH) until their gonadotropins reached the normal range. Serum levels of T, E2, DHT, and levels of immunologically active and biologically active LH and FSH were measured. We found that administration of each steroid increased serum levels of the infused steroid to the upper physiologic range. Administration of T or E2 resulted in decreased mean levels of biologically and immunologically active LH and FSH; administration of DHT did not alter gonadotropin secretion. These data suggest that some of the direct effect of T at the pituitary level in men is mediated by E2, whereas peripherally formed DHT may not play an important role in this process.
Publication
Journal: Human Genetics
September/24/1976
Abstract
Four 46,XY siblings with congenital bilateral megalorchidia, marcogenitosomia, and severe mental deficiency were investigated. The testicular size was significantly larger than age-matched normal males. A normal hypothalamic-pituitary gonadotropin function was demonstrated by the finding of normal levels of luteinizing and follicle-stimulating hormones in blood samples drawn at frequent intervals and by normal responses to gonadotropin-releasing hormone and testosterone administration. A normal testicular function was shown by the finding of normal (a) plasma testosterone and estradiol levels, (b) gonadal response to human chorionic gonadotropin, (c) sperm analysis, and (d) morphology and cell architecture of the testes. Adrenal function was found to be within normal limits. These results demonstrated the existence of normofunctional testicular hyperplasia. The family studies suggested that this distinct congenital disorders is inherited as an X-linked recessive trait.
Publication
Journal: CNS Drugs
April/28/2005
Abstract
It is well known that epilepsy, antiepileptic drugs (AEDs), and the reproductive system have complex interactions. Fertility is lower in both men and women with epilepsy than in the general population. Moreover, reproductive endocrine disorders are more common among patients with epilepsy than among the population in general. These disorders have been attributed both to epilepsy itself and to use of AEDs. The use of the liver enzyme-inducing AEDs phenobarbital, phenytoin and carbamazepine increases serum sex hormone-binding globulin (SHBG) concentrations in both men and women with epilepsy. Over time, the increase in serum SHBG levels leads to diminished bioactivity of testosterone and estradiol, which may result in diminished potency in men and menstrual disorders in some women, and thus to reduced fertility. Liver enzyme-inducing AEDs also reduce the efficacy of oral contraceptives. Valproic acid medication may have effects on serum androgen concentrations and it reduces serum follicle stimulating hormone levels in men with epilepsy. However, the clinical significance of valproic acid-related reproductive endocrine changes in men is unknown. On the other hand, in women, use of valproic acid appears to be associated with a frequent occurrence of reproductive endocrine disorders characterised by polycystic changes in the ovaries, high serum testosterone concentrations (hyperandrogenism) and menstrual disorders. These disorders are especially common among women who have gained weight during valproic acid treatment. There are some discrepancies regarding the reported occurrence of reproductive endocrine disorders in women taking valproic acid for epilepsy. However, most studies also including patients receiving valproic acid for other reasons than epilepsy, and studies in different non-epileptic animal models, have shown an association between valproic acid medication and hyperandrogenism and related reproductive endocrine disorders. From a practical point of view, the length of the menstrual cycles and bodyweight should be monitored in women with epilepsy after commencement of treatment with valproic acid. A serum testosterone assay is helpful in following the possible biochemical endocrine changes. Ultrasonography of the ovaries (preferably transvaginal) is indicated if clinical assessment and serum testosterone measurement imply that there is a clinically significant valproic acid-related reproductive endocrine problem. That would be the case if the menstrual cycles were irregular or prolonged (usually >35 days) and serum testosterone levels elevated, especially with associated weight gain. The endocrine effects of the new AEDs have not been widely studied. However, it seems they may offer an alternative if reproductive endocrine problems emerge during treatment with the older AEDs.
Publication
Journal: Molecular and Cellular Endocrinology
June/1/1993
Abstract
Clusterin, alpha 2-macroglobulin and testins are three novel Sertoli cell proteins whose physiological functions may be related to cell-cell interactions in the seminiferous epithelium of the testis. We have demonstrated the biosynthesis of clusterin, alpha 2-macroglobulin, and testins by Sertoli cells in vitro using pulse-chase labeling analysis. For clusterin, two precursors with an apparent molecular weight (M(r)) of 72,000 (PH) and 66,000 (PL) were detected in the Sertoli cell cytosol in addition to the alpha (M(r) 43,000) and beta (M(r) 35,000) subunits of the mature protein. However, the precursors were not secreted into the medium since only the alpha and beta subunits of clusterin were detected. For alpha 2-macroglobulin and testins, no precursor molecules were detected either in the Sertoli cell cytosol or culture medium. The polarized secretory pattern of these proteins and their regulation by follicle stimulating hormone (FSH) and testosterone (T) were examined using a bicameral culture chamber that mimics the in vivo physiological conditions. Clusterin was secreted almost exclusively into the apical chamber of the bicameral culture unit with an apical:basal ratio of 30:1. In contrast, alpha 2-macroglobulin and testins had an apical:basal ratio of 1:1 and 1.5:1, respectively. Thus, the polarized secretory pattern for clusterin is different from alpha 2-macroglobulin and testins. It was noted that FSH and T, the known Sertoli cell regulators, did not affect the secretion of either clusterin or alpha 2-macroglobulin. Due to the morphological intimacy between Sertoli cells and germ cells in the adluminal compartment of the testis, the effects of germ cell-conditioned medium were investigated. Addition of germ cell-conditioned medium (1-30 micrograms protein) to the apical chamber of the bicameral culture unit caused a dose-dependent inhibition of clusterin and testins apical secretion and a slight but statistically significant stimulation of their basal secretion. In contrast, the secretion of alpha 2-macroglobulin by Sertoli cells was stimulated both apically and basally. These observations suggest that germ cell-conditioned medium contains a biological factor(s) that differentially regulates the bidirectional secretion of Sertoli cell proteins. These studies therefore reveal the complicated regulatory processes involved in cell-cell interactions in the seminiferous epithelium.
Publication
Journal: British Medical Journal
December/15/1973
Abstract
A standard intravenous 100 mug luteinizing hormone/follicle stimulating hormone-releasing hormone (LH/FSH-RH) test was used to assess the pituitary gonadotrophin responses in 155 patients with a variety of diseases of the hypothalamic-pituitary-gonadal axis. In all but nine patients there was an increase in circulating levels of either LH or FSH in response to the releasing hormone though 137 (88%) were clinically hypogonadal. It was not possible with this test to distinguish between hypothalamic and pituitary causes of hypogonadotrophic hypogonadism, since a variety of LH and FSH responses emerged within the disease groups. However, primary gonadal failure characteristically resulted in exaggerated gonadotrophin response. The potential therapeutic use of the gonadotrophin releasing decapeptide is suggested in certain patients with hypogonadotrophic hypogonadism.
Publication
Journal: Endocrine research communications
December/19/1975
Abstract
Methods for the isolation and culture of enriched populations of Sertoli cells from 20-60 day old rats are described. The identity of the Sertoli cells was verified by bright light and electron microscopy. Freshly isolated Sertoli cells specifically bound follicle stimulating hormone (FSH) but not luteinizing hormone (LH) and responded to FSH stimulation with dramatic increase in cyclic AMP level. Isolated Sertoli cells, maintained in culture for 11 days, showed no evidence of proliferation but retained their characteristic ultrastructural features and FSH binding ability. Incubation of cultured cells with FSH resulted in a significant stimulation of cyclic AMP and androgen binding protein (ABP). Since the freshly isolated or cultured cells were predominantly (greater than 80%) Sertoli cells, these results provide direct evidence that the Sertoli cells represent a primary target site for FSH activity in the testes. The culture method also provides a valuable in vitro model for the study of chronic effects of various agents on the Sertoli cell.
Publication
Journal: Molecular Endocrinology
February/9/1998
Abstract
Recently, a family of novel, serine/threonine protein kinases has been identified. One of these transcriptionally inducible, immediate-early genes encodes serum/glucocorticoid inducible-protein kinase, sgk. By in situ hybridization, we show that sgk expression in the rat ovary is selectively localized to granulosa cells. In culture, FSH or forskolin, activators of the protein kinase A (PKA) pathway, rapidly (2 h) and transiently increased sgk mRNA levels in undifferentiated granulosa cells. Sgk mRNA exhibited a biphasic expression pattern, with maximal levels observed at 48 h of FSH/forskolin as granulosa cells differentiate to the preovulatory phenotype. Deletion analyses using sgk promoter-reporter constructs (-4.0 kb to -35 bp) identified a region between -63 and -43 bp that mediated FSH and forskolin-responsive transcription in undifferentiated and differentiated granulosa cells. This G/C-rich region 1) conferred both basal and inducible transcription to the minimal -35 sgk promoter chloramphenicol acetyltransferase reporter construct, 2) specifically bound Sp1 and Sp3 present in granulosa cell extracts, and 3) bound recombinant Sp1. Mutation of 2 bp in this region not only prevented Sp1 and Sp3 binding, but also abolished the PKA-mediated transactivation observed when using the wild type construct. Sp1 and Sp3 DNA-binding activity and protein levels did not change significantly during sgk induction. Collectively, these data indicate that Sp1/Sp3 transactivation of the sgk promoter likely involves regulated, phosphorylation-dependent interaction with other factors. Thus the novel, biphasic induction of sgk that correlates with granulosa cell progression from proliferation to differentiation appears to involve sequential, coordinated actions of FSH, PKA, and transcription factors, including Sp1 and Sp3.
Publication
Journal: The American journal of physiology
June/8/1988
Abstract
Previous studies of episodic hormone secretion of the hypothalamic-pituitary-gonadal axis in normal men have produced conflicting results due to examinations of small cohorts of subjects or to limited sampling techniques. We evaluated gonadotropin and testosterone (T) secretory patterns in 20 normal men by sampling blood at 10-min intervals for luteinizing hormone (LH) and follicle-stimulating hormone (FSH). T concentrations were also analyzed at 20-min intervals in 10 subjects. A previously unappreciated spectrum of gonadotropin and T secretory patterns was observed in normal men. Both mean LH concentrations and mean LH pulse amplitudes varied fourfold between individuals. LH interpulse intervals varied from 30 to 480 min (mean 119 +/- 32). Results also suggested a relative refractory period at the level of the hypothalamus or pituitary. In three subjects, a striking nighttime accentuation of LH pulsations was noted. Through use of Fourier analysis, a diurnal variation in LH was observed in the population (P less than 0.02). Mean FSH levels showed marked variation between individual subjects, with discrete pulses rarely observed. No diurnal variation in FSH secretion was noted. Serum T concentrations determined at 6-h intervals ranged from 105 to 1,316 ng/dl between subjects. When T was measured at 20-min intervals, marked intermittent declines in the T concentrations to levels well below the normal range were observed in 3 of 10 subjects. T secretion was found to lag behind LH secretion by approximately 40 min (P less than 0.02).
Publication
Journal: Psychoneuroendocrinology
March/12/2003
Abstract
BACKGROUND
An association between abnormal changes in reproductive endocrine function during the perimenopause and the onset of depression in some women has been suggested but remains controversial.
METHODS
We examined basal plasma hormone levels in two samples of women with well characterized, first onset depression (major or minor) during the perimenopause and matched comparison groups of asymptomatic women. Results were compared by analysis of variance.
RESULTS
No significant diagnosis-related differences were observed in plasma hormone measures of the following: follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), estrone (E1), total (T) or free testosterone (FT), or the E2/LH ratio. We did identify significantly lower morning plasma dehydroepiandrosterone (DHEA) and its sulphated metabolite DHEA-S (but not cortisol) levels in the depressed women compared to the non-depressed comparison group. Women with hot flushes (regardless of the presence of depression) were significantly older than women without flushes, had significantly higher plasma levels of FT, LH and FSH, and had significantly lower E2/LH ratios.
CONCLUSIONS
Women with first onset depression during the perimenopause are not distinguished from controls on the basis of basal hormone measures of ovarian estrogens, testosterone, or gonadotropins. However, perimenopause-related changes in E2 may interact with low levels of DHEA in some women to increase their vulnerability to develop depression. In contrast to perimenopause-related vasomotor symptoms, depression during the perimenopause is not associated with a simple hormone deficiency state. The relatively low levels of E2 and E1 in the depressed women may have met statistical significance in a much larger and homogenous sample.
Publication
Journal: Endocrinology
January/16/2003
Abstract
Previous studies have suggested that FSH may be involved in regulation of Leydig cell function. We have examined this directly using two mouse models with null mutations in either the FSH beta-subunit (FSHbetaKO mice) or the FSH receptor (FSHRKO mice). Circulating LH levels were normal in adult FSHbetaKO mice, but were significantly increased in FSHRKO mice. Intratesticular testosterone levels increased normally in FSHbetaKO mice from birth to adulthood, whereas testosterone levels in FSHRKO mice failed to increase normally after puberty and were significantly reduced in adult animals. This was associated with reduced levels of mRNA encoding cytochrome P450 side-chain cleavage, 3beta-hydroxysteroid dehydrogenase type VI, and steroidogenic acute regulatory protein in FSHRKO mice. Leydig cell number was normal in FSHbetaKO mice during development, but in FSHRKO mice Leydig cell number increased slowly after puberty and was significantly reduced in the adult animal. Transfection studies showed that the FSHR exhibits constitutive activity in the absence of agonist stimulation. The results indicate, therefore, that Sertoli cells regulate the development of Leydig cell number and that constitutive activity within the FSHR is sufficient to stimulate this process. The presence of the hormone itself is not required when circulating LH levels are adequate.
Publication
Journal: Biology of Reproduction
November/17/1985
Abstract
Four orchidectomized rhesus monkeys (3-3.5 yr of age) were treated for 62 days with daily i.m. injections of hydrocortisone acetate (HCA) at a dose of 10-20 mg/(kg BW X day), and blood samples were obtained daily or every other day before, during, and after treatment. Hydrocortisone acetate injections resulted in a progressive rise in mean plasma cortisol from basal concentrations of 17-35 micrograms/100 ml prior to initiation of steroid treatment to approximately 150 micrograms/100 ml 5 wk later. When serum cortisol concentrations reached 100 micrograms/100 ml, 3-4 wk after the initiation of HCA treatment, circulating luteinizing hormone (LH) and follicle-stimulating hormone (FSH) began to decline, reaching nondetectable concentrations 35 days later. Withdrawal of HCA resulted in a return in plasma cortisol concentrations to pretreatment control levels, which was associated with a complete restoration of gonadotropin secretion. In 2 animals, administration of an intermittent i.v. infusion of gonadotropin-releasing hormone (GnRH) (0.1 micrograms/min for 3 min once every hour), which appears to stimulate the gonadotropes in a physiologic manner, reversed the cortisol-induced inhibition of gonadotropin secretion, restoring circulating LH and FSH concentrations to within 80-100% of control. These results suggest that, in the rhesus monkey, the major site of the inhibitory action of cortisol on gonadotropin release resides at a suprapituitary level and is mediated by interruption of hypothalamic GnRH release.
Publication
Journal: Journal of Urology
March/5/2012
Abstract
OBJECTIVE
Anogenital distance is a marker for endocrine disruption in animal studies in which decreased distance has been associated with testicular dysfunction. In this study we investigated whether anogenital distance was associated with reproductive hormone levels in adult men.
METHODS
A total of 116 men (mean age 36.1 ± 8.0 years) were evaluated at an andrology clinic in Houston. Anogenital distance (the distance from the posterior aspect of the scrotum to the anal verge) and penile length were measured using digital calipers. Testis size was estimated by physical examination. Linear regression was used to determine correlations between genital measurements and hormone levels.
RESULTS
Anogenital distance (r = 0.20, p = 0.03) and penile length (r = 0.20, p = 0.03) were significantly associated with serum testosterone levels while total testis size was not (r = 0.17, p = 0.07). No relationship between genital length and luteinizing hormone, follicle-stimulating hormone or estradiol was identified. After adjusting for age the serum testosterone increased by 20.1 ng/dl (95% CI 1.8, 38.4; p = 0.03) for each 1 cm increase in anogenital distance. On multivariable models no statistically significant relationship existed between penile length and testosterone levels. Moreover men with hypogonadal testosterone levels (less than 300 ng/dl) had a significantly shorter anogenital distance compared to men with higher testosterone levels (31.6 vs 37.3 mm, p = 0.02).
CONCLUSIONS
Anogenital distance may provide a novel metric to assess testicular function in men. Assuming that anogenital distance at birth predicts adult anogenital distance, our findings suggest a fetal origin for adult testicular function.
Publication
Journal: Cancer
January/30/2013
Abstract
BACKGROUND
The objective of this study was to document the differences in testosterone (T) levels between crizotinib-treated and noncrizotinib-treated patients with metastatic nonsmall cell lung cancer (NSCLC).
METHODS
Testosterone levels were measured in 19 men with metastatic NSCLC who received crizotinib and in 19 men with metastatic NSCLC who did not receive crizotinib. Clinical characteristics of the patients were compared, and additional hormone assays were performed as appropriate. Two patients who began crizotinib and 4 patients who had dose interruptions or who stopped crizotinib therapy had serial hormone measurements, permitting the documentation of dynamic hormone changes on and off crizotinib treatment.
RESULTS
Total T levels were low (<241 ng/dL) in 19 of 19 (100%) crizotinib-treated men and in 6 of 19 men (32%) with metastatic NSCLC who did not receive crizotinib (mean T levels, 131 ng/dL and 311 ng/dL, respectively; P = .0002). Only 1 in 5 patients who had anaplastic lymphoma kinase (ALK) gene rearrangements and had not yet received crizotinib had low T. The initiation of crizotinib in 2 patients who had previously normal T levels was associated with a rapid decreases in T and in luteinizing hormone and follicle stimulating hormone levels within 14 to 21 days. Discontinuation of crizotinib led to increases back to normal T levels.
CONCLUSIONS
Crizotinib therapy caused rapid suppression of T levels in men. The current results indicated that the site of action must include a central (hypothalamic or pituitary) effect, but additional direct testicular effects could not be excluded. Further work is required to assess the correlation between low T levels and crizotinib side effects as well as the exact molecular mechanism and site of drug toxicity.
Publication
Journal: Journal of Urology
April/2/2012
Abstract
OBJECTIVE
We determined empirical medical therapy practice patterns for idiopathic infertility.
METHODS
We performed a survey of 7,745 practicing American Urological Association members from July to November 2010. Respondents were questioned on empirical medical therapy use, patient evaluation and selection, and preferred medications.
RESULTS
A total of 387 urologists (5%) participated in the survey, of whom 16% had infertility fellowship training, two-thirds used empirical medical therapy and 78% treated with empirical medical therapy and surgery. Laboratory values important for identifying ideal candidates include sperm concentration, serum follicle-stimulating hormone and serum testosterone. The most common medications used were clomiphene citrate, human chorionic gonadotropin and anastrozole. Of respondents 25% would treat infertile males with testosterone while the patient actively pursued pregnancy. Overall 60.5% of respondents would treat with empirical therapy for 3 to 6 months. Of fellowship trained and general urologist respondents 70% and 47%, respectively, counseled patients that empirical medical therapy has unknown effects on pregnancy and sperm count.
CONCLUSIONS
Empirical medical therapy is used by two-thirds of survey respondents for idiopathic male infertility. There is no clear, universal pattern to the evaluation or identification of the ideal patient for such therapy among those surveyed. There is no consensus on the optimal medication and considerable ambiguity exists as to perceived effects on fertility. Of concern is that 25% of respondents use exogenous testosterone, a medication known for its contraceptive potential, for male infertility treatment. These findings confirm the need for additional studies to establish recommendations on the empirical use of medical therapy in the setting of male infertility.
Publication
Journal: The journals of gerontology. Series A, Biological sciences and medical sciences
February/19/2013
Abstract
BACKGROUND
Concerns about potential adverse effects of testosterone on prostate have motivated the development of selective androgen receptor modulators that display tissue-selective activation of androgenic signaling. LGD-4033, a novel nonsteroidal, oral selective androgen receptor modulator, binds androgen receptor with high affinity and selectivity. Objectives. To evaluate the safety, tolerability, pharmacokinetics, and effects of ascending doses of LGD-4033 administered daily for 21 days on lean body mass, muscle strength, stair-climbing power, and sex hormones.
METHODS
In this placebo-controlled study, 76 healthy men (21-50 years) were randomized to placebo or 0.1, 0.3, or 1.0 mg LGD-4033 daily for 21 days. Blood counts, chemistries, lipids, prostate-specific antigen, electrocardiogram, hormones, lean and fat mass, and muscle strength were measured during and for 5 weeks after intervention.
RESULTS
LGD-4033 was well tolerated. There were no drug-related serious adverse events. Frequency of adverse events was similar between active and placebo groups. Hemoglobin, prostate-specific antigen, aspartate aminotransferase, alanine aminotransferase, or QT intervals did not change significantly at any dose. LGD-4033 had a long elimination half-life and dose-proportional accumulation upon multiple dosing. LGD-4033 administration was associated with dose-dependent suppression of total testosterone, sex hormone-binding globulin, high density lipoprotein cholesterol, and triglyceride levels. follicle-stimulating hormone and free testosterone showed significant suppression at 1.0-mg dose only. Lean body mass increased dose dependently, but fat mass did not change significantly. Hormone levels and lipids returned to baseline after treatment discontinuation.
CONCLUSIONS
LGD-4033 was safe, had favorable pharmacokinetic profile, and increased lean body mass even during this short period without change in prostate-specific antigen. Longer randomized trials should evaluate its efficacy in improving physical function and health outcomes in select populations.
load more...