bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence That Relaxin Inhibits Apoptosis in the Cervix and the Vagina during the Second Half of Pregnancy in the Rat*
Authors: Zhao Shuangping , Fields P. A. , Sherwood O. D.
Published: January 2014

The growth of the cervix and vagina that occurs during the second half of rat pregnancy is accompanied by an increase in both epithelial and stromal cells. Neither the mechanism(s) that regulates this accumulation of cells nor its hormonal control is known. To test the hypothesis that the rate of apoptosis declines during the second half of pregnancy, cervices and vaginas were collected on days 5, 10, 15, 18, and 21 of pregnancy. Terminal deoxynucleotidyl transferase-mediated deoxyuridine 5′-triphosphate nick end-labeling was used to detect apoptotic cells. The rate of apoptosis declined (P < 0.05) in epithelial and stromal cells in both the cervix and vagina during the second half of pregnancy, when blood levels of relaxin are increasing. To test the hypothesis that relaxin inhibits apoptosis, cervices and vaginas were collected 6, 12, 24, 48, and 72 h after the neutralization of endogenous relaxin, on days 19–21 of pregnancy, with a monoclonal antibody for rat relaxin. Both the terminal deoxynucleotidyl transferase-mediated deoxyuridine 5′-triphosphate nick end-labeling method and electron microscopy were used to detect apoptotic cells. Withdrawal of relaxin caused an increase in the rate of apoptosis in both the cervix and the vagina (P < 0.05). It is concluded that the rate of apoptosis declines in the cervix and the vagina during the second half of rat pregnancy, and that relaxin likely contributes to this process.
Comparative Analysis of Pharmacologic and/or Genetic Disruption of Cyclooxygenase-1 and Cyclooxygenase-2 Function in Female Reproduction in Mice*
Authors: Reese Jeff , Zhao Xuemei , Ma Wen-Ge , Brown Naoko , Maziasz Timothy J. , Dey S. K.
Published: January 2014

Cyclooxygenase (COX)-derived prostaglandins are critical in female reproduction. Gene targeting studies show that ovulation, fertilization, implantation, and decidualization are defective in COX-2 deficient mice. We used genetic and pharmacologic approaches to perturb COX function and examine the differential and synergistic effects of inhibition of COX-1, COX-2, or of both isoforms on reproductive outcomes during early pregnancy in mice. The results demonstrate that simultaneous inhibition of COX-1 and COX-2 produces more severe effects on early pregnancy events than inhibition of either isoform alone. The effects of pharmacological inhibition of COX-2 on female reproductive functions were less severe than the null mutation of the COX-2 gene. A combined approach showed that COX-2 inhibition in COX-1−/− mice induced complete reproductive failure, suggesting a lack of alternative sources of prostaglandin synthesis. This investigation raises caution regarding the indiscriminate use of COX inhibitors and shows for the first time the distinct and overlapping pathways of the cyclooxygenase systems in female reproduction.
Prepro-Orexin and Orexin Receptor mRNAs Are Differentially Expressed in Peripheral Tissues of Male and Female Rats
Authors: Jöhren Olaf , Neidert Steffi J. , Kummer Marco , Dendorfer Andreas , Dominiak Peter
Published: January 2014

Orexins are produced specifically by neurons located in the lateral hypothalamus. Recent results suggested peripheral actions of orexins. Therefore, we analyzed the mRNA expression of prepro-orexin and the orexin receptor subtypes OX1 and OX2 in peripheral rat tissues. Using real-time quantitative RT-PCR we detected significant amounts of prepro-orexin mRNA in testis, but not in ovaries. OX1 receptor mRNA was highly expressed in the brain and at lower levels in the pituitary gland. Only small amounts of OX1 receptor mRNA were found in other tissues such as kidney, adrenal, thyroid, testis, ovaries, and jejunum. Very high levels of OX2 receptor mRNA, 4-fold higher than in brain, were found in adrenal glands of male rats. Low amounts of OX2 receptor mRNA were present in lung and pituitary. In adrenal glands, OX2 receptor mRNA was localized in the zona glomerulosa and reticularis by in situ hybridization, indicating a role in adrenal steroid synthesis and/or release. OX1 receptor mRNA in the pituitary and OX2 receptor mRNA in the adrenal gland were much higher in male than in female rats. In the hypothalamus, OX1 receptor mRNA was slightly elevated in female rats. The differential mRNA expression of orexin receptor subtypes in peripheral organs indicates discrete peripheral effects of orexins and the existence of a peripheral orexin system. This is supported by the detection of orexin A in rat plasma. Moreover, the sexually dimorphic expression of OX1 and OX2 receptors in the hypothalamus, pituitary, and adrenal glands suggests gender-specific roles of orexins in the control of endocrine functions.
Glucose Relays Information Regarding Nutritional Status to the Neural Circuits That Control the Somatotropic, Corticotropic, and Gonadotropic Axes in Adult Male Rhesus Macaques
Authors: Lado-Abeal Joaquin , Veldhuis Johannes D. , Norman Reid L.
Published: January 2014

In male mammals, the neuroendocrine responses to fasting include increased GH and cortisol secretion and suppressed LH and T levels. Because blood glucose levels fall during fasting, we hypothesized that this modest, but consistent, change in blood glucose was a metabolic signal for the neuroendocrine adjustments of reproductive and metabolic hormones. Glucose (d-dextrose, 480 kcal/d) was infused into fasted (48 h) adult male rhesus macaques; and LH, cortisol, and GH were measured in plasma from samples collected at 15-min intervals for the last 15 h of the fast. We analyzed hormone secretion by deconvolution analysis, and the orderliness of release patterns by the approximate entropy statistic. Circulating blood glucose was 76 ± 7 mg/dl in the fed control group, significantly higher (P < 0.01) than the level of 56 ± 3 mg/dl in the fasted group. The increase in GH pulsatility and the 2-fold elevation in cortisol levels observed in the fasted male macaques were prevented by parenteral glucose delivery. The suppression of LH in fasted animals was not relieved by glucose infusions but seemed to be partially prevented in three of the animals. These findings are consistent with the hypothesis that glucose serves as a signal of nutritional status controlling adaptive neuroendocrine responses to fasting in the primate.
Dietary Phosphorus Transcriptionally Regulates 25-Hydroxyvitamin D-1α-Hydroxylase Gene Expression in the Proximal Renal Tubule
Authors: Zhang Martin Y. H. , Wang Xuemei , Wang Jonathan T. , Compagnone Nathalie A. , Mellon Synthia H. , Olson Jean L. , Tenenhouse Harriet S. , Miller Walter L. , Portale Anthony A.
Published: January 2014

Synthesis of the hormone 1,25-dihydroxyvitamin D, the biologically active form of vitamin D, occurs in the kidney and is catalyzed by the mitochondrial cytochrome P450 enzyme, 25-hydroxyvitamin D-1α-hydroxylase (1α-hydroxylase). We sought to characterize the effects of changes in dietary phosphorus on the kinetics of renal mitochondrial 1α-hydroxylase activity and the renal expression of P450c1α and P450c24 mRNA, to localize the nephron segments involved in such regulation, and to determine whether transcriptional mechanisms are involved. In intact mice, restriction of dietary phosphorus induced rapid, sustained, approximately 6- to 8-fold increases in renal mitochondrial 1α-hydroxylase activity and renal P450c1α mRNA abundance. Immunohistochemical analysis of renal sections from mice fed the control diet revealed the expression of 1α-hydroxylase protein in the proximal convoluted and straight tubules, epithelial cells of Bowman’s capsule, thick ascending limb of Henle’s loop, distal tubule, and collecting duct. In mice fed a phosphorusrestricted diet, immunoreactivity was significantly increased in the proximal convoluted and proximal straight tubules and epithelial cells of Bowman’s capsule, but not in the distal nephron. Dietary phosphorus restriction induced a 2-fold increase in P450c1α gene transcription, as shown by nuclear run-on assays. Thus, the increase in renal synthesis of 1,25-dihydroxyvitamin D induced in normal mice by restricting dietary phosphorus can be attributed to an increase in the renal abundance of P450c1α mRNA and protein. The increase in P450c1α gene expression, which occurs exclusively in the proximal renal tubule, is due at least in part to increased transcription of the P450c1α gene.
Identification of a Potential Receptor for Both Peptide Histidine Isoleucine and Peptide Histidine Valine
Authors: Tse Dicky Lai-Yin , Pang Ronald Ting-Kai , Wong Anderson On-Lam , Chan Siu-Ming , Vaudry Hubert , Chow Billy Kwok-Chong
Published: January 2014

Peptide histidine isoleucine (PHI), peptide histidine valine (PHV), and vasoactive intestinal polypeptide (VIP) are cosynthesized from the same precursor and share high levels of structural similarities with overlapping biological functions. In this study, the first PHI/PHV receptor was isolated and characterized in goldfish. To study this receptor using homologous peptides, we have also characterized the goldfish prepro-PHI/VIP, and, surprisingly, a shorter transcript lacking the VIP coding region was isolated. A PHI/VIP precursor without the VIP coding sequence has never before been reported. Initial functional expression of the PHI/PHV receptor in Chinese hamster ovary cells revealed that it could be activated by human PHV [50% effective concentration (EC50): 43 nm] and to a lesser extent human PHI (EC50: 133 nm) and helodermin (EC50: 166 nm) but not fish and mammalian pituitary adenylate cyclase-activating polypeptides and VIPs. Subsequent studies indicated that, similar to the pituitary adenylate cyclase-activating polypeptide receptors (PAC1-R, VPAC1-R, and VPAC2-R), the receptor isolated in this study is able to interact with goldfish PHI and its C-terminally extended form, PHV with EC50 values 93 and 43 nm, respectively. Northern blot and RT-PCR/Southern blot analyses revealed that the PHI/VIP gene is expressed in the intestine, brain, and gall bladder and the PHI/PHV receptor gene is primarily expressed in the pituitary and to a lesser extend in the intestine and gall bladder, suggesting that PHI/PHV may play a role, notably in the regulation of pituitary function. In conclusion, our results demonstrate for the first time the existence of a PHI/PHV receptor, indicating that the functions of PHI and PHV could be mediated by their own receptor in addition to VIP receptors.
Evidence that Brain-Derived Neurotrophic Factor Acts as an Autocrine Factor on Pituitary Melanotrope Cells of Xenopus laevis
Authors: Kramer Bianca M. R. , Cruijsen Peter M. J. M. , Ouwens Debbie T. W. M. , Coolen Marcel W. , Martens Gerard J. M. , Roubos Eric W. , Jenks Bruce G.
Published: January 2014

We have investigated the physiological regulation and functional significance of brain-derived neurotrophic factor (BDNF) in the endocrine melanotrope cells of the pituitary pars intermedia of the amphibian Xenopus laevis, which can adapt its skin color to the light intensity of its environment. In black-adapted animals, melanotrope cells produce and release α-melanophore-stimulating hormone (α-MSH). In white-adapted animals, the activity of melanotrope cells is inhibited by neuronal input. Using Western blotting and immunocytochemistry at the light and electron microscopical level, we have detected both the BDNF precursor and the mature BDNF protein in Xenopus melanotrope cells. In situ hybridization and RT-PCR revealed the presence of BDNF mRNA in the pituitary pars intermedia, indicating that BDNF is synthesized in the melanotropes. Real-time quantitative RT-PCR showed that levels of BDNF mRNA in melanotrope cells are about 25 times higher in black- than in white-adapted animals. Although there is no difference in the amount of stored mature BDNF, the amount of BDNF precursor protein is 3.5 times higher in melanotropes of black-adapted animals than in those of white-adapted animals. These data indicate that BDNF mRNA expression and BDNF biosynthesis are up-regulated in active melanotrope cells. Because immunoelectron microscopy showed that BDNF is located in melanotrope secretory granules, BDNF is probably coreleased with α-MSH via the regulated secretory pathway. Superfusion and 3H-amino acid incorporation studies demonstrated that BDNF stimulates the release of α-MSH and the biosynthesis of its precursor protein, POMC. Our results provide evidence that BDNF regulates the activity of Xenopus melanotrope cells in an autocrine fashion.
Cellular and Molecular Events Associated with the Bone-Protecting Activity of the Noncalcemic Vitamin D Analog Ro-26-9228 in Osteopenic Rats
Authors: Peleg Sara , Uskokovic Milan , Ahene Ago , Vickery Brian , Avnur Zafrira
Published: January 2014

We have examined several analogs of 1α,25-dihydroxyvitamin D3 [1,25-(OH)2D3] in an animal model of osteoporosis (ovariectomized rats) to identify a compound with a greater therapeutic range than 1,25-(OH)2D3 for treatment of this bone disease. Here, we report that one analog, Ro-26-9228, had a bone-protecting effect but did not induce hypercalcemia at a wide concentration range. Analysis of biochemical markers and the bone histomorphometry of analog-treated rats suggested that Ro-26-9228 acted by inhibiting bone resorption and increasing the number of differentiated osteoblasts. To determine the basis for the segregation between hypercalcemia and bone-protecting action, we examined gene expression in tissues that regulate calcium homeostasis. We found that 1,25-(OH)2D3 induced 24-hydroxylase mRNA expression in the duodena of ovariectomized rats, but Ro-26-9228 did not. Furthermore, in the duodena of intact animals, 1,25-(OH)2D3 induced a significant increase in calbindin D 9K and plasma membrane calcium pump 1 mRNAs, but Ro-26-9228 had no effect on these mRNAs. On the other hand, the osteoblast-specific gene products osteocalcin and osteopontin were significantly up-regulated in trabecular bone by both the natural hormone and Ro-26-9228. Further investigation of gene-regulatory events in trabecular bone revealed that both 1,25-(OH)2D3 and Ro-26-9228 up-regulated TGF β1 and β2 mRNAs. We concluded that the unique properties of Ro-26-9228 include preferential gene regulation in osteoblasts over duodenum and effective induction of growth factors in bone.
Stress Activation of Cortex and Hippocampus Is Modulated by Sex and Stage of Estrus
Authors: Figueiredo Helmer F. , Dolgas Charles M. , Herman James P.
Published: January 2014

Sex plays a major role in stress integration and stress-related affective disease states. Notably, neurocircuits regulating organismic responses to stress are prime targets for central gonadal steroid action. To assess the roles of sex and estrous cycle in central stress integration, we analyzed c-fos mRNA expression in hypothalamic-pituitary-adrenocortical-related regions of stressed male and cycling female (proestrous, estrous, and diestrous) rats. At 60 min after the onset of acute restraint stress, all animal groups showed induction of c-fos mRNA in the frontal cortex, cingulate cortex, piriform cortex, hippocampus, hypothalamic paraventricular nucleus (PVN), medial amygdala, and lateral septum. However, the magnitude of c-fos induction in cortical and hippocampal regions was substantially lower in proestrous and estrous females compared with males and diestrous females. Sex- and estrus cycle-related changes are region specific, as no difference in c-fos induction occurred in the hypothalamic PVN, medial amygdala, or ventrolateral septum in any group. Furthermore, induction of c-fos mRNA in limbic cortexes (but not hippocampus) was positively correlated with progesterone and negatively correlated with ACTH levels. Taken together, this study indicates that cortical structures are differentially stress activated in females depending on the phase of the estrous cycle, perhaps in a progesterone-dependent fashion.
Identification and Characterization of Novel Estrogen Receptor-β-Sparing Antiprogestins
Authors: Sathya Ganesan , Jansen Michelle S. , Nagel Susan C. , Cook C. Edgar , McDonnell Donald P.
Published: January 2014

The steroid hormones estrogen and progesterone together regulate the development and maintenance of the female reproductive system. The actions of these two hormones are mediated by their respective nuclear receptors located within overlapping cell populations in target organs. The molecular mechanism of action of these two hormones has been defined to a large extent using estrogen receptor (ER) and progesterone receptor (PR) antagonists. In the case of ER, the available antagonists are highly receptor selective. With respect to PR, however, the available antiprogestins also interact with the receptors for glucocorticoids, mineralocorticoids, and androgens. Whereas these cross-reactivities can usually be managed in studies of female reproductive function, it is the recent demonstration that RU486 is an effective antagonist of the β-isoform of ER that suggested the need for more selective antiprogestins. In this study, we used cell-based transcriptional assays combined with screens using coactivator peptide analogs to identify two novel classes of antiprogestins that distinguish themselves from the antiprogestin RU486 in the manner they interact with PR. One class exhibits the characteristics of a pure antiprogestin in that its members bind to the receptor and induce a conformational change that prevents the presentation of two potential coactivator binding surfaces on the protein. The second class of compounds distinguish themselves from RU486 in that they are ERβ sparing. When tested in vivo the ER-sparing antiprogestins were as effective as RU486 in suppressing superovulation. It is anticipated that the availability of these new antiprogestins will advance the studies of PR pharmacology in a manner similar to how the availability of selective ER modulators has helped the study of ER action.
Specifically PNPLA3-Mediated Accumulation of Liver Fat in Obese Patients with Type 2 Diabetes
Authors: Petit Jean Michel , Guiu Boris , Masson David , Duvillard Laurence , Jooste Valerie , Buffier Perrine , Terriat Beatrice , Bouillet Benjamin , Brindisi Marie-Claude , Loffroy Romaric , Robin Isabelle , Hillon Patrick , Cercueil Jean-Pierre , Verges Bruno
Published: January 2014

J Clin Endocrinol Metab, published September 8, 2010, 10.1210/jc.2010-0814
Structural Decay of Bone Microarchitecture in Men with Prostate Cancer Treated with Androgen Deprivation Therapy
Authors: Hamilton E. J. , Ghasem-Zadeh A. , Gianatti E. , Lim-Joon D. , Bolton D. , Zebaze R. , Seeman E. , Zajac J. D. , Grossmann M.
Published: January 2014

J Clin Endocrinol Metab, 10.1210/jc.2010-0902
Polymorphism in Vitamin D-Binding Protein as a Genetic Risk Factor in the Pathogenesis of Endometriosis
Authors: Faserl Klaus , Golderer Georg , Kremser Leopold , Lindner Herbert , Sarg Bettina , Wildt Ludwig , Seeber Beata
Published: January 2014

Context: Previous studies have implicated a deficiency in the inflammatory response in women who develop endometriosis. The specific immunological deficits have not been completely elucidated.

Objective: Our objective was to identify differences in protein expression in serum that might shed light on the pathophysiology of endometriosis.

Design and Setting: This cross-sectional study of women undergoing laparoscopy between 2003 and 2005 took place at a university medical center.

Patients: Patients included consenting women age 18-49 yr undergoing surgery for pain and/or infertility or elective tubal ligation. Women with acute or chronic medical conditions were excluded.

Intervention: Blood was collected preoperatively.

Main Outcome Measure: Proteomic analysis of serum was done using two-dimensional difference gel electrophoresis.

Results: We found 25 protein spots with a significant difference in abundance between women with endometriosis and controls, including acute-phase proteins and complement components. The abundance of vitamin D-binding protein was higher in all endometriosis pools by a factor of approximately 3 compared with the control pool (P < 0.02). Analysis of specific allele products using nano-LC-ESI-MS indicated that it was the GC*2 allele product that was in greater concentration in serum pools, as well as in single validation samples, in women with endometriosis (P = 0.006). In contrast to the GC*1 allele product, which is readily converted to a potent macrophage factor (Gc protein-derived macrophage-activating factor), the GC*2 allele product undergoes practically no such conversion.

Conclusions: We speculate that the inability to sufficiently activate macrophages’ phagocytotic function in those carrying the GC*2 polymorphism (more prevalent in endometriosis) may allow endometriotic tissues to implant in the peritoneal cavity. Future studies evaluating specific vitamin D-binding protein polymorphisms as a risk factor for endometriosis in larger populations of women are warranted.
Clinical, Biochemical, and Molecular Characterization of Macronodular Adrenocortical Hyperplasia of the Zona Reticularis: A New Syndrome
Authors: Ghayee Hans K. , Rege Juilee , Watumull Lori M. , Nwariaku Fiemu E. , Carrick Kelley S. , Rainey William E. , Miller Walter L. , Auchus Richard J.
Published: January 2014

Context: Macronodular adrenocortical hyperplasia classically presents with progressive hypercortisolemia and Cushing syndrome. We describe a 29-year-old man with massive macronodular adrenocortical hyperplasia without hypercortisolemia but rather markedly elevated and nonsuppressible production of dehydroepiandrosterone (DHEA) and its sulfate (DHEAS).

Objective: To characterize the clinical and molecular features of this case and to determine whether the tissue biochemically resembles the zona reticularis or fetal adrenal.

Setting: University clinic, hospital, and laboratories.

Design: Static and dynamic blood and urine testing were performed preoperatively. Tissue was studied by light microscopy, immunoblot, RNA microarray, and enzyme assay.

Participant: A 29-year-old man with incidentally discovered bilateral adrenal enlargement.

Intervention: Bilateral adrenalectomy.

Main Outcome Measures: Molecular studies compared with control samples.

Results: Hypercortisolism and 21-hydroxylase deficiency were excluded. DHEA, DHEAS, and 17-hydroxypregnenolone were markedly elevated and did not suppress with dexamethasone 2 mg/d for 4 days. Homogenates of the adrenals demonstrated high 17-hydroxylase, good 17,20-lyase, and low or absent 21-hydroxylase and 3β-hydroxysteroid dehydrogenase activities. Immunoblots confirmed robust expression of cytochrome P450c17 and AKR1C3 but not P450c21. Microarray analysis demonstrated high CYP11A1 and CYP17A1 expression but low or absent HSD3B1, HSD3B2, and CYP21A2 expression. Expression of mRNA for cytochrome b5 (CYB5A) and AKR1C3, markers of the zona reticularis, were markedly elevated.

Conclusion: This is the first case of macronodular hyperplasia of the adrenal zona reticularis confirmed with studies of enzyme activity, mRNA expression, and protein identification. We speculate that this condition can be clinically silent in men but might cause severe hyperandrogenemia in women.
Sustained Endoplasmic Reticulum Stress as a Cofactor of Oxidative Stress in Decidual Cells from Patients with Early Pregnancy Loss
Authors: Liu Ai-Xia , He Wei-Hua , Yin Li-Jun , Lv Ping-Ping , Zhang Yu , Sheng Jian-Zhong , Leung Peter C. K. , Huang He-Feng
Published: January 2014

Background: Oxidative stress (OS) is a common pathological background for different etiologies of early pregnancy loss (EPL). It has been suggested that elevated reactive oxygen species trigger endoplasmic reticulum (ER) stress by influencing ER function. However, it is unclear whether ER stress is associated with EPL.

Objectives: The aim of the study was to determine whether and how ER stress occurs during the development of EPL.

Approaches: Proteomic analysis was performed on decidua from women with EPL, and then ER stress markers, redox status, apoptotic features, and cell viability were analyzed in EPL decidual cells (DCs).

Results: EPL decidua were characterized by decreased levels of glucose-regulated protein 78 (GPR78) and valosin-containing protein and burdened with ubiquitinated proteins. Evidence of ER stress-induced apoptosis in EPL DCs was demonstrated by extensive dilation of ER, morphological features of apoptosis, and activation of caspase-4 and caspase-12. Furthermore, H2O2 reduced the viabilities in both EPL and control DCs, whereas EPL DCs were more vulnerable to additional OS challenge than the controls as a result of failed induction of GRP78 expression. The cell survival percentages of DCs were dose-dependently reduced by H2O2 and could be reversed in the presence of vitamin E. This effect was partly mediated by reducing the amount of misfolded proteins rather than regulating GRP78 expression.

Conclusions: The sum of these observations demonstrate for the first time that sustained ER stress occurs in EPL DCs and the potentially vicious relationship between ER stress and OS is likely to play an important role in the development of EPL.
Robust Leptin Secretory Responses to Dexamethasone in Obese Subjects*
Authors: Dagogo-Jack Samuel , Selke Gregg , Melson Angela K. , Newcomer John W.
Published: January 2014

Although leptin reverses obesity in rodents, its function and regulation in humans are unknown. Glucocorticoids have been reported to stimulate leptin production in both rodents and humans, but data assessing the effect of obesity on dynamic leptin secretory responses are unavailable. We, therefore, studied 52 lean and obese subjects [20 men and 32 women; aged 19–84 yr; body mass index (BMI) range, 16–47 kg/m2] randomized to treatment with dexamethasone (total dose, 10 mg/4 days) or placebo. Compared with placebo, dexamethasone increased (P = 0.0001) plasma leptin levels by 64–111% above baseline values within 2–4 days. The increases occurred in all ages, showed no sexual dimorphism, and were particularly robust in obese subjects. After dexamethasone treatment, significant interactions were observed between the change in plasma leptin and BMI (P = 0.0001), baseline plasma leptin (P = 0.0006) and plasma dexamethasone levels (P = 0.04), but not age (P = 0.28); an apparent interaction with plasma insulin no longer was significant after controlling for BMI. These results confirm dexamethasone-induced hyperleptinemia in humans and further demonstrate that the response is not defective in obesity.
Spontaneous Nocturnal Growth Hormone Secretion in Anorexia Nervosa
Authors: Scacchi Massimo , Pincelli Angela I. , Caumo Andrea , Tomasi Paolo , Delitala Giuseppe , Baldi Gabriella , Cavagnini Francesco
Published: January 2014

In anorexia nervosa, serum GH levels are increased under basal conditions and respond abnormally to provocative stimuli. We report here, for the first time, an analysis of pulsatile GH secretion in these patients performed by Cluster algorithm. Seven anorectic and six normal weight, healthy women underwent serial blood sampling at 20-min intervals from 2030–0830 h for GH estimation. The total area under the curve (AUC; micrograms per L/min) was elevated 4-fold in anorectic patients compared to controls (4743.0 ± 1520.09 vs. 1148.6 ± 519.27; P < 0.01), largely due to an increase in the nonpulsatile fraction (3212.5 ± 990.45 vs. 378.7 ± 123.27; P < 0.01). Accordingly, the valley mean value was higher in anorectic than in control subjects (5.9 ± 2.25 vs. 1.0 ± 1.30 μg/L; P < 0.01). Furthermore, pulsatile AUC was also greater in anorectic patients (1530.4 ± 654.72 vs. 769.8 ± 404.02; P < 0.01) due to a significant increase in GH peak frequency (5.0 ± 0.81 vs. 3.0 ± 0.89; P < 0.01). No correlations were observed in these patients between body mass index and any of the parameters of spontaneous GH release, whereas a positive correlation was found between insulin-like growth factor I levels and pulsatile AUC (r2 = 0.583; P < 0.05), peak height (r2 = 0.743; P = 0.01), peak increment (r2 = 0.801; P < 0.01), and GH valley mean (r2 = 0.576; P < 0.05).

In conclusion, it appears that the enhanced GH secretion in anorexia nervosa is the result of an increased frequency of secretory pulses superimposed on enhanced tonic GH secretion. Although this latter is consistent with a reduction of hypothalamic SRIH tone, the former may be accounted for by an increased number of GHRH discharges. Considering that in normal weight and obese subjects parameters of GH release are negatively correlated with adiposity indexes, the lack of such a negative correlation in our patients suggests that the enhancement of spontaneous GH release in anorectic patients is not merely the consequence of malnutrition-dependent impairment of insulin-like growth factor I production, but reflects a more complex hypothalamic dysregulation of GH release.
Ovarian Origin of Plasma and Peritoneal Fluid Prorenin in Early Pregnancy and in Patients with Ovarian Hyperstimulation Syndrome*
Authors: Itskovitz-Eldor Joseph , Kol Shahar , Lewit Nathan , Sealey Jean E.
Published: January 2014

Prorenin is the major product of renin gene expression in the ovary. Plasma levels of prorenin are elevated in ovarian-stimulated patients and during early pregnancy. To further elucidate the source of the elevated plasma levels of prorenin, we measured prorenin, renin activity, angiotensinogen, and steroid hormone levels in the plasma, luteal fluids (luteal cysts), ascitic fluid, and in ovarian venous samples collected from a patient with severe ovarian hyperstimulation syndrome (OHSS) and ectopic pregnancy. Prorenin/renin was also measured in plasma and in peritoneal fluid obtained during therapeutic paracentesis from four patients with OHSS.

Several corpora luteal fluids were obtained that were rich in estradiol (E2) and progesterone (P). Ovarian venous E2 and P were 20-fold higher than in arterial blood and as high or higher than the levels detected in the luteal fluids. The ratios of the hormonal levels in ascitic fluid and plasma were 1.9 for P and 1.4 for E2. A wide range of prorenin concentrations [1279 ± 918 sd ng/mL/hr, n = 6] were found in corpora luteal fluids, but in each the prorenin concentration was higher than in plasma (494 ng/mL/hr). Prorenin but not renin was higher (+23%) in ovarian venous than arterial blood. Prorenin in the 7 liters of ascitic fluid aspirated (2686 ng/mL/hr) was 5-fold higher than in plasma and similar to the levels measured in the corpora lutea with the highest prorenin concentrations. Renin in luteal cysts and ascitic fluid constituted 3% and 6% of the total renin (renin + prorenin), respectively. Total renin was also higher in peritoneal fluid (1538 ± 925 ng/mL/hr) than in plasma (375 ± 237 ng/mL/hr) of the 4 additional patients with severe OHSS.

These findings indicate that the ovary secretes prorenin during early pregnancy and that its secretion is directed preferentially from the luteal cysts into the peritoneal cavity. In light of recent evidence of an effect of prorenin on the vascular system, the presence of a huge reservoir of prorenin in the peritoneal cavity of patients with OHSS suggests a potential role for prorenin in the pathogenesis of this syndrome.
Twenty-Four-Hour Profiles of Luteinizing Hormone, Follicle-Stimulating Hormone, Testosterone, and Estradiol Levels: A Semilongitudinal Study throughout Puberty in Healthy Boys*
Authors: Albertsson-Wikland Kerstin , Rosberg Sten , Lannering Birgitta , Dunkel Leo , Selstam Gunnar , Norjavaara Ensio
Published: January 2014

To follow and correlate gonadotropin and sex steroid changes throughout puberty, 24-h profiles of LH, FSH, testosterone, and estradiol were taken on several occasions for between 2–9.5 yr in 12 healthy boys, aged 8.7–18.2 yr. Serum concentrations of LH and FSH were measured every 20 min, whereas testosterone and estradiol were measured every 2–4 h during the 24-h period. The prepubertal boys (Tanner stage 1) were subdivided into two groups: Pre 1, with a testicular volume of 1–2 mL, and Pre 2, with a testicular volume of 3 mL. Pubertal stages were classified, according to testicular volume, as early puberty (pubertal stage 2; 4–9 mL), midpuberty (pubertal stages 3–4; 10–15 mL), and late puberty (pubertal stage 5; ≥16 mL). Mean levels of LH and FSH increased with pubertal development, although the increase in LH was greater than that in FSH. These increases were due to elevated basal levels of LH and FSH as well as to increases in the number of peaks and the peak amplitudes of LH. No diurnal rhythm was found in boys at stage Pre 1. Thereafter, a clear diurnal rhythm appeared for LH, and later in puberty, an ultradian rhythm was superimposed, as shown by time-sequence analyses. A diurnal rhythm also existed for FSH, but was much less marked than that for LH despite a clear covariation between LH and FSH, as shown from cross-correlation studies. Testosterone also showed diurnal variations from the late prepubertal stage, followed by increasing levels during both day and night in puberty.

We conclude that during puberty, gonadotropin levels rise differently for LH and FSH, which may be due to the development of differences in feedback mechanisms. Despite covariation between LH and FSH, only LH showed a clear diurnal variation. In parallel, nocturnal variations in testosterone and estradiol were found. Changes in mean levels of LH, testosterone, and estradiol as well as their mean daytime and nighttime levels follow each other from the prepubertal stages to late puberty.
Expression of Steroid Receptors and Steroidogenic Enzymes in the Baboon (Papio anubis) Corpus Luteum during the Menstrual Cycle and Early Pregnancy1
Authors: Hild-Petito Sheri , Fazleabas Asgerally T.
Published: January 2014

As estrogen and progesterone are proposed regulators of luteal function, this study was undertaken to correlate the presence of receptors for these steroids with luteal function during early pregnancy. Corpora lutea (CL) were obtained from nonpregnant baboons during the midluteal [ML; days 7–8 postovulation (PO)] and late luteal (LL; days 11–12 PO) phases of the menstrual cycle or from pregnant baboons on days 18, 25, 29, or 31–33 PO. Estrogen and progestin receptors (ER and PR, respectively) and 3β-hydroxysteroid dehydrogenase (3βHSD) were detected by immunocytochemistry using specific monoclonal (H222 for ER; JZB39 for PR) or polyclonal (S683 for 3βHSD) antibodies. In addition, ribonucleic acid (RNA) was extracted from CL, processed for Northern blot analysis, and probed with complementary DNAs to human PR, human 3βHSD, and rat aromatase. Levels of messenger RNA (mRNA) for 3βHSD were quantified by laser densitometric scanning, and the data were normalized to the expression of a housekeeping gene (glyceraldehyde-3-phosphate dehydrogenase) to correct for loading differences. CL did not demonstrate specific nuclear stain for ER at any stage of the menstrual cycle or pregnancy. In contrast, PR-positive cells were present during the ML phase, but decreased during the LL phase (P < 0.05). PR-positive cells were maintained during early pregnancy at levels comparable to the ML phase (P > 0.05). Staining for 3βHSD was present at all stages of the cycle and pregnancy. Although the percent of 3βHSD-positive cells appeared to decrease as pregnancy proceeded, this was not statistically different (P > 0.05). The complementary DNA to PR hybridized to multiple transcripts (∼4.4, 3.1, 1.6, and 0.95 kilobases) in CL of the cycle. A single transcript (∼1.8 kilobases) for 3βHSD was present in CL at all stages of the cycle and pregnancy. The level of 3βHSD mRNA was highest during the ML phase and declined significantly (P < 0.05) during the LL phase and early pregnancy. Three transcripts (∼3.6, 3.0, and 1.7 kilobases) for aromatase were detected in CL of the cycle and pregnancy. Aromatase mRNA increased during early pregnancy. These results support the concept of PR-mediated events, but not ER-regulated processes in the primate CL. Furthermore, the data suggest that the steroidogenic enzymes 3βHSD and aromatase are differentially regulated during early pregnancy.
Increased Plasma Leptin Concentration in End-Stage Renal Disease1
Authors: Merabet Eddine , Dagogo-Jack Samuel , Coyne Daniel W. , Klein Samuel , Santiago Julio V. , Hmiel S. Paul , Landt Michael
Published: January 2014

Leptin is a 16-kDa protein recently identified as the obese gene product involved in body weight regulation. Administration of recombinant leptin to ob/ob mice, which have a genetic defect in leptin production, reduces food intake and increases energy expenditure. Leptin is synthesized by fat cells, and in normal humans, plasma concentrations are proportional to adiposity. The physiological actions and the degradation pathways of leptin in humans are unknown. We investigated renal elimination of leptin by comparing plasma leptin concentrations in end-stage renal disease (ESRD) patients with normal controls. Our hypothesis was that if renal filtration is a significant route of elimination, the hormone would accumulate in ESRD patients. Mean plasma levels in 141 ESRD patients (26.8 ± 5.7 and 38.3 ± 5.6 μg/L for males and females, respectively) were significantly higher (P< 0.001) than mean values obtained in normal controls (11.9 ± 3.1 and 21.2 ± 3.0 μg/L for males and females, respectively). Leptin concentrations in ESRD patients correlated directly with body mass index (BMI; r = 0.77 for men and 0.78 for women). The rate of increase in leptin concentrations with BMI was significantly greater in ESRD patients (5.5 and 6.6 μg/L/U BMI for men and women, respectively) than in normal controls (1.4 and 2.6 μg/L/U for men and women, respectively). Pre- and postdialysis leptin levels in hemodialysis patients were similar. Western blot of plasma from ESRD patients with high leptin levels showed bands corresponding to the intact protein (16 kDa) with no lesser or greater molecular mass species observed. Leptin concentrations in patients with ESRD did not correlate with measures of residual renal function (serum creatinine,β 2-microglobulin, PTH, or GH levels). Similarly, we found no correlation between leptin levels and the number of years patients had been on dialysis or with recent weight changes. We conclude that intact leptin is increased in ESRD patients, but does not appear to cause decreased weight. As leptin levels did not correlate with residual renal function, increased production may account for the high levels observed.
Immunohistochemical Localization of Gonadotropin and Gonadal Steroid Receptors in Human Pineal Glands1
Authors: Luboshitzky Rafael , Dharan Muralee , Goldman Dalia , Hiss Yehuda , Herer Paula , Lavie Peretz
Published: January 2014

Recently, we demonstrated that melatonin secretion was increased in male patients with GnRH deficiency and decreased to normal levels during testosterone treatment. These data suggested that gonadal steroids modulate melatonin secretion, probably by activating specific receptors in the pineal gland. We used immunohistochemistry to localize gonadotropin (LH and FSH) and gonadal steroid (androgens and estrogens) receptors in human pineal glands. Tissues were obtained at autopsy from 25 males, aged 19–87 yr, and five prepubertal children, aged 0.2–10 yr. Positive staining for all four types of receptors (LH, FSH, androgen, and estrogen) in the pineal parenchymal cells, pinealocytes, was evident in all 30 glands examined. Double staining revealed that nuclear receptors (androgen or estrogen) coexisted with cytoplasmatic receptors (LH or FSH) in the same cells. The results demonstrate the presence of gonadotropin and gonadal steroid receptors in human pinealocytes from infancy to old age.
Ribonucleic Acid Expression of the Clustered Imprinted Genes, p57KIP2, Insulin-Like Growth Factor II, and H19, in Adrenal Tumors and Cultured Adrenal Cells1
Authors: Liu Jianqi , Kahri Arvi I. , Heikkilä Päivi , Voutilainen Raimo
Published: January 2014

The recently cloned cyclin-dependent kinase inhibitor gene p57KIP2 is genomically imprinted and located on human chromosome 11p15.5. This region contains two other imprinted genes, insulin-like growth factor II (IGF-II) and H19, both of which seem to be implicated in adrenal neoplasms. We analyzed the expression of the putative tumor suppressor p57KIP2 gene by Northern blotting in normal and hyperplastic adrenals, adrenocortical tumors, and pheochromocytomas. The expression of p57KIP2 messenger ribonucleic acid (mRNA) correlated positively with H19 and negatively with IGF-II RNA in adrenocortical tissues. p57KIP2 mRNA (and H19 RNA) was abundantly expressed in normal human adrenals, adrenocortical adenomas from patients with Cushing’s or Conn’s syndrome or without clinical evidence of hormone overproduction, hyperplastic adrenals, and tumor-adjacent adrenal tissues, in which IGF-II mRNA expression was low. In most adrenocortical carcinomas and virilizing adrenal adenomas, very low levels of both p57KIP2 and H19 RNAs were observed, whereas IGF-II was highly expressed. In pheochromocytomas, p57KIP2 and H19 RNA expression was highly variable, but on the average it was about 45% and 27%, respectively, of that in normal and tumor-adjacent adrenals.

In cultured adrenocortical cells, ACTH and dibutyryl cAMP treatment slightly reduced the predominant 1.7-kilobase (kb) transcript of p57KIP2 gene, but induced a 2.5-kb transcript with a simultaneous increase in H19 RNA expression. The stimulatory effect of ACTH on the 2.5-kb p57KIP2 and H19 transcript accumulation was enhanced by exogenous IGF-II and IGF-I. Our data show that p57KIP2 and H19 RNAs are expressed usually in parallel in normal and pathological adrenocortical tissues. The decreased expression of both p57KIP2 and H19 RNAs in conjunction with elevated IGF-II mRNA expression in hormonally active adrenocortical carcinomas suggests that the loss of expression of the putative tumor suppressor genes p57KIP2 and H19 may be involved in the pathogenesis of these neoplasms.
Thyroid Hormone and Estrogen Receptor Expression in Normal Pituitary and Nonfunctioning Tumors of the Anterior Pituitary1
Authors: Gittoes Neil J. L. , McCabe Christopher J. , Verhaeg Julie , Sheppard Michael C. , Franklyn Jayne A.
Published: January 2014

Nonfunctioning tumors (NFTs) of the anterior pituitary often express elevated levels of the glycoprotein hormone α-subunit, which, under normal physiological conditions, is under negative feedback control by thyroid and gonadal steroid hormones. We postulate that inappropriately elevated levels of expression of α-subunit in the face of normal levels of these target organ hormones may reflect an abnormality of thyroid hormone receptors (TRs) and/or gonadal steroid receptors in NFTs. Using immunocytochemistry and Western blotting we have examined TR and estrogen receptor (ER) protein expression in normal human anterior pituitary glands and NFTs. Pretranslational expression of these receptors was examined using semiquantitative reverse transcriptase-PCR. Expression of all TR variant and ER proteins was reduced in pituitary tumors compared with that in normal pituitaries. The expression of messenger ribonucleic acids encoding the TRβ1 and TRβ2 isoforms and ER was also significantly reduced in tumors compared with normal tissues, although there was no difference between tumors and normals in the level of expression of TRα1 and α2 messenger ribonucleic acids. We suggest that reduced expression of TRs and ER may account for inappropriate expression of the glycoprotein hormoneα -subunit gene in some NFTs and may contribute to uncontrolled tumor growth.
Studies of the Impact of a Liver Glucokinase Promoter Variant on Glucose Tolerance and Insulin Sensitivity Index1
Authors: Urhammer Søren A. , Hansen Torben , Jensen Liselotte Brix , O. Clausen Jesper , Hansen Lars , Chui Ken C. , Pedersen Oluf
Published: January 2014

Because a frequently occurring nucleotide substitution at position− 258 in the liver glucokinase promoter has been reported to be associated with impaired promoter activity, we have examined in Danish Caucasians whether this variant is associated with alterations in glucose tolerance and/or the insulin sensitivity index (Si). Among 246 Danish Caucasian patients with noninsulin-dependent diabetes mellitus, the allelic frequency of the −258 promoter variant was 15.2% (95% confidence interval: 12.0–18.4%) vs. 16.5% (13.2–19.8%) among 242 matched control subjects. In the control group, the glucokinase variant was not related to serum insulin or plasma glucose levels before or during an oral glucose tolerance test. Neither was the gene variant among 380 young, healthy subjects associated with altered Si or altered insulin secretion after an iv glucose load. We conclude that in Danish Caucasians, the −258 glucokinase promoter variant has no impact on glucose tolerance, whole-body Si, or insulin secretion.
Testosterone Replacement in Older Hypogonadal Men: A 12-Month Randomized Controlled Trial
Authors: Sih Rahmawati , Morley John E. , Kaiser Fran E. , Perry Horace M. , Patrick Ping , Ross Candie
Published: January 2014

A decline in testicular function is recognized as a common occurrence in older men. However data are sparse regarding the effects of hypogonadism on age-associated physical and cognitive declines. This study was undertaken to examine the year-long effects of testosterone administration in this patient population.

Fifteen hypogonadal men (mean age 68 ± 6 yr) were randomly assigned to receive a placebo, and 17 hypogonadal men (mean age 65± 7 yr) were randomly assigned to receive testosterone. Hypogonadism was defined as a bioavailable testosterone <60 ng/dL. The men received injections of placebo or 200 mg testosterone cypionate biweekly for 12 months. The main outcomes measured included grip strength, hemoglobin, prostate-specific antigen, leptin, and memory.

Testosterone improved bilateral grip strength (P < 0.05 by ANOVA) and increased hemoglobin (P < 0.001 by ANOVA). The men assigned to testosterone had greater decreases in leptin than those assigned to the control group (mean ± sem: −2.0 ± 0.9 ng/dL vs. 0.8 ± 0.7 ng/dL; P < 0.02). There were no significant changes in prostate-specific antigen or memory. Three subjects receiving placebo and seven subjects receiving testosterone withdrew from the study. Three of those seven withdrew because of an abnormal elevation in hematocrit.

Testosterone supplementation improved strength, increased hemoglobin, and lowered leptin levels in older hypogonadal men. Testosterone may have a role in the treatment of frailty in males with hypogonadism; however, older men receiving testosterone must be carefully monitored because of its potential risks.
Insulin Secretion and Sensitivity in Black Versus White Prepubertal Healthy Children1
Authors: Arslanian Silva , Suprasongsin Chittiwat , Janosky Janine E.
Published: January 2014

We had previously demonstrated greater insulin secretion and lower insulin sensitivity in black pubertal adolescents compared with whites. This study aimed to investigate whether similar black/white differences are present in the prepubertal period or are characteristics of the pubertal period. Twelve black and 11 white healthy prepubertal children, matched for age, body mass index, and Tanner I pubertal development, underwent a 2-h hyperglycemic clamp (225 mg/dL). Physical fitness was assessed by maximal oxygen consumption (VO2max) measurement during graded bicycle ergometry, and resting energy expenditure was measured by indirect calorimetry after overnight fast.

Fasting and first phase insulin concentrations were higher in blacks than in whites [14.7 ± 1.3 vs. 10.4 ± 1.2 (P = 0.02) and 76.9 ± 6.8 vs. 52.1 ± 6.4 μU/mL (P = 0.016)]. There were no differences in second phase insulin levels and insulin sensitivity index. Both maximal oxygen consumption (VO2max) and resting energy expenditure were lower in black children, whereas insulin-like growth factor I was higher. After controlling for these differences, race contributed significantly to basal insulin, but not to first phase insulin.

In summary, previously reported black/white differences in insulin secretion and sensitivity during adolescence may have their origin in early childhood manifested as hyperinsulinemia. However, genetic (race) vs. environmental factors (physical activity/fitness and energy balance) should be carefully scrutinized as potential factors responsible for such differences.