Hormonal, metabolic and inflammatory circulating biomarker profiles in obese and non-obese Brazilian middle-aged women

AIM

To investigate circulating hormonal, metabolic and inflammatory biomarker profiles in obese and non-obese middle-aged women.

METHODS

A total of 110 women, aged 40-60 years, were included in this cross-sectional study. Patients were allocated, according to the occurrence of menopause and body mass index (BMI), into four groups: PM0 (premenopausal non-obese), PM1 (premenopausal obese), M0 (postmenopausal non-obese), and M1 (postmenopausal obese). Serum levels of gonadotropins, sex hormones, lipid markers, leptin, hs-CRP and interleukin-6 were obtained using either colorimetric or immunoenzymatic assays. Univariate and correlation analyses were performed among all clinical and laboratorial parameters. Principal component analysis was used to characterize subsets of biomarkers, which had their discriminatory capacity tested using discriminant function analysis.

RESULTS

Levels of gonadotropins and female sex hormones were similar between PM0 and PM1 and between M0 and M1 (p > 0.05), all of them varied between PM0 and M0 (p < 0.05), but only estradiol was significantly altered in the comparison between PM1 and M1 (p = 0.027). Regarding metabolic markers, leptin was lower in PM0 than in M0 (p = 0.010) and higher in M1 than in M0 (p = 0.046). In premenopausal women, BMI correlated only to leptin, while it correlated to several other markers in postmenopausal women. A combination of FSH and leptin serum levels significantly discriminated the four groups (Wilks's lambda < 0.001, in canonical functions 1 and 2).

CONCLUSION

A combined analysis of hormonal biomarkers may potentially distinguish obese from non-obese women with distinct menopause status. Further research is thus required to clarify the clinical significance of such findings.

Enzyme-linked immunosorbent assay of relaxin-like gonad-stimulating peptide in the starfish Patiria (Asterina) pectinifera

A relaxin-like gonad-stimulating peptide (RGP) from starfish Patiria (Asterina) pectinifera is the first identified invertebrate gonadotropin for final gamete maturation. Recently, we succeeded in obtaining specific antibodies against P. pectinifera RGP (PpeRGP). In this study, the antibodies were used for the development of a specific and sensitive enzyme-linked immunosorbent assay (ELISA) for the measurement of PpeRGP. A biotin-conjugated peptide that binds to peroxidase-conjugated streptavidin is specifically detectable using 3,3',5,5'-tetramethylbenzidine (TMB)/hydrogen peroxide as a substrate; therefore, biotin-conjugated RGP (biotin-PpeRGP) was synthesized chemically. Similarly to PpeRGP, synthetic biotin-PpeRGP bound to the antibody against PpeRGP. In binding experiments with biotin-PpeRGP using wells coated with the antibody, a displacement curve was obtained using serial concentrations of PpeRGP. The ELISA system showed that PpeRGP could be measured in the range 0.01-10pmol per 50µl assay buffer. On the contrary, the B-chains of PpeRGP, Asterias amurensis RGP, Aphelasterias japonica RGP, and human relaxin showed minimal cross-reactivity in the ELISA, except that the A-chain of PpeRGP affected it slightly. These results strongly suggest that this ELISA system is highly specific and sensitive with respect to PpeRGP.

Development of a homologous radioimmunoassay for red seabream follicle stimulating hormone and regulation of gonadotropins by GnRH in red seabream, Pagrus major

Using a recombinant chimeric single-chain follicle stimulating hormone (FSH), we established a radioimmunoassay (RIA) for red seabream (Pagrus major) FSH (pmFSH) which became a powerful tool for studying reproductive physiology. We studied the profiles in plasma and pituitary concentrations of FSH and luteinizing hormone (LH) during sexual maturation. A pre-established RIA for red seabream LH was used for the LH measurements. The regulation of FSH and LH secretion from the pituitary was investigated using a gonadotropin-releasing hormone analog (GnRHa) in vivo and in vitro. Marked differences in plasma and pituitary FSH levels were observed between males and females; pituitary FSH content in males was much higher than that in females during all seasons, and plasma FSH levels in males were high during the spawning season, whereas those in females were unchanged. In contrast, plasma and pituitary levels of LH were elevated before and during the spawning season in males and females. Injecting or implanting (cholesterol pellet) a GnRHa into adult and juvenile red seabream resulted in significant increases in plasma LH concentrations; however, no significant change was observed in plasma FSH. Moreover, GnRHa stimulated only LH secretion in an in vitro experiment using dispersed pituitary cells. The discrete FSH and LH secretion profiles revealed suggest differential roles for the two gonadotropins during red seabream gametogenesis. In addition, the marked difference in pituitary FSH levels in males and females suggests the relative significance of FSH in male reproduction.

Symptoms of gonadal dysfunction are more predictive of hypopituitarism than nonspecific symptoms in screening for pituitary dysfunction following moderate or severe traumatic brain injury

OBJECTIVE

The economic and logistic burden of screening for hypopituitarism following moderate/severe traumatic brain injury (TBI) is considerable. A key recommendation in published guidelines is to prioritize for screening those patients with symptoms suggestive of pituitary dysfunction. The purpose of this study was to evaluate the utility of targeted screening for hypopituitarism in long-term survivors after moderate/severe TBI using referrals on the basis of symptoms.

DESIGN

In group 1 (G1), consecutive, unselected patients were screened from the Irish National Neurosurgery Centre, whereas in group 2 (G2) patients were targeted based on the presence of symptoms suggestive of pituitary dysfunction.

PATIENTS

A total of 137 patients (113 male) were systematically screened (G1) and compared to 112 patients (77 male) referred for pituitary evaluation on the basis of suggestive symptoms (G2).

MAIN OUTCOME MEASURES

The rate of GH, ACTH, gonadotrophin (GT), TSH and ADH deficiency was compared among groups.

RESULTS

Patients referred with menstrual dysfunction had more GH (50% vs 11%, P = 0·001), ACTH (60% vs 14%, P < 0·0001), GT (90% vs 16%, P < 0·0001) deficiency and any pituitary hormone deficit (80% vs 33%, P = 0·003) than G1. Men with symptoms of hypogonadism had more GH (33% vs 11%, P = 0·003), GT (58% vs 16%, P < 0·0001) and TSH (16% vs 1%, P = 0·03) deficiency than G1. Patients with nonspecific symptoms were no more likely to have hypopituitarism than those consecutively screened.

CONCLUSIONS

Symptoms of hypogonadism are sufficiently predictive of hypopituitarism to justify screening for hypopituitarism after moderate/severe TBI. Nonspecific symptoms of hypopituitarism are no more predictive than unselected screening.

Current trends in mass spectrometry of peptides and proteins: Application to veterinary and sports-doping control

Detection of misuse of peptides and proteins as growth promoters is a major issue for sport and food regulatory agencies. The limitations of current analytical detection strategies for this class of compounds, in combination with their efficacy in growth-promoting effects, make peptide and protein drugs highly susceptible to abuse by either athletes or farmers who seek for products to illicitly enhance muscle growth. Mass spectrometry (MS) for qualitative analysis of peptides and proteins is well-established, particularly due to tremendous efforts in the proteomics community. Similarly, due to advancements in targeted proteomic strategies and the rapid growth of protein-based biopharmaceuticals, MS for quantitative analysis of peptides and proteins is becoming more widely accepted. These continuous advances in MS instrumentation and MS-based methodologies offer enormous opportunities for detection and confirmation of peptides and proteins. Therefore, MS seems to be the method of choice to improve the qualitative and quantitative analysis of peptide and proteins with growth-promoting properties. This review aims to address the opportunities of MS for peptide and protein analysis in veterinary control and sports-doping control with a particular focus on detection of illicit growth promotion. An overview of potential peptide and protein targets, including their amino acid sequence characteristics and current MS-based detection strategies is, therefore, provided. Furthermore, improvements of current and new detection strategies with state-of-the-art MS instrumentation are discussed for qualitative and quantitative approaches.

Gonadotropin and sex steroid levels in HIV-infected premenopausal women and their association with subclinical atherosclerosis in HIV-infected and -uninfected women in the women's interagency HIV study (WIHS)

BACKGROUND

HIV-infected women may experience prolonged amenorrhea, suggesting altered gonadotropin and sex hormone levels. However, the impact of these endocrine disruptions on atherosclerosis has not been evaluated in women living with, or at risk for, HIV infection. We investigated the association of sex hormone and gonadotropin concentrations with subclinical atherosclerosis in HIV-infected and -uninfected premenopausal women in the Women's Interagency HIV Study.

METHODS

Using B-mode ultrasound, the common carotid artery intima-media thickness and distensibility were measured once. Cycle-specific FSH, total estradiol (E2), and inhibin-B concentrations were measured in 584 (414 HIV infected, 170 HIV uninfected) women. Random concentrations of total T, dehydroepiandrosterone sulphate, and SHBG were measured in 1094 (771 HIV infected, 323 HIV uninfected) women. The endocrine analytes were measured at or before the ultrasound visit. Sex hormones, FSH, and SHBG concentrations were compared between HIV-infected and -uninfected women using nonparametric testing. Linear regression models were used to evaluate the association of sex hormones, FSH, and SHBG with carotid artery intima-media thickness and distensibility adjusted for confounders. Separate analyses were conducted by HIV status.

RESULTS

Compared with HIV-uninfected women, E2, T, and dehydroepiandrosterone sulphate concentrations were significantly lower and SHBG was higher in HIV-infected women. Adjusted for the confounders, T was significantly positively associated with distensibility (β-estimate = .04, P = .0005) among HIV-infected women, and the magnitude of association did not differ by CD4 cell count. E2 was significantly positively associated with distensibility among HIV-infected women with CD4 count less than 350 cells/μL.

CONCLUSIONS

HIV-infected women had reduced estrogen and androgen compared with HIV-uninfected premenopausal women. T deficiency is linked with carotid artery stiffness, regardless of immune suppression, whereas E2 deficiency is linked with carotid stiffness among immunocompromised HIV-infected premenopausal women. Further research is warranted to understand the impact of endocrine dysregulation on the accelerated cardiovascular disease risk in HIV-infected women.

Molecular characterization of Chinese sturgeon gonadotropins and cellular distribution in pituitaries of mature and immature individuals

Chinese sturgeon (Acipenser sinensis) is a rare and endangered species, and also an important resource for the sturgeon aquaculture industry. To understand molecular characterization of Chinese sturgeon gonadotropins (GTHs), we cloned the full-length cDNAs of gonadotropin subunits common alpha (GTH-alpha), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from a pituitary cDNA library of mature female. Two subtypes of GTH-alpha were identified. The nucleotide sequences of A. sinensis common alpha I (AsGTH-alpha I), common alpha II (AsGTH-alpha II), FSHbeta (AsFSHbeta) and LHbeta (AsLHbeta) subunit cDNAs are 345, 363, 387 and 414bp in length, and encode mature peptides of 115, 121, 129 and 138aa, respectively. Then, three polyclonal antibodies were prepared from the in vitro expressed AsGTH-alpha I, AsFSHbeta and AsLHbeta mature proteins, respectively. Significant expression differences were revealed between immature and mature sturgeon pituitaries. Western blot detection and immunofluoresence localization revealed the existence of three-gonadotropin subunits (AsGTH-alpha, AsFSHbeta and AsLHbeta) in mature sturgeon pituitaries, but only AsFSHbeta was detected in immature individual pituitaries during early stages in the sturgeon life, and obvious difference was observed between males and females. In males, AsFSHbeta was expressed in 4-year-old individuals, whereas in females, AsFSHbeta was just expressed in 5-year-old individuals.

Gonadotropins and female sex steroid hormones in cyst fluid and serum from patients with ovarian tumors

The objective of the present study was to determine the concentrations of LH, FSH, 17beta-estradiol and progesterone in ovarian cyst fluid and serum from patients with benign and malignant ovarian tumors and to assess the correlation of the gonadotropin and female sex steroid hormone concentrations with menopausal and tumor status. Ovarian cyst fluid and blood samples were prospectively collected from 103 patients with ovarian tumors. Seventy-four of the patients had benign ovarian tumors while 29 patients had malignant ovarian tumors. Malignant ovarian tumors showed significantly higher LH and FSH cyst fluid concentrations compared to concentrations from patients with benign tumors. Within the malignant subset, LH and FSH concentrations correlated with increasing FIGO stage and grade. Furthermore, LH and FSH cyst fluid concentrations showed strong correlations (r > 0.62) with serum concentrations in case of malignant tumors, especially in postmenopausal women, but not in case of benign tumors. The highest gonadotropin concentrations were observed in cyst fluid from malignant ovarian tumors. The most probable explanation for this is an increased vascular permeability within the cysts. Supportive evidence for such an increased vascular permeability is our previous finding of significantly higher VEGF concentrations in cyst fluid from malignant ovarian tumors. The possibility of ectopic production of LH and FSH by malignant ovarian tissue cannot completely be ruled out.

Hormones: what the testis really sees

Various barriers in the testis may prevent hormones from readily reaching the cells they are supposed to stimulate, especially the hydrophilic hormones from the pituitary. For example, LH must pass through or between the endothelial cells lining the blood vessels to reach the surface of the Leydig cells, and FSH has the additional barrier of the peritubular myoid cells before it reaches the Sertoli cells. The specialised junctions between pairs of Sertoli cells would severely restrict the passage of peptides from blood to the luminal fluid and therefore to the cells inside this barrier, such as the later spermatocytes and spermatids. There is evidence in the literature that radioactively labelled LH does not pass readily into the testis from the blood, and the concentration of native LH in the interstitial extracellular fluid surrounding the Leydig cells in rats is only about one-fifth of that in blood plasma. Furthermore, after injection with LHRH, there are large rises in LH in the blood within 15 min, at which time the Leydig cells have already responded by increasing their content of testosterone, but with no significant change in the concentration of LH in the interstitial extracellular fluid. Either the Leydig cells respond to very small changes in LH, or the testicular endothelial cells in some way mediate the response of the Leydig cells to LH, for which there is now some evidence from co-cultures of endothelial and Leydig cells. The lipophilic steroid hormones, such as testosterone, which are produced by the Leydig cells, have actions within the seminiferous tubules in the testis but also in other parts of the body. They should pass more readily through cells than the hydrophilic peptides; however, the concentration of testosterone in the fluid inside the seminiferous tubules is less than in the interstitial extracellular fluid in the testis, especially after stimulation by LH released after injection of LHRH and despite the presence inside the tubules of high concentrations of an androgen-binding protein. The concentration of testosterone in testicular venous blood does not rise to the same extent as that in the interstitial extracellular fluid, suggesting that there may also be some restriction to movement of the steroid across the endothelium. There is a very poor correlation between the concentrations of testosterone in fluids from the various compartments of the testis and in peripheral blood plasma. Determination of the testosterone concentration in the whole testis is also probably of little predictive value, because the high concentrations of lipid in the Leydig cells would tend to concentrate testosterone there, and hormones inside these cells are unlikely to have any direct effect on other cells in the testis. The best predictor of testosterone concentrations around cells in the testis is the level of testosterone in testicular venous blood, the collection of which for testosterone analysis is a reasonably simple procedure in experimental animals and should be substituted for tissue sampling. There seems to be no simple way of determining the concentrations of peptide hormones in the vicinity of the testicular cells.

Development of real-time RT-PCR assays for eel gonadotropins and their application to the comparison of in vivo and in vitro effects of sex steroids

Gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), are key factors in the brain-pituitary-gonad axis and understanding their regulation remains essential for future management of eel reproduction. In this regard, we developed quantitative real-time RT-PCR (qrtRT-PCR) assays for the expression of European eel LHbeta, FSHbeta and GPalpha subunits, using the Light Cycler system. The qrtRT-PCR was adapted to permit detection of the three gonadotropin subunit mRNAs in individual pituitaries and in dispersed pituitary cells. The validated assays were applied to investigate the effects of sex steroids (estrogens and androgens) on gonadotropin subunit expression, in vivo in steroid-injected eels, and in vitro by steroid treatments of primary cultures of eel pituitary cells. In vivo, a stimulation of LHbeta mRNA was observed after estradiol (E2) treatments, while testosterone (T) or the non-aromatizable androgen dihydrotestosterone (DHT) had no effect. Concerning FSHbeta expression, slight but non-significant decreases were observed after both E2 and androgen treatments. Different results were obtained in vitro: E2 induced an increase in FSHbeta mRNA levels but had no effect on LHbeta expression. In contrast, androgens (T and DHT) stimulated LHbeta expression while no significant variation was observed on FSHbeta mRNA levels following androgen treatment. Concerning the GPalpha mRNA, no significant effect of sexual steroids was observed in vivo or in vitro. This demonstrated specific direct actions of steroids on gonadotropin subunit expression. The differences observed between in vivo and in vitro experiments may be explained by the involvement of cerebral control, including GnRH and dopamine neurons, and their specific regulation by sex steroids. The data indicate that sex steroid feedbacks on gonadotropins are exerted via multiple pathways, indirectly at the brain level and directly on pituitary gonadotrope cells.

Standardization of FSH, LH and hCG--current position and future prospects

Gonadotropin measurements contribute significantly to patient management in both endocrinology and oncology. Differences in calibration, antibody specificities and assay design mean that gonadotropin results obtained in different methods are still not comparable. Comparing patient results obtained in different methods therefore remains problematic, whether for individual patient care, when assessing the results of multicentre clinical trials, or when formulating national and international guidelines and recommendations. Achieving improved comparability of results for these important analytes will require clear descriptive nomenclature, accurate calibration with highly purified standards, careful characterization of what gonadotropin isoforms methods are measuring, broad recommendations about the most clinically appropriate antibody combinations, and increased awareness of clinically relevant interferences and the action required to minimise their effect. Encouraging manufacturers to standardize and carefully describe the evaluation methods they use, such that data from different manufacturers can readily be compared, is also a pre-requisite for future progress.

An introduction to mass spectrometry based proteomics-detection and characterization of gonadotropins and related molecules

This review introduces fundamental aspects of mass spectrometry (MS) based proteomics and illustrates how MS is an effective tool for the analysis of glycoprotein hormones. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and electrospray ionization (ESI) MS are complementary approaches that have been applied for the analysis of gonadotropins, e.g. to characterize differences in the oligosaccharide distribution of commercial human chorionic gonadotropin preparations, for isolated nicked beta-subunit, and identification of a metabolite of placental transforming growth factor in pharmaceutical hCG preparations. Immunoaffinity trapping and concentration of digested sample extract prior to MS analysis confers analytical sensitivity akin to immunoassay. A desirable objective would be to develop for clinical purposes a rapid procedure for MS detection and characterization of gonadotropins. Refinement of on-target immobilization and digestion for subsequent ionization by MALDI may eventually help to provide this capability. The advent of hybrid mass spectrometers will further advance the characterization of these complex molecules.

Effects of occupational solvent exposure on reproductive hormone concentrations and fecundability in men

BACKGROUND

Little is known about the effects of organic solvents on male reproductive health. To assess fertility and reproductive endocrine function in solvent-exposed men, we investigated time-to-pregnancy using a retrospective cohort design and cross-sectionally measured reproductive hormone concentrations in painters and millwrights compared to a reference group of carpenters.

METHODS

Detailed occupational, exposure, medical, and time-to-pregnancy histories were obtained by telephone interview. Plasma luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone concentrations were determined by immunoassay. Exposure indices, which summarized working life exposure to total solvents, chlorinated solvents, aromatic solvents, and thinners, degreasers, varnishes, and adhesives as a category were calculated from exposure histories.

RESULTS

FSH concentrations increased significantly with increasing exposure indices for all solvents and for chlorinated solvents. There were no significant associations of solvent exposure indices with LH or testosterone levels. LH, FSH, and testosterone concentrations also did not differ by job title. Using Cox regression, time-to-pregnancy was non-significantly longer in the painters and millwrights than the carpenters. There was no significant association between time-to-pregnancy and any of the solvent exposure indices; however, it should be noted that some of the pregnancies occurred more than 20 years previously, potentially reducing the reliability of the retrospectively collected pregnancy and exposure data.

CONCLUSIONS

The significant associations between FSH levels and solvent exposure indices suggest the potential for adverse effects of solvent exposures on reproductive function in men.

Cocaine- and amphetamine-regulated transcript peptide in the rat anterior pituitary gland is localized in gonadotrophs and suppresses prolactin secretion

Cocaine- and amphetamine-regulated transcript (CART) mRNA and CART peptide are abundant in the hypothalamic nuclei that control anterior pituitary function. CART peptide has also been localized in the anterior pituitary gland itself, although its role in pituitary function has not as yet been elucidated. In the present study, we investigated the localization and function of CART peptide in the anterior pituitary gland. Immunohistochemical observations revealed that CART peptide colocalized with FSH and LH in gonadotroph cells but that it was absent from the other hormone-producing cells. Immunoelectronmicroscopy suggested that CART peptide and gonadotropin were colocalized in the same secretory granules. CART peptide suppressed prolactin release from dispersed anterior pituitary cells 15 min after its addition into the media [basal production, 234.9 +/- 14.6 ng/ml vs. CART 55-102 peptide 100 nm, 125.0 +/- 18.2 ng/ml (P < 0.01, n = 5)]. Prolactin release was suppressed by CART in a dose-related manner; on the other hand, CART peptide did not affect the secretion of other anterior pituitary hormones. CART peptide synthesis by these cells was elevated 15 min after the addition of leptin to the media (100 nm), as determined by immunoblotting, but LHRH (10 nm) did not significantly affect CART peptide expression. These findings suggest that CART synthesis in the anterior pituitary may be stimulated by leptin and that CART peptide may play a role in the regulation of anterior pituitary hormone secretion in the rat.

Probing the orientation of surface-immobilized immunoglobulin G by time-of-flight secondary ion mass spectrometry

Static time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful surface analysis technique for the characterization of protein films because of its chemical selectivity and surface sensitivity. In this study, static ToF-SIMS and principal component analysis (PCA), a multivariate data analysis method, were combined to probe the orientation of surface-immobilized immunoglobulin G (IgG). IgG orientation can enhance its ability to detect its antigen in immunoassay techniques. The IgG used in this work is the mouse monoclonal anti-human chorionic gonadotropin (anti-hCG). Anti-hCG films on different well-defined substrates have been studied using its F(ab')2 and Fc fragments as references. Atomic force microscopy was used to characterize these protein films before static ToF-SIMS analysis. The results from PCA of ToF-SIMS spectra were related to the antibody primary amino acid composition and its three-dimensional structure.

Stress and female reproductive function: A study of daily variations in cortisol, gonadotrophins, and gonadal steroids in a rural Mayan population

We report here on a longitudinal study of stress and women's reproduction in a small Kaqchikel Mayan community in rural Guatemala. Current understanding of the effects of stress on the reproductive axis in women is mostly derived from clinical studies of individual stressors. Little is known, however, about the cumulative effects of "real life" stress. Cortisol increases in response to a broad variety of individual stressors (Tilbrook et al., 2002). In this article, we evaluate the association between daily fluctuations in women's urinary cortisol and reproductive hormones: estrone conjugates (E(1)C), pregnandiol glucuronide (PdG), luteinizing hormone (LH), and follicle stimulating hormone (FSH). To assess the association between daily changes in cortisol levels and changes in the profiles of the reproductive hormones, we used a random coefficients model based on polynomial regression. The sample includes 92 menstrual cycles provided by 24 participants over a year-long prospective study. Increases in urinary cortisol levels were associated with significant increases in gonadotrophin and progestin levels during the follicular phase. Also, in a time window between days 4 and 10 after ovulation, increased cortisol levels were associated with significantly lower progestin levels. These results are significant because untimely increases in gonadotrophins and low midluteal progesterone levels have previously been reported to impinge on the ovulatory and luteinization processes and to reduce the chances of successful implantation (Ferin, 1999; Baird et al., 1999). Future research should consider the possibility that stress may affect fecundability and implantation without necessarily causing amenorrhoea or oligomenorrhoea.

Relationship between insulin resistance and gonadotropin dissociation in obese and nonobese women with polycystic ovary syndrome

OBJECTIVE

To test the interdependence between insulin resistance (IR) and gonadotropin dissociation (GD) in polycystic ovary syndrome (PCOS).

DESIGN

Cross-sectional prospective study.

SETTING

Clinical research center.

PATIENT(S)

Thirty-two PCOS patients aged 19-34 years; 16 obese (BMI > or = 27) and 16 nonobese (BMI < 27).

INTERVENTION(S)

A 75-g oral glucose tolerance test (OGTT) and a 100-microg i.v. GnRH test were performed on different days. Blood was taken at 0, 30, 60, 90, 120, and 180 minutes in each test. Serum glucose, insulin, LH, and FSH were measured.

MAIN OUTCOME MEASURE(S)

Area under the curve was calculated for glucose, insulin, and glucose-to-insulin ratio (GIR), and for LH, FSH, and LH-FSH ratio.

RESULT(S)

Glucose, insulin, and GIR were not modified significantly during the GnRH test, nor LH, FSH and LH-FSH ratio throughout the OGTT. There were no significant differences in GIR response of patients with and without GD, nor in LH-FSH ratio of patients with and without IR, after OGTT and GnRH test. However, obese patients with IR had a significantly larger (P<.04) area under the curve for LH-FSH ratio than those without IR after GnRH test, but not after OGTT test.

CONCLUSION(S)

Insulin resistance and GD do not appear to be related events in PCOS, suggesting that each one might be determined by different genetic disorders. However, IR can affect GD after chronic stimulation in obese patients.

The neuropeptide Y Y1 receptor mediates NPY‐induced inhibition of the gonadotrope axis under poor metabolic conditions

Hypothalamic neuropeptide Y (NPY) plays a central role in the control of food intake, energy balance, and modulation of neuroendocrine functions. In particular, an increase in NPY expression participates in the inhibition of the reproductive activity under poor nutritional conditions. The present study was designed to evaluate further the involvement of the Y1 subtype of NPY receptors in these effects. Food intake, body weight gain, and the onset of puberty were studied in groups of wild-type and Y1 deficient mice that were either fed ad libitum or subjected to a 30% restriction in food intake. This moderate feeding restriction induced a similar deficit in body weight gain in wild-type and in Y1 knockout mice. However, although wild-type mice experienced the expected delay of puberty, all mice in the food restriction group and lacking Y1 could go through puberty over the time of the experiment despite decreases in circulating leptin levels and increases in hypothalamic NPY expression. This observation demonstrates that the absence of Y1 impairs the perception of decreasing energy stores by the gonadotrope axis, demonstrating a physiological role for Y1 in the sensing of endogenous metabolic parameters by the hypothalamus.

The orphan nuclear receptor, steroidogenic factor 1, regulates neuronal nitric oxide synthase gene expression in pituitary gonadotropes

Steroidogenic factor 1 (SF-1), an essential nuclear receptor, plays key roles in steroidogenic cell function within the adrenal cortex and gonads. It also contributes to reproductive function at all three levels of the hypothalamic-pituitary-gonadal axis. SF-1 regulates genes in the steroidogenic pathway, such as LHbeta, FSHbeta, and steroid hydroxylase. Abundant evidence suggests that nitric oxide (NO) has an important role in the control of reproduction due to its ability to control GnRH secretion from the hypothalamus and the preovulatory LH surge in pituitary gonadotropes. Recently, we cloned and characterized the promoter of mouse neuronal NO synthase (nNOS). nNOS is localized at all three levels of the hypothalamic-pituitary-gonadal axis to generate NO. We find that its major promoter resides at exon 2 in the pituitary gonadotrope alphaT3-1 cell line and that there is a nuclear hormone receptor binding site in this region, to which SF-1 can bind and regulate nNOS transcription. Mutation of the nuclear hormone receptor binding site dramatically decreases basal promoter activity and abolishes SF-1 responsiveness. A dominant negative of SF-1, in which the transactivation (AF-2) domain of SF-1 was deleted, inhibits nNOS exon 2 promoter activity. Dosage-sensitive reversal- adrenal hypoplasia congenita critical region on the X chromosome, gene 1 (DAX-1), which colocalizes and interferes with SF-1 actions in multiple cell lineages, negatively modulates SF-1 regulation of nNOS transcription. These findings demonstrate that mouse nNOS gene expression is regulated by the SF-1 gene family in pituitary gonadotropes. nNOS, a member of the cytochrome p450 gene family, could be one of the downstream effector genes, which mediates SF-1's reproductive function and developmental patterning.

Investigation into the duality of gonadotropic cells of Mediterranean yellowtail (Seriola dumerilii, Risso 1810): immunocytochemical and ultrastructural studies

Two antisera against the follicle-stimulating hormone-like gonadotropin (FSH) of Mediterranean (M.) yellowtail, anti-My FSHa and anti-My FSHb, were obtained. Anti-My FSHa serum specifically recognized FSH cells and did not react with any other pituitary cell type, while anti-My FSHb serum recognized the alpha-subunit of the pituitary glycoprotein hormones and immunostained FSH, luteinizing hormone-like gonadotropin (LH), and thyrotropin (TSH) cells. Anti-My FSHa serum, together with a previously obtained anti-My LHbeta serum, were used to further investigate the duality of gonadotropic cells in M. yellowtail by light and electron microscopic immunocytochemistry; three immunologically different gonadotropic cell populations expressing FSH, LH, or both hormones, were revealed. The three cell populations had the same regional distribution in the pituitary gland: the proximal pars distalis, including the thin ring surrounding the pars intermedia. However, while FSH cells were found isolated or forming small clusters, LH cells formed strands or compact groups, and were more numerous than FSH cells. FSH/LH cells were scarce. At the ultrastructural level, vesicular, granular, and intermediate FSH, LH, and FSH/LH cells were found; secretory granules and globules, on the one hand, or conspicuous dilated cisternae of rough endoplasmic reticulum (or both) predominated, respectively, in these cell types. The production of either FSH or LH, or both hormones, was not reflected in the ultrastructural features of gonadotropic cells. Thus, a single morphological cell type of varying ultrastructure depending on the functional stage seemed to encompass all gonadotropic cells in M. yellowtail. All forms of FSH, LH, and FSH/LH cells were found in involution.

[Identification of the existence of luteinizing hormone in pituitary vacuoles of rats]

It is generally believed that glycoprotein hormone exists in granules of the gonadotrophin (GTH) cells, and recent studies on the formation and secretion of glycoprotein hormones also concern much on the changes in the pituitary granules. In our previous studies, it was found that the secretion of luteinizing hormone (LH) was closely related to the morphological changes in pituitary vacuoles of rats, and the morphology of GTH cells was also closely related to the changes in vacuolar morphology. Therefore, it appears that there exists an inseparable relationship between the storage and secretion of LH and pituitary vacuoles. In order to examine whether the pituitary vacuoles contain LH in rats, and to further explore if LH is stored and released by the pituitary vacuoles, the vacuoles were separated and purified from pituitary, cortex and liver tissues by density gradient centrifugation. The vacuolar protein components, LH and glycoproteins were determined by the methods of SDS-PAGE, Western immunoblot and Con A/HRP, respectively. The results showed that (1) abundant protein components with various molecular masses were present in the vacuoles of the pituitary, cortex and liver in male, female and ovariectomized rats, and some of the protein components were similar in the molecular mass; (2) both pituitary tissues and vacuoles contained LH, and their LH levels had no significant difference by quantitative analysis of extracted protein samples; and (3) glycoproteins of various molecular masses were found in the vacuoles of the pituitary, cortex and liver, but the same position of stained glycoprotein band and LH molecular mass was only observed in the pituitary vacuoles. From the results given above, it can be concluded that LH specifically exists in the pituitary vacuoles, although there are some similar protein components in various cellular vacuoles. The possibility was further demonstrated at the molecular level that the pituitary vacuoles may have the function of storing and releasing LH due to the pituitary vacuoles containing LH with assembled glycone.

Cushing's disease due to plurihormonal adrenocorticotropic hormone and gonadotropin-producing pituitary adenoma

A 67-year-old woman presented with clinical features of hypercortisolism in association with an invasive pituitary macroadenoma. Adrenocorticotropic hormone (ACTH)-dependent Cushing's disease was documented, and the resected tumor was chromophobic, weakly positive with periodic-Schiff reagent, and showed immunostaining for ACTH and beta-endorphin in a minority of adenoma cells. Both luteinizing hormone and alpha-subunit staining were also observed, but no follicle-stimulating hormone reactivity was seen. Ultrastructurally, the tumor showed typical features of a gonadotroph adenoma of female type. Immunoelectron microscopy showed that ACTH was not produced in corticotrophs, but in cells with the characteristic features of gonadotrophs. This represents the second report of a plurihormonal gonadotroph adenoma producing sufficient ACTH to result in pituitary-dependent Cushing's disease.

Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes?

The objective of the present study was to examine whether hypothyroidism affects the reproductive system of adult female rats by evaluating ovarian morphology, uterus weight and the changes in serum and pituitary concentrations of prolactin and gonadotropins. Three-month-old female rats were divided into three groups: control (N = 10), hypothyroid (N = 10), treated with 0.05% 6-propyl-2-thiouracil (PTU) in drinking water for 60 days, and T4-treated group (N = 10), receiving daily sc injections of L-thyroxine (0.8 microg/100 g body weight) during the last 10 days of the experiment. At the end of 50 days of hypothyroidism no hypothyroid animal showed a regular cycle, while 71% of controls as well as the T4-treated rats showed regular cycles. Corpora lutea, growing follicles and mature Graafian follicles were found in all ovaries studied. The corpora lutea were smaller in both the hypothyroid and T4-replaced rats. Graafian follicles were found in 72% of controls and only in 34% of hypothyroid and 43% of T4-treated animals. Serum LH, FSH, progesterone and estradiol concentrations did not differ among the three groups. Serum prolactin concentration and the pituitary content of the three hormones studied were higher in the hypothyroid animals compared to control. T4 treatment restored serum prolactin concentration to the level found in controls, but only partially normalized the pituitary content of gonadotropins and prolactin. In conclusion, the morphological changes caused by hypothyroidism can be a consequence of higher prolactin production that can block the secretion and action of gonadotropins, being the main cause of the changes observed.

Immunocytochemical localization of different cell types in the adenohypophysis of the cichlid fish Cichlasoma dimerus (Heckel, 1840)

The adenohypophysis of the cichlid fish Cichlasoma dimerus was studied using the avidin-biotin-peroxidase method with antisera raised against piscine pituitary hormones and heterologous antisera against mammalian pituitary hormones. Antiserum raised against rabbit ACTH recognized a group of cells bordering the neurohypophysis (NH) in the rostral pars distalis (RPD). Anti-chum salmon prolactin (PRL) identified a compact group of cells in the periphery of the RPD. Gonadotropin II (GTH II), thyrotropin (TSH) and growth hormone (GH)-ir cells were localized in the proximal pars distalis. Ir-GTH II cells were also observed in the dorsal area of the pars intermedia (PI). Ir-GTH I cells could not be identified using anti-chum salmon GTH I, this may be due either to a failure of the antisera to recognize the gonadotropin or to a low expression of the hormone in adults of this species. PAS positive cells from the PI bound specifically with three different antisera raised against somatolactin (SL) of four different fish species. These cells surrounded deep branches of the NH in the PI.

Ultrastructural features of apoptosis in human pituitary adenomas

Although several recent studies deal with various molecular aspects of apoptosis, or programmed cell death, very little information is available on the ultrastructural changes associated with apoptosis in the adenohypophysis and its role in the regulation of pituitary adenoma growth and progression. This paper describes the distinct ultrastructural sequences that develop during the various phases of the apoptotic process. The study is based on the ultrastructural investigation of more than 8,000 surgically removed pituitary biopsies, which were examined by histology and immunocytochemistry for diagnostic purposes. No apoptosis was found in normal adenohypophysis and it is also a rare event in pituitary adenomas. When present, adenomatous adenohypophysial cells exhibit common and characteristic apoptotic changes. The ultrastructural alterations of membraneous organelles associated with apoptosis are similar to those previously reported in other tissues. It is noteworthy that apoptosis is clearly distinguishable from the ubiquitous dark cells denoting the common way of cell death. The findings suggest that apoptosis in pituitary adenomas is not a random event. Practically every specimen containing multiple apoptotic cells represents corticotroph adenoma. Occasional examples occur in lactotroph or gonadotroph adenomas. Although electron microscopic specimens are admittedly small, the large number of investigated cases gives credence to the observations.

An immunocytochemical study of the pituitary gland of the white seabream (Diplodus sargus)

The adenohypophysis of the white seabream (Diplodus sargus) was studied using histochemical and immunocytochemical techniques. The adenohypophysis was composed of rostral pars distalis, proximal pars distalis and pars intermedia. Prolactin (anti-chum salmon prolactin positive) and adrenocorticotropic (anti-human ACTH positive) cells were found in the rostral pars distalis. Prolactin cells were organized into follicles, while ACTH cells were arranged in cords around neurohypophyseal tissue branches that penetrated the rostral pars distalis. In the proximal pars distalis, somatotropic (anti-chum salmon and anti-gilthead seabream growth hormone positive), gonadotropic (anti-chum salmon beta-gonadotrophin II and anti-carp beta-gonadotrophin II positive, but anti-chum salmon beta-gonadotrophin I negative) and thyrotropic (anti-human beta-thyrotropin positive) cells were observed. Growth hormone cells were restricted to the dorsal and ventral part of the proximal pars distalis. They were clustered or surrounded the neurohypophyseal branches. Only one type of gonadotrophin cell was identified and they were clustered or isolated in the proximal pars distalis. Scattered groups of thyrotropin cells were located throughout the proximal pars distalis. In the pars intermedia somatolactin (anti-chum salmon and anti-gilthead seabream somatolactin positive) and melanotropic (anti-alpha-melanotropic hormone positive) cells were localized. In addition, gonadotrophin cells surrounded the pars intermedia or distributed evenly between somatolactin and melanotropic hormone cells. Somatolactin cells were periodic acid-Schiff negative and surrounded the neurohypophyseal branches intermingled with melanotropic cells. These cells were also immunoreactive to anti-human ACTH antiserum.

Roles of melatonin in gonadal maturation of underyearling precocious male masu salmon

Testicular maturation of underyearling precocious male masu salmon (Oncorhynchus masou) is affected by photoperiod. It is accelerated by a short photoperiod (light-dark cycles of 8:16 h; LD 8:16) and delayed by a long photoperiod (LD 16:8). Circulating melatonin levels are high during the night and low during the day:the duration of the nocturnal elevation is longer under a short than under a long photoperiod, suggesting mediation of photoperiodic signals by melatonin. This study examined whether melatonin administration mimics short photoperiodic effects and whether it accelerates the testicular development of underyearling male masu salmon reared under a long photoperiod. Fish were randomly selected in June and were divided into two groups. They were reared under LD 16:8 (lights on 04:00-20:00 h) and fed pellets sprayed with melatonin (0.5 mg melatonin/kg body weight/day) or vehicle once a day at 11:00 h until October. The plasma melatonin profile of the melatonin-treated group was similar to that expected under a short photoperiod. Melatonin treatment had a stimulatory effect on the gonadosomatic index and pituitary gonadotropin (GTH) I contents. Plasma testosterone levels were significantly higher in the melatonin-treated group than in the control group in August. However, spermiation was observed in October in both groups and no significant differences were observed in GTH II contents in the pituitary in the two groups throughout the experiment. These results suggest that mimicking a short photoperiod by melatonin administration stimulated testicular development but did not completely activate the brain-pituitary-gonadal axis in precocious male masu salmon. Thus, melatonin is suggested to be one of the factors that mediates the transduction of photoperiodic information to the brain-pituitary-gonadal axis.

Plasma endothelin and LH-RH, LH, FSH, prolactin, progesterone, 17alpha-hydroxyprogesterone, estrone, 17beta-estradiol, delta4-androstenedione, testosterone, active renin, angiotensin-II and ANP levels in blood and LH, estrone and 17beta-estradiol and pregnanediol levels in urine of normal cycling women

In order to investigate the endothelin (ET) levels and their relationship to various hormones during the menstrual cycle, we measured endothelin-1, -2 and -3 (ET-1, -2 and -3), big ET-1 and big ET-3 levels in 27 normally cycling women (mean age 27 years). Simultaneous determination of luteinizing hormone-releasing hormone (LH-RH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, progesterone, 17alpha-hydroxyprogesterone (17-OHP), estrone, 17beta-estradiol, delta4-androstenedione, testosterone, active renin, angiotensin-II (A-II) and atrial natriuretic peptide (ANP) in blood, and LH, estrone and 17beta-estradiol and pregnanediol levels in urine was made in the same 27 women. The levels of ET-2 in plasma were found to be 20% of those of ET-1. In addition, ET-1 levels were measured in the endometrium of the normal uterus. Plasma ET-1 and ET-3 levels fluctuated during the menstrual cycle, with a peak at the luteal phase, but showed only a negative relationship (p < 0.01) to each other at the menstrual phase, whereas big ET-1 and big ET-3 levels showed no significant changes. Plasma ET-1 and ET-3 levels showed no significant relationship to the big ETs. As for the relationship to other hormones, plasma ET-3 had a negative relationship (p < 0.01) to prolactin and a positive correlation (p < 0.01) with ANP during the entire menstrual cycle. Plasma ET-1 and ET-3 showed a partial positive or negative correlation to LH, FSH, prolactin and ANP levels, depending upon the cycle phase, whereas plasma ETs and big ETs were unrelated to other hormones in the blood, and LH, estrone, 17beta-estradiol and pregnanediol in the urine throughout the menstrual cycle. At each menstrual stage, plasma ET-3 levels were more significantly related to LH, FSH, prolactin and ANP than ET-1, indicating a closer relationship between ET-3 and these circulating hormones during the menstrual cycle. The ET-1 level showed no significant change in the endometrium during the menstrual cycle.

Menstrual bleeding, hormones, and the menopausal transition

The perimenopause represents a time of great variability in reproductive hormone dynamics and menstrual cycle characteristics, but age-related changes begin prior to this. These changes include a gradual increase in follicle stimulating hormone (FSH) levels, a gradual shortening of mean cycle length, and a decline in the number of ovarian follicles. The onset of perimenopause is thought to occur with the first break in menstrual cycle regularity. With the onset of cycle irregularities, hormone concentrations exhibit large increases in variability and unpredictability, rather than following a gradual trend with the approach of menopause, the final menstrual period. Abrupt spikes in gonadotropins and considerable fluctuations in estradiol and inhibin levels have been observed. Variability is the norm in the perimenopause, with hormonal fluctuations contributing to the visible signs of menstrual cycle and bleeding irregularities. To date there is no single endocrine indicator to serve as an adequate marker of menopausal status. This paper provides a review of research to date on patterns of reproductive hormones and menstrual bleeding during the menopausal transition. An understanding of such patterns can contribute to a better ability to distinguish "normal" transitional events from more serious pathology.

Bioassays of gonadotropins

Bioassays constitute a unique approach to determine the functional aspects of gonadotropins. Indeed, these highly complex glycoprotein hormones, including pituitary lutropin (LH) and follitropin (FSH), are heterogeneous in terms of both peptidic and carbohydrate moieties, and, as a consequence, the bioactivity of the different molecular forms often does not match their immunoreactivity. In this article, we review the different types of LH and FSH bioassays. Conventional methods for measuring FSH bioactivity are first described and include the in vivo Steelman and Pohley bioassay, the radioligand receptor assays (RRAs), the in vitro Sertoli cell bioassay, the in vitro granulosa cell bioassay, and the inhibin immunoassay. Recent methods based on cell lines transfected with cloned receptors, particularly the human FSH receptor, are then described. Methods for developing these assays are presented, and the advantages and disadvantages of the different bioassays are discussed.

Effect of thymectomy on serum gonadotrophins and testosterone concentration

There is controversy about the relationship between thymic secretion and secretion of gonadotrophins and testosterone. One group of scientists reported that thymus is stimulatory to gonadotrophins and testosterone secretion, and according to other group thymic secretion is inhibitory to gonadotrophins and testosterone secretion. So we tried to observe what exactly happens to serum gonadotrophins and testosterone level following thymectomy. Thymectomy was performed in prepubertal animals and after 45 days of their operation serum gonadotrophins were measured by ELISA technique and serum testosterone was measured by RIA technique. The present study reveals a significant fall in serum FSH level along with significant rise in serum LH and testosterone level in male albino rats following thymectomy in comparison to that of sham thymectomized rats. It appears that thymus has an inhibitory influence on LH secreting gonadotrophs which has been withdrawn following thymectomy and as a result there occurs an increase in serum LH level. This LH stimulates interstitial cells of leydig and cause thereby an increase in serum testosterone level. The result also gives an indication that among the gonadotrophs in pituitary, one type is concerned with the secretion of LH while some gonadotrophs are concerned with secretion of FSH only; and the thymus possibly maintains the FSH secreting gonadotrophs intact at least till the age of puberty. Thymectomy may cause some disorganization of FSH secreting gonadotrophs which results in the fall in serum FSH level in thymectomized animals in comparison to that of sham thymectomized animal group.

Chronological study of the appearance of adenohypophysial cells in the ayu (Plecoglossus altivelis)

We previously reported the chronological appearance of adenohypophysial cells in freshwater teleosts using an immunocytochemical technique. The present study investigated the chronological appearance of adenohypophysial cells in the ayu, which is spawned and has its early development in brackish water, and the results were compared with those obtained in freshwater and seawater teleosts, as well as in other vertebrates. In the adult teleostean adenohypophysis, seven or eight types of secretory cells have been distinguished, each of which produce different hormones: prolactin (PRL), growth hormone (GH), thyroid stimulating hormone (TSH), gonadotropic hormones (GTH I and GTH II), adrenocorticotropic hormone (ACTH), melanophore stimulating hormone (MSH) and somatolactin (SL). In the pituitary of adult ayu, seven distinct types of glandular cells (PRL, GH, TSH, GTH, ACTH, MSH and SL cells) were identified. Chronologically, a few immunoreactive (ir)-PRL and ir-GH cells appeared in the ventral side of the pituitary one day before hatching. Then, just after hatching, ir-GTH cells were observed in the central to dorsal portion; ir-ACTH cells were found distributed in the anterior portion and some ir-MSH and a few ir-SL cells were seen in the posterior portion of the pituitary. Finally, a small number of ir-TSH cells were identified 50 days after hatching. These results differed from those obtained in other fishes previously reported with regard to the times of appearance of the PRL and GH cells. PRL cells appeared first, followed by GH cells in the freshwater teleosts, PRL and GH cells appeared at the same time in the brackishwater teleosts, while GH cells appeared first and PRL cells appeared last in the seawater teleosts. These results reflect the fact that PRL plays a major role in osmoregulation among freshwater teleosts, as compared with GH, which plays a similar role in seawater teleosts. It seems that both PRL and GH may play important roles in osmoregulation in brackishwater fish.

Immunochemical identification of thyrotropes and gonadotropes in the pars distalis and pars tuberalis of the toad (Bufo boreas) with reference to ontogenic changes

Morphologically distinct secretory cells in the pituitary pars distalis and pars tuberalis of larval and adult toads (Bufo boreas) immunoreactive cells in the pars distalis. Thyrotropin immunoactivity appears in pars tuberalis and pars distalis before gonadotropin immunoreactivity during early development. Antisera which distinguish gonadotropes (stained with human and sea turtle LH beta) and thyrotropes (stained with human TSH beta) as separate cell types in the pars distalis of the adult toad immunoreact with the same single type of cell in the pars distalis of the tadpole up through metamorphosis, suggesting the existence of a single pluripotent, glycoprotein-producing precursor cell early in development. Gonadotropin antisera do not react with the pars tuberalis in tadpoles or adults.

[Pre-ovulatory peaks of gonadotropins. Recent data]

From recent data we know that: The duration of the LH peak seems to be more important than its amplitude for the induction of ovulation. Ovulation induction by hCG is not physiological; the absence of an FSH surge, and the long duration of LH activity would contribute to some of the luteal phase abnormalities. Recombinant hLH, on the other hand could give better results provided its action last about 48 hours. The results, however, are not as expected, probably because of the type of isoforms injected. The circulating FSH and LH isoforms found during the preovulatory peak of gonadotropins have a much higher in vitro biological activity than those found at other periods of the cycle. The production of FSH and LH recombinant of different biological activity is in process. The mechanism of the preovulatory peak of gonadotropins is still not fully understood. The respective role of GnRH and of the ovarian steroids has yet to be precisely determined in the human being. Ovarian peptides very probably also play a role.

Precocious puberty in children with myelomeningocele: treatment with gonadotropin-releasing hormone analogues

In patients with myelomeningocele (MMC), growth is influenced by a large number of growth-retarding factors due to the neurological defect. Moreover, endocrine disorders have been found to contribute to short stature in MMC patients. Central precocious puberty (CPP) is a common problem. Due to growth disturbances and difficulties in obtaining standardized measurements, MMC patients have been excluded from gonadotropin-releasing hormone (GnRH) analogue studies in the past. We report on eight patients (six female, two male) with MMC, hydrocephalus, and CPP who were treated with GnRH analogues: triptorelin intramuscularly (N=5) or leuprorelin subcutaneously (N=3). Auxological data and hormone levels were assessed before treatment and every 6 months during treatment. The median chronological ages (CA) at the start of treatment were 8.6 years (females) and 8.4 years (males). Bone age (BA) was accelerated in all cases prior to treatment and two girls were already menstruating. Elevated gonadotropin serum levels and sex steroid levels decreased during treatment, although no complete suppression to prepubertal levels was reached. Progression of pubertal development and menses stopped in all patients. The tempo of BA acceleration (deltaBA:deltaCA) decreased, but no significant improvement in height standard deviation score BA and predicted adult height resulted. No side effects during treatment were observed. CPP in MMC patients has to be considered as early as possible to enable an early diagnosis and corresponding treatment. Further prospective studies on the effects of GnRH analogues in MMC patients are necessary.

Immunocytochemical localization of testis ecdysiotropin in the pupa of the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae)

Antiserum against testis ecdysiotropin isolated from the gypsy moth, Lymantria dispar, reacted with neurons in the protocerebrum, optic and antennal lobes, subesophageal, thoracic and abdominal ganglia, as well as in nerve tracts extending through the optic lobes, tritocerebrum, and interganglionic connectives of the pupal stage of these insects. Testis ecdysiotropin is a peptide required by immature moths to initiate production of testes ecdysteroid, which is necessary for the development of the male reproductive system and initiation of spermatogenesis. Antiserum against testis ecdysiotropin also detected an accumulation of testis ecdysiotripic-like material between the inner and outer testis sheaths of pupae. The localization of this peptide in the imaginal disks of the last larval stage, cells and nerve fibers in the optic and antennal lobes of the pupa of both sexes, as well as in the testes during development of the adult reproductive system indicates that testis ecdysiotropin has a much larger impact on adult metamorphosis than development of the reproductive system and initiation of gametogenesis. Although this peptide may have a modulatory role in the central nervous system (CNS), it may also initiate a cascade of activity required for the development of the adult nervous system, in addition to its role in reproduction.

[Do androgens modulate luteinizing hormone secretion in women?]

In hyperandrogenic states an abnormal pattern of LH secretion in women is observed, which is presumed to result from a direct action of androgen or its conversion to estrogen. Two strategies are available to study the effect of testosterone on LH secretion. One involves the use of non-steroidal compounds that block the negative feedback actions of endogenous androgens by binding to androgen receptors; the other consists only in the administration of androgens. Following these two strategies, we first studied the pulsatile gonadotrophin secretion in hyperandrogenic women, following flutamide administration, a specific androgen receptor blocker. Flutamide treatment was followed by a decrease in LH pulse amplitude and mean LH concentrations, demonstrating that androgen receptor blockade reduces LH secretion in hyperandrogenic women. To establish the level at which the androgen effect is exerted, we further studied the acute effect of testosterone (hyperandrogenic levels) and the blockade of its receptor on LH secretion in patients with severe hypothalamic deficiency treated with pulsatile GnRH (GnRHp). LH pulse profiles were assessed under GnRHp treatment alone, during testosterone and during testosterone and flutamide administration. Testosterone increased LH secretion and LH pulse amplitude. Flutamide significantly reverted the LH increase induced by testosterone. These results strongly suggest that testosterone in the hyperandrogenic female range, may facilitate LH secretion by the pituitary, effect that is reversed by the blockade of the androgen receptor.

5 alpha-reductase deficiency in patients with micropenis

The enzyme 5 alpha-reductase (5 alpha R), by virtue of its peripheral 5 alpha-reduction of testosterone (T) to dihydrotestosterone (DHT), is believed to play a major role in the differentiation and the subsequent growth of the penis. However, recent studies have reported 5 alpha R deficiency (5 alpha RD) in patients with isolated micropenis and hypothesized that 5 alpha RD is not invariably associated with genital ambiguity. In Egypt, 5 alpha RD has been reported frequently among intersex patients. The aim of this study was to assess the role of 5 alpha RD in the development of micropenis among Egyptian patients with abnormal sexual development. The study included 29 patients who were categorized into three groups (isolated micropenis, 9 patients; microphallus with genital ambiguity, 11 patients; genital ambiguity with normal-sized phallus, 9 patients). Activity of 5 alpha R was assessed by estimating T/DHT ratios in the basal state in pubertal subjects and following human chorionic gonadotropin (HCG) stimulation test in prepubertals. The results showed that the incidence of 5 alpha RD was much higher in cases of ambiguous genitalia with micropenis (5 families out of 10, 50%) than in those with isolated microphallus (1/9, 11.1%) or those with ambiguous genitalia and normal-sized phallus (1/8, 12.5%). In conclusion, the study showed that isolated micropenis is a heterogeneous disorder and that 5 alpha RD, despite its relative prevalence in Egypt, has a minimal role in the aetiology. On the other hand, 5 alpha RD seems to correlate with penile length in intersex cases.

Immunohistochemistry and tinctorial affinity of adenohypophysial cells of the rat snake Ptyas mucosus (Colubridae)

Immunocharacteristics of the adenohypophysial cells of the rat snake Ptyas mucosus (Colubridae) were studied with an unlabeled antibody enzyme technique (PAP method) using rabbit antisera against mammalian/synthetic hypophysial hormones. Adenohypophysial cells were identified on the basis of their specific immunoreactivity with various heterologous antisera. As in other reptiles, there was regional localization of pars distalis (PD) cell types in this snake. The gonadotropic (GTH) cells were identified by their specific immunoreactivity with anti-porcine (p)LH beta serum and were distributed uniformly throughout the PD. The thyrotropic (TSH) cells, recognized by their specific immunoreactivity with anti-human (h)TSH beta serum, were found in the medial PD. The prolactin (PRL) and growth hormone (GH) cells were revealed by their specific immunoreactivity with anti-ovine (o)PRL and anti-hGH sera, respectively; the former were confined to the anterior two-thirds of the PD, and the latter were restricted to the posterior third of the PD. The corticotropic (ACTH) cells, identified by their specific immunoreactivity with the anti-ACTH1-24 serum, were localized in the anterior two-thirds of the PD. Though both ACTH and PRL cells were confined to the same area of the PD, they could be distinguished by their distinctive morphology and distribution pattern. Cells of the pars intermedia were revealed by their immunoreactivity to anti-alpha MSH (melanophore-stimulating hormone) and anti-ACTH1-24 sera. Among each adenohypophysial cell type, there was variation in the intensity of immunoreactivity and morphological features, which may be due to their heterogeneity, reflecting various stages of cellular activity. Unlike most other snake species, the occurrence of a rudimentary pars tuberalis in P. mucosus containing a few immunoreactive GTH and TSH cells appeared to be a novel finding. The occurrence of the PRL-like and TSH-like immunoreactivity seen in certain neuronal perikarya and fibers of the hypothalamus and median eminence conforms with earlier observations in other tetrapods. To resolve certain discrepancies in the literature, the tinctorial affinities of immunohistochemically identified adenohypophysial cell types of P. mucosus were studied using various conventional staining methods and were compared with those of other reptilian species studied earlier, including snakes of the family Colubridae.

Role of different GnRH agonist regimens in pituitary suppression and the outcome of controlled ovarian hyperstimulation

Gonadotrophin-releasing hormone (GnRH) agonists have become irreplaceable addition to gonadotrophins in ovulation induction for assisted reproduction. Of the several schemes currently employed, long regimens appear to be maximally effective to optimize patient scheduling and to improve clinical results.

The pars tuberalis of the ewe: no effect of season or ovariectomy on the distribution, density or presence of immunoreactive cells

This study investigated whether season or long-term ovariectomy influence the presence, distribution and density of immunoreactive cells in the ovine pars tuberalis. Three groups of ewes were used: breeding season (BS; n=5), anoestrous (AS; n=8) and ovariectomised (OVX; n=4). Two rams were also investigated for possible sex-dependent differences. Employing standard immunocytochemical techniques, paraformaldehyde-fixed sagittal pars tuberalis and pars distalis sections were immunoreacted against luteinising hormone, luteinising hormone beta-subunit, thyroid-stimulating hormone, prolactin, growth hormone, beta-endorphin and adrenocorticotrophic hormone. Numerous gonadotrophs were detected in the anteroventral region of the pars tuberalis and there was no significant difference in the density (gonadotrophs/0.01 mm2; BS: 44+/-13, AS: 29+/-2, OVX: 27+/-4) or percentage of total cells (%; BS: 48+/-8, AS: 45+/-4, OVX: 49+/-2); the rams also appeared similar (27+/-2 gonadotrophs/0.01 mm2; 49+/-1%). In contrast, few gonadotrophs (less than 1%) were detected in the anterodorsal and posterior pars tuberalis regions. Apart from occasional thyrotrophs in the anteroventral pars tuberalis (less than 4%), no other pars distalis hormone-containing cells were detected in the pars tuberalis. This study demonstrates, therefore, that the anteroventral pars tuberalis represents an enriched population of immunoreactive gonadotrophs, whose number and distribution is similar in variable endocrine states. The protein phenotype(s) of cells in the other pars tuberalis regions remains undetermined.

Diagnostic value of gonadal steroid hormones and gonadotropins in ovarian cystic lesions

During a 12-mo period the fluid aspirated from 32 ovarian cystic lesions was assayed for 17 beta-estradiol (E2), progesterone (P), testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). All cysts were subsequently subjected to histologic or cytologic examination. In 84.6% (11/13) of the proven follicular cysts, the E2 content was greater than 100 pg/ml, in 76.9% (10/13) the P content was greater than 13 ng/ml, and in 69% (9/13) the T content was greater than 0.5 ng/ml. In 94.7% (18/19) of the ovarian cysts of other types, the E2 content was less than 100 pg/ml and the P content was less than 13 ng/ml. The FSH and LH contents of both types of cysts were variable, and no consistent pattern was discerned. In contrast, cytologic examination identified 69.2% (9/13) of the follicular cysts. In conclusion, consideration of the E2 and P contents with cytologic examination allowed the identification of all follicular cysts. Accordingly we recommend the estimation of E2 and P as part of the assessment of all ovarian cyst aspirates obtained from premenopausal patients.

Altered glycosylation of pituitary gonadotropins in anorexia nervosa: an alternative explanation for amenorrhea

To investigate the relevance of glycoprotein polymorphism to gonadotropin bioactivity in vivo, plasma follicle-stimulating hormone (FSH) and luteinizing hormone (LH), 17 beta-estradiol (E2), testosterone and sex hormone binding globulin (SHBG) levels in 17 amenorrheic women affected with anorexia nervosa (14-29 years) and 10 age-matched normally cycling women were evaluated. Plasma FSH and LH levels were assayed using radioimmunoassay (RIA) and immunoradiometric assay (IRMA) methods, before and after concanavalin A-Sepharose (Con A) affinity chromatography. Significant RIA-IRMA differences in FSH and LH plasma values were present only in women with anorexia nervosa (p < 0.005). Moreover, in these patients both FSH and LH showed a reduced binding to the Con A, expressed as a percentage of unbound, suggesting altered glycosylation of these moieties. In conclusion, these findings hypothesize the involvement of glycosylation polymorphism in RIA-IRMA differences; support the usefulness of both RIA and IRMA methods in FSH and LH evaluation, before and after Con A chromatography; and suggest a new pathogenetic pathway to explain amenorrhea in anorexia nervosa.

Clinical and ultrastructural comparison of immunohistochemically inactive and gonadotropin-producing pituitary adenomas

A clinicoendocrinological and ultrastructural comparison of immunohistochemically inactive pituitary adenomas from 14 patients and gonadotropin-positive pituitary adenomas from 26 patients was carried out. Clinicoendocrinological characteristics were similar except the male to female ratios. The immunohistochemically unstable antigenicity of gonadotropin prevents clear immunohistochemical characterization, but the difference between the two types is not absolute and may be an indication of a cell line relationship.

[Most common neoplasms of female genital organs and hypo-thalamic-hypophysial-ovarian regulation in the postmenopausal period]

Levels of FSH, LH and E2 were evaluated by means of EIA methods in 62 post-menopausal women qualified for operation treatment. In 46 cases neoplasms of uterus body and in 16 cases neoplasms of uterus cervix and an ovary were stated. Higher level of estradiol and lower levels of gonadotrophins were shown in cases with uterus body neoplasms and opposite, lower estradiol levels and higher gonadotrophins values in cases with cervix and ovarian neoplasms. The outcome suggests possibility of function of hypothalamic-hypophysial-ovarian axis in post-menopausal period. Level of estradiol can be also used as a diagnostic marker to uterus body neoplasms.

Estradiol production by granulosa cells of normal and polycystic ovaries: relationship to menstrual cycle history and concentrations of gonadotropins and sex steroids in follicular fluid

The underlying cause of anovulation in polycystic ovary syndrome is unknown. Circulating levels of immuno- and bioactive FSH are within the normal range, and the follicles contain measurable levels of bioactive FSH. The aim of this study was to compare estradiol (E2) production in response to FSH by granulosa cells from normal ovaries with those from polycystic ovaries derived from both anovulatory (anovPCO) and ovulatory subjects (ovPCO). Intrafollicular levels of immunoactive FSH, E2, and androstenedione in follicles of less than 12 mm were also measured. Follicular fluid steroid concentrations were obtained from 41 pairs of normal ovaries and 23 pairs of polycystic ovaries (8 anovPCO and 15 ovPCO). In size-matched follicles from each group there were no significant differences in follicular fluid FSH or E2 concentrations, but androstenedione levels were significantly higher in 5- to 11-mm follicles from ovPCO than in corresponding follicles from normal ovaries. Dose responses to FSH were determined in granulosa cells derived from 9 pairs of normal ovaries, 7 anovPCO, and 8 ovPCO. Cells from anovPCO produced 6- to 10-fold more E2 in response to FSH than normal cells, although there was no significant difference in the ED50 values. The response in cells from ovPCO was reduced compared to normal, but this difference did not reach significance. In summary, as judged by their FSH and E2 contents, polycystic ovaries do not have a higher proportion of atretic follicles than normal. Indeed, cells from anovPCO are hyperesponsive to FSH in vitro. This could be explained by stimulation of aromatase in vivo by either paracrine or, more probably, by endocrine factors, of which insulin is an arguable candidate.