WorldWideScience

Sample records for pituitary hormone release inhibiting hormones

  1. Growth hormone-releasing hormone stimulates cAMP release in superfused rat pituitary cells.

    OpenAIRE

    Horváth, J E; Groot, K. de; Schally, A V

    1995-01-01

    The release of growth hormone (GH) and cAMP was studied in superfused rat pituitary cells by infusing growth hormone-releasing hormone (GHRH) at different doses or a combination of GHRH and somatostatin 14 (SS-14). Three-minute pulses of GHRH caused a dose-dependent GH and cAMP release (effective concentration of 50% of the maximal biological effect is 0.21 nM and 52.5 nM, respectively). The lowest effective doses of GHRH in the superfusion system were 0.03 nM for GH release and 0.3 nM for cA...

  2. Pituitary mammosomatotroph adenomas develop in old mice transgenic for growth hormone-releasing hormone

    DEFF Research Database (Denmark)

    Asa, S L; Kovacs, K; Stefaneanu, L

    1990-01-01

    It has been shown that mice transgenic for human growth hormone-releasing hormone (GRH) develop hyperplasia of pituitary somatotrophs and mammosomatotrophs, cells capable of producing both growth hormone and prolactin, by 8 months of age. We now report for the first time that old GRH-transgenic m......-transgenic mice, 16 to 24 months of age, develop pituitary mammosomatotroph adenomas. These findings provide conclusive evidence that protracted stimulation of secretory activity can cause proliferation, hyperplasia and adenoma of adenohypophysial cells....

  3. Decreased hypothalamic growth hormone-releasing hormone content and pituitary responsiveness in hypothyroidism.

    OpenAIRE

    Katakami, H; Downs, T. R.; Frohman, L A

    1986-01-01

    The effects of thyroidectomy (Tx) and thyroxine replacement (T4Rx) on pituitary growth hormone (GH) secretion and hypothalamic GH-releasing hormone (GRH) concentration were compared to define the mechanism of hypothyroid-associated GH deficiency. Thyroidectomized rats exhibited a complete loss of pulsatile GH secretion with extensive reduction in GRH responsiveness and pituitary GH content. Cultured pituitary cells from Tx rats exhibited reduced GRH sensitivity, maximal GH responsiveness, and...

  4. Development of gonadotropin-releasing hormone secretion and pituitary response.

    Science.gov (United States)

    Glanowska, Katarzyna M; Burger, Laura L; Moenter, Suzanne M

    2014-11-05

    Acquisition of a mature pattern of gonadotropin-releasing hormone (GnRH) secretion from the CNS is a hallmark of the pubertal process. Little is known about GnRH release during sexual maturation, but it is assumed to be minimal before later stages of puberty. We studied spontaneous GnRH secretion in brain slices from male mice during perinatal and postnatal development using fast-scan cyclic voltammetry (FSCV) to detect directly the oxidation of secreted GnRH. There was good correspondence between the frequency of GnRH release detected by FSCV in the median eminence of slices from adults with previous reports of in vivo luteinizing hormone (LH) pulse frequency. The frequency of GnRH release in the late embryonic stage was surprisingly high, reaching a maximum in newborns and remaining elevated in 1-week-old animals despite low LH levels. Early high-frequency GnRH release was similar in wild-type and kisspeptin knock-out mice indicating that this release is independent of kisspeptin-mediated excitation. In vivo treatment with testosterone or in vitro treatment with gonadotropin-inhibitory hormone (GnIH) reduced GnRH release frequency in slices from 1-week-old mice. RF9, a putative GnIH antagonist, restored GnRH release in slices from testosterone-treated mice, suggesting that testosterone inhibition may be GnIH-dependent. At 2-3 weeks, GnRH release is suppressed before attaining adult patterns. Reduction in early life spontaneous GnRH release frequency coincides with the onset of the ability of exogenous GnRH to induce pituitary LH secretion. These findings suggest that lack of pituitary secretory response, not lack of GnRH release, initially blocks downstream activation of the reproductive system.

  5. Activation of GABA B receptors in the anterior pituitary inhibits prolactin and luteinizing hormone secretion.

    Science.gov (United States)

    Lux-Lantos, V; Rey, E; Libertun, C

    1992-11-01

    Previous work from our laboratory showed that baclofen could lower serum prolactin (PRL) levels acting at the central nervous system. The present experiments were designed to evaluate whether the gamma-aminobutyric acid B agonist was also effective in inhibiting hormone release at the pituitary level. In monolayer cultures of adenohypophyseal dispersed cells, baclofen inhibited basal PRL secretion after 1 or 2 h of incubation. This inhibition was significantly abolished by three antagonists: phaclofen, 3-aminopropyl-phosphonic acid and 4-aminobutylphosphonic acid. Furthermore, baclofen inhibited the thyrotropin-releasing hormone-induced PRL release in a concentration-dependent manner. With regard to gonadotropin secretion, baclofen was unable to modify basal luteinizing hormone (LH) secretion, but significantly inhibited the LH-releasing hormone-induced LH release. These results show that baclofen, in addition to its central neuroendocrine effects, inhibits pituitary hormone secretion, under basal and/or stimulated conditions, by direct action at the pituitary level.

  6. Gonadotropin-releasing hormone agonist-induced pituitary apoplexy

    Directory of Open Access Journals (Sweden)

    Fergus Keane

    2016-06-01

    Full Text Available Pituitary apoplexy represents an uncommon endocrine emergency with potentially life-threatening consequences. Drug-induced pituitary apoplexy is a rare but important consideration when evaluating patients with this presentation. We describe an unusual case of a patient with a known pituitary macroadenoma presenting with acute-onset third nerve palsy and headache secondary to tumour enlargement and apoplexy. This followed gonadotropin-releasing hormone (GNRH agonist therapy used to treat metastatic prostate carcinoma. Following acute management, the patient underwent transphenoidal debulking of his pituitary gland with resolution of his third nerve palsy. Subsequent retrospective data interpretation revealed that this had been a secretory gonadotropinoma and GNRH agonist therapy resulted in raised gonadotropins and testosterone. Hence, further management of his prostate carcinoma required GNRH antagonist therapy and external beam radiotherapy. This case demonstrates an uncommon complication of GNRH agonist therapy in the setting of a pituitary macroadenoma. It also highlights the importance of careful, serial data interpretation in patients with pituitary adenomas. Finally, this case presents a unique insight into the challenges of managing a hormonal-dependent prostate cancer in a patient with a secretory pituitary tumour.

  7. Pituitary Apoplexy After Thyrotropin-releasing Hormone Stimulation Test in a Patient with Pituitary Macroadenoma

    Directory of Open Access Journals (Sweden)

    Huei-Fang Wang

    2007-09-01

    Full Text Available Pituitary apoplexy is a rare complication of pituitary tumors. We report a case of a 41-year-old female with acromegaly due to a pituitary macroadenoma, who developed pituitary apoplexy after a thyrotropin-releasing hormone (TRH 200 mg intravenous injection stimulation test. Neither emergency computed tomography (CT scans nor magnetic resonance imaging (MRI, performed 6 hours and 12 hours, respectively, after the active episode, disclosed the evidence of acute hemorrhage or infarction. Two days later, the pituitary mass, removed by transsphenoidal approach, showed ischemic necrosis and acute hemorrhage. The TRH test is generally safe for evaluating pituitary function, but pituitary apoplexy may occur after the procedure. CT and MRI may miss the diagnosis of pituitary apoplexy, especially if performed immediately after the acute episode.

  8. Pituitary adenomas in mice transgenic for growth hormone-releasing hormone

    DEFF Research Database (Denmark)

    Asa, S L; Kovacs, K; Stefaneanu, L

    1992-01-01

    It has been shown that mice transgenic for human GH-releasing hormone (GRH) develop hyperplasia of pituitary somatotrophs, lactotrophs, and mammosomatotrophs, cells capable of producing both GH and PRL, by 8 months of age. We now report that GRH transgenic mice 10-24 months of age develop pituita...... somatotrophs or mammosomatotrophs to cells with features of the glycoprotein hormone cell line. These findings provide conclusive evidence that protracted GRH stimulation of secretory activity can result in proliferation, hyperplasia, and adenoma of adenohypophysial cells....

  9. Effects of retinoic acid on growth hormone-releasing hormone receptor, growth hormone secretagogue receptor gene expression and growth hormone secretion in rat anterior pituitary cells.

    Science.gov (United States)

    Maliza, Rita; Fujiwara, Ken; Tsukada, Takehiro; Azuma, Morio; Kikuchi, Motoshi; Yashiro, Takashi

    2016-06-30

    Retinoic acid (RA) is an important signaling molecule in embryonic development and adult tissue. The actions of RA are mediated by the nuclear receptors retinoic acid receptor (RAR) and retinoid X receptor (RXR), which regulate gene expression. RAR and RXR are widely expressed in the anterior pituitary gland. RA was reported to stimulate growth hormone (GH) gene expression in the anterior pituitary cells. However, current evidence is unclear on the role of RA in gene expression of growth hormone-releasing hormone receptor (Ghrh-r), growth hormone secretagogue receptor (Ghs-r) and somatostatin receptors (Sst-rs). Using isolated anterior pituitary cells of rats, we examined the effects of RA on gene expression of these receptors and GH release. Quantitative real-time PCR revealed that treatment with all-trans retinoic acid (ATRA; 10(-6) M) for 24 h increased gene expression levels of Ghrh-r and Ghs-r; however, expressions of Sst-r2 and Sst-r5 were unchanged. Combination treatment with the RAR-agonist Am80 and RXR-agonist PA024 mimicked the effects of ATRA on Ghrh-r and Ghs-r gene expressions. Exposure of isolated pituitary cells to ATRA had no effect on basal GH release. In contrast, ATRA increased growth hormone-releasing hormone (GHRH)- and ghrelin-stimulated GH release from cultured anterior pituitary cells. Our results suggest that expressions of Ghrh-r and Ghs-r are regulated by RA through the RAR-RXR receptor complex and that RA enhances the effects of GHRH and ghrelin on GH release from the anterior pituitary gland.

  10. Expression of growth hormone (GH)-releasing factor gene in GH-producing pituitary adenoma.

    Science.gov (United States)

    Wakabayashi, I; Inokuchi, K; Hasegawa, O; Sugihara, H; Minami, S

    1992-02-01

    Pituitary cells synthesize various neuropeptides that influence pituitary hormone secretion. GH-releasing factor (GRF) may also be produced by normal or pituitary tumor cells. We examined GRF gene expression in pituitary tumors. Standard techniques for the analysis of GRF gene expression did not appear to be suitable. Highly sensitive reverse transcription coupled to polymerase chain reaction was used. Specimens of pituitary adenoma were obtained by transsphenoidal adenomectomy from six patients with acromegaly and three patients with no clinical evidence of pituitary hormone overproduction; non-functioning adenoma. Pituitary glands were collected at autopsy from three patients who died from nonendocrine disorders. A specific GRF gene transcript was detected in five out of six GH-producing pituitary adenomas, whereas this was not found in three separate specimens of nonfunctioning pituitary adenoma or anterior and posterior pituitary tissue. The data suggest that GRF is synthesized as an intrinsic product in human GH-producing pituitary adenoma.

  11. A regulator of G Protein signaling, RGS3, inhibits gonadotropin-releasing hormone (GnRH-stimulated luteinizing hormone (LH secretion

    Directory of Open Access Journals (Sweden)

    Musgrove Lois C

    2001-11-01

    Full Text Available Abstract Background Luteinizing hormone secreted by the anterior pituitary gland regulates gonadal function. Luteinizing hormone secretion is regulated both by alterations in gonadotrope responsiveness to hypothalamic gonadotropin releasing hormone and by alterations in gonadotropin releasing hormone secretion. The mechanisms that determine gonadotrope responsiveness are unknown but may involve regulators of G protein signaling (RGSs. These proteins act by antagonizing or abbreviating interaction of Gα proteins with effectors such as phospholipase Cβ. Previously, we reported that gonadotropin releasing hormone-stimulated second messenger inositol trisphosphate production was inhibited when RGS3 and gonadotropin releasing hormone receptor cDNAs were co-transfected into the COS cell line. Here, we present evidence for RGS3 inhibition of gonadotropin releasing hormone-induced luteinizing hormone secretion from cultured rat pituitary cells. Results A truncated version of RGS3 (RGS3T = RGS3 314–519 inhibited gonadotropin releasing hormone-stimulated inositol trisphosphate production more potently than did RSG3 in gonadotropin releasing hormone receptor-bearing COS cells. An RSG3/glutathione-S-transferase fusion protein bound more 35S-Gqα than any other member of the G protein family tested. Adenoviral-mediated RGS3 gene transfer in pituitary gonadotropes inhibited gonadotropin releasing hormone-stimulated luteinizing hormone secretion in a dose-related fashion. Adeno-RGS3 also inhibited gonadotropin releasing hormone stimulated 3H-inositol phosphate accumulation, consistent with a molecular site of action at the Gqα protein. Conclusions RGS3 inhibits gonadotropin releasing hormone-stimulated second messenger production (inositol trisphosphate as well as luteinizing hormone secretion from rat pituitary gonadotropes apparently by binding and suppressing the transduction properties of Gqα protein function. A version of RGS3 that is amino

  12. Estradiol potentiation of gonadotropin-releasing hormone responsiveness in the anterior pituitary is mediated by an increase in gonadotropin-releasing hormone receptors

    Energy Technology Data Exchange (ETDEWEB)

    Menon, M.; Peegel, H.; Katta, V.

    1985-02-15

    In order to investigate the mechanism by which 17 beta-estradiol potentiates the action of gonadotropin-releasing hormone on the anterior pituitary in vitro, cultured pituitary cells from immature female rats were used as the model system. Cultures exposed to estradiol at concentrations ranging from 10(-10) to 10(-6) mol/L exhibited a significant augmentation of luteinizing hormone release in response to a 4-hour gonadotropin-releasing hormone (10 mumol/L) challenge at a dose of 10(-9) mol/L compared to that of control cultures. The estradiol augmentation of luteinizing hormone release was also dependent on the duration of estradiol exposure. When these cultures were incubated with tritium-labeled L-leucine, an increase in incorporation of radiolabeled amino acid into total proteins greater than that in controls was observed. A parallel stimulatory effect of estradiol on iodine 125-labeled D-Ala6 gonadotropin-releasing hormone binding was observed. Cultures incubated with estradiol at different concentrations and various lengths of time showed a significant increase in gonadotropin-releasing hormone binding capacity and this increase was abrogated by cycloheximide. Analysis of the binding data showed that the increase in gonadotropin-releasing hormone binding activity was due to a change in the number of gonadotropin-releasing hormone binding sites rather than a change in the affinity. These results suggest that (1) estradiol treatment increases the number of pituitary receptors for gonadotropin-releasing hormone, (2) the augmentary effect of estradiol on luteinizing hormone release at the pituitary level might be mediated, at least in part, by the increase in the number of binding sites of gonadotropin-releasing hormone, and (3) new protein synthesis may be involved in estradiol-mediated gonadotropin-releasing hormone receptor induction.

  13. Single-Cell Phenotypic Characterization of Human Pituitary GHomas and Non-Functioning Adenomas Based on Hormone Content and Calcium Responses to Hypothalamic Releasing Hormones.

    Science.gov (United States)

    Senovilla, Laura; Núñez, Lucía; de Campos, José María; de Luis, Daniel A; Romero, Enrique; García-Sancho, Javier; Villalobos, Carlos

    2015-01-01

    Human pituitary tumors are generally benign adenomas causing considerable morbidity due to excess hormone secretion, hypopituitarism, and other tumor mass effects. Pituitary tumors are highly heterogeneous and difficult to type, often containing mixed cell phenotypes. We have used calcium imaging followed by multiple immunocytochemistry to type growth hormone secreting (GHomas) and non-functioning pituitary adenomas (NFPAs). Individual cells were typed for stored hormones and calcium responses to classic hypothalamic releasing hormones (HRHs). We found that GHomas contained growth hormone cells either lacking responses to HRHs or responding to all four HRHs. However, most GHoma cells were polyhormonal cells responsive to both thyrotropin-releasing hormone (TRH) and GH-releasing hormone. NFPAs were also highly heterogeneous. Some of them contained ACTH cells lacking responses to HRHs or polyhormonal gonadotropes responsive to LHRH and TRH. However, most NFPAs were made of cells storing no hormone and responded only to TRH. These results may provide new insights on the ontogeny of GHomas and NFPAs.

  14. Simultaneous measurement of hormone release and secretagogue binding by individual pituitary cells

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.F.; Neill, J.D.

    1987-08-01

    The quantitative relationship between receptor binding and hormone secretion at the single-cell level was investigated in the present study by combining a reverse hemolytic plaque assay for measurement of luteinizing hormone (LH) secretion from individual pituitary cells with an autoradiographic assay of /sup 125/I-labeled gonadontropin-releasing hormone (GnRH) agonist binding to the same cells. In the plaque assay, LH secretion induces complement-mediated lysis of the LH-antibody-coated erythrocytes around the gonadotropes, resulting in areas of lysis (plaques). LH release from individual gonadotropes was quantified by comparing radioimmunoassayable LH release to hemolytic area in similarly treated cohort groups of cells; plaque area was linearly related to the amount of LH secreted. Receptor autoradiography was performed using /sup 125/I-labeled GnRH-A (a superagonist analog of GnRH) both as the ligand and as the stimulant for LH release in the plaque assay. The grains appeared to represent specific and high-affinity receptors for GnRH because (i) no pituitary cells other than gonadotropes bound the labeled ligand and (ii) grain development was progressively inhibited by coincubation with increasing doses of unlabeled GnRH-A. The authors conclude that GnRH receptor number for any individual gonadotrope is a weak determinant of the amount of LH it can secrete; nevertheless, full occupancy of all its GnRH receptors is required for any gonadotrope to reach its full LH-secretory capacity. Apparently the levels of other factors comprising the steps along the secretory pathway determine the secretory capacity of an individual cell.

  15. Effects of zeranol on in vitro growth hormone release by lamb and rat pituitary cells.

    Science.gov (United States)

    Phelps, C J; Wiggins, J P; Wangsness, P J

    1988-10-01

    A series of experiments was conducted to evaluate the effect of zeranol on release and synthesis of growth hormone (GH) by anterior pituitary cells established in either static or continuous flow cultures. Young adult male rats, slaughter-age lambs and juvenile lambs were used as sources of pituitary cells. In static primary cell cultures, no consistent effect of zeranol at 10(-7), 10(-9) or 10(-11) M was demonstrated by either rat or ovine cells. Rat pituitaries established in perifusion culture chambers showed no repeatable response to zeranol. Dissociated cells from lambs established in perifusion culture, however, had significant increases in release of GH in response to 37% of zeranol pulse exposures. When dissociated cells from juvenile lamb pituitaries were used, up to 10-fold increases in GH release consistently were measured within minutes of exposure to zeranol.

  16. Gonadotropin-releasing hormone is prerequisite for the constitutive expression of pituitary annexin A5.

    Science.gov (United States)

    Yonezawa, Tomohiro; Watanabe, Aiko; Kurusu, Shiro; Kawaminami, Mitsumori

    2015-01-01

    Annexin A5 (ANXA5), a member of the structurally related family of annexin proteins, is expressed in pituitary gonadotropes. We previously reported that ANXA5 expression is stimulated by gonadotropin-releasing hormone (GnRH). In the present study, we investigated ANXA5 expression in the anterior pituitary gland of GnRH-deficient mutant hypogonadal (hpg) mice. RT-PCR demonstrated that luteinizing hormone β subunit (LHβ) and ANXA5 mRNA levels were both lower in the pituitary gland of hpg mice than in wild-type mice. Immunohistochemistry showed that ANXA5 expression throughout the pituitary gland was very low in hpg mice, suggesting that ANXA5 is diminished in gonadotropes and also in other cell types. Subcutaneous administration of a GnRH analogue, des-gly10 (Pro9)-GnRH ethylamide (1 μg/day for 7 days), augmented the expression of LHβ and ANXA5 in the pituitary gland in hpg mice. However, LHβ- and ANXA5-positive cells did not show exactly matched spatial distributions. These findings suggest that GnRH is necessary for constitutive ANXA5 expression in the pituitary gland, not only in gonadotropes but also in other pituitary gland cell types. A close relationship between ANXA5 and LHβ expression was confirmed. It is suggested that a significant role of ANXA5 in the physiologic secretion of LH.

  17. Role of calcium in gonadotropin releasing hormone-induced luteinizing hormone secretion from the bovine pituitary

    Energy Technology Data Exchange (ETDEWEB)

    Kile, J.P.

    1986-01-01

    The hypothesis was tested that GnRH acts to release LH by increasing calcium uptake by gonadotroph which in turn stimulates calcium-calmodulin activity and results in LH release from bovine pituitary cells as it does in the rat. Pituitary glands of calves (4-10 months of age) were enzymatically dispersed (0.2% collagenase) and grown for 5 days to confluency in multiwell plates (3 x 10/sup 5//well). Cells treated with GnRH Ca/sup + +/ ionophore A23187, and ouabain all produced significant releases of LH release in a pronounced all or none fashion, while thorough washing of the cells with 0.5 mM EGTA in Ca/sup + +/-free media prevented the action of GnRH. GnRH caused a rapid efflux of /sup 45/Ca/sup + +/. Both GnRH-stimulated /sup 45/Ca efflux and LH release could be partially blocked by verapamil GnRH-induced LH release could also be blocked by nifedipine and tetrodotoxin, although these agents did not affect /sup 45/Ca efflux. The calmodulin antagonists calmidazolium and W7 were found to block GnRH induced LH release, as well as LH release induced by theophylline, KC PGE/sub 2/ and estradiol. These data indicated that: (1) calcium is required for GnRH action, but extracellular Ca/sup + +/ does not regulate LH release; (2) GnRH elevates intracellular Ca/sup + +/ by opening both voltage sensitive and receptor mediated Ca/sup + +/ channels; (3) activation of calmodulin is one mechanism involved in GnRH-induced LH release.

  18. Synthetic peptide with inhibin-like activity preferentially inhibits follitropin secretion in comparison with lutropin-releasing hormone antagonists

    Energy Technology Data Exchange (ETDEWEB)

    Sairam, M.R.; Ramasharma, K.; Li, C.H.

    1987-04-01

    Biological activity of a synthetic peptide with inhibin-like activity under in vitro and in vivo conditions was compared with three highly potent synthetic lutropin-releasing hormone antagonists. Unlike the synthetic lutropin-releasing hormone antagonists, which effectively inhibited both lutropin and follitropin secretion from the pituitary, the inhibin-like peptide showed a preferential effect by inhibiting follitropin release both in vitro and in vivo. Thus, small peptides such as inhibin-like peptide with a sequence unrelated to lutropin-releasing hormone may provide a basis for design of selective inhibitors of gonadotropin release. FSH and LH were measured by radioimmunoassay.

  19. Single-Cell Phenotypic Characterization of Human Pituitary GHomas and Non-Functioning Adenomas Based on Hormone Content and Calcium Responses to Hypothalamic Releasing Hormones

    Science.gov (United States)

    Senovilla, Laura; Núñez, Lucía; de Campos, José María; de Luis, Daniel A.; Romero, Enrique; García-Sancho, Javier; Villalobos, Carlos

    2015-01-01

    Human pituitary tumors are generally benign adenomas causing considerable morbidity due to excess hormone secretion, hypopituitarism, and other tumor mass effects. Pituitary tumors are highly heterogeneous and difficult to type, often containing mixed cell phenotypes. We have used calcium imaging followed by multiple immunocytochemistry to type growth hormone secreting (GHomas) and non-functioning pituitary adenomas (NFPAs). Individual cells were typed for stored hormones and calcium responses to classic hypothalamic releasing hormones (HRHs). We found that GHomas contained growth hormone cells either lacking responses to HRHs or responding to all four HRHs. However, most GHoma cells were polyhormonal cells responsive to both thyrotropin-releasing hormone (TRH) and GH-releasing hormone. NFPAs were also highly heterogeneous. Some of them contained ACTH cells lacking responses to HRHs or polyhormonal gonadotropes responsive to LHRH and TRH. However, most NFPAs were made of cells storing no hormone and responded only to TRH. These results may provide new insights on the ontogeny of GHomas and NFPAs. PMID:26106585

  20. The hypothalamic-pituitary response in SLE. Regulation of prolactin, growth hormone and cortisol release.

    Science.gov (United States)

    Rovenský, J; Blazícková, S; Rauová, L; Jezová, D; Koska, J; Lukác, J; Vigas, M

    1998-01-01

    It has been suggested that neuroendocrine regulation plays an important role in the pathogenesis and activation of autoimmune diseases. The aim of this investigation was to clarify the hypothalamic-pituitary response to a well-defined stimulus under standardised conditions in patients with SLE. Plasma concentrations of prolactin (PRL), growth hormone (GH) and cortisol were determined in venous blood drawn through an indwelling cannula during insulin-induced hypoglycaemia (0.1 U/kg b.w., i.v.) in ten patients and in 12 age-, gender- and weight-matched healthy subjects. Basal PRL concentrations were higher in patients vs healthy controls (12 vs 6 ng/ml, P < 0.01), though still within the physiological range. Insulin-induced plasma PRL and GH were significantly increased both in patients and healthy subjects; however, the increments or areas under the curves were not different in the two groups. Plasma cortisol response showed moderate attenuation in patients. Sensitivity of pituitary lactotrothrops to thyrotropin-releasing hormone (TRH) administration (200 microg, i.v.) was the same in patients and control subjects. In SLE patients with low activity of the disease the sensitivity of pituitary PRL release to TRH administration remained unchanged. The hypothalamic response to stress stimulus (hypoglycaemia) was comparable in patients and healthy subjects.

  1. Homologous and heterologous regulation of pituitary receptors for ghrelin and growth hormone-releasing hormone.

    Science.gov (United States)

    Luque, Raúl M; Kineman, Rhonda D; Park, Seungjoon; Peng, Xiao-Ding; Gracia-Navarro, Francisco; Castaño, Justo P; Malagon, María M

    2004-07-01

    Secretion of GH by pituitary somatotropes is primarily stimulated by the hypothalamic GHRH through the activation of a specific G protein-coupled receptor, GHRH receptor (GHRH-R). GH is also released in response to ghrelin, a peptide produced in the stomach, hypothalamus, and pituitary that activates somatotropes via a distinct G protein-coupled receptor, referred to as the GH secretagogue receptor (GHS-R). Here, we have analyzed the expression of both GHRH-R and GHS-R (by multiplex RT-PCR) in porcine pituitary cell cultures, after acute (4 h) treatment with GHRH or ghrelin as well as with other regulators of somatotropes (somatostatin, dexamethasone). Exposure of cultures to GHRH decreased GHRH-R mRNA content and also diminished GHS-R transcript levels. Likewise, ghrelin down-regulated both GHS-R and GHRH-R expression. Interestingly, administration of the activator of adenylate cyclase, forskolin, decreased GHRH-R mRNA levels but had no effect on GHS-R, thus suggesting a distinct contribution of the various intracellular signals operating in somatotropes to the regulation of the expression of these receptors. Accordingly, an atypical activator of adenylate cyclase in the pig somatotrope is low-dose (10(-13) m) somatostatin, which also suppressed GHRH-R mRNA levels without altering GHS-R expression. Finally, dexamethasone did not modify GHRH-R or GHS-R expression. In summary, our data show for the first time that ghrelin, as well as GHRH, mediates homologous and heterologous down-regulation of their own receptor synthesis. However, our results also indicate that the expression of porcine GHRH-R and GHS-R is regulated by distinct signals that may differ from those reported in other mammalian species.

  2. Growth hormone response to growth hormone-releasing peptide-2 in growth hormone-deficient Little mice

    OpenAIRE

    PERONI, CIBELE N.; Cesar Y. Hayashida; Nancy Nascimento; LONGUINI, VIVIANE C.; Toledo, Rodrigo A.; Paolo Bartolini; Bowers, Cyril Y.; Toledo,Sergio P. A.

    2012-01-01

    OBJECTIVE: To investigate a possible direct, growth hormone-releasing, hormone-independent action of a growth hormone secretagogue, GHRP-2, in pituitary somatotroph cells in the presence of inactive growth hormone-releasing hormone receptors. MATERIALS AND METHODS: The responses of serum growth hormone to acutely injected growth hormone-releasing P-2 in lit/litmice, which represent a model of GH deficiency arising frommutated growth hormone-releasing hormone-receptors, were compared to those ...

  3. Internalization and recycling of receptor-bound gonadotropin-releasing hormone agonist in pituitary gonadotropes

    Energy Technology Data Exchange (ETDEWEB)

    Schvartz, I.; Hazum, E.

    1987-12-15

    The fate of cell surface gonadotropin-releasing hormone (GnRH) receptors on pituitary cells was studied utilizing lysosomotropic agents and monensin. Labeling of pituitary cells with a photoreactive GnRH derivative, (azidobenzoyl-D-Lys6)GnRH, revealed a specific band of Mr = 60,000. When photoaffinity-labeled cells were exposed to trypsin immediately after completion of the binding, the radioactivity incorporated into the Mr = 60,000 band decreased, with a concomitant appearance of a proteolytic fragment (Mr = 45,000). This fragment reflects cell surface receptors. Following GnRH binding, the hormone-receptor complexes underwent internalization, partial degradation, and recycling. The process of hormone-receptor complex degradation was substantially prevented by lysosomotropic agents, such as chloroquine and methylamine, or the proton ionophore, monensin. Chloroquine and monensin, however, did not affect receptor recycling, since the tryptic fragment of Mr = 45,000 was evident after treatment with these agents. This suggests that recycling of GnRH receptors in gonadotropes occurs whether or not the internal environment is acidic. Based on these findings, we propose a model describing the intracellular pathway of GnRH receptors.

  4. Growth hormone-releasing factor regulates growth hormone mRNA in primary cultures of rat pituitary cells.

    OpenAIRE

    Gick, G G; Zeytin, F N; BRAZEAU, P.; Ling, N C; Esch, F S; Bancroft, C

    1984-01-01

    A peptide with high intrinsic activity for specifically stimulating the secretion of immunoreactive growth hormone (GH; somatotropin) has been characterized and reproduced by total synthesis. This peptide, human pancreatic growth hormone-releasing factor, 44-amino-acid form (hpGRF1-44-NH2), was isolated from a tumor localized in the pancreas of a patient with acromegaly. We report here the effect of this growth hormone-releasing factor (GRF) on GH release and the GH mRNA levels in monolayer c...

  5. Dexamethasone increases growth hormone (GH)-releasing hormone (GRH) receptor mRNA levels in cultured rat anterior pituitary cells.

    Science.gov (United States)

    Tamaki, M; Sato, M; Matsubara, S; Wada, Y; Takahara, J

    1996-06-01

    To examine the effects of glucocorticoid (GC) on growth hormone (GH)-releasing hormone (GRH) receptor gene expression, a highly-sensitive and quantitative reverse-transcribed polymerase chain reaction (RT-PCR) method was used in this study. Rat anterior pituitary cells were isolated and cultured for 4 days. The cultured cells were treated with dexamethasone for 2, 6, and 24 h. GRH receptor mRNA levels were determined by competitive RT-PCR using a recombinant RNA as the competitor. Dexamethasone significantly increased GRH receptor mRNA levels at 5 nM after 6- and 24 h-incubations, and the maximal effect was found at 25 nM. The GC receptor-specific antagonist, RU 38486 completely eliminated the dexamethasone-induced enhancement of GRH receptor mRNA levels. Dexamethasone did not alter the mRNA levels of beta-actin and prolactin at 5 nM for 24 h, whereas GH mRNA levels were significantly increased by the same treatment. The GH response to GRH was significantly enhanced by the 24-h incubation with 5 nM dexamethasone. These findings suggest that GC stimulates GRH receptor gene expression through the ligand-activated GC receptors in the rat somatotrophs. The direct effects of GC on the GRH receptor gene could explain the enhancement of GRH-induced GH secretion.

  6. Hormones

    Science.gov (United States)

    Hormones are your body's chemical messengers. They travel in your bloodstream to tissues or organs. They work ... glands, which are special groups of cells, make hormones. The major endocrine glands are the pituitary, pineal, ...

  7. Possible participation of calcium in growth hormone release and in thyrotropin-releasing hormone and human pancreatic growth hormone-releasing factor synergy in a primary culture of chicken pituitary cells.

    Science.gov (United States)

    Perez, F M; Malamed, S; Scanes, C G

    1989-09-01

    We previously reported that thyrotropin-releasing hormone (TRH) and human pancreatic growth hormone-releasing factor (hpGRF) exert synergistic (greater than additive) effects on growth hormone (GH) release from chicken pituitary cells in primary culture. In the present studies the possible participation of calcium in GH release and in TRH and hpGRF synergy was investigated. Following dispersion with collagenase, cells were cultured for 48 hr prior to exposure (2 hr) to test agents. Cultured cells were exposed to a range of calcium concentrations (0, 0.02, 0.2, and 2.0 mM) in the presence and absence of secretagogues. These results demonstrated that basal GH release was not altered by the concentration of calcium in the medium: however, secretagogue-induced GH release required calcium. Thus, TRH, hpGRF, 8 Br-cAMP, or forskolin stimulated GH release in the absence of calcium. Furthermore, synergistic GH release evoked by TRH and hpGRF, 8 Br-cAMP, or forskolin was observed only at the highest calcium concentration (2.0 mM). In other studies, ionomycin (10(-5) M), a calcium ionophore, stimulated GH release to a value about 125% over the basal (absence of test agent) value. Ionomycin-induced GH release was not affected by TRH (5.0 ng/ml); the combined effects of ionomycin (10(-7)-10(-5) M) and hpGRF (5.0 ng/ml) on GH release were less than additive. However, ionomycin (10(-5) M) further increased GH release over that resulting from the synergistic action of TRH and hpGRF (5.0 ng/ml each). Verapamil (a calcium channel blocker) did not affect GH release induced by either TRH or hpGRF (5.0 ng/ml each). However, this agent did inhibit synergistic GH release evoked by TRH and hpGRF, 8 Br-cAMP, forskolin, or isobutylmethylxanthine. These results suggest that calcium participates in secretagogue-induced GH release from chicken somatotrophs in vitro.

  8. The novel somatostatin analog SOM230 is a potent inhibitor of hormone release by growth hormone- and prolactin-secreting pituitary adenomas in vitro

    NARCIS (Netherlands)

    L.J. Hofland (Leo); A-J. van der Lely (Aart-Jan); S.W.J. Lamberts (Steven); A. Beckers (Albert); J. van der Hoek (Joost); P.M. van Koetsveld (Peter); W.W. de Herder (Wouter); M. Waaijers (Marlijn); D. Sprij-Mooij (Diana); C. Bruns (Christian); G. Weckbecker (Gisbert); R.A. Feelders (Richard)

    2004-01-01

    textabstractTo determine the inhibitory profile of the novel somatostatin (SRIF) analog SOM230 with broad SRIF receptor binding, we compared the in vitro effects of SOM230, octreotide (OCT), and SRIF-14 on hormone release by cultures of different types of secreting pituitary adenom

  9. Investigation of Responsiveness to Thyrotropin-Releasing Hormone in Growth Hormone-Producing Pituitary Adenomas

    Directory of Open Access Journals (Sweden)

    Sang Ouk Chin

    2013-01-01

    Full Text Available Objective. The aim of this study was to investigate how the paradoxical response of GH secretion to TRH changes according to tumor volumes. Methods. Patients with newly diagnosed acromegaly were classified as either TRH responders or nonresponders according to the results of a TRH stimulation test (TST, and their clinical characteristics were compared according to responsiveness to TRH and tumor volumes. Results. A total of 41 acromegalic patients who underwent the TST were included in this study. Between TRH responders and nonresponders, basal GH, IGF-I levels, peak GH levels, and tumor volume were not significantly different, but the between-group difference of GH levels remained near significant over the entire TST time. during the TST were significantly different according to the responsiveness to TRH. Peak GH levels and during the TST showed significantly positive correlations with tumor volume with higher levels in macroadenomas than in microadenomas. GH levels over the entire TST time also remained significantly higher in macroadenomas than in microadenomas. Conclusion. Our data demonstrated that the paradoxical response of GH secretion to TRH in GH-producing pituitary adenomas was not inversely correlated with tumor volumes.

  10. The pituitary growth hormone cell in space

    Science.gov (United States)

    Hymer, Wesley C.; Grindeland, R.

    1989-01-01

    Growth hormone (GH), produced and secreted from specialized cells in the pituitary gland, controls the metabolism of protein, fat, and carbohydrate. It is also probably involved in the regulation of proper function of bone, muscle and immune systems. The behavior of the GH cell system was studied by flying either isolated pituitary cells or live rats. In the latter case, pituitary GH cells are prepared on return to earth and then either transplanted into hypophysectomized rats or placed into cell culture so that function of GH cells in-vivo vs. in-vitro can be compared. The results from three flights to date (STS-8, 1983; SL-3, 1985; Cosmos 1887, 1987) established that the ability of GH cells to release hormone, on return to earth, is compromised. The mechanism(s) responsible for this attenuation response is unknown. However, the data are sufficiently positive to indicate that the nature of the secretory defect resides directly within the GH cells.

  11. Active immunization to luteinizing hormone releasing hormone to inhibit the induction of mammary tumors in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Ravdin, P.M.; Jordan, V.C.

    1988-01-01

    Immunization of female rats with a bovine serum albumin-luteinizing hormone releasing hormone conjugate results in suppression of dimethylbenzanthracene mammary tumor incidence. Tumor incidence was 1.3, and 1.29 tumors per rat in bovine serum albumin alone (n = 10) and unimmunized (n = 18) control groups, but no tumors were found in the bovine serum albumin-luteinizing hormone releasing hormone conjugate immunized animals (n = 10). In a second experiment immunization with bovine serum albumin-luteinizing hormone releasing hormone conjugates reduced tumor incidence to 0.3 tumors per rat (n = 10) from the 1.2 tumors per animal seen in the control animals (n = 10) immunized with bovine serum albumin alone. Bovine serum albumin-luteinizing hormone immunization caused the production of anti-LHRH antibodies, an interruption of estrous cycles, lowered serum estradiol and progesterone levels, and atrophy of the ovaries and uteri. Immunization BSA-hormone conjugates is a novel anti-tumor strategy.

  12. Estrogen inhibits corticotropin-releasing hormone production in primary human placental cells

    Institute of Scientific and Technical Information of China (English)

    唐晓露; 倪鑫; 由振东; 何平; 惠宁; 顾清; 孙刚

    2003-01-01

    Objective: To study the inhibition effects of estrogen on the production of corticotropin-releasing hormone in human placental cells. Methods: Primary cultured placental cells were treated by ICI182, 780, a complete ER antagonist, and Tamoxifen, an ERα-mixed agonist/antagonist and ERβ antagonist for 24 h. The supernatant was havested for the radioimmunoassay of CRH. Results: 17β-estradiol inhibited the secretion of corticotropin-releasing hormone in human placental (P<0.05). ICI182, 780 stimulated the secretion of corticotropin-releasing hormone in human placental (P<0.05). Conclusion: Estrogen represses the synthesis and secretion of corticotropin-releasing hormone in human placental, which is possibly mediated by ERα.

  13. Cytoplasmic kinases downstream of GPR30 suppress gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone secretion from bovine anterior pituitary cells.

    Science.gov (United States)

    Rudolf, Faidiban O; Kadokawa, Hiroya

    2016-01-01

    GPR30 is known as a membrane receptor for picomolar concentrations of estradiol. The GPR30-specific agonist G1 causes a rapid, non-genomic suppression of gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) secretion from bovine anterior pituitary (AP) cells. A few studies have recently clarified that protein kinase A (PKA) and phosphorylated extracellular signal-regulated kinase (pERK) might be involved in cytoplasmic signaling pathways of GPR30 in other cells. Therefore, we tested the hypothesis that PKA and ERK kinase (MEK) are important cytoplasmic mediators for GPR30-associated non-genomic suppression of GnRH-induced LH secretion from bovine AP cells. Bovine AP cells (n = 8) were cultured for 3 days under steroid-free conditions. The AP cells were previously treated for 30 min with one of the following: 5000 nM of PKA inhibitor (H89), 1000 nM of MEK inhibitor (U0126), or a combination of H89 and U0126. Next, the AP cells were treated with 0.01 nM estradiol for 5 min before GnRH stimulation. Estradiol treatment without inhibitor pretreatment significantly suppressed GnRH-induced LH secretion (P < 0.01). In contrast, estradiol treatment after pretreatment with H89, U0126 or their combination had no suppressive effect on GnRH-induced LH secretion. The inhibitors also inhibited the G1 suppression of GnRH-induced LH secretion. Therefore, these data supported the hypothesis that PKA and MEK (thus, also pERK) are the intracellular mediators downstream of GPR30 that induce the non-genomic suppression of GnRH-induced LH secretion from bovine AP cells by estradiol or G1.

  14. New trends in combined use of gonadotropin-releasing hormone antagonists with gonadotropins or pulsatile gonadotropin-releasing hormone in ovulation induction and assisted reproductive technologies.

    Science.gov (United States)

    Gordon, K; Danforth, D R; Williams, R F; Hodgen, G D

    1992-10-01

    The use of gonadotropin-releasing hormone agonists as adjunctive therapy with gonadotropins for ovulation induction in in vitro fertilization and other assisted reproductive technologies has become common clinical practice. With the recent advent of potent gonadotropin-releasing hormone antagonists free from the marked histamine-release effects that stymied earlier compounds, an attractive alternative method may be available. We have established the feasibility of combining gonadotropin-releasing hormone antagonist-induced inhibition of endogenous gonadotropins with exogenous gonadotropin therapy for ovulation induction in a nonhuman primate model. Here, the principal benefits to be gained from using the gonadotropin-releasing hormone antagonist rather than the gonadotropin-releasing hormone agonist are the immediate inhibition of pituitary gonadotropin secretion without the "flare effect," which brings greater safety and convenience for patients and the medical team and saves time and money. We have also recently demonstrated the feasibility of combining gonadotropin-releasing hormone antagonist with pulsatile gonadotropin-releasing hormone therapy for the controlled restoration of gonadotropin secretion and gonadal steroidogenesis culminating in apparently normal (singleton) ovulatory cycles. This is feasible only with gonadotropin-releasing hormone antagonists because, unlike gonadotropin-releasing hormone agonists, they achieve control of the pituitary-ovarian axis without down regulation of the gonadotropin-releasing hormone receptor system. This capacity to override gonadotropin-releasing hormone antagonist-induced suppression of pituitary-ovarian function may allow new treatment modalities to be employed for women who suffer from chronic hyperandrogenemia with polycystic ovarian disease.

  15. Purification and cultivation of human pituitary growth hormone secreting cells

    Science.gov (United States)

    Hymer, W. C.

    1978-01-01

    The maintainance of actively secreting human pituitary growth hormone cells (somatotrophs) in vitro was studied. The primary approach was the testing of agents which may be expected to increase the release of the human growth hormone (hGH). A procedure for tissue procurement is described along with the methodologies used to dissociate human pituitary tissue (obtained either at autopsy or surgery) into single cell suspensions. The validity of the Biogel cell column perfusion system for studying the dynamics of GH release was developed and documented using a rat pituitary cell system.

  16. Effect of Chlorotriazine Pesticides on Gonadotrophin Releasing Hormone in the Neuronal GT1-7 Cell Line and Hypothalamic Explants

    Science.gov (United States)

    Gonadotrophin releasing hormone (GnRH) stimulates the release of pituitary luteinizing hormone (LH) and follicle stimulating hormone. These pituitary hormones are necessary for normal reproductive function in both males and females. It is well recognized that disruption of nor...

  17. Repetitive Stimulation of the Pituitary with Growth-Hormone-Releasing Hormone Alters the Proportion of 22 and 20 Kilodalton Human-Growth Hormone Released

    Directory of Open Access Journals (Sweden)

    Peter C. Hindmarsh

    2010-01-01

    Full Text Available Background/Aims. 20 Kilodalton-hGH (20 K-hGH is the second most abundant pituitary GH variant after 22 K-hGH. In the steady state the proportion of 20 : 22 K-hGH appears constant; does this proportion change with repetitive somatotroph stimulation? Methods. Forty adult males were randomised to receive a GHRH(1–29NH2 bolus (0.5 μg/kg (n=20 or 1.0 μg/kg (n=20, preceded or followed by a saline bolus, 1 week apart. Four to six weeks later, 10 subjects received 0.5 μg/kg GHRH(1–29NH2 at 0, 60, 120, and 180 minutes. Clearance rate of 22 and 20 K-hGH was measured in 10 subjects. Results. Total amount/proportion of 22 K-hGH/20 K-hGH secreted was similar for both GHRH(1–29NH2 doses. Repetitive stimulation reduced the amount of 22 K-hGH released whereas the amount of 20 K-hGH did not change significantly leading to an increase in the proportion of 20 K-hGH (P=.05. Half-life of 20 and 22 K-hGH were not significantly different (P=.55. Conclusions. Repetitive stimulation of the somatotroph may alter the proportion of GH variant released.

  18. Repetitive Stimulation of the Pituitary with Growth-Hormone-Releasing Hormone Alters the Proportion of 22 and 20 Kilodalton Human-Growth Hormone Released

    Directory of Open Access Journals (Sweden)

    Robinson IainCAF

    2010-05-01

    Full Text Available Background/Aims. 20 Kilodalton-hGH (20 K-hGH is the second most abundant pituitary GH variant after 22 K-hGH. In the steady state the proportion of 20 : 22 K-hGH appears constant; does this proportion change with repetitive somatotroph stimulation? Methods. Forty adult males were randomised to receive a GHRH(1–29 bolus   ( or   (, preceded or followed by a saline bolus, 1 week apart. Four to six weeks later, 10 subjects received   GHRH(1–29 at 0, 60, 120, and 180 minutes. Clearance rate of 22 and 20 K-hGH was measured in 10 subjects. Results. Total amount/proportion of 22 K-hGH/20 K-hGH secreted was similar for both GHRH(1–29 doses. Repetitive stimulation reduced the amount of 22 K-hGH released whereas the amount of 20 K-hGH did not change significantly leading to an increase in the proportion of 20 K-hGH . Half-life of 20 and 22 K-hGH were not significantly different . Conclusions. Repetitive stimulation of the somatotroph may alter the proportion of GH variant released.

  19. Corticotropin-releasing hormone (CRH) stimulates cocaine- and amphetamine-regulated transcript gene (CART1) expression through CRH type 1 receptor (CRHR1) in chicken anterior pituitary.

    Science.gov (United States)

    Mo, Chunheng; Cai, Guoqing; Huang, Long; Deng, Qiuyang; Lin, Dongliang; Cui, Lin; Wang, Yajun; Li, Juan

    2015-12-01

    Cocaine- and amphetamine-regulated transcript (CART) peptide(s) is generally viewed as neuropeptide(s) and can control food intake in vertebrates, however, our recent study revealed that CART1 peptide is predominantly expressed in chicken anterior pituitary, suggesting that cCART1 peptide is a novel pituitary hormone in chickens and its expression is likely controlled by hypothalamic factor(s). To test this hypothesis, in this study, we examined the spatial expression of CART1 in chicken anterior pituitary and investigated the effect of hypothalamic corticotropin-releasing hormone (CRH) on pituitary cCART1 expression. The results showed that: 1) CART1 is expressed in both caudal and cephalic lobes of chicken anterior pituitary, revealed by quantitative real-time PCR (qPCR), western blot and immuno-histochemical staining; 2) CRH potently stimulates cCART1 mRNA expression in cultured chick pituitary cells, as examined by qPCR, and this effect is blocked by CP154526 (and not K41498), an antagonist specific for chicken CRH type I receptor (cCRHR1), suggesting that cCRHR1 expressed on corticotrophs mediates this action; 3) the stimulatory effect of CRH on pituitary cCART1 expression is inhibited by pharmacological drugs targeting the intracellular AC/cAMP/PKA, PLC/IP3/Ca(2+), and MEK/ERK signaling pathways. This finding, together with the functional coupling of these signaling pathways to cCRHR1 expressed in CHO cells demonstrated by luciferase reporter assay systems, indicates that these intracellular signaling pathways coupled to cCRHR1 can mediate CRH action. Collectively, our present study offers the first substantial evidence that hypothalamic CRH can stimulate pituitary CART1 expression via activation of CRHR1 in a vertebrate species.

  20. Two gonadotropin-releasing hormone receptor subtypes with distinct ligand selectivity and differential distribution in brain and pituitary in the goldfish (Carassius auratus)

    OpenAIRE

    Illing, Nicola; Troskie, Brigitte E.; Nahorniak, Carol S.; Janet P Hapgood; Peter, Richard E.; Millar, Robert P.

    1999-01-01

    In the goldfish (Carassius auratus) the two endogenous forms of gonadotropin-releasing hormone (GnRH), namely chicken GnRH II ([His5,Trp7,Tyr8]GnRH) and salmon GnRH ([Trp7,Leu8]GnRH), stimulate the release of both gonadotropins and growth hormone from the pituitary. This control is thought to occur by means of the stimulation of distinct GnRH receptors. These receptors can be distinguished on the basis of differential gonadotropin and growth hormone releasing activities of naturally occurring...

  1. Pituitary and mammary growth hormone in dogs

    NARCIS (Netherlands)

    Bhatti, Sofie Fatima Mareyam

    2006-01-01

    Several pathological (e.g. obesity and chronic hypercortisolism) and non-pathological (e.g. ageing) states in humans are characterized by a reduction in pituitary growth hormone (GH) secretion. Chronic hypercortisolism in humans is also associated with an impaired GH response to various stimuli. Pit

  2. Centrally Applied Somatostatin Inhibits the Estrogen-Induced Luteinizing Hormone Surge via Hypothalamic Gonadotropin-Releasing Hormone Cell Activation in Female Rats

    NARCIS (Netherlands)

    Vugt, van H.H.; Swarts, J.J.M.; Heijning, van de H.J.M.; Beek, van der E.M.

    2004-01-01

    Overexpression of growth hormone (GH) as well as GH-deficiency dramatically impairs reproductive function. Decreased reproductive function as a result of altered GH release is, at least partially, due to changes at the hypothalamic-pituitary level. We hypothesize that hypothalamic somatostatin (SOM)

  3. Biochemical and pharmacological characterization of the thyrotropin releasing hormone (TRH) receptor from clonal GH sub 4 C sub 1 pituitary cells

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, W.J.

    1987-01-01

    The effect of drugs with anesthetic properties on the activity of the pituitary thyrotropin-releasing hormone (TRH) receptor was determined in the clonal GH{sub 4}C{sub 1} somatomammotropic cell line. Classic local anesthetics and other drugs with anesthetic activity inhibited binding of ({sup 3}H)methyl-TRH to cell receptors at concentrations known to produce anesthetic effects on the membrane. The inhibition of TRH receptor binding by tetracaine was competitive and temperature and pH dependent. Verapamil and tetracaine inhibited TRH-stimulated prolactin secretion at concentrations that inhibited peptide binding. TRH-stimulated prolactin secretion was equivalent with or without Ca{sup 2+} channel activity. Verapamil and tetracaine also inhibited basal prolactin and secretion stimulated by drugs that bypass membrane receptors, db-cAMP and TPA. These results indicate that inhibition of TRH binding and responses by diverse drugs results from an anesthetic effect on the cell membrane.

  4. Response of luteinizing hormone and follicle stimulating hormone to luteinizing hormone-releasing hormone in prepubertal and pubertal chidren, as measured by a highly sensitive immunradiometric assay

    OpenAIRE

    樋口,譲二

    1992-01-01

    To investigate the age-related changes in the pituitary responsiveness to luteinizing hormone-releasing hormone (LH-RH), the consentrations of serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured before and after LH-RH administra-tion using the highly sensitive immunoradiometric assay (IRMA) in 283 normal children (161 males and 77 females) between 4 and 14 years old and in 22 patients (18 males and 4 females) with pituitary dwarfism. Then, the area of response ...

  5. Interleukin-8 production from human somatotroph adenoma cells is stimulated by interleukin-1β and inhibited by growth hormone releasing hormone and somatostatin

    DEFF Research Database (Denmark)

    Vindeløv, Signe Diness; Hartoft-Nielsen, Marie-Louise; Rasmussen, Åse Krogh;

    2011-01-01

    Pituitary adenomas cause morbidity and mortality due to their localization and influence on pituitary hormone secretion. Although the pathogenesis of pituitary adenomas is unclear, studies have indicated that cytokines are involved. We investigated the role of cytokines, in particular interleukin...... (IL)-8, in the pathogenesis of growth hormone (GH) producing tumours.......Pituitary adenomas cause morbidity and mortality due to their localization and influence on pituitary hormone secretion. Although the pathogenesis of pituitary adenomas is unclear, studies have indicated that cytokines are involved. We investigated the role of cytokines, in particular interleukin...

  6. Hormonal and morphological study of the pituitaries in reeler mice

    National Research Council Canada - National Science Library

    Lombardero, Matilde; Kovacs, Kalman; Horvath, Eva; Salazar, Ignacio

    2007-01-01

    .... Since the brain is one of the main regulator of pituitary hormone secretion and no information was reported regarding pituitary function and structure in these mutant mice, we studied pituitary...

  7. Growth hormone-releasing factor induces c-fos expression in cultured primary pituitary cells

    DEFF Research Database (Denmark)

    Billestrup, Nils; Mitchell, R L; Vale, W;

    1987-01-01

    GH-releasing factor (GRF) and somatostatin regulates the secretion and biosynthesis of GH as well as the proliferation of GH-producing cells. In order to further characterize the mitogenic effect of GRF, we studied the expression of the proto-oncogene c-fos in primary pituitary cells. Maximal...

  8. Interleukin 1. alpha. inhibits prostaglandin E sub 2 release to suppress pulsatile release of luteinizing hormone but not follicle-stimulating hormone

    Energy Technology Data Exchange (ETDEWEB)

    Rettori, V.; McCann, S.M. (Univ. of Texas Southwestern Medical Center, Dallas (United States)); Gimeno, M.F. (CEFYBO, Buenos Aires (Argentina)); Karara, A. (Vanderbilt Univ., Nashville, TN (United States)); Gonzalez, M.C. (Univ. de La Laguno, Tenerife (Spain))

    1991-04-01

    Interleukin 1{alpha} (IL-1{alpha}), a powerful endogenous pyrogen released from monocytes and macrophages by bacterial endotoxin, stimulates corticotropin, prolactin, and somatotropin release and inhibits thyrotropin release by hypothalamic action. The authors injected recombinant human IL-1{alpha} into the third cerebral ventricle, to study its effect on the pulsatile release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in conscious, freely moving, ovariectomized rats. Intraventricular injection of 0.25 pmol of IL-1{alpha} caused an almost immediate reduction of plasma LH concentration. To determine the mechanism of the suppression of LH release, mediobasal hypothalamic fragments were incubated in vitro with IL-1{alpha} (10 pM) and the release of LH-releasing hormone (LHRH) and prostaglandin E{sub 2} into the medium was measured by RIA in the presence or absence of nonrepinephrine. 1{alpha} reduced basal LHRH release and blocked LHRH release induced by nonrepinephrine. In conclusion, IL-1{alpha} suppresses LH but not FSH release by an almost complete cessation of pulsatile release of LH in the castrated rat. The mechanism of this effect appears to be by inhibition of prostaglandin E{sub 2}-mediated release of LHRH.

  9. Genetics Home Reference: combined pituitary hormone deficiency

    Science.gov (United States)

    ... and lack the ability to have biological children (infertility). The condition can also be associated with a ... for triggering the release of several hormones that direct the development of many parts of the body. ...

  10. Purification and cultivation of human pituitary growth hormone secreting cells

    Science.gov (United States)

    Hymer, W. C.

    1979-01-01

    Efforts were directed towards maintenance of actively secreting human pituitary growth hormone cells (somatotrophs) in vitro. The production of human growth hormone (hGH) by this means would be of benefit for the treatment of certain human hypopituitary diseases such as dwarfism. One of the primary approaches was the testing of agents which may logically be expected to increase hGH release. The progress towards this goal is summarized. Results from preliminary experiments dealing with electrophoresis of pituitary cell for the purpose of somatotroph separation are described.

  11. Dissociation between the effects of somatostatin (SS) and octapeptide SS-analogs on hormone release in a small subgroup of pituitary- and islet cell tumors

    NARCIS (Netherlands)

    L.J. Hofland (Leo); W.W. de Herder (Wouter); H.A. Visser-Wisselaar (Heleen); C. van Uffelen; M. Waaijers (Marlijn); J. Zuyderwijk; P. Uitterlinden (Piet); P.M. van Koetsveld (Peter); S.W.J. Lamberts (Steven); J.M. Kros (Johan)

    1997-01-01

    textabstractThe effects of somatostatin (SS-14 and/or SS-28) and of the three octapeptide SS-analogs that are available for clinical use (octreotide, BIM-23014 and RC-160) on hormone release by primary cultures of 15 clinically nonfunctioning pituitary adenomas (NFA), 7

  12. Dynamic pituitary hormones change after traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Ping Zheng

    2014-01-01

    Full Text Available Objective: To study the dynamic changes of pituitary hormones in traumatic brain injury (TBI and to correlate the severity and neurological outcome. Patients and Methods: Dynamic changes in the pituitary hormones were evaluated in 164 patients with TBI on day-1, day-7, day-14, day-21, and day-28 post injury. Admission TBI severity and long-term outcome were assessed with Glasgow Coma Scale (GCS score and Glasgow Outcome Scale (GOS score. The pituitary hormonal changes were correlated with TBI severity and outcome. Results: Of the 164 patients included in the study, pituitary dysfunction was found in 84 patients and in the remaining 80 patients pituitary function was normal. Most of the pituitary hormone deficiencies observed resolved over time; however, a significant proportion of patients had pituitary dysfunction at one month post injury. The hormones associated with poor outcome included growth hormone, thyrotropic hormone, and gonadotropic hormone. Conclusion: Dynamic changes of pituitary hormones in patients with TBI may reflect the severity of injury and also determine the outcome. Deficiency of growth hormone, gonadotropic hormone, and thyrotropic hormone can adversely affect neurological outcome.

  13. Immunoreactive neuronal pathways of growth hormone-releasing hormone (GRH) in the brain and pituitary of the teleost Gadus morhua.

    Science.gov (United States)

    Pan, J X; Lechan, R M; Lin, H D; Jackson, I M

    1985-01-01

    Using an antiserum directed against the C-terminus of hGRH(1-44)NH2 and another recognizing the mid portion to C-terminal of hGRH(1-40)OH, we identify two immunocytochemically distinct GRH-immunoreactive systems in the brain of the codfish, Gadus morhua. The antiserum directed against GRF(1-44)NH2 stains cell bodies exclusively in the rostral pars distalis. The other antiserum immunoreactive with GRF(1-40)OH reacts with a population of parvocellular and magnocellular neuronal cell bodies in the hypothalamus and with two major axonal pathways which project toward the median eminence and terminate primarily in the pars nervosa. These results indicate the presence of at least two forms of hGRH-like peptides in the teleost which may have different roles in the regulation of pituitary function.

  14. Multiple intracellular signallings involved in regulation of on channels by GH releasing or inhibitory hormones in pituitary somatotropes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Influx of Ca2- via Ca2+ channels is the major step triggering exocytosis of pituitary somatotropes to release growth hormone (GH). Voltage-gated Ca2+ and K+ channels, the primary determinants of the influx of Ca2+ in somatotropes, are regulated by GH-releasing hornone (GHRH) and somatostatin (SRIF) through G protein-coupled signalling systems. Using whole-cell patch-clamp techniques, the changes of the Ca2+ and K+ currents in primary cultured somatotropes were recorded and signalling systems were studied using pharmacological reagents and intracellular dialysis of non-permeable molecules including antibodies and antisense oligonucleotides. GHRH increased both L-and T-types Ca2+ currents and decreased transient (I4) and delayed rectified (Ik) K+ currents. The increase in Ca2+ currents by GHRH was mediated by cAMP/protein kinase A system but the decrease in K+ currents required normal function of protein kinase C system. The GHRH-induced alteration of Ca2+ and K+ currents augments the influx of Ca2+ , leading to an increase in the [ Ca2+ ]i and the GH secretion. In contrary, a significant reduction in Ca2+ currents and increase in K currents were obtained in response to SRIF. The ion channel response to SRIF was demonstrated as a membrane delimited pathway and can be recorded by classic whole-cell configuration, Intracellular dialysis of anti-αi3 antibodies attenuated the increase in K + currents by SRIF whereas anti-αo antibodies blocked the reduction in the Ca2+ current by SRIF. Dialysis of antisense oligonucleotides specific for αo2 sub-units also attenuated the inhibition of SRIF on the Ca2+current. The Gi3 protein mediated the increase in K + currents and the Go2 protein mediated the reduction in the Ca2 +current by SRIF. The SRIF-induced alteration of Ca2 + and K + currents diminished the influx of Ca2+ , leading to a decrease in the [ Ca2+ ]i and the GH secretion. It is therefore concluded that multiple signalling systems are employed in the ion channel

  15. The chicken pituitary-specific transcription factor Pit-1 is involved in the hypothalamic regulation of pituitary hormones

    NARCIS (Netherlands)

    As, van P.; Janssens, K.; Pals, K.; Groef, De B.; Onagbesan, O.M.; Bruggeman, V.; Darras, V.M.; Denef, C.; Decuypere, E.

    2006-01-01

    Pit-1 is a pituitary-specific POU-domain DNA binding factor, which binds to and trans-activates promoters of growth hormone- (GH), prolactin- (PRL) and thyroid stimulating hormone-beta- (TSHbeta) encoding genes. Thyrotropin-releasing hormone (TRH) is located in the hypothalamus and stimulates TSH, G

  16. Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone

    Energy Technology Data Exchange (ETDEWEB)

    Bajusz, S.; Janaky, T.; Csernus, V.J.; Bokser, L.; Fekete, M.; Srkalovic, G.; Redding, T.W.; Schally, A.V. (Tulane Univ. School of Medicine, New Orleans, LA (USA))

    1989-08-01

    Metal complexes related to the cytotoxic complexes cisplatin (cis-diamminedichloroplatinum(II)) and transbis(salicylaldoximato)copper(II) were incorporated into suitably modified luteinizing hormone-releasing hormone (LH-RH) analogues containing D-lysine at position 6. Some of the metallopeptides thus obtained proved to be highly active LH-RH agonists or antagonists. Most metallopeptide analogues of LH-RH showed high affinities for the membrane receptors of rat pituitary and human breast cancer cells. Some of these metallopeptides had cytotoxic activity against human breast cancer and prostate cancer and prostate cancer cell lines in vitro. Such cytostatic metallopeptides could be envisioned as targeted chemotherapeutic agents in cancers that contain receptors for LH-RH-like peptides.

  17. Thyrotropin-releasing hormone provokes abnormal follicle-stimulating hormone (FSH) and luteinizing hormone responses in men who have pituitary adenomas and FSH hypersecretion.

    Science.gov (United States)

    Snyder, P J; Muzyka, R; Johnson, J; Utiger, R D

    1980-10-01

    Serum FSH ad LH concentrations after the administration of TRH were measured in 10 men who had pituitary adenomas associated with FSH hypersecretion. Similar measurements were made in 12 men who had pituitary adenomas but no FSH hypersecretion, in 10 age-matched, normal men, and in 5 men who had primary hypergonadism. The mean serum LH concentration in the men who had pituitary adenomas and FSH hypersecretion increased 136% after TRH administration, significantly greataer (P < 0.005) than the 48% increase in the normal men or the 51% increase in the men who had pituitary adenomas without FSH hypersecretion. Serum LH did not increase at all in the men who had primary hypoganadism. The serum FSH concentration did not increase in any of the normal men, in the men who had pituitary adenomas without FSH hypersecretion, or in the men who had primary hypogonadism, but did increase in 5 of the 10 men who had FSH hypersecretion; the mean increase in these 5 men was 38%. The exaggerated LH responses and the nonspecific FSH responses to TRH of the men who had pituitary adenomas associated with FSH hypersecretion suggest that control of both FSH and LH secretion by these adenomas is abnormal and, therefore, that these adenomas are likely gonadotroph cell adenomas.

  18. A central theory of preterm and term labor: putative role for corticotropin-releasing hormone.

    Science.gov (United States)

    Majzoub, J A; McGregor, J A; Lockwood, C J; Smith, R; Taggart, M S; Schulkin, J

    1999-01-01

    Near the end of human pregnancy the concentration of placental corticotropin-releasing hormone in maternal blood rises exponentially. The rate of elevation of corticotropin-releasing hormone and its duration through time have been linked to the time of onset of labor. Paradoxically, although glucocorticoids are known to inhibit corticotropin-releasing hormone production within the hypothalamic-pituitary-adrenal axis, cortisol actually increases corticotropin-releasing hormone levels in several areas outside the hypothalamus, including the placenta. Placental corticotropin-releasing hormone may be an important component of a system that controls the normal maturation of the fetus and signals the initiation of labor. Abnormal elevations in corticotropin-releasing hormone, which may be a hormonal response to stressors arising in either the mother, placenta, or fetus, may prove to participate in the premature onset of parturition.

  19. Luteinizing hormone (LH) and prolactin-releasing pituitary tumor: possible malignant transformation of the LH cell line.

    Science.gov (United States)

    Spertini, F; Deruaz, J P; Perentes, E; Pelet, B; Gomez, F

    1986-05-01

    A pituitary tumor was diagnosed in a prepubertal 13-yr-old girl, who had elevated plasma LH (58 mIU/ml) and PRL (93 ng/ml) levels; decreased GH, ACTH, and FSH secretion; and diabetes insipidus. After surgery, plasma LH and PRL declined, but not to normal levels. Conventional external radiotherapy to the pituitary was immediately followed by a decrease in LH to prepubertal values (0.7 mIU/ml), while PRL levels became normal only after a long course of bromocriptine therapy. The pituitary tumor was composed of two distinct cell types: small polygonal cells, which were PRL positive by immunohistochemistry, and clusters of pleomorphic large frequently mitotic polynucleated cells, which were LH positive, some of them also being positive for the alpha-subunit or beta LH but not for beta FSH. Four years after surgery and radiotherapy, the patient deteriorated neurologically. Computed tomographic scan showed widespread frontal and periventricular tumor, which had the histological features of a poorly differentiated carcinoma. No PRL, LH, or alpha- or beta-subunits were detectable on immunocytochemistry. While the PRL-positive cells of the pituitary tumor displayed the histological and clinical features of PRL adenomas, the morphological characteristics of LH cells and the sharp decline of plasma LH levels after radiotherapy were suggestive of malignant transformation. In this context, the later brain tumor could have been the result of subependymal spread of the pituitary tumor after it lost its hormone-secreting capacity.

  20. Prenatal development of gonadotropin-releasing hormone receptors in the rat anterior pituitary

    Energy Technology Data Exchange (ETDEWEB)

    Jennes, L. (Wright State Univ. School of Medicine, Dayton, OH (USA))

    1990-02-01

    The development of pituitary GnRH receptors was studied in the rat with in vitro and in vivo autoradiography. GnRH receptors were first seen in pituitary primordia of 13-day-old fetuses. The binding was specific and saturable and was abolished in the presence of 10 microM synthetic GnRH. To examine whether GnRH was available to the fetus, amnionic fluid was collected on days E 12-18. RIA analyses showed that GnRH levels in the amnionic fluid were low on days 12 and 13 (0-20 pM/ml) and rose to 225 pM/ml on day E 16 before they declined to 110 pM/ml on fetal day E 18. The highest levels of GnRH in the amnionic fluid on day E 16 coincided with the first appearance of immunoreactive LH cells, as determined by immunohistochemistry. Intravenous injection of 500 microliters amnionic fluid into pentobarbital-anesthetized adult rats caused a transient 40-60% increase in circulating serum LH in the recipient animal. To show that GnRH from the amnionic fluid has access to the developing pituitary, the 125I-labeled GnRH agonist Buserelin was injected into the amnionic fluid of 13-, 14-, and 15-day-old fetuses in the presence or absence of 10 microM unlabeled GnRH. Autoradiographic analysis of the fetal tissue indicated that the labeled GnRH agonist bound to specific receptors in the primordial pituitaries. The results suggest that the pituitary gonadotropes are differentiated before day E 13 because the expression of GnRH receptors is already an indication of cell determination. Since GnRH is present in the amnionic fluid in a biologically active form and can reach the fetal pituitary, it is concluded that GnRH may be an important factor determining the onset LH synthesis, but not the differentiation, of primordial pituitary cells.

  1. Anterior Pituitary Leptin Expression Changes in Different Reproductive States: Stimulation, in vitro, by Gonadotropin Releasing Hormone (GnRH)

    OpenAIRE

    Akhter, Noor; Johnson, Brandy W.; Crane, Christopher; Iruthayanathan, Mary; Zhou, Yi-Hong; Kudo, Akihiko; Childs, Gwen V.

    2006-01-01

    This study was designed to learn more about the changes in expression of rat anterior pituitary (AP) leptin during the estrous cycle. QRT-PCR assays of cycling rat AP leptin mRNA showed 2—fold increases from metestrus to diestrus followed by an 86% decrease on the morning of proestrus. Percentages of leptin cells increased in proestrus and pregnancy to 55–60% of AP cells. Dual labeling for leptin proteins and growth hormone (GH) or gonadotropins, showed that the rise in leptin protein-bearing...

  2. Butyrate increases intracellular calcium levels and enhances growth hormone release from rat anterior pituitary cells via the G-protein-coupled receptors GPR41 and 43.

    Directory of Open Access Journals (Sweden)

    Maria Consolata Miletta

    Full Text Available Butyrate is a short-chain fatty acid (SCFA closely related to the ketone body ß-hydroxybutyrate (BHB, which is considered to be the major energy substrate during prolonged exercise or starvation. During fasting, serum growth hormone (GH rises concomitantly with the accumulation of BHB and butyrate. Interactions between GH, ketone bodies and SCFA during the metabolic adaptation to fasting have been poorly investigated to date. In this study, we examined the effect of butyrate, an endogenous agonist for the two G-protein-coupled receptors (GPCR, GPR41 and 43, on non-stimulated and GH-releasing hormone (GHRH-stimulated hGH secretion. Furthermore, we investigated the potential role of GPR41 and 43 on the generation of butyrate-induced intracellular Ca2+ signal and its ultimate impact on hGH secretion. To study this, wt-hGH was transfected into a rat pituitary tumour cell line stably expressing the human GHRH receptor. Treatment with butyrate promoted hGH synthesis and improved basal and GHRH-induced hGH-secretion. By acting through GPR41 and 43, butyrate enhanced intracellular free cytosolic Ca2+. Gene-specific silencing of these receptors led to a partial inhibition of the butyrate-induced intracellular Ca2+ rise resulting in a decrease of hGH secretion. This study suggests that butyrate is a metabolic intermediary, which contributes to the secretion and, therefore, to the metabolic actions of GH during fasting.

  3. Butyrate increases intracellular calcium levels and enhances growth hormone release from rat anterior pituitary cells via the G-protein-coupled receptors GPR41 and 43.

    Science.gov (United States)

    Miletta, Maria Consolata; Petkovic, Vibor; Eblé, Andrée; Ammann, Roland A; Flück, Christa E; Mullis, Primus-E

    2014-01-01

    Butyrate is a short-chain fatty acid (SCFA) closely related to the ketone body ß-hydroxybutyrate (BHB), which is considered to be the major energy substrate during prolonged exercise or starvation. During fasting, serum growth hormone (GH) rises concomitantly with the accumulation of BHB and butyrate. Interactions between GH, ketone bodies and SCFA during the metabolic adaptation to fasting have been poorly investigated to date. In this study, we examined the effect of butyrate, an endogenous agonist for the two G-protein-coupled receptors (GPCR), GPR41 and 43, on non-stimulated and GH-releasing hormone (GHRH)-stimulated hGH secretion. Furthermore, we investigated the potential role of GPR41 and 43 on the generation of butyrate-induced intracellular Ca2+ signal and its ultimate impact on hGH secretion. To study this, wt-hGH was transfected into a rat pituitary tumour cell line stably expressing the human GHRH receptor. Treatment with butyrate promoted hGH synthesis and improved basal and GHRH-induced hGH-secretion. By acting through GPR41 and 43, butyrate enhanced intracellular free cytosolic Ca2+. Gene-specific silencing of these receptors led to a partial inhibition of the butyrate-induced intracellular Ca2+ rise resulting in a decrease of hGH secretion. This study suggests that butyrate is a metabolic intermediary, which contributes to the secretion and, therefore, to the metabolic actions of GH during fasting.

  4. Effect of growth hormone (GH)-releasing hormone (GRH) on plasma GH in relation to magnitude and duration of GH deficiency in 26 children and adults with isolated GH deficiency or multiple pituitary hormone deficiencies: evidence for hypothalamic GRH deficiency.

    Science.gov (United States)

    Schriock, E A; Lustig, R H; Rosenthal, S M; Kaplan, S L; Grumbach, M M

    1984-06-01

    Synthetic, amidated, 44 amino acid GH-releasing hormone ( GRH -44) was administered iv at a dose of 5 micrograms/kg to 20 patients with severe GH deficiency (GHD), 6 children and adolescents with partial GHD, and 6 non-GH deficient ( NGHD ) children and adolescents. The 17 patients with severe GHD that responded to GRH -44 had lower peak concentrations of plasma GH than the NGHD individuals (5.0 +/- 1.2 (SEM) vs. 27.2 +/- 3.5 ng/ml; P less than 0.0001). The children and adolescents with severe GHD tended to have higher peak GH responses to GRH -44 than the GHD adults (6.9 +/- 1.7 vs. 2.4 +/- 0.3 ng/ml) although the difference was not significant. The peak GH concentration was attained earlier in the GHD children and adolescents than in the GHD adults (28 +/- 4.7 vs. 69.3 +/- 13 min, P less than 0.004). There was a negative correlation between chronological age and peak plasma GH response to GRH in the children and adolescents with severe GHD (r = -0.758, P less than 0.02). Children and adolescents with partial GHD had a higher mean peak concentration of plasma GH (13. 1 +/- 1.8 ng/ml) than the children, adolescents, and adults with severe GHD (P less than 0.04), but one lower than the NGHD children and adolescents (P less than 0.05). In both severe and partial GHD the GH response to GRH was greater than that elicited by standard pharmacological tests. Serum somatomedin-C did not increase after a single pulse of GRH -44 in the 12 GHD patients studied. PRL increased minimally 30 min after 5 micrograms/kg iv GRH -44 in patients with multiple hypothalamic-pituitary hormone deficiencies but not in patients with isolated GHD or in NGHD individuals. The GH responses to GRH suggest that the majority of patients with isolated GHD as well as those with multiple hypothalamic-pituitary hormone deficiencies have deficiency of hypothalamic GRH . Lack of a GH response to a single pulse of GRH does not exclude GRH deficiency as priming of the somatotrope with multiple pulses of

  5. Effect of growth hormone replacement therapy on pituitary hormone secretion and hormone replacement therapies in GHD adults

    DEFF Research Database (Denmark)

    Hubina, Erika; Mersebach, Henriette; Rasmussen, Ase Krogh;

    2004-01-01

    We tested the impact of commencement of GH replacement therapy in GH-deficient (GHD) adults on the circulating levels of other anterior pituitary and peripheral hormones and the need for re-evaluation of other hormone replacement therapies, especially the need for dose changes.......We tested the impact of commencement of GH replacement therapy in GH-deficient (GHD) adults on the circulating levels of other anterior pituitary and peripheral hormones and the need for re-evaluation of other hormone replacement therapies, especially the need for dose changes....

  6. Growth hormone-releasing peptide-6 inhibits cerebellar cell death in aged rats.

    Science.gov (United States)

    Pañeda, Covadonga; Arroba, Ana I; Frago, Laura M; Holm, Anne Mette; Rømer, John; Argente, Jesús; Chowen, Julie A

    2003-08-26

    Insulin-like growth factor (IGF)-I is essential for cerebellar granule neuron survival and a decline in IGF-I is implicated in various age-dependent processes. Here we show that IGF-I mRNA levels are decreased in the cerebellum of old rats compared with young rats and this was associated with increased cell death and activation of caspases 3 and 9. Growth hormone-releasing peptide (GHRP)-6, a synthetic ligand for the ghrelin receptor, increased IGF-I mRNA levels, decreased cell death and inhibited caspase 3 and 9 activation in the cerebellum of aged rats. These results suggest that increasing IGF-I expression in the cerebellum can decrease cell death in aged rats via inhibition of caspase 3 and 9 activation.

  7. alpha-Melanocyte-stimulating-hormone precursors in the pig pituitary

    DEFF Research Database (Denmark)

    Fenger, M

    1986-01-01

    The occurrence of intermediates from the processing of ACTH-(1-39) [adrenocorticotropic hormone-(1-39)] to alpha-melanocyte-stimulating hormone was investigated in normal pig pituitaries by the use of sensitive and specific radioimmunoassays for ACTH-(1-13), ACTH-(1-14), ACTH-(1-13)-NH2 and ACTH-(1...

  8. Pituitary and placental hormone levels in pseudocyesis.

    Science.gov (United States)

    Osotimehin, B O; Ladipo, O A; Adejuwon, C A; Otolorin, E O

    1981-10-01

    Twelve patients with clinical features of pseudocyesis were divided into two groups according to the presence or absence of galactorrhea. The mean serum prolactin level of patients with galactorrhea was significantly higher than the normal values of the patients without galactorrhea. The mean serum levels of luteinizing hormone and follicle-stimulating hormone were markedly elevated in patients without galactorrhea. This was especially true of luteinizing hormone. Serum levels of human chorionic gonadotropin were undetectable in all patients. The significance of these observations is discussed.

  9. Growth hormone (GH)-releasing activity of chicken GH-releasing hormone (GHRH) in chickens.

    Science.gov (United States)

    Harvey, S; Gineste, C; Gaylinn, B D

    2014-08-01

    Two peptides with sequence similarities to growth hormone releasing hormone (GHRH) have been identified by analysis of the chicken genome. One of these peptides, chicken (c) GHRH-LP (like peptide) was previously found to poorly bind to chicken pituitary membranes or to cloned and expressed chicken GHRH receptors and had little, if any, growth hormone (GH)-releasing activity in vivo or in vitro. In contrast, a second more recently discovered peptide, cGHRH, does bind to cloned and expressed cGHRH receptors and increases cAMP activity in transfected cells. The possibility that this peptide may have in vivo GH-releasing activity was therefore assessed. The intravenous (i.v.) administration of cGHRH to immature chickens, at doses of 3-100 μg/kg, significantly increased circulating GH concentrations within 10 min of injection and the plasma GH levels remained elevated for at least 30 min after the injection of maximally effective doses. The plasma GH responses to cGHRH were comparable with those induced by human (h) or porcine (p) GHRH preparations and to that induced by thyrotropin releasing hormone (TRH). In marked contrast, the i.v. injection of cGHRH-LP had no significant effect on circulating GH concentrations in immature chicks. GH release was also increased from slaughterhouse chicken pituitary glands perifused for 5 min with cGHRH at doses of 0.1 μg/ml or 1.0 μg/ml, comparable with GH responses to hGHRH1-44. In contrast, the perifusion of chicken pituitary glands with cGHRH-LP had no significant effect on GH release. In summary, these results demonstrate that cGHRH has GH-releasing activity in chickens and support the possibility that it is the endogenous ligand of the cGHRH receptor.

  10. [Stimulation test of the adenohypophysis with arginine, gonadotropin-releasing hormone (GRH), and thyrotropin-releasing hormone (TRH) in 45, XO patients with Turner's syndrome (author's transl)].

    Science.gov (United States)

    Rudolf, K; Kyank, H; Göretzlehner, G; Kunkel, S

    1980-01-01

    Pituitary stimulation tests with arginine, gonadotropin-releasing hormone (GRH) and thyrotropin-releasing hormone (TRH) were performed in five 45, XO patients with Turner's syndrome. Their ages ranged from 12--17 years. Serum levels of LH, FSH, PRL, HGH, and TSH were measured by RIA. The hypothalamo-pituitary system appeared normal in the patients with Turner's syndrome.

  11. Inhibition of maternal behaviour by central infusion of corticotrophin-releasing hormone in marmoset monkeys.

    Science.gov (United States)

    Saltzman, W; Boettcher, C A; Post, J L; Abbott, D H

    2011-11-01

    Stress can inhibit maternal behaviour and increase rates of child abuse in humans and other animals; however, the neuroendocrine mechanisms are not known. To determine whether corticotrophin-releasing hormone (CRH) plays a role in stress-induced disruption of maternal behaviour in primates, we characterised the effects of acute i.c.v. infusions of CRH on maternal and abusive behaviour in common marmoset monkeys (Callithrix jacchus). Nulliparous females were implanted with indwelling i.c.v. guide cannulae before conception. Between 18 and 58 days after the birth of her first infants, each female underwent a series of i.c.v. infusions of human CRH (0, 2, 8 and 25 μg) in 8 μl of artificial cerebrospinal fluid. In the 70 min after infusion, marmosets were tested with one of their infants, first in their home cage and, subsequently, in an unfamiliar cage in which the infant was confined in a transparent box on the cage floor. In the home cage, the highest dose of CRH significantly reduced the amount of time that mothers spent carrying their infants, as compared to vehicle alone, although it did not reliably affect aggression toward the infant or other behaviours. In the confined-infant test, the highest dose of CRH significantly reduced the amount of time that mothers spent on the cage floor, increased mothers' vocalisation rates, and tended to reduce their activity levels and time spent in proximity to their infant. Twenty-five micrograms of CRH also elicited significant elevations in plasma adrenocorticotrophic hormone and cortisol concentrations compared to vehicle. These results indicate that i.c.v.-administered CRH reduces maternal behaviour in marmoset mothers, in both familiar and unfamiliar environments, but does not increase infant abuse.

  12. Marked changes of arginine vasopressin, oxytocin, and corticotropin-releasing hormone in hypophysial portal plasma after pituitary stalk damage in the rat.

    Science.gov (United States)

    Makara, G B; Sutton, S; Otto, S; Plotsky, P M

    1995-05-01

    Mechanical compression of the pituitary stalk with the help of a blunt stereotaxic knife results in posterior pituitary denervation (PPD) and sprouting proximal to the injury, leading to formation of an ectopic neurohypophysis in the stalk. This provides an experimental model for those cases in which traumatic damage severs the nerve fibers to the neural lobe but does not obliterate the hypophysial-portal circulation. The effect of PPD on the hypophysial-portal concentration profile of putative ACTH secretagogues as well as basal and stimulated ACTH secretion in vitro were investigated at varying times after PPD. The contents of arginine vasopressin (AVP) and oxytocin (OT) in extracts of the stalk median eminence 1 week after PPD were markedly elevated, whereas corticotropin-releasing hormone (CRH) content was unaffected. Levels of these three neuropeptides in hypophysial-portal blood collected under anesthesia from the proximal stump of the transected stalk (or the ectopic neural lobe) were measured at weekly intervals in groups of rats after sham or PPD surgery. Hypophysial-portal AVP levels showed a monotonic increase with time after PPD from a 1.8-fold elevation at 1 week post-PPD to a maximum concentration 6-fold greater than that in sham groups at 4 weeks post-PPD. Portal plasma OT levels also exhibited extreme elevation. In contrast, portal plasma CRH levels showed an initial 72% decline 1 week post-PPD. We suggest that mechanical damage to the pituitary stalk and the subsequent sprouting redirected secretion of AVP and OT from the neural lobe to the pituitary stalk. This caused sustained elevations of portal plasma concentrations of AVP and OT. The resulting tonic exposure to AVP and/or OT may down-regulate anterior pituitary receptors to these neurohypophyseal peptides and indirectly decrease CRH release into the portal circulation.

  13. Relative effectiveness of carp pituitary extract, luteinizing hormone releasing hormone analog LHRHa injections and LHRHa implants for producing hybrid catfish fry

    Science.gov (United States)

    Adoption of the hybrid catfish (channel catfish, Ictalruus punctatus, female x blue catfish, I. furcatus, male) is increasing in the catfish industry. The most effective way to produce fry is hormone induced spawning of females coupled with hand stripping and in vitro fertilization. The success of...

  14. Adrenocorticotropic hormone and cortisol in calves after corticotropin-releasing hormone

    NARCIS (Netherlands)

    Veissier, I.; Reenen, van C.G.; Andanson, S.; Leushuis, I.E.

    1999-01-01

    The aim for this study was to analyze responsiveness of the hypothalamo-pituitary-adrenocortical axis to exogenous bovine corticotropin-releasing hormone (bCRH) in calves. Two dose-response studies were carried out, using either bCRH alone (dose rates of 0, .01, .03, and .1 μg bCRH/kg live weight) o

  15. Hypothalamic regulation of thyroid-stimulating hormone and prolactin release : the role of thyrotrophin-releasing hormone

    NARCIS (Netherlands)

    G.A.C. van Haasteren (Goedele)

    1995-01-01

    textabstractThyrotrophin-releasing-hormone (TRH), a tripeptide, is produced by hypothalamic neurons and transported along their axons to the median eminence (ME). From there it is released at nerve terminals into hypophyseal portal blood. It is then transported to the anterior pituitary gland where

  16. Ligand-biased regulation of PtdIns(3,4,5)P3-dependent signal transduction in GPCR control of pituitary hormone release.

    Science.gov (United States)

    Pemberton, Joshua G; Chang, John P

    2016-12-01

    Biased signaling describes the selective activation of signal transduction cascades by structurally-related ligands downstream of shared G protein-coupled receptors (GPCRs). Although class I phosphoinositide 3-kinases (PI3Ks) are important components of GPCR-controlled transduction networks, little is known regarding the potential for biased regulation of class I PI3K-dependent signaling. The full compliment of class I PI3K catalytic subunits (p110α, p110β, p110δ and p110γ) first appear in bony fishes and, despite being associated with distinct cellular functions, all class I PI3Ks produce the lipid second-messenger phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3). We have previously shown that two endogenous gonadotropin-releasing hormones (GnRH2 and GnRH3), which both signal through shared Gαq/11-coupled receptors, selectively activate different subsets of class I PI3K isoforms in their control of hormone release from goldfish (Carassius auratus) pituitary cells. Here, we tested the hypothesis that the biased activation of class I PI3K isoforms results in the selective recruitment of PtdIns(3,4,5)P3-sensitive effectors downstream of GnRH-stabilized GPCRs using pharmacological mapping. Our results reveal that distinct PtdIns(3,4,5)P3-sensitive effectors are involved in the differential control of GnRH2- and GnRH3-stimulated, as well as basal, hormone release and implicate the participation of non-canonical PtdIns(3,4,5)P3-sensitive transduction elements. Furthermore, observations using a selective inhibitor of the shared Gβγ-effector interaction surface indicate a role for Gβγ-dependent signaling in the integrated control of pituitary hormone exocytosis. These novel findings add to our understanding of functional selectivity in GPCR signal transduction networks, in general, and reveal the complexity of biased signaling downstream of class I PI3K catalytic activity.

  17. Diacylglycerol acyltransferase-1 (DGAT1 inhibition perturbs postprandial gut hormone release.

    Directory of Open Access Journals (Sweden)

    Hua V Lin

    Full Text Available Diacylglycerol acyltransferase-1 (DGAT1 is a potential therapeutic target for treatment of obesity and related metabolic diseases. However, the degree of DGAT1 inhibition required for metabolic benefits is unclear. Here we show that partial DGAT1 deficiency in mice suppressed postprandial triglyceridemia, led to elevations in glucagon-like peptide-1 (GLP-1 and peptide YY (PYY only following meals with very high lipid content, and did not protect from diet-induced obesity. Maximal DGAT1 inhibition led to enhanced GLP-1 and PYY secretion following meals with physiologically relevant lipid content. Finally, combination of DGAT1 inhibition with dipeptidyl-peptidase-4 (DPP-4 inhibition led to further enhancements in active GLP-1 in mice and dogs. The current study suggests that targeting DGAT1 to enhance postprandial gut hormone secretion requires maximal inhibition, and suggests combination with DPP-4i as a potential strategy to develop DGAT1 inhibitors for treatment of metabolic diseases.

  18. Improved response of growth hormone to growth hormone-releasing hormone and reversible chronic thyroiditis after hydrocortisone replacement in isolated adrenocorticotropic hormone deficiency.

    Science.gov (United States)

    Inagaki, Miho; Sato, Haruhiro; Miyamoto, Yoshiyasu; Hirukawa, Takashi; Sawaya, Asako; Miyakogawa, Takayo; Tatsumi, Ryoko; Kakuta, Takatoshi

    2009-07-20

    We report a 44-year-old Japanese man who showed a reversible blunted response of growth hormone (GH) to GH-releasing hormone (GRH) stimulation test and reversible chronic thyroiditis accompanied by isolated ACTH deficiency. He was admitted to our hospital because of severe general malaise, hypotension, and hypoglycemia. He showed repeated attacks of hypoglycemia, and his serum sodium level gradually decreased. Finally, he was referred to the endocrinology division, where his adrenocorticotropic hormone (ACTH) and cortisol values were found to be low, and his GH level was slightly elevated. An increased value of thyroid stimulating hormone (TSH) and decreased values of free triidothyronine and free thyroxine were observed along with anti-thyroglobulin antibody, suggesting chronic thyroiditis. Pituitary stimulation tests revealed a blunted response of ACTH and cortisol to corticotropin-releasing hormone, and a blunted response of GH to GRH. Hydrocortisone replacement was then started, and this improved the patient's general condition. His hypothyroid state gradually ameliorated and his titer of anti-thyroglobulin antibody decreased to the normal range. Pituitary function was re-evaluated with GRH stimulation test under a maintenance dose of 20 mg/day hydrocortisone and showed a normal response of GH to GRH. It is suggested that re-evaluation of pituitary and thyroid function is useful for diagnosing isolated ACTH deficiency after starting a maintenance dose of hydrocortisone in order to avoid unnecessary replacement of thyroid hormone.

  19. Resistance to growth hormone releasing hormone and gonadotropins in Albright's hereditary osteodystrophy.

    Science.gov (United States)

    Mantovani, Giovanna; Spada, Anna

    2006-05-01

    Heterozygous inactivating mutations in the Gs alpha gene cause Albright's hereditary osteo-dystrophy (AHO). Consistent with the observation that only maternally inherited mutations lead to resistance to hormone action (pseudohypoparathyroidism type Ia [PHP-Ia), recent studies have provided evidence for a predominant maternal origin of Gs alpha transcripts in endocrine organs, such as thyroid, gonad and pituitary. Accordingly, patients with PHP-Ia display variable degrees of resistance to parathyroid hormone (PTH), thyroid stimulating hormone (TSH), gonadotropins and growth hormone (GH) releasing hormone (GHRH). Although the incidence and the clinical and biochemical characteristics of PTH and TSH resistance have been widely investigated and described, the cause and significance of the reproductive dysfunction in AHO is still poorly understood. The clinical finding of alterations of GH secretion in these patients was described for the first time only 2 years ago. The present report briefly reviews the literature focusing on the actual knowledge about these last two subjects.

  20. Thyroid hormone and estrogen regulate exercise-induced growth hormone release.

    Directory of Open Access Journals (Sweden)

    Daniele Leão Ignacio

    Full Text Available Growth hormone (GH regulates whole body metabolism, and physical exercise is the most potent stimulus to induce its secretion in humans. The mechanisms underlying GH secretion after exercise remain to be defined. The aim of this study was to elucidate the role of estrogen and pituitary type 1 deiodinase (D1 activation on exercise-induced GH secretion. Ten days after bilateral ovariectomy, animals were submitted to 20 min of treadmill exercise at 75% of maximum aerobic capacity and tissues were harvested immediately or 30 min after exercise. Non-exercised animals were used as controls. A significant increase in D1 activity occurred immediately after exercise (~60% in sham-operated animals and GH was higher (~6-fold 30 min after exercise. Estrogen deficient rats exhibited basal levels of GH and D1 activity comparable to those found in control rats. However, after exercise both D1 activity and serum GH levels were blunted compared to sedentary rats. To understand the potential cause-effect of D1 activation in exercise-induced GH release, we pharmacologically blocked D1 activity by propylthiouracil (PTU injection into intact rats and submitted them to the acute exercise session. D1 inhibition blocked exercise-induced GH secretion, although basal levels were unaltered. In conclusion, estrogen deficiency impairs the induction of thyroid hormone activating enzyme D1 in the pituitary, and GH release by acute exercise. Also, acute D1 activation is essential for exercise-induced GH response.

  1. Thyroid hormone and estrogen regulate exercise-induced growth hormone release.

    Science.gov (United States)

    Ignacio, Daniele Leão; da S Silvestre, Diego H; Cavalcanti-de-Albuquerque, João Paulo Albuquerque; Louzada, Ruy Andrade; Carvalho, Denise P; Werneck-de-Castro, João Pedro

    2015-01-01

    Growth hormone (GH) regulates whole body metabolism, and physical exercise is the most potent stimulus to induce its secretion in humans. The mechanisms underlying GH secretion after exercise remain to be defined. The aim of this study was to elucidate the role of estrogen and pituitary type 1 deiodinase (D1) activation on exercise-induced GH secretion. Ten days after bilateral ovariectomy, animals were submitted to 20 min of treadmill exercise at 75% of maximum aerobic capacity and tissues were harvested immediately or 30 min after exercise. Non-exercised animals were used as controls. A significant increase in D1 activity occurred immediately after exercise (~60%) in sham-operated animals and GH was higher (~6-fold) 30 min after exercise. Estrogen deficient rats exhibited basal levels of GH and D1 activity comparable to those found in control rats. However, after exercise both D1 activity and serum GH levels were blunted compared to sedentary rats. To understand the potential cause-effect of D1 activation in exercise-induced GH release, we pharmacologically blocked D1 activity by propylthiouracil (PTU) injection into intact rats and submitted them to the acute exercise session. D1 inhibition blocked exercise-induced GH secretion, although basal levels were unaltered. In conclusion, estrogen deficiency impairs the induction of thyroid hormone activating enzyme D1 in the pituitary, and GH release by acute exercise. Also, acute D1 activation is essential for exercise-induced GH response.

  2. Blood-brain barrier to peptides: (/sup 3/H)gonadotropin-releasing hormone accumulation by eighteen regions of the rat brain and by anterior pituitary

    Energy Technology Data Exchange (ETDEWEB)

    Ermisch, A.; Ruehle, H.J. (Karl-Marx-Universitaet, Leipzig (German Democratic Republic). Sektion Biowissenschaften); Klauschenz, E.; Kretzschmar, R. (Akademie der Wissenschaften der DDR, Berlin. Inst. fuer Wirkstofforschung)

    1984-01-01

    After intracarotid injection of (/sup 3/H)gonadotropin-releasing hormone ((/sup 3/H)GnRH) the mean accumulation of radioactivity per unit wet weight of 18 brain samples investigated and the anterior pituitary was 0.38 +- 0.11% g/sup -1/ of the injected tracer dose. This indicates a low but measurable brain uptake of the peptide. The brain uptake of (/sup 3/H)GnRH in blood-brain barrier (BBB)-protected regions is 5% of that of separately investigated (/sup 3/H)OH. In BBB-free regions the accumulation of radioactivity was more than 25-fold higher than in BBB-protected regions. The accumulation of (/sup 3/H)GnRH among regions with BBB varies less than among regions with leaky endothelia. The data presented for (/sup 3/H)GnRH are similar to those for other peptides so far investigated.

  3. Spectrum of Adrenal Dysfunction in Patients with Acquired Immunodeficiency Syndrome Evaluation of Adrenal and Pituitary Reserve with ACTH and Corticotropin-Releasing Hormone Testing.

    Science.gov (United States)

    Freda, P U; Papadopoulos, A D; Wardlaw, S L; Goland, R S

    1997-07-01

    Patients with acquired immunodeficiency syndrome (AIDS) have been reported to develop abnormalities of the endocrine system and in particular of the hypothalamic-pituitary-adrenal (HPA) axis. To define the abnormalities of HPA function in AIDS patients better, we performed ACTH and ovine corticotropin-releasing hormone (oCRH) testing in a group of AIDS patients and oCRH testing in a group of healthy subjects. Our study found that in AIDS patients with normal ACTH testing, oCRH testing revealed a variety of subclinical abnormalities of ACTH and cortisol responses. Although we did not find frank adrenal insufficiency in any of these AIDS patients, it remains to be determined if any of the subclinical abnormalities we identified are predictive of clinically significant adrenal insufficiency; it may be that as AIDS patients live longer, the subclinical abnormalities will progress to adrenal insufficiency. (Trends Endocrinol Metab 1997;8:173-180). (c) 1997, Elsevier Science Inc.

  4. Insight into the neuroendocrine site and cellular mechanism by which cortisol suppresses pituitary responsiveness to gonadotropin-releasing hormone.

    Science.gov (United States)

    Breen, Kellie M; Davis, Tracy L; Doro, Lisa C; Nett, Terry M; Oakley, Amy E; Padmanabhan, Vasantha; Rispoli, Louisa A; Wagenmaker, Elizabeth R; Karsch, Fred J

    2008-02-01

    Stress-like elevations in plasma glucocorticoids rapidly inhibit pulsatile LH secretion in ovariectomized sheep by reducing pituitary responsiveness to GnRH. This effect can be blocked by a nonspecific antagonist of the type II glucocorticoid receptor (GR) RU486. A series of experiments was conducted to strengthen the evidence for a mediatory role of the type II GR and to investigate the neuroendocrine site and cellular mechanism underlying this inhibitory effect of cortisol. First, we demonstrated that a specific agonist of the type II GR, dexamethasone, mimics the suppressive action of cortisol on pituitary responsiveness to GnRH pulses in ovariectomized ewes. This effect, which became evident within 30 min, documents mediation via the type II GR. We next determined that exposure of cultured ovine pituitary cells to cortisol reduced the LH response to pulse-like delivery of GnRH by 50% within 30 min, indicating a pituitary site of action. Finally, we tested the hypothesis that suppression of pituitary responsiveness to GnRH in ovariectomized ewes is due to reduced tissue concentrations of GnRH receptor. Although cortisol blunted the amplitude of GnRH-induced LH pulses within 1-2 h, the amount of GnRH receptor mRNA or protein was not affected over this time frame. Collectively, these observations provide evidence that cortisol acts via the type II GR within the pituitary gland to elicit a rapid decrease in responsiveness to GnRH, independent of changes in expression of the GnRH receptor.

  5. Psychoneuromedulator role of corticotrophin releasing hormone in PCOS

    OpenAIRE

    Farideh Zafari Zangeneh; Mohammad Mehdi Naghizadeh; Masoumeh Masoumi

    2016-01-01

    Background: Polycystic ovary syndrome (PCOS) is a common complex condition in women associated with reproductive and metabolic systems and also psychological disorders. There is considerable evidence to suggest that the sympathetic nervous system is involved in PCO and metabolic syndromes. Noradrenalin (NA), corticotrophin releasing hormone (CRH) and nerve growth factor (NGF) are the strong stimulants for two axes: hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-ovarian (HPO) ...

  6. Evaluation of adrenal function in patients with hypothalamic and pituitary disorders : comparison of serum cortisol, urinary free cortisol and the human-corticotrophin releasing hormone test with the insulin tolerance test

    NARCIS (Netherlands)

    Dullaart, RPF; Pasterkamp, SH; Beentjes, JAM; Sluiter, WJ

    1999-01-01

    OBJECTIVE This study aimed to evaluate the performance of screening tests (serum cortisol and 24-h urinary free cortisol) and the human-corticotrophin releasing hormone (h-CRH) test in the assessment of adrenal function in patients with hypothalamic-pituitary disorders. DESIGN Summary receiver opera

  7. Evaluation of adrenal function in patients with hypothalamic and pituitary disorders : comparison of serum cortisol, urinary free cortisol and the human-corticotrophin releasing hormone test with the insulin tolerance test

    NARCIS (Netherlands)

    Dullaart, RPF; Pasterkamp, SH; Beentjes, JAM; Sluiter, WJ

    1999-01-01

    OBJECTIVE This study aimed to evaluate the performance of screening tests (serum cortisol and 24-h urinary free cortisol) and the human-corticotrophin releasing hormone (h-CRH) test in the assessment of adrenal function in patients with hypothalamic-pituitary disorders. DESIGN Summary receiver opera

  8. Short-Chain Fatty Acids Inhibit Growth Hormone and Prolactin Gene Transcription via cAMP/PKA/CREB Signaling Pathway in Dairy Cow Anterior Pituitary Cells

    Directory of Open Access Journals (Sweden)

    Jian-Fa Wang

    2013-10-01

    Full Text Available Short-chain fatty acids (SCFAs play a key role in altering carbohydrate and lipid metabolism, influence endocrine pancreas activity, and as a precursor of ruminant milk fat. However, the effect and detailed mechanisms by which SCFAs mediate bovine growth hormone (GH and prolactin (PRL gene transcription remain unclear. In this study, we detected the effects of SCFAs (acetate, propionate, and butyrate on the activity of the cAMP/PKA/CREB signaling pathway, GH, PRL, and Pit-1 gene transcription in dairy cow anterior pituitary cells (DCAPCs. The results showed that SCFAs decreased intracellular cAMP levels and a subsequent reduction in PKA activity. Inhibition of PKA activity decreased CREB phosphorylation, thereby inhibiting GH and PRL gene transcription. Furthermore, PTX blocked SCFAs- inhibited cAMP/PKA/CREB signaling pathway. These data showed that the inhibition of GH and PRL gene transcription induced by SCFAs is mediated by Gi activation and that propionate is more potent than acetate and butyrate in inhibiting GH and PRL gene transcription. In conclusion, this study identifies a biochemical mechanism for the regulation of SCFAs on bovine GH and PRL gene transcription in DCAPCs, which may serve as one of the factors that regulate pituitary function in accordance with dietary intake.

  9. Influence of catecholamines, prostaglandins and thyroid hormones on growth hormone secretion by chicken pituitary cells in vitro.

    Science.gov (United States)

    Donoghue, D J; Perez, F M; Diamante, B S; Malamed, S; Scanes, C G

    1990-01-01

    In young chickens plasma concentrations of growth hormone (GH) are depressed by prostaglandins (PG) E1 and E2, epinephrine, norepinephrine, alpha 2 and beta agonists or thyroid hormones. A primary culture of chicken adenohypophyseal cells was used to examine the direct effects of these agents at the level of the pituitary as evaluated by GH release in the presence and absence of growth hormone releasing factor (GRF). Following collagenase dispersion and culture (preincubation, 48 hr) cells were exposed (incubation, 2 hr) to test agents, except for thyroid hormones which were added during the preincubation, and incubation period. Growth hormone release was increased (P less than .05) in the presence of PGE1 (10(-8)M by 34%; 10(-7)M by 54%), PGE2 (10(-8)M by 29%; 10(-7)M by 29%), PGF2 alpha (10(-8)M by 28%), and the beta agonist isoproterenol (10(-7)M by 46%). Basal GH release from chicken pituitary cells was not affected by dopamine, norepinephrine, epinephrine, thyroxine (T4), triiodothyronine (T3), or alpha adrenergic agonists. Growth hormone releasing factor stimulated GH release was not affected by the presence of prostaglandins E1, E2 or F2 alpha in the incubation media. However, GRF stimulated GH release was reduced by high doses of catecholamines: dopamine (10(-6)M by 34%), norepinephrine (10(-6)M by 74%), epinephrine (10(-8)M by 47%; 10(-7)M by 41%; 10(-6)M by 89%), and by the alpha 1 adrenergic agonist, phenylephrine (10(-7)M by 52%), the alpha 2 agonist, clonidine (10(-8)M by 34%; 10(-7)M by 83%) and the beta agonist, isoproterenol (10(-7)M by 64%).(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Does prolonged pituitary down-regulation with gonadotropin-releasing hormone agonist improve the live-birth rate in in vitro fertilization treatment?

    Science.gov (United States)

    Ren, Jianzhi; Sha, Aiguo; Han, Dongmei; Li, Ping; Geng, Jie; Ma, Chaihui

    2014-07-01

    To evaluate the effects of a prolonged duration of gonadotropin-releasing hormone agonist (GnRH-a) in pituitary down-regulation for controlled ovarian hyperstimulation (COH) on the live-birth rate in nonendometriotic women undergoing in vitro fertilization and embryo transfer (IVF-ET). Retrospective cohort study. University-affiliated hospital. Normogonadotropic women undergoing IVF. Three hundred seventy-eight patients receiving a prolonged pituitary down-regulation with GnRH-a before ovarian stimulation and 422 patients receiving a GnRH-a long protocol. Live-birth rate per fresh ET. In comparison with the long protocol, the prolonged down-regulation protocol required a higher total dose of gonadotropins. A lower serum luteinizing hormone (LH) level on the starting day of gonadotropin and the day of human chorionic gonadotropin (hCG) and a fewer number of oocytes and embryos were observed in the prolonged down-regulation protocol. However, the duration of stimulation and number of high-quality embryos were comparable between the two groups. A statistically significantly higher implantation rate (50.27% vs. 39.69%), clinical pregnancy rate (64.02% vs. 56.87%) and live-birth rate per fresh transfer cycle (55.56% vs. 45.73%) were observed in the prolonged protocol. Prolonged down-regulation in a GnRH-a protocol might increase the live-birth rates in normogonadotropic women. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  11. Ontogeny of pituitary growth hormone and growth hormone mRNA in the chicken.

    Science.gov (United States)

    McCann-Levorse, L M; Radecki, S V; Donoghue, D J; Malamed, S; Foster, D N; Scanes, C G

    1993-01-01

    The changes in pituitary growth hormone (GH) mRNA levels have been determined by Northern blot analysis and laser densitometry during embryonic development and posthatch growth of white Leghorn cockerels. Pituitary GH mRNA levels were observed to progressively increase between 18 days of embryonic development to a maximum at 4 weeks of age (posthatch). Subsequently, pituitary GH mRNA levels declined between 4 and 8 weeks of age, and between 12 weeks of age and adulthood. Pituitary GH contents showed increases during embryonic development and posthatch growth that paralleled the rise in GH mRNA. The decline in pituitary GH mRNA levels between 4 weeks of age and adulthood occurs when GH secretion has been observed previously to decline.

  12. Kisspeptin regulates gonadotropin-releasing hormone secretion in gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats

    Institute of Scientific and Technical Information of China (English)

    Haogang Xue; Chunying Yang; Xiaodong Ge; Weiqi Sun; Chun Li; Mingyu Qi

    2013-01-01

    Kisspeptin is essential for activation of the hypothalamo-pituitary-gonadal axis. In this study, we established gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats. Rats were injected with 1, 10, or 100 pM kisspeptin-10, a peptide derived from full-length kisspeptin, into the arcuate nucleus and medial preoptic area, and with the kisspeptin antagonist peptide 234 into the lateral cerebral ventricle. The results of immunohistochemical staining revealed that pulsatile luteinizing hormone secretion was suppressed after injection of antagonist peptide 234 into the lateral cerebral ventricle, and a significant increase in luteinizing hormone level was observed after kisspeptin-10 injection into the arcuate nucleus and medial preoptic area. The results of an enzyme-linked immunosorbent assay showed that luteinizing hormone levels during the first hour of kisspeptin-10 infusion into the arcuate nucleus were significantly greater in the 100 pM kisspeptin-10 group than in the 10 pM kisspeptin-10 group. These findings indicate that kisspeptin directly promotes gonadotropin-releasing hormone secretion and luteinizing hormone release in gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats. The arcuate nucleus is a key component of the kisspeptin-G protein-coupled receptor 54 signaling pathway underlying regulating luteinizing hormone pulse secretion.

  13. A newborn presented with cholestasis and diagnosed with congenital pituitary hormone deficiency

    OpenAIRE

    ÖZALKAYA, ELİF; Akdağ, Arzu; DENİZ PAPATYA, ESRA; TOPÇUOĞLU, Sevilay

    2016-01-01

    An infrequent reason of neonatal cholestasis is congenital pituitary hormone deficiency. Clinical manifestations of cholestasis and hypoglycaemia in the neonatal period. Gestational week 37, 3700 grams, girl baby born with cesarean sectioning. Hypoglicemia symptoms developed at postnatal first and cholestasis at postnatal third week. Multiple pituitary hormone deficiency was identified.  Cholestasis symptoms recovered with growth hormone therapy. Congenital pituitary hormone deficiency should...

  14. Immunoreactive gonadotropin-releasing hormone-like material in the brain and the pituitary gland during the periovulatory period in the brown trout (Salmo trutta L.): relationships with the plasma and pituitary gonadotropin.

    Science.gov (United States)

    Breton, B; Motin, A; Billard, R; Kah, O; Geoffre, S; Precigoux, G

    1986-01-01

    In fish there are few data on the gonadotropin-releasing hormone (Gn-RH) neurosecretory activity, which could explain long- and short-term variations of the gonadotropin secretion. There is no biological species specificity between mammal and fish Gn-RH; although there is a structural difference, they are, on the contrary, characterized by a high immunological specificity which does not allow measurement of fish Gn-RH using radioimmunoassay for LH-RH. We have synthesized salmon Gn-RH according to the formula recently proposed by Sherwood (N. Sherwood, L. Eiden, M. Brownstein, J. Spies, J. Rivier, and W. Vale, 1983. Proc. Natl. Acad. Sci. USA 80, 2794-2798). Its activity has been tested by its ability to stimulate the gonadotropin hormone (GtH) secretion in vivo in testosterone-implanted juvenile rainbow trout, and for the recognition of synthesized Gn-RH (s-Gn-RH) perykaria by a specific antibody raised against the s-Gn-RH in regions of the brain described as containing LH-RH immunoreactive-like material. A radioimmunoassay has been developed for the salmon Gn-RH, and its specificity to measure trout Gn-RH has been tested. Using this assay, the brain and pituitary Gn-RH contents have been measured throughout the final phases of maturation and ovulation. Brain Gn-RH increases from the end of vitellogenesis (8.9 +/- 0.76 ng/brain) to ovulation (more than 15 ng/brain). Pituitary Gn-RH is lower (1.58 +/- 0.69 ng/pituitary) at the end of vitellogenesis and follows a similar profile as in the brain, except for a significant decrease just prior the beginning of oocyte maturation. The correlations between Gn-RH levels and GtH pituitary and plasma levels show that total brain Gn-RH is never correlated to the GtH, suggesting that the increase in the brain Gn-RH content is related to a Gn-RH system closely related to maturation and ovulation, which remains to be investigated. On the contrary, pituitary Gn-RH levels are well correlated with pituitary and plasma GtH levels

  15. Phosphorylation substrates for protein kinase C in intact pituitary cells: characterization of a receptor-mediated event using novel gonadotropin-releasing hormone analogues

    Energy Technology Data Exchange (ETDEWEB)

    Strulovici, B.; Tahilramani, R.; Nestor, J.J. Jr.

    1987-09-22

    The involvement of protein kinase C in the signal transduction of gonadotropin-releasing hormone (GnRH) action was investigated with a GnRH superagonist, partial agonists, and antagonists in intact rat pituitary cells. Exposure of /sup 32/P-labeled cells to GnRH or to the superagonist (D-Nal(2)/sup 6/)GnRH induced the enhanced phosphorylation of 42-, 34-, 11-, and 10-kDa proteins and the dephosphorylation of a 15-kDa protein as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis/autoradiography. This effect was blocked in a dose-dependent manner by potent GnRG antagonists. Downregulation of protein kinase C by prolonged incubation of the pituitary cells with high concentrations of active phorbol esters abolished protein kinase C activity and also prevented the phosphorylation induced by GnRN, or (D-Nal(2)/sup 6/)GnRH. The same effect was obtained by preincubating the cells with the protein kinase C inhibitor H-7. In this study the authors identify for the first time physiological substrates for protein kinase C in intact pituitary cells. They demonstrate a close quantitative correlation between the extent of translocation of protein kinase C, levels of phosphorylation of specific substrates in the intact cells, and the biological activity of the GnRH analogues with varying affinity for the GnRH receptor. These data strengthen the contention that the physiological effects of GnRH are primarily mediated via the phosphatidylinositol/Ca/sup 2 +/ signal transfer system and represent a first step toward defining the physiological substrates of protein kinase C and their role in the cascade of events that starts upon binding of GnRH to its receptor.

  16. Active immunization against gonadotropin-releasing hormone : an effective tool to block the fertility axis in mammals

    NARCIS (Netherlands)

    Turkstra, Jouwert Anne

    2005-01-01

    Gonadotropin releasing hormone (GnRH) plays a pivotal role in fertility and reproduction in mammals. It induces the release of luteinising hormone (LH) en follicle stimulating hormone (FSH) from the pituitary. These hormones are responsible for gonadal steroid production and indirectly for gametogen

  17. Influence of apricot kernels on blood plasma levels of selected anterior pituitary hormones in male and female rabbits in vivo

    Directory of Open Access Journals (Sweden)

    Katarína Michalcová

    2016-05-01

    Full Text Available Amygdalin is represented in the family Rosacea more precisely in an apricot kernels and an almonds. There are a lot of components such as trace elements, vitamins, carbohydrates, organic acids, esters, phenols, terpenoids, except cyanogenic glycoside in the seeds. It is known that bioregulators can modulate the activity of specific enzymes and hormones very exactly at low levels and in a short time. The aim of our study was examine the effects of selected doses (0, 60, 300, 420 mg/kg b.w. of apricot kernels in feed on the plasma levels of anterior pituitary hormones in young male and female rabbits in vivo. A sensitive, biochemical method, ELISA was used to determine the hormones prolactin (PRL, luteinizing hormone (LH and follicle stimulating hormone (FSH. 28-day application of apricot kernels did not affect the concentration of PRL, LH, FSH in blood plasma of males. No significant (P≤0.05 differences in case of PRL and LH levels in the blood plasma of females were found. On the other hand a significant (P≤0.05 inhibition of FSH release induced by kernels at the doses 300, 420 mg/kg was found. Our results indicate that apricot kernels could affect secretion of anterior pituitary hormone FSH in female rabbits.

  18. Genetic and non-genetic causes of Isolated Growth Hormone Deficiency and Combined Pituitary Hormone Deficiency: Results of the HYPOPIT study

    NARCIS (Netherlands)

    L.C.G. Graaff, de (Laura Corina Geertruida)

    2008-01-01

    textabstractHypopituitarism, the deficiency of one or more pituitary hormones, causes stunted growth and severe health problems. Understanding the etiology of pituitary hormone deficiencies is important for anticipation of clinical problems, for genetic counselling and for possible prevention. This

  19. Specific involvement of gonadal hormones in the functional maturation of growth hormone releasing hormone (GHRH) neurons.

    Science.gov (United States)

    Gouty-Colomer, Laurie-Anne; Méry, Pierre-François; Storme, Emilie; Gavois, Elodie; Robinson, Iain C; Guérineau, Nathalie C; Mollard, Patrice; Desarménien, Michel G

    2010-12-01

    Growth hormone (GH) is the key hormone involved in the regulation of growth and metabolism, two functions that are highly modulated during infancy. GH secretion, controlled mainly by GH releasing hormone (GHRH), has a characteristic pattern during postnatal development that results in peaks of blood concentration at birth and puberty. A detailed knowledge of the electrophysiology of the GHRH neurons is necessary to understand the mechanisms regulating postnatal GH secretion. Here, we describe the unique postnatal development of the electrophysiological properties of GHRH neurons and their regulation by gonadal hormones. Using GHRH-eGFP mice, we demonstrate that already at birth, GHRH neurons receive numerous synaptic inputs and fire large and fast action potentials (APs), consistent with effective GH secretion. Concomitant with the GH secretion peak occurring at puberty, these neurons display modifications of synaptic input properties, decrease in AP duration, and increase in a transient voltage-dependant potassium current. Furthermore, the modulation of both the AP duration and voltage-dependent potassium current are specifically controlled by gonadal hormones because gonadectomy prevented the maturation of these active properties and hormonal treatment restored it. Thus, GHRH neurons undergo specific developmental modulations of their electrical properties over the first six postnatal weeks, in accordance with hormonal demand. Our results highlight the importance of the interaction between the somatotrope and gonadotrope axes during the establishment of adapted neuroendocrine functions.

  20. Regulation of pituitary hormones and cell proliferation by components of the extracellular matrix

    Directory of Open Access Journals (Sweden)

    M. Paez-Pereda

    2005-10-01

    Full Text Available The extracellular matrix is a three-dimensional network of proteins, glycosaminoglycans and other macromolecules. It has a structural support function as well as a role in cell adhesion, migration, proliferation, differentiation, and survival. The extracellular matrix conveys signals through membrane receptors called integrins and plays an important role in pituitary physiology and tumorigenesis. There is a differential expression of extracellular matrix components and integrins during the pituitary development in the embryo and during tumorigenesis in the adult. Different extracellular matrix components regulate adrenocorticotropin at the level of the proopiomelanocortin gene transcription. The extracellular matrix also controls the proliferation of adrenocorticotropin-secreting tumor cells. On the other hand, laminin regulates the production of prolactin. Laminin has a dynamic pattern of expression during prolactinoma development with lower levels in the early pituitary hyperplasia and a strong reduction in fully grown prolactinomas. Therefore, the expression of extracellular matrix components plays a role in pituitary tumorigenesis. On the other hand, the remodeling of the extracellular matrix affects pituitary cell proliferation. Matrix metalloproteinase activity is very high in all types of human pituitary adenomas. Matrix metalloproteinase secreted by pituitary cells can release growth factors from the extracellular matrix that, in turn, control pituitary cell proliferation and hormone secretion. In summary, the differential expression of extracellular matrix components, integrins and matrix metalloproteinase contributes to the control of pituitary hormone production and cell proliferation during tumorigenesis.

  1. Effects of lamprey PQRFamide peptides on brain gonadotropin-releasing hormone concentrations and pituitary gonadotropin-β mRNA expression.

    Science.gov (United States)

    Daukss, Dana; Gazda, Kristen; Kosugi, Takayoshi; Osugi, Tomohiro; Tsutsui, Kazuyoshi; Sower, Stacia A

    2012-06-01

    Within the RFamide peptide family, PQRFamide peptides that include neuropeptide FF and AF possess a C-terminal Pro-Gln-Arg-Phe-NH(2) motif. We previously identified PQRFamide peptides, lamprey PQRFa, PQRFa-related peptide (RP)-1 and -RP-2 by immunoaffinity purification in the brain of lamprey, one of the most ancient vertebrate species [13]. Lamprey PQRFamide peptide precursor mRNA was expressed in regions predicted to be involved in neuroendocrine regulation in the hypothalamus. However, the putative function(s) of lamprey PQRFamide peptides (PQRFa, PQRFa-RP-1 and PQRFa-RP-2) were not examined nor was the distribution of PQRFamide peptides examined in other tissues besides the brain. The objective of this study was to determine tissue distribution of lamprey PQRFamide peptide precursor mRNA, and to examine the effects of PQRFamide peptides on brain gonadotropin-releasing hormone (GnRH)-I, -II, and -III protein concentrations, and pituitary gonadotropin (GTH)-β mRNA expression in adult lampreys. Lamprey PQRFamide peptide precursor mRNA was expressed in the eye and the brain. Lamprey PQRFa at 100 μg/kg increased brain concentrations of lamprey GnRH-II compared with controls. PQRFa, PQRFa-RP-1 and PQRFa-RP-2 did not significantly change brain protein concentrations of either lamprey GnRH-I, -III, or lamprey GTH-β mRNA expression in the pituitary. These data suggest that one of the PQRFamide peptides may act as a neuroregulator of at least the lamprey GnRH-II system in adult female lamprey.

  2. Novel mechanisms of growth hormone regulation: growth hormone-releasing peptides and ghrelin

    Directory of Open Access Journals (Sweden)

    A.-M.J. Lengyel

    2006-08-01

    Full Text Available Growth hormone secretion is classically modulated by two hypothalamic hormones, growth hormone-releasing hormone and somatostatin. A third pathway was proposed in the last decade, which involves the growth hormone secretagogues. Ghrelin is a novel acylated peptide which is produced mainly by the stomach. It is also synthesized in the hypothalamus and is present in several other tissues. This endogenous growth hormone secretagogue was discovered by reverse pharmacology when a group of synthetic growth hormone-releasing compounds was initially produced, leading to the isolation of an orphan receptor and, finally, to its endogenous ligand. Ghrelin binds to an active receptor to increase growth hormone release and food intake. It is still not known how hypothalamic and circulating ghrelin is involved in the control of growth hormone release. Endogenous ghrelin might act to amplify the basic pattern of growth hormone secretion, optimizing somatotroph responsiveness to growth hormone-releasing hormone. It may activate multiple interdependent intracellular pathways at the somatotroph, involving protein kinase C, protein kinase A and extracellular calcium systems. However, since ghrelin has a greater ability to release growth hormone in vivo, its main site of action is the hypothalamus. In the current review we summarize the available data on the: a discovery of this peptide, b mechanisms of action of growth hormone secretagogues and ghrelin and possible physiological role on growth hormone modulation, and c regulation of growth hormone release in man after intravenous administration of these peptides.

  3. Multicenter study on adult growth hormone level in postoperative pituitary tumor patients.

    Science.gov (United States)

    Cheng, Jing-min; Gu, Jian-wen; Kuang, Yong-qin; Ma, Yuan; Xia, Xun; Yang, Tao; Lu, Min; He, Wei-qi; Sun, Zhi-yong; Zhang, Yan-chao

    2015-03-01

    The objective of this study is to observe the adult growth hormone level in postoperative pituitary tumor patients of multi-centers, and explore the change of hypophyseal hormones in postoperative pituitary tumor patients. Sixty patients with pituitary tumor admitted during March, 2011-March, 2012 were selected. Postoperative hypophyseal hormone deficiency and the change of preoperative, intraoperative, and postoperative growth hormone levels were recorded. Growth hormone hypofunction was the most common hormonal hypofunction, which took up to 85.0 %. Adrenocortical hormone hypofunction was next to it and accounted for 58.33 %. GH + ACTH + TSH + Gn deficiency was the most common in postoperative hormone deficiency, which took up to 40.00 %, and GH + ACTH + TSH + Gn + AVP and GH deficiencies were next to it and accounted for 23.33 and 16.67 %, respectively. The hormone levels in patients after total pituitary tumor resection were significantly lower than those after partial pituitary tumor resection, and the difference was statistically significant; growth hormone and serum prolactin levels after surgery in two groups were decreased, and the difference was statistically significant. The incidence rate of growth hormone deficiency in postoperative pituitary tumor patients is high, which is usually complicated with deficiency of various hypophyseal hormones. In clinical, we should pay attention to the levels of the hypopnyseal hormones, and take timely measures to avoid postoperative complications.

  4. Investigation of the serum levels of anterior pituitary hormones in male children with autism

    National Research Council Canada - National Science Library

    Iwata, Keiko; Matsuzaki, Hideo; Miyachi, Taishi; Shimmura, Chie; Suda, Shiro; Tsuchiya, Kenji J; Matsumoto, Kaori; Suzuki, Katsuaki; Iwata, Yasuhide; Nakamura, Kazuhiko; Tsujii, Masatsugu; Sugiyama, Toshirou; Sato, Kohji; Mori, Norio

    2011-01-01

    .... To test whether the anterior pituitary hormones and cortisol could be useful as biological markers for autism, we assessed the basal serum levels of these hormones in subjects with autism and normal controls...

  5. Gigantism caused by growth hormone secreting pituitary adenoma.

    Science.gov (United States)

    Rhee, Noorisaem; Jeong, Kumi; Yang, Eun Mi; Kim, Chan Jong

    2014-06-01

    Gigantism indicates excessive secretion of growth hormones (GH) during childhood when open epiphyseal growth plates allow for excessive linear growth. Case one involved a 14.7-year-old boy presented with extreme tall stature. His random serum GH level was 38.4 ng/mL, and failure of GH suppression was noted during an oral glucose tolerance test (OGTT; nadir serum GH, 22.7 ng/mL). Magnetic resonance imaging (MRI) of the brain revealed a 12-mm-sized pituitary adenoma. Transsphenoidal surgery was performed and a pituitary adenoma displaying positive immunohistochemical staining for GH was reported. Pituitary MRI scan was performed 4 months after surgery and showed recurrence/residual tumor. Medical treatment with a long-acting somatostatin analogue for six months was unsuccessful. As a result, secondary surgery was performed. Three months after reoperation, the GH level was 0.2 ng/mL and insulin-like growth factor 1 was 205 ng/mL. Case two involved a 14.9-year-old boy, who was referred to our department for his tall stature. His basal GH level was 9.3 ng/mL, and failure of GH suppression was reported during OGTT (nadir GH, 9.0 ng/mL). Pituitary MRI showed a 6-mm-sized pituitary adenoma. Surgery was done and histopathological examination demonstrated a pituitary adenoma with positive staining for GH. Three months after surgery, the GH level was 0.2 ng/mL and nadir GH during OGTT was less than 0.1 ng/mL. Pituitary MRI scans showed no residual tumor. We present two cases of gigantism caused by a GH-secreting pituitary adenoma with clinical and microscopic findings.

  6. Sulfated gastrin stimulates ghrelin and growth hormone release but inhibits insulin secretion in cattle.

    Science.gov (United States)

    Zhao, Hongqiong; Yannaing, Swe; Thanthan, Sint; Kuwayama, Hideto

    2011-11-01

    This study was designed to determine the effects of gastrin on the circulating levels of ghrelin, growth hormone (GH), insulin, glucagon and glucose in ruminants. Two experiments were done in eight Holstein steers. Animals were randomly assigned to receive intravenous bolus injections: (1) 0.1% bovine serum albumin in saline as vehicle, 0.8, 4.0 and 20.0 μg/kg body weight (BW) of bovine sulfated gastrin-34; (2) vehicle, 0.53 μg/kg BW of bovine sulfated gastrin-17 alone or combined with 20.0 μg/kg BW of [D-Lys(3)]-GHRP-6, the selective antagonist of GHS-R1a. Blood samples were collected from -10 to 150 min relative to injection time. Concentrations of acyl and total ghrelin in response to gastrin-34 injection were significantly increased in a dose-dependent manner. Concentrations of GH were also markedly elevated by gastrin-34 injection; however, the effect of 20.0 μg/kg was weaker than that of 4.0 μg/kg. The three doses of gastrin-34 equally decreased insulin levels within 15 min and maintained the level until the time of last sampling. Gastrin-34 had no effect (P > 0.05) on the levels of glucagon and glucose. Levels of acyl ghrelin increased after administration of gastrin-17 alone or combined with [D-Lys(3)]-GHRP-6; however, [D-Lys(3)]-GHRP-6 did not block the elevation of GH by gastrin-17. The present results indicate that sulfated gastrin stimulates both ghrelin and GH release, but the GHS-R1a may not contribute to the release of GH by gastrin. Moreover, sulfated gastrin seems to indirectly maintain the homeostasis of blood glucose through the down-regulation of insulin in ruminants.

  7. Purification and Cultivation of Human Pituitary Growth Hormones Secreting Cells

    Science.gov (United States)

    Hymer, W. C.; Todd, P.; Grindeland, R.; Lanham, W.; Morrison, D.

    1985-01-01

    The rat and human pituitary gland contains a mixture of hormone producing cell types. The separation of cells which make growth hormone (GH) is attempted for the purpose of understanding how the hormone molecule is made within the pituitary cell; what form(s) it takes within the cell; and what form(s) GH assumes as it leaves the cell. Since GH has a number of biological targets (e.g., muscle, liver, bone), the assessment of the activities of the intracellular/extracellular GH by new and sensitive bioassays. GH cells contained in the mixture was separated by free flow electrophoresis. These experiments show that GH cells have different electrophoretic mobilities. This is relevant to NASA since a lack of GH could be a prime causative factor in muscle atrophy. Further, GH has recently been implicated in the etiology of motion sickness in space. Continous flow electrophoresis experiment on STS-8 showed that GH cells could be partially separated in microgravity. However, definitive cell culture studies could not be done due to insufficient cell recoveries.

  8. GH and Pituitary Hormone Alterations After Traumatic Brain Injury.

    Science.gov (United States)

    Karaca, Züleyha; Tanrıverdi, Fatih; Ünlühızarcı, Kürşad; Kelestimur, Fahrettin

    2016-01-01

    Traumatic brain injury (TBI) is a crucially important public health problem around the world, which gives rise to increased mortality and is the leading cause of physical and psychological disability in young adults, in particular. Pituitary dysfunction due to TBI was first described 95 years ago. However, until recently, only a few papers have been published in the literature and for this reason, TBI-induced hypopituitarism has been neglected for a long time. Recent studies have revealed that TBI is one of the leading causes of hypopituitarism. TBI which causes hypopituitarism may be characterized by a single head injury such as from a traffic accident or by chronic repetitive head trauma as seen in combative sports including boxing, kickboxing, and football. Vascular damage, hypoxic insult, direct trauma, genetic predisposition, autoimmunity, and neuroinflammatory changes may have a role in the development of hypopituitarism after TBI. Because of the exceptional structure of the hypothalamo-pituitary vasculature and the special anatomic location of anterior pituitary cells, GH is the most commonly lost hormone after TBI, and the frequency of isolated GHD is considerably high. TBI-induced pituitary dysfunction remains undiagnosed and therefore untreated in most patients because of the nonspecific and subtle clinical manifestations of hypopituitarism. Treatment of TBI-induced hypopituitarism depends on the deficient anterior pituitary hormones. GH replacement therapy has some beneficial effects on metabolic parameters and neurocognitive dysfunction. Patients with TBI without neuroendocrine changes and those with TBI-induced hypopituitarism share the same clinical manifestations, such as attention deficits, impulsion impairment, depression, sleep abnormalities, and cognitive disorders. For this reason, TBI-induced hypopituitarism may be neglected in TBI victims and it would be expected that underlying hypopituitarism would aggravate the clinical picture of TBI

  9. IN VITRO CELL CULTURE AND HORMONE RADIOIMMUNOASSAY OF HUAMAN PITUITARY ADENOMAS

    Institute of Scientific and Technical Information of China (English)

    陆汉魁; 林祥通; 等

    1994-01-01

    Tissues from 30 human pituitary adenomas are monolayer-cell-cultured in vitro.Hormone secretion of GH,PRL,TSH,LH and FSH by cells into medium is detected by radioimmunoassay .The pattern and amount of hormone(s0 in the medium are used to determine the nature of the cells and thus to establish functional classification of pituitary adenomas.The results show that cell culture technique provides and easy and suitable mode for investigating the nature of pituitary adenomas.Hormone radioimmunoassay of culture medium is precise and reliable and represents the whole adenoma tissue.Further studies can lead to clearer understandngs of the pathology of pituitary adenomas.

  10. Identification of a novel pituitary-specific chicken gonadotropin-releasing hormone receptor and its splice variants.

    Science.gov (United States)

    Shimizu, Mamiko; Bédécarrats, Grégoy Y

    2006-11-01

    In all vertebrates, GnRH regulates gonadotropin secretion through binding to a specific receptor on the surface of pituitary gonadotropes. At least two forms of GnRH exist within a single species, and several corresponding GnRH receptors (GNRHRs) have been isolated with one form being pituitary specific. In chickens, only one type of widely expressed GNRHR has previously been identified. The objectives of this study were to isolate a chicken pituitary-specific GNRHR and to determine its expression pattern during a reproductive cycle. Using a combined strategy of PCR and rapid amplification of cDNA ends (RACE), a new GNRHR (chicken GNRHR2) and two splice variants were isolated in domestic fowl (Gallus gallus domesticus). Full-length GNRHR2 and one of its splice variant mRNAs were expressed exclusively in the pituitary, whereas mRNA of the other splice variant was expressed in most brain tissues examined. The deduced amino acid sequence of full-length chicken GNRHR2 reveals a seven transmembrane domain protein with 57%-65% homology to nonmammalian GNRHRs. Semiquantitative real-time PCR revealed that mRNA levels of full-length chicken GNRHR2 in the pituitary correlate with the reproductive status of birds, with maximum levels observed during the peak of lay and 4 wk postphotostimulation in females and males, respectively. Furthermore, GnRH stimulation of GH3 cells that were transiently transfected with cDNA that encodes chicken GNRHR2 resulted in a significant increase in inositol phosphate accumulation. In conclusion, we isolated a novel GNRHR and its splice variants in chickens, and spatial and temporal gene expression patterns suggest that this receptor plays an important role in the regulation of reproduction.

  11. GROWTH HORMONE-, ALPHA-SUBUNIT AND THYROTROPIN-COSECRETING PITUITARY-ADENOMA IN FAMILIAL SETTING OF PITUITARY-TUMOR

    NARCIS (Netherlands)

    LINKS, TP; MONKELBAAN, JF; DULLAART, RPF; VANHAEFTEN, TW

    1993-01-01

    A patient with acromegaly and hyperthyroidism due to a growth hormone-, thyrotrophin- and alpha-subunit-secreting pituitary adenoma is described. His deceased father had suffered from a pituitary tumour, and was likely to have had acromegaly as well. Plasma growth hormone and insulin-like growth fac

  12. Pituitary transplantation: Part 1. Successful reconstitution of pituitary-dependent hormone levels.

    Science.gov (United States)

    Tulipan, N B; Zacur, H A; Allen, G S

    1985-03-01

    Neonatal or adult pituitary glands were transplanted to the median eminence of adult rats of the same or a histoincompatible inbred strain. The hormonal status of 39 transplanted rats and of control animals was evaluated by serial determination of serum prolactin and thyroxine. Grafts of neonatal tissue to adults of the same strain resulted in normal postoperative hormone levels. This indicates not only that pituitary grafts had survived, but also that the transplants were under hypothalamic control. Grafts of adult tissue were less successful. The prolactin value was lower, but still within the normal range, whereas the thyroxine value was lower than normal, suggesting that viable pituitary tissue had survived but was not under hypothalamic control. Transplantation across a histocompatibility barrier was uniformly unsuccessful. Postoperative prolactin levels were low and thyroxine levels were not significantly different from those in hypophysectomized controls.

  13. Radiation therapy alone for growth hormone-producing pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Plataniotis, G.A.; Kouvaris, J.R.; Vlahos, L.; Papavasiliou, C. [Athens Univ. (Greece). Dept. of Radiology

    1998-09-01

    We present our experience in the treatment of growth hormone (GH)-producing pituitary adenomas using irradiation alone. Between 1983 and 1991, 21 patients suffering from GH-secreting pituitary adenomas were treated with radiotherapy alone. Two bilateral opposing coaxial fields were used in 10 patients and in the remaining 11 a third frontovertex field was added. Treatment was given in 1.8-2 Gy daily fractions and total dose ranged between 45 and 54 Gy. Treatment was given using a cobalt unit. Four patients treated with somatostatin prior to and 14 patients treated after the end of radiotherapy experienced symptom relief for 6-28 weeks. The 5-year actuarial rate of disease control was 72%. Five out of six failed patients had macroadenomas. Hypopituitarism was observed in 5/21 (24%) patients. Whereas RT alone is effective in the treatment of microadenomas, this is not true for large infiltrative macroadenomas. (orig.)

  14. Role of gonadotrophin releasing hormone baseline concentrations in the control of pituitary gonadotrophin and ovarian steroid secretion in the pseudopregnant rat

    NARCIS (Netherlands)

    Schuiling, GA; Valkhof, N; Koiter, TR

    1996-01-01

    To study the effect of moderately elevated gonadotrophin releasing hormone (GnRH) baseline concentrations during the luteal and the follicular phase, pseudopregnant rats were infused s.c. with GnRH at several doses for 5 days, These rats were also treated with oestradiol or sham-treated during the l

  15. Multiple-scale neuroendocrine signals connect brain and pituitary hormone rhythms

    Science.gov (United States)

    Romanò, Nicola; Guillou, Anne; Martin, Agnès O; Mollard, Patrice

    2017-01-01

    Small assemblies of hypothalamic “parvocellular” neurons release their neuroendocrine signals at the median eminence (ME) to control long-lasting pituitary hormone rhythms essential for homeostasis. How such rapid hypothalamic neurotransmission leads to slowly evolving hormonal signals remains unknown. Here, we show that the temporal organization of dopamine (DA) release events in freely behaving animals relies on a set of characteristic features that are adapted to the dynamic dopaminergic control of pituitary prolactin secretion, a key reproductive hormone. First, locally generated DA release signals are organized over more than four orders of magnitude (0.001 Hz–10 Hz). Second, these DA events are finely tuned within and between frequency domains as building blocks that recur over days to weeks. Third, an integration time window is detected across the ME and consists of high-frequency DA discharges that are coordinated within the minutes range. Thus, a hierarchical combination of time-scaled neuroendocrine signals displays local–global integration to connect brain–pituitary rhythms and pace hormone secretion. PMID:28193889

  16. Familial growth hormone releasing factor deficiency in pseudopseudohypoparathyroidism.

    OpenAIRE

    Stirling, H F; Barr, D G; Kelnar, C J

    1991-01-01

    A mother with pseudopseudohypoparathyroidism and her short son showed poor spontaneous growth hormone secretion, and provocation tests suggested a deficiency of growth hormone releasing factor. This is the first report of growth hormone releasing factor deficiency in pseudopseudohypoparathyroidism. The boy has responded well to growth hormone treatment over a period of three years.

  17. Pituitary binding and internalization of radioiodinated gonadotropin-releasing hormone agonist and antagonist ligands in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wynn, P.C.; Suarez-Quian, C.A.; Childs, G.V.; Catt, K.J.

    1986-10-01

    In rat pituitary gonadotrophs, the rates of binding and endocytosis of two GnRH superagonist analogs, (D-Ala6,Pro9-NEt)GnRH and (D-Lys6,Pro9-NEt)GnRH, were compared with those of the potent antagonist analog (N-acetyl-D-pCl-Phe1,2,D-Trp3,D-Lys6,D-Ala10)GnRH by quantitative electron microscopic autoradiography. In dispersed pituitary cells, the two agonist analogs showed similar binding kinetics and comparable degrees of sequestration, as measured by their resistance to dissociation by low pH buffer. However, quantification of silver grain localization suggested that cellular internalization of the (D-Ala6)GnRH agonist increased more rapidly than that of the (D-Lys6)GnRH analog. These discrepancies, and the finding that a larger amount of the specifically bound /sup 125/I-(D-Ala6)GnRH agonist was removed during glutaraldehyde fixation, indicated that the proportional internalization of this analog was over estimated by quantitative autoradiography owing to loss of cell surface-bound radioligand. We, therefore, employed radioiodinated D-Lys6-substituted analogs to analyze the receptor binding and cellular uptake of GnRH agonist and antagonist derivatives in vivo. After iv injection, a high proportion of the /sup 125/I-(D-Lys6)GnRH agonist was translocated into pituitary gonadotrophs within 60 min, whereas the D-Lys6 antagonist was predominantly associated with the plasma membrane during that time. Four hours after injection of the antagonist, an appreciable proportion of silver grains was associated with intracellular organelles, and this trend increased progressively at later time points. The relatively prolonged cellular processing of the GnRH antagonist is consistent with in vivo binding kinetics, and its slower internalization may reflect the basal rate of GnRH receptor turnover in the cell membrane.

  18. Metabolism of growth hormone releasing peptides.

    Science.gov (United States)

    Thomas, Andreas; Delahaut, Philippe; Krug, Oliver; Schänzer, Wilhelm; Thevis, Mario

    2012-12-04

    New, potentially performance enhancing compounds have frequently been introduced to licit and illicit markets and rapidly distributed via worldwide operating Internet platforms. Developing fast analytical strategies to follow these new trends is one the most challenging issues for modern doping control analysis. Even if reference compounds for the active drugs are readily obtained, their unknown metabolism complicates effective testing strategies. Recently, a new class of small C-terminally amidated peptides comprising four to seven amino acid residues received considerable attention of sports drug testing authorities due to their ability to stimulate growth hormone release from the pituitary. The most promising candidates are the growth hormone releasing peptide (GHRP)-1, -2, -4, -5, -6, hexarelin, alexamorelin, and ipamorelin. With the exemption of GHRP-2, the entity of these peptides represents nonapproved pharmaceuticals; however, via Internet providers, all compounds are readily available. To date, only limited information on the metabolism of these substances is available and merely one metabolite for GHRP-2 is established. Therefore, a comprehensive in vivo (po and iv administration in rats) and in vitro (with human serum and recombinant amidase) study was performed in order to generate information on urinary metabolites potentially useful for routine doping controls. The urine samples from the in vivo experiments were purified by mixed-mode cation-exchange solid-phase extraction and analyzed by ultrahigh-performance liquid chromatography (UHPLC) separation followed by high-resolution/high-accuracy mass spectrometry. Combining the high resolution power of a benchtop Orbitrap mass analyzer for the first metabolite screening and the speed of a quadrupole/time-of-flight (Q-TOF) instrument for identification, urinary metabolites were screened by means of a sensitive full scan analysis and subsequently confirmed by high-accuracy product ion scan experiments. Two

  19. Ectopic Adrenocorticotropic Hormone-Secreting Pituitary Adenomas: An Underestimated Entity.

    Science.gov (United States)

    Knappe, Ulrich J; Jaspers, Christian; Buschsieweke, Desirée; Reinbold, Wolf-Dieter; Alomari, Ali; Saeger, Wolfgang; Ehlenz, Klaus; Mann, W Alexander; Kann, Peter Herbert; Feldkamp, Joachim

    2017-04-01

    The diagnosis of Cushing disease is based on endocrinological pa-rameters, with no single test being specific. In some patients, dynamic thin-slice sellar magnetic resonance imaging fails to detect a pituitary tumor. The purpose of this study is to investigate the role of ectopic pituitary adenoma in this situation. In a retrospective chart review, 5 patients (6%) with ectopic adenomas were identified in 83 consecutive patients undergoing transsphenoidal surgery for adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas by 1 surgeon. In all 5 patients (all female, 32-41 years of age), an exclusively extrasellar ACTH-secreting adenoma was excised. Three adenomas were located in the cavernous sinus, 1 in the sphenoid sinus, and 1 in the ethmoidal cells. Histologically, none of the tumors showed signs of aggressiveness. Three of the 5 adenomas specifically expressed somatostatin receptor 5. In 4 patients with Cushing disease, postoperative remission was obtained, with 1 recurrence after 14 months. In the patient with Nelson syndrome, ACTH decreased from >800 to ectopic adenoma (positive for somatostatin receptor 5) in the ethmoidal cells turned out to be positive on gallium 68 DOTATATE positron emission tomography/computed tomography. The incidence of primarily ectopic ACTH-secreting adenomas in this series was 6%. In cases of negative MRI findings, an ectopic ACTH-secreting adenoma should be taken into account. 68 Ga DOTATATE positron emission tomography/computed tomography may identify ectopic pituitary adenomas. Hypophysectomy should always be avoided in primary surgery for CD.

  20. contribution of growth hormone-releasing hormone and ...

    African Journals Online (AJOL)

    hormone (GHRH) and increased somatostatin secretion to this phenomenon. ... negative feedback effects of IGF-1 or combinations of these factors. Studies to ..... increase in lean body mass and reduction in adipose tissue.6. Reduced GH ...

  1. Dual pathways of calcium entry in spike and plateau phases of luteinizing hormone release from chicken pituitary cells: sequential activation of receptor-operated and voltage-sensitive calcium channels by gonadotropin-releasing hormone

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J.S.; Wakefield, I.K.; King, J.A.; Mulligan, G.P.; Millar, R.P.

    1988-04-01

    It has previously been shown that, in pituitary gonadotrope cells, the initial rise in cytosolic Ca2+ induced by GnRH is due to a Ca2+ mobilization from intracellular stores. This raises the possibility that the initial transient spike phase of LH release might be fully or partially independent of extracellular Ca2+. We have therefore characterized the extracellular Ca2+ requirements, and the sensitivity to Ca2+ channel blockers, of the spike and plateau phases of secretion separately. In the absence of extracellular Ca2+ the spike and plateau phases were inhibited by 65 +/- 4% and 106 +/- 3%, respectively. Both phases exhibited a similar dependence on concentration of extracellular Ca2+. However, voltage-sensitive Ca2+ channel blockers D600 and nifedipine had a negligible effect on the spike phase, while inhibiting the plateau phase by approximately 50%. In contrast, ruthenium red, Gd3+ ions, and Co2+ ions inhibited both spike and plateau phases to a similar extent as removal of extracellular Ca2+. A fraction (35 +/- 4%) of spike phase release was resistant to removal of extracellular Ca2+. This fraction was abolished after calcium depletion of the cells by preincubation with EGTA in the presence of calcium ionophore A23187, indicating that it depends on intracellular Ca2+ stores. Neither absence of extracellular Ca2+, nor the presence of ruthenium red or Gd3+ prevented mobilization of 45Ca2+ from intracellular stores by GnRH. We conclude that mobilization of intracellular stored Ca2+ is insufficient by itself to account for full spike phase LH release.

  2. Growth hormone release from chicken anterior pituitary cells in primary culture: TRH and hpGRF synergy, protein synthesis, and cyclic adenosine 3'5'-monophosphate.

    Science.gov (United States)

    Perez, F M; Malamed, S; Scanes, C G

    1989-01-01

    Our earlier work showed that the effects of thyrotropin-releasing hormone (TRH) and human pancreatic growth hormone-releasing factor (hpGRF) on growth hormone (GH) release are synergistic (greater than additive) in a primary culture of chicken adenohypophyseal cells. The purpose of the present studies was to investigate the possible participation of protein synthesis and cyclic adenosine 3'5'-monophosphate (cAMP) in GH release. Following culture (48 hr), cells were incubated for 2 hr with test agents. Cycloheximide (an inhibitor of protein synthesis) had no effect on basal (absence of test agent) GH release or hpGRF-induced GH release. However, cycloheximide abolished the synergy between TRH and hpGRF. Although neither TRH nor hpGRF alone stimulated GH production (intracellular GH plus GH release) during a 2-hr incubation period, in combination these secretagogues increased total GH. These findings suggest that GH release from the chicken somatotroph under conditions of TRH and hpGRF synergy requires protein synthesis. In other studies, cells were exposed to agents inducing the formation of cAMP and either TRH or hpGRF. 8 Br-cAMP (10(-3) M), forskolin (10(-6) M), or isobutylmethylxanthine (IBMX; 10(-3) M) alone stimulated GH release to values between 30 and 50% over the basal value. The combined effects of each of these agents and TRH on GH release were synergistic. Similarly, IBMX and hpGRF exerted synergistic effects on GH release. In contrast, no synergy was shown between hpGRF and either 8 Br-cAMP or forskolin; their combined actions were less than additive.

  3. Reevaluation of the electrophysiological actions of thyrotropin-releasing hormone in a rat pituitary cell line (GH3).

    Science.gov (United States)

    Simasko, S M

    1991-04-01

    The electrophysiological actions of TRH were examined in the clonal pituitary cell line GH3 with the use of the perforated patch variation of the standard whole cell patch-clamp technique. The action of TRH on spontaneously spiking cells was to cause a brief hyperpolarization (first phase action), followed by a period during which action potential behavior was significantly modified (second phase action). The modifications during second phase action included a reduction in the slope of the up-stroke, a reduced peak potential, an increase in duration, and a depolarizing shift of the after-hyperpolarization. The modification of voltage- and calcium-dependent conductances that underlie these changes were investigated in voltage clamp experiments. During first phase action TRH was found to increase calcium-dependent potassium current. During second phase action TRH was found to significantly reduce the L-type calcium current (35%), with no alteration in the T-type calcium current. The second phase action of TRH on calcium-dependent potassium conductance was complex. First, a decrease was observed. This was followed by an increase that did not become fully manifest until after TRH was washed from the cell. TRH caused no change in voltage-dependent potassium current. These results indicate that the second phase action of TRH on action potential behavior in GH3 cells is mediated by a reduction in L-type calcium current and alterations in the behavior of calcium-dependent potassium currents, but not through changes in voltage-dependent potassium currents.

  4. HPG-axis hormones during puberty : A study on the association with hypothalamic and pituitary volumes

    NARCIS (Netherlands)

    Peper, Jiska S.; Brouwer, Rachel M.; van Leeuwen, Marieke; Schnack, Hugo G.; Boomsma, Dorret I.; Kahn, Rene S.; Pol, Hilleke E. Hulshoff

    2010-01-01

    Objective: During puberty, the hypothalamus-pituitary-gonadal (HPG) axis is activated, leading to increases in luteinizing hormone (LH), follicle stimulating hormone (FSH) and sex steroids (testosterone and estradiol) levels. We aimed to study the association between hypothalamic and pituitary volum

  5. AN INVESTIGATION ON THE LUTEINIZING HORMONE STORAGE AND ITS RELEASE IN RAT PITUITARY GONADOTROPHS WITH IMMUNOCYTOCHEMICAL METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHOUShou-Kang; XIEZhong-Ming; DAIMao-Zhong

    1989-01-01

    The aim of this immanocytochcmical study is to determine the morphological changes of gonadotrophs during different phases of estrous cycle in female rats and after trealment with LH-RH in male rats. The morphological changes observed were in c1ose relationship with LH storage and its release.

  6. Review: Gonadotropin-inhibitory hormone action in the brain and pituitary

    Directory of Open Access Journals (Sweden)

    Takayoshi eUbuka

    2012-11-01

    Full Text Available Gonadotropin-inhibitory hormone (GnIH was first identified in the Japanese quail as a hypothalamic neuropeptide inhibitor of gonadotropin secretion. Subsequent studies have shown that GnIH is present in the brains of birds including songbirds, and mammals including humans. The identified avian and mammalian GnIH peptides universally possess an LPXRFamide (X = L or Q motif at their C-termini. Mammalian GnIH peptides are also designated as RFamide-related peptides from their structures. The receptor for GnIH is the G protein-coupled receptor 147 (GPR147, which is thought to be coupled to Gαi protein. Cell bodies of GnIH neurons are located in the paraventricular nucleus (PVN in birds and the dorsomedial hypothalamic area (DMH in mammals. GnIH neurons in the PVN or DMH project to the median eminence to control anterior pituitary function. GPR147 is expressed in the gonadotropes and GnIH suppresses synthesis and release of gonadotropins. It was further shown in immortalized mouse gonadotrope cell line (LT2 cells that GnIH inhibits gonadotropin-releasing hormone (GnRH induced gonadotropin subunit gene transcriptions by inhibiting adenylate cyclase/cAMP/PKA dependent ERK pathway. GnIH neurons also project to GnRH neurons in the preoptic area, and GnRH neurons express GPR147 in birds and mammals. Accordingly, GnIH may inhibit gonadotropin synthesis and release by decreasing the activity of GnRH neurons as well as directly acting on the gonadotropes. GnIH also inhibits reproductive behavior possibly by acting within the brain. GnIH expression is regulated by a nocturnal hormone melatonin and stress in birds and mammals. Accordingly, GnIH may play a role in translating environmental information to inhibit reproductive physiology and behavior of birds and mammals. Finally, GnIH has therapeutic potential in the treatment of reproductive cycle and hormone-dependent diseases, such as precocious puberty, endometriosis, uterine fibroids, and prostatic and

  7. Mid-pregnancy corticotropin-releasing hormone levels in association with postpartum depressive symptoms

    NARCIS (Netherlands)

    Iliadis, Stavros I; Sylvén, Sara; Hellgren, Charlotte; Olivier, Jocelien D.; Schijven, Dick; Comasco, Erika; Chrousos, George P; Sundström Poromaa, Inger; Skalkidou, Alkistis

    2016-01-01

    BACKGROUND: Peripartum depression is a common cause of pregnancy- and postpartum-related morbidity. The production of corticotropin-releasing hormone (CRH) from the placenta alters the profile of hypothalamus-pituitary-adrenal axis hormones and may be associated with postpartum depression. The purpo

  8. Adipokines (Leptin, Adiponectin, Resistin) Differentially Regulate All Hormonal Cell Types in Primary Anterior Pituitary Cell Cultures from Two Primate Species.

    Science.gov (United States)

    Sarmento-Cabral, André; Peinado, Juan R; Halliday, Lisa C; Malagon, María M; Castaño, Justo P; Kineman, Rhonda D; Luque, Raúl M

    2017-03-06

    Adipose-tissue (AT) is an endocrine organ that dynamically secretes multiple hormones, the adipokines, which regulate key physiological processes. However, adipokines and their receptors are also expressed and regulated in other tissues, including the pituitary, suggesting that locally- and AT-produced adipokines might comprise a regulatory circuit that relevantly modulate pituitary cell-function. Here, we used primary pituitary cell-cultures from two normal nonhuman-primate species [Papio-anubis/Macaca-fascicularis] to determine the impact of different adipokines on the functioning of all anterior-pituitary cell-types. Leptin and resistin stimulated GH-release, a response that was blocked by somatostatin. Conversely, adiponectin decreased GH-release, and inhibited GHRH-, but not ghrelin-stimulated GH-secretion. Furthermore: 1) Leptin stimulated PRL/ACTH/FSH- but not LH/TSH-release; 2) adiponectin stimulated PRL-, inhibited ACTH- and did not alter LH/FSH/TSH-release; and 3) resistin increased ACTH-release and did not alter PRL/LH/FSH/TSH-secretion. These effects were mediated through the activation of common (AC/PKA) and distinct (PLC/PKC, intra-/extra-cellular calcium, PI3K/MAPK/mTOR) signaling-pathways, and by the gene-expression regulation of key receptors/transcriptional-factors involved in the functioning of these pituitary cell-types (e.g. GHRH/ghrelin/somatostatin/insulin/IGF-I-receptors/Pit-1). Finally, we found that primate pituitaries expressed leptin/adiponectin/resistin. Altogether, these and previous data suggest that local-production of adipokines/receptors, in conjunction with circulating adipokine-levels, might comprise a relevant regulatory circuit that contribute to the fine-regulation of pituitary functions.

  9. Antimüllerian hormone in gonadotropin releasing-hormone antagonist cycles

    DEFF Research Database (Denmark)

    Arce, Joan-Carles; La Marca, Antonio; Mirner Klein, Bjarke

    2013-01-01

    To assess the relationships between serum antimüllerian hormone (AMH) and ovarian response and treatment outcomes in good-prognosis patients undergoing controlled ovarian stimulation using a gonadotropin-releasing hormone (GnRH) antagonist protocol.......To assess the relationships between serum antimüllerian hormone (AMH) and ovarian response and treatment outcomes in good-prognosis patients undergoing controlled ovarian stimulation using a gonadotropin-releasing hormone (GnRH) antagonist protocol....

  10. Postoperative pituitary hormonal disturbances and hormone replacement therapy time and dosage in children with craniopharyngiomas

    Institute of Scientific and Technical Information of China (English)

    LI Gui-mei; SUN Xiao-jun; SHAO Peng

    2008-01-01

    BackgroundThe proliferative activity and penetration into the hypothalamic structures in children craniopharyngiomas (CP) often make radical resection difficult. Therefore, complete resection of CP often results in permanent multiple pituitary hormone deficiency (MPHD). This study aimed to elucidate the postoperative pituitary hormonal disturbances, and hormone replacement therapy (HRT) time and dosage in children with CP.Methods Twenty patients with growth retardation and CP after resection, comprising 14 boys and 6 girls, with a mean age of (10.63 3.18) years (Group A) and 10 male patients of group A aged >10 years (Group B) were entailed. Thirty age-, sex- and Tanner stage-matched normal children (control Group A), and 44 male older children >10 years (control Group B) served as controls. The serum concentrations of insulin-like growth factor-1 (IGF-1), growth hormone (GH), free thyroxine (FT4), thyroid-stimulating hormone (TSH), adrenocorticortropic hormone (ACTH), cortisol (COR), follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), testosterone (T) and estradiol (E2) were measured in the CP patients after resection and in controls. The appropriate time and dosage of HRT were investigated. Linear correlation analysis was made between levothyroxine (L-T4) dosage and primary FT4 in CP patients after resection. Results All cases had MPHD. The serum peak GH, IGF-1, FT4 and COR levels of Group A were significantly lower than that of the control Group A. The serum IGF-1 concentration increased to the normal level after 3 months of rhGH therapy; the serum FSH, LH, and T levels were significantly decreased (P <0.001); however, E2 and PRL were significantly increased (P <0.001) in Group B compared with the control Group B; 18 cases were found to have central diabetes insipidus (Dl) by water deprivation test and MRI. There was a significant negative linear regression (r= -0.8, P <0.001) between L-T4 and primary FT4 in Group A patients with CP

  11. Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

    Science.gov (United States)

    Gosselink, K. L.; Grindeland, R. E.; Roy, R. R.; Zhong, H.; Bigbee, A. J.; Grossman, E. J.; Edgerton, V. R.

    1998-01-01

    There are forms of growth hormone (GH) in the plasma and pituitary of the rat and in the plasma of humans that are undetected by presently available immunoassays (iGH) but can be measured by bioassay (bGH). Although the regulation of iGH release is well documented, the mechanism(s) of bGH release is unclear. On the basis of changes in bGH and iGH secretion in rats that had been exposed to microgravity conditions, we hypothesized that neural afferents play a role in regulating the release of these hormones. To examine whether bGH secretion can be modulated by afferent input from skeletal muscle, the proximal or distal ends of severed hindlimb fast muscle nerves were stimulated ( approximately 2 times threshold) in anesthetized rats. Plasma bGH increased approximately 250%, and pituitary bGH decreased approximately 60% after proximal nerve trunk stimulation. The bGH response was independent of muscle mass or whether the muscles were flexors or extensors. Distal nerve stimulation had little or no effect on plasma or pituitary bGH. Plasma iGH concentrations were unchanged after proximal nerve stimulation. Although there may be multiple regulatory mechanisms of bGH, the present results demonstrate that the activation of low-threshold afferents from fast skeletal muscles can play a regulatory role in the release of bGH, but not iGH, from the pituitary in anesthetized rats.

  12. Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

    Science.gov (United States)

    Gosselink, K. L.; Grindeland, R. E.; Roy, R. R.; Zhong, H.; Bigbee, A. J.; Grossman, E. J.; Edgerton, V. R.

    1998-01-01

    There are forms of growth hormone (GH) in the plasma and pituitary of the rat and in the plasma of humans that are undetected by presently available immunoassays (iGH) but can be measured by bioassay (bGH). Although the regulation of iGH release is well documented, the mechanism(s) of bGH release is unclear. On the basis of changes in bGH and iGH secretion in rats that had been exposed to microgravity conditions, we hypothesized that neural afferents play a role in regulating the release of these hormones. To examine whether bGH secretion can be modulated by afferent input from skeletal muscle, the proximal or distal ends of severed hindlimb fast muscle nerves were stimulated ( approximately 2 times threshold) in anesthetized rats. Plasma bGH increased approximately 250%, and pituitary bGH decreased approximately 60% after proximal nerve trunk stimulation. The bGH response was independent of muscle mass or whether the muscles were flexors or extensors. Distal nerve stimulation had little or no effect on plasma or pituitary bGH. Plasma iGH concentrations were unchanged after proximal nerve stimulation. Although there may be multiple regulatory mechanisms of bGH, the present results demonstrate that the activation of low-threshold afferents from fast skeletal muscles can play a regulatory role in the release of bGH, but not iGH, from the pituitary in anesthetized rats.

  13. A retrospective review of pituitary MRI findings in children on growth hormone therapy

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Sarah L.; Lawrence, Sarah [University of Ottawa, Division of Endocrinology, Children' s Hospital of Eastern Ontario, Ottawa (Canada); Laffan, Eoghan [Children' s University Hospital, Pediatric Radiology, Dublin 1 (Ireland)

    2012-07-15

    Patients with congenital hypopituitarism might have the classic triad of pituitary stalk interruption syndrome, which consists of: (1) an interrupted or thin pituitary stalk, (2) an absent or ectopic posterior pituitary (EPP), and (3) anterior pituitary hypoplasia or aplasia. To examine the relationship between pituitary anatomy and the degree of hormonal dysfunction. This study involved a retrospective review of MRI findings in all children diagnosed with congenital growth hormone deficiency from 1988 to 2010 at a tertiary-level pediatric hospital. Of the 52 MRIs reviewed in 52 children, 26 children had normal pituitary anatomy and 26 had one or more elements of the classic triad. Fourteen of fifteen children with multiple pituitary hormone deficiencies had structural anomalies on MRI. Twelve of 37 children with isolated growth hormone deficiency had an abnormal MRI. Children with multiple pituitary hormone deficiencies were more likely to have the classic triad than children with isolated growth hormone deficiency. A normal MRI was the most common finding in children with isolated growth hormone deficiency. (orig.)

  14. Arg-Phe-amide-related peptides influence gonadotropin-releasing hormone neurons

    Institute of Scientific and Technical Information of China (English)

    Haluk Kelestimur; Emine Kacar; Aysegul Uzun; Mete Ozcan; Selim Kutlu

    2013-01-01

    The hypothalamic Arg-Phe-amide-related peptides, gonadotropin-inhibitory hormone and orthologous mammalian peptides of Arg-Phe-amide, may be important regulators of the hypothalamus-pituitary-gonadal reproductive axis. These peptides may modulate the effects of kisspeptins because they are presently recognized as the most potent activators of the hypothalamus-pituitary-gonadal axis. However, their effects on gonadotropin-releasing hormone neurons have not been investigated. In the current study, the GT1–7 cell line-expressing gonadotropin-releasing hormone was used as a model to explore the effects of Arg-Phe- amide-related peptides on kisspeptin activation. Intracellular calcium concentration was quantified using the calcium-sensitive dye, fura-2 acetoxymethyl ester. Gonadotropin-releasing hormone released into the medium was detected via enzyme-linked immunosorbent assay. Results showed that 100 nmol/L kisspeptin-10 significantly increased gonadotropin-releasing hormone levels (at 120 minutes of exposure) and intracellular calcium concentrations. Co-treatment of kisspeptin with 1 μmol/L gonadotropin-inhibitory hormone or 1 μmol/L Arg-Phe-amide-related peptide-1 significantly attenuated levels of kisspeptin-induced gonadotropin-releasing hormone but did not affect kisspeptin-induced elevations of intracellular calcium concentration. Overall, the results suggest that gonadotropin-inhibitory hormone and Arg-Phe-amide-related peptide-1 may have inhibitory effects on kisspeptin-activated gonadotropin-releasing hormone neurons independent of the calcium signaling pathway.

  15. Giant growth-hormone secreting pituitary tumour with etracranial extension

    Energy Technology Data Exchange (ETDEWEB)

    Ip Taipang; Chan Fuluk; Kung Annie Waichee; Lam Karen Siuling [Univ. of Hong Kong, Queen Mary Hospital (Hong Kong). Depts. of Medicine and Diagnostic Radiology

    1996-02-01

    A 19 year old female patient with typical features of acromegaly was found to have an extensive pituitary tumour with suprasellar, lateral and inferior extensions. Magnetic resonance imaging (MRI) also showed a portion of the tumour extending from the right cavernous sinus through the foramen ovale to become extracranial. Serum growth hormone (GH) was 52.6 mU/L basally and remained elevated after oral glucose, confirming the diagnosis of acromegaly. Treatment with the long-acting somatostatin analogue, octreotide, for 6 months led to a 30% reduction in tumour volume of the intracranial portion but no effect on the extracranial and sphenoidal extensions. She was subsequently treated with trans-sphenoidal surgery followed by external irradiation. The possibility of perineural spread of the tumour was considered. 9 refs., 1 tab., 1 fig.

  16. MRI of pituitary macroadenomas with reference to hormonal activity

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, P.; Nyman, R. (Akademiska Sjukhuset, Uppsala (Sweden). Dept. of Diagnostic Radiology); Burmann, P. (Akademiska Sjukhuset, Uppsala (Sweden). Dept. of Internal Medicine); Lundberg, P.O. (Akademiska Sjukhuset, Uppsala (Sweden). Dept. of Neurology)

    1992-02-01

    In 115 patients with pituitary macroadenomas, the findings on mid-field MRI were correlated with the hormonal activity of the tumours. Adenomas secreting growth hormone (GH), prolactin (PRL) and clinically nonsecretory adenomas were studied. Tumour size, invasiveness and signal intensity patterns were recorded. Relaxation times and ratios of signal intensity and proton density (relative to the corpus callosum) were analysed in areas of apparently solid tissue in a subgroup of 59 previously untreated patients. Invasiveness was more common in PRL- and GH-secreting adenomas than in the nonsecreting ones. Diffuse invasion of the base of the skull was most common in prolactinomas, and associated with a lower frequency of suprasellar tumour extension. In prolactinomas, a correlation was found between the maximum serum PRL level and tumour size. Haemorrhagic, cystic or necrotic areas were less common in GH-secreting tumours than in the other types. Haemorrhage was more common in prolactinomas than in nonsecreting tumours. MR parameters were similar in prolactinomas and nonsecreting adenomas, but indicated a smaller amount of water in GH-secreting tumours. (orig.).

  17. Hormonal contraception for human males: prospects

    Institute of Scientific and Technical Information of China (English)

    P.R.K.Reddy

    2000-01-01

    Development of an ideal hormonal contraceptive for man has been the goal of several research workers during the past few decades. Suppression of pituitary gonadotropic hormones, which in turn would inhibit spermatogenesis while maintaining normal libido and potentia has been the approach for a contraceptive agent. Intramuscularly administered and orally active testosterone or testosterone in combination with progesterone have been shown to cause inhibition of spermatogenesis resulting in azoospermia in normal men. Similarly testosterone has been used in combination with gonadotropin releasing hormone antagonists and agonists to inhibit pituitary gonadotropic hormone release. Immunological approach to neutralize the circulating levels of follicle stimulating hormone has also been shown to cause inhibition of spermatogenesis. The available literature shows that testosterone causes reversible azoospermia without any significant side effects in Asian population effectively and appears to be a promising chemical for control of fertility in man.( Asian J Androl 2000 ; 2 : 46 - 50 )

  18. Luteinizing hormone-releasing hormone receptor antagonist may reduce postmenopausal flushing

    NARCIS (Netherlands)

    Gastel, P. van; Zanden, M. van der; Telting, D.; Filius, M.; Bancsi, L.; Boer, H. de

    2012-01-01

    OBJECTIVE: Hormone therapy (HT) is the most effective treatment of postmenopausal (PMP) flushing; however, its use is often contraindicated. As an alternative option, we explored the efficacy of the luteinizing hormone-releasing hormone (LHRH) receptor antagonist cetrorelix in women with severe PMP

  19. Psychosocial stress inhibits amplitude of gonadotropin-releasing hormone pulses independent of cortisol action on the type II glucocorticoid receptor.

    Science.gov (United States)

    Wagenmaker, Elizabeth R; Breen, Kellie M; Oakley, Amy E; Tilbrook, Alan J; Karsch, Fred J

    2009-02-01

    Our laboratory has developed a paradigm of psychosocial stress (sequential layering of isolation, blindfold, and predator cues) that robustly elevates cortisol secretion and decreases LH pulse amplitude in ovariectomized ewes. This decrease in LH pulse amplitude is due, at least in part, to a reduction in pituitary responsiveness to GnRH, caused by cortisol acting via the type II glucocorticoid receptor (GR). The first experiment of the current study aimed to determine whether this layered psychosocial stress also inhibits pulsatile GnRH release into pituitary portal blood. The stress paradigm significantly reduced GnRH pulse amplitude compared with nonstressed ovariectomized ewes. The second experiment tested if this stress-induced decrease in GnRH pulse amplitude is mediated by cortisol action on the type II GR. Ovariectomized ewes were allocated to three groups: nonstress control, stress, and stress plus the type II GR antagonist RU486. The layered psychosocial stress paradigm decreased GnRH and LH pulse amplitude compared with nonstress controls. Importantly, the stress also lowered GnRH pulse amplitude to a comparable extent in ewes in which cortisol action via the type II GR was antagonized. Therefore, we conclude that psychosocial stress reduces the amplitude of GnRH pulses independent of cortisol action on the type II GR. The present findings, combined with our recent observations, suggest that the mechanisms by which psychosocial stress inhibits reproductive neuroendocrine activity at the hypothalamic and pituitary levels are fundamentally different.

  20. Action of luteinizing hormone-releasing hormone in rat ovarian cells: Hormone production and signal transduction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian.

    1989-01-01

    The present study was conducted to investigate the hypothesis that the breakdown of membrane phosphoinositides may participate in the actions of luteinizing hormone-releasing hormone (LHRH) on hormone production in rat granulosa cells. In cells prelabeled with ({sup 3}H)inositol or ({sup 3}H)arachidonic acid (AA), treatment with LHRH increased the formation of radiolabeled inositol 1,4,5-trisphosphate (IP{sub 3}) and diacylglycerol (DG), and the release of radiolabeled AA. Since IP{sub 3} induces intracellular Ca{sup 2+} mobilization, changes in the cytosolic free calcium ion concentrations ((Ca{sup 2+})i) induced by LHRH were studied in individual cells using fura-2 microspectrofluorimetry. Alterations in (Ca{sup 2+})i induced by LHRH were rapid and transient, and could be completely blocked by a LHRH antagonist. Sustained perifusion of LHRH resulted in a desensitization of the (Ca{sup 2+})i response to LHRH. LHRH treatment accelerated (Ca{sup 2+})i depletion in the cells perifused with Ca{sup 2+} free medium, indicating the involvement of intracellular Ca{sup 2+} pool(s) in (Ca{sup 2+})i changes. The actions of LHRH on the regulation of progesterone (P{sub 4}) and prostaglandin E{sub 2} (PGE{sub 2}) production were also examined. LHRH increased basal P{sub 4} production and attenuated FSH induced P{sub 4} production. Both basal and FSH stimulated PGE{sub 2} formation were increased by LHRH. Since LHRH also increased the formation of DG that stimulates the activity of protein kinase C, an activator of protein kinase C (12-0-tetradecanolyphorbol-13-acetate: TPA) was used with the Ca{sup 2+} ionophore A23187 and melittin (an activator of phospholipase A{sub 2}) to examine the roles of protein kinase C, Ca{sup 2+} and free AA, respectively, in LHRH action.

  1. Acceleration of wound healing by growth hormone-releasing hormone and its agonists

    OpenAIRE

    Dioufa, Nikolina; Schally, Andrew V.; Chatzistamou, Ioulia; Moustou, Evi; Block, Norman L.; Owens, Gary K.; Papavassiliou, Athanasios G; Kiaris, Hippokratis

    2010-01-01

    Despite the well-documented action of growth hormone-releasing hormone (GHRH) on the stimulation of production and release of growth hormone (GH), the effects of GHRH in peripheral tissues are incompletely explored. In this study, we show that GHRH plays a role in wound healing and tissue repair by acting primarily on wound-associated fibroblasts. Mouse embryonic fibroblasts (MEFs) in culture and wound-associated fibroblasts in mice expressed a splice variant of the receptors for GHRH (SV1). ...

  2. High-Cholesterol Diet Disrupts the Levels of Hormones Derived from Anterior Pituitary Basophilic Cells.

    Science.gov (United States)

    Yang, J; Zhang, X; Liu, Z; Yuan, Z; Song, Y; Shao, S; Zhou, X; Yan, H; Guan, Q; Gao, L; Zhang, H; Zhao, J

    2016-03-01

    Emerging evidence shows that elevated cholesterol levels are detrimental to health. However, it is unclear whether there is an association between cholesterol and the pituitary. We investigated the effects of a high-cholesterol diet on pituitary hormones using in vivo animal studies and an epidemiological study. In the animal experiments, rats were fed a high-cholesterol or control diet for 28 weeks. In rats fed the high-cholesterol diet, serum levels of thyroid-stimulating hormone (TSH; also known as thyrotrophin), luteinising hormone (LH) and follicle-stimulating hormone (FSH) produced by the basophilic cells of the anterior pituitary were elevated in a time-dependent manner. Among these hormones, TSH was the first to undergo a significant change, whereas adrenocorticotrophic hormone (ACTH), another hormone produced by basophilic cells, was not changed significantly. As the duration of cholesterol feeding increased, cholesterol deposition increased gradually in the pituitary. Histologically, basophilic cells, and especially thyrotrophs and gonadotrophs, showed an obvious increase in cell area, as well as a potential increase in their proportion of total pituitary cells. Expression of the β-subunit of TSH, FSH and LH, which controls hormone specificity and activity, exhibited a corresponding increase. In the epidemiological study, we found a similar elevation of serum TSH, LH and FSH and a decrease in ACTH in patients with hypercholesterolaemia. Significant positive correlations existed between serum total cholesterol and TSH, FSH or LH, even after adjusting for confounding factors. Taken together, the results of the present study suggest that the high-cholesterol diet affected the levels of hormones derived from anterior pituitary basophilic cells. This phenomenon might contribute to the pituitary functional disturbances described in hypercholesterolaemia.

  3. A possible role of SchistoFLRFamide in inhibition of adipokinetic hormone release from locust corpora cardiaca.

    Science.gov (United States)

    Vullings, H G; Ten Voorde, S E; Passier, P C; Diederen, J H; Van Der Horst, D J; Nässel, D R

    1998-12-01

    The distribution and actions of FMRFamide-related peptides (FaRPs) in the corpora cardiaca of the locust Locusta migratoria were studied. Antisera to FMRFamide and SchistoFLRFamide (PDVDHVFLRFamide) label neuronal processes that impinge on glandular cells in the glandular lobe of the corpora cardiaca known to produce adipokinetic hormones. Electron microscopic immunocytochemistry revealed that these FaRP-containing processes form synaptoid contacts with the glandular cells. Approximately 12% of the axon profiles present in the glandular part of the corpus cardiacum contained SchistoFLRFamide-immunoreactive material. Retrograde tracing of the axons in the nervus corporis cardiaci II with Lucifer yellow revealed 25-30 labelled neuronal cell bodies in each lateral part of the protocerebrum. About five of these in each hemisphere reacted with the SchistoFLRFamide-antiserum. Double-labelling immunocytochemistry showed that the FaRP-containing processes in the glandular lobe of the corpora cardiaca are distinct from neuronal processes, reacting with an antiserum to the neuropeptide locustatachykinin. The effect of the decapeptide SchistoFLRFamide and the tetrapeptide FMRFamide on the release of adipokinetic hormone I (AKH I) from the cells in the glandular part of the corpus cardiacum was studied in vitro. Neither the deca- nor the tetrapeptide had any effect on the spontaneous release of AKH I. Release of AKH I induced by the phosphodiesterase inhibitor IBMX, however, was reduced significantly by both peptides. These results point to an involvement of FaRPs as inhibitory modulators in the regulation of the release of adipokinetic hormone from the glandular cells.

  4. β-Hydroxybutyric acid inhibits growth hormone-releasing hormone synthesis and secretion through the GPR109A/extracellular signal-regulated 1/2 signalling pathway in the hypothalamus.

    Science.gov (United States)

    Fu, S-P; Liu, B-R; Wang, J-F; Xue, W-J; Liu, H-M; Zeng, Y-L; Huang, B-X; Li, S-N; Lv, Q-K; Wang, W; Liu, J-X

    2015-03-01

    β-Hydroxybutyric acid (BHBA) has recently been shown to regulate hormone synthesis and secretion in the hypothalamus. However, little is known about the effects of BHBA-mediated hormone regulation or the detailed mechanisms by which BHBA regulates growth hormone-releasing hormone (GHRH) synthesis and secretion. In the present study, we examined the expression of the BHBA receptor GPR109A in primary hypothalamic cell cultures. We hypothesised that BHBA regulates GHRH via GPR109A and its downstream signals. Initial in vivo studies conducted in rats demonstrated that GHRH mRNA expression in the hypothalamus was strongly inversely correlated with BHBA levels in the cerebrospinal fluid during postnatal development (r = -0.89, P hypothalamus in both in vivo and in vitro, and this effect was also inhibited by PTX in vitro. In primary hypothalamic cells, BHBA activated the extracellular signal-regulated kinase (ERK)1/2, p38 and c-Jun N-terminal kinase mitogen-activated protein kinase (MAPK) kinases, as shown by western blot analysis. Moreover, inhibition of ERK1/2 with U0126 attenuated the BHBA-mediated reduction in Gsh-1 expression and GHRH synthesis and secretion. These results strongly suggest that BHBA directly regulates GHRH synthesis and secretion via the GPR109A/ERK1/2 MAPK pathway, and also that Gsh-1 is essential for this function. © 2015 British Society for Neuroendocrinology.

  5. Influence of leptin on luteinizing hormone and follicle stimulating hormone secreted from cultured rat anterior pituitary cells

    Institute of Scientific and Technical Information of China (English)

    Yuebing Qiao; Xiuyan Ma; Huixian Cui

    2008-01-01

    BACKGROUND: Leptin may regulate reproductive function via release of hypothalamic neuropeptide Y. However, it is unknown whether this regulatory effect is limited to the hypothalamus. OBJECTIVE: To detect the effect of different dosages of leptin on luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion from in vitro cultured rat anterior pituitary cells. DESIGN: Contrast study based on cells. SETTING: This study was performed in the Basic Institute of Chengde Medical College, Chengde City, Hebei Province, China from March to June 2007. MATERIALS: Eighteen female Wistar rats of three months of age, weighing 200-220 g, and of clean grade were used. Leptin was provided by Peprotech Company, DMEM culture medium by Invitrogen Company, and the radioimmunological kit by Beijing Zhongshan Jinqiao Biotechnology Co., Ltd. METHODS: Three glandular organs were regarded as one group for culture of anterior pituitary cells. In the control group, saline was added to the culture medium instead of leptin. In the leptin group, leptin was prepared into different concentrations of 1×10-12, 1×10-11, 1×10-9, 1×10-7, and 1×10-6 mol/L for stimulation of cultured cells. The culture supernatant was obtained at three hours after additional of saline/leptin. MAIN OUTCOME MEASURES: Contents of LH and FSH were detected by radioimmunology. RESULTS: Following leptin stimulation, LH release increased with increasing concentrations of leptin up to 1×10-9 mol/L, where LH release peaked. LH release then progressively decreased with increasing leptin concentrations (P<0.01). LH release in the leptin (1×10-12, 1×10-11, 1×10-7, and 1×10-6 mol/L) groups was significantly higher than that in the control group (P<0.01). FSH content in the leptin (1×10-11, 1×10-9, and 1×10-7 mol/L) groups was significantly higher than that in the control group (P<0.01). CONCLUSION: Leptin can directly affect pituitary tissue to promote the secretion of LH and FSH in a dose-dependent manner.

  6. MRI of growth hormone-secreting pituitary adenomas: factors determining pretreatment hormone levels

    Energy Technology Data Exchange (ETDEWEB)

    Saeki, N.; Iuchi, T.; Eda, M.; Yamaura, A. [Dept. of Neurological Surgery, Chiba University School of Medicine (Japan); Isono, S. [Dept. of Neurological Surgery, Anesthesiology, Chiba University School of Medicine, Chiba (Japan)

    1999-10-01

    Preoperative serum growth hormone (GH) level is one of the most important determinants of outcome. Our aim was to assess MRI findings which may correlate with pretreatment GH levels in GH-secreting adenomas. We retrospectively studied 29 patients with acromegaly caused by a pituitary adenoma. Tumor size (height, width, thickness and volume), suprasellar extension, sphenoid or cavernous sinus invasion, signal intensity and contrast enhancement were studied. Linear regression analysis or Fisher's exact probability test was used for statistical analysis. Factors related to high GH levels were the maximum dimension of the tumour (r = 0.496, P < 0.01), its volume (r = 0.439, P < 0.05), spenoid sinus invasion (P < 0.01) and intracavernous carotid artery encasement (P < 0.01). The other items were not related to serum GH levels. Since we believe surgery is the first choice of treatment and the cavernous sinus is difficult of access with a conventional surgical approach, preoperative assessment of invasion into the cavernous sinus is critical for predicting the surgical outcome. Low GH levels (5-50 ng/ml) were found with tumours medial to the intercarotid line and high levels (more than 101 ng/ml) with invasive tumours with carotid artery encasement. Variable GH levels were noted with tumours extending beyond the intercarotid line. Because functioning adenomas invading the cavernous sinus tend to have markedly high hormone levels, and only patients with carotid artery encasement showed markedly elevated GH levels, we believe carotid artery encasement a reliable MRI indicator of cavernous sinus invasion. (orig.)

  7. Gamma irradiation effects on human growth hormone producing pituitary adenoma tissue. An analysis of morphology and hormone secretion in an in vitro model system

    Energy Technology Data Exchange (ETDEWEB)

    Anniko, M. (Karolinska sjukhuset, Stockholm (Sweden). Dept. of Oto-Rhino-Laryngology); Arndt, J. (Karolinska sjukhuset, Stockholm (Sweden). Dept. of Radiophysics, Radiumhemmet); Raehn, T. (Karolinska sjukhuset, Stockholm (Sweden). Dept. of Neurosurgery); Werner, S. (Karolinska sjukhuset, Stockholm (Sweden). Dept. of Endocrinology)

    1982-01-01

    Irradiation-induced effects on pituitary cell morphology and secretion of growth hormone (GH) and prolactin (PRL) have been analysed using an in vitro system. Specimens for organ culture were were obtained from three patients with pituitary tumours causing acromegaly but with different clinical activity of disease. Specimens were followed in vitro 1 h - 6 days after single-dose gamma irradiation (/sup 60/Co) with 70 100 and 150 Gy, respectively. These doses are used in clinical work for the stereotactic radiosuregery of pituitary adenomas. Considerable fluctuations in hormone secretion/release occurred during the first 24h after irradiation. All three tumours showed individual differences concern ing irradiation-induced morphological damage. Only a minor variation occurred between specimens from the same tumour. An individual sensitivity to irradiation of pituitary tumours in vitro is documented. The great number of surviving pituitary tumour cells one week after irradiation-many with an intact ultrastructure and containing hormone granules-indicated an initial high degree of radioresistance.

  8. HIV gp120 inhibits the somatotropic axis: A possible GH-releasing hormone receptor mechanism for the pathogenesis of AIDS wasting

    Science.gov (United States)

    Mulroney, Susan E.; McDonnell, Kevin J.; Pert, Candace B.; Ruff, Michael R.; Resch, Zachary; Samson, Willis K.; Lumpkin, Michael D.

    1998-01-01

    AIDS is often associated with growth retardation in children and wasting in adults. The dissociated envelope protein of the HIV (HIV-1), gp120, can be found in significant concentrations in the parenchyma and cerebrospinal fluid of brains in infected individuals, even in the earliest stages of HIV-1 disease. On the basis of this and the fact that we observed pentapeptide sequence homology between GH-releasing hormone (GHRH) and the V2 receptor-binding region of gp120, we initiated experiments to determine whether gp120 could affect GH secretion and growth in vivo and/or interact with anterior pituitary GHRH receptors in vitro. Although acute IV administration of gp120 in conscious rats had no effect on plasma GH levels, acute administration of gp120 (400 ng) into the brain significantly suppressed pulsatile GH release over a 6-h period compared with saline-injected controls. Furthermore, the putative gp120 antagonist, Peptide T (DAPTA), prevented the suppression of GH by gp120. In support of these in vivo findings, gp120 also significantly (P < 0.05) suppressed GHRH-stimulated GH release in static cultures of dispersed pituitary cells and from cells undergoing perifusion with the peptides. DAPTA prevented the GH suppression by gp120 in both of the pituitary cell paradigms. Furthermore, chronic administration of gp120 into the third ventricle significantly reduced body weight in juvenile rats, compared with saline-injected controls. Thus, gp120 appears to act both at the hypothalamus and pituitary to suppress GH release, and its action at these two locations is associated with a significant loss in body weight in chronically treated young animals. These findings may suggest a specific mechanism for the pathogenesis of wasting in HIV-1 patients that involves blockade of endogenous GHRH receptors by gp120. PMID:9465119

  9. Hypothalamic-pituitary-thyroid axis hormones stimulate mitochondrial function and biogenesis in human hair follicles.

    Science.gov (United States)

    Vidali, Silvia; Knuever, Jana; Lerchner, Johannes; Giesen, Melanie; Bíró, Tamás; Klinger, Matthias; Kofler, Barbara; Funk, Wolfgang; Poeggeler, Burkhard; Paus, Ralf

    2014-01-01

    Thyroid hormones regulate mitochondrial function. As other hypothalamic-pituitary-thyroid (HPT) axis hormones, i.e., thyrotropin-releasing hormone (TRH) and thyrotropin (TSH), are expressed in human hair follicles (HFs) and regulate mitochondrial function in human epidermis, we investigated in organ-cultured human scalp HFs whether TRH (30 nM), TSH (10 mU ml(-1)), thyroxine (T4) (100 nM), and triiodothyronine (T3) (100 pM) alter intrafollicular mitochondrial energy metabolism. All HPT-axis members increased gene and protein expression of mitochondrial-encoded subunit 1 of cytochrome c oxidase (MTCO1), a subunit of respiratory chain complex IV, mitochondrial transcription factor A (TFAM), and Porin. All hormones also stimulated intrafollicular complex I/IV activity and mitochondrial biogenesis. The TSH effects on MTCO1, TFAM, and porin could be abolished by K1-70, a TSH-receptor antagonist, suggesting a TSH receptor-mediated action. Notably, as measured by calorimetry, T3 and TSH increased follicular heat production, whereas T3/T4 and TRH stimulated ATP production in cultured HF keratinocytes. HPT-axis hormones did not increase reactive oxygen species (ROS) production. Rather, T3 and T4 reduced ROS formation, and all tested HPT-axis hormones increased the transcription of ROS scavengers (catalase, superoxide dismutase 2) in HF keratinocytes. Thus, mitochondrial biology, energy metabolism, and redox state of human HFs are subject to profound (neuro-)endocrine regulation by HPT-axis hormones. The neuroendocrine control of mitochondrial biology in a complex human mini-organ revealed here may be therapeutically exploitable.

  10. Luteinizing hormone-releasing hormone induces thyroxine release together with testosterone in the neotenic axolotl Ambystoma mexicanum.

    Science.gov (United States)

    Jacobs, G F; Kühn, E R

    1988-09-01

    In male neotenic axolotls Ambystoma mexicanum plasma concentrations of thyroxine (T4) and testosterone were increased following intravenous injection of 10 micrograms luteinizing hormone-releasing hormone. A dose of 50 micrograms influenced only plasma T4 levels. This observation suggests for the first time that a hypothalamic hormone is capable of stimulating the thyroidal axis in the neotenic axolotl.

  11. Changes in pituitary growth hormone cells prepared from rats flown on Spacelab 3

    Science.gov (United States)

    Grindeland, R.; Hymer, W. C.; Farrington, M.; Fast, T.; Hayes, C.; Motter, K.; Patil, L.; Vasques, M.

    1987-01-01

    The effect of exposure to microgravity on pituitary gland was investigated by examining cells isolated from anterior pituitaries of rats flown on the 7-day Spacelab 3 mission and, subsequently, cultured for 6 days. Compared with ground controls, flight cells contained more intracellular growth hormone (GH); however, the flight cells released less GH over the 6-day culture period and after implantation into hypophysectomized rats than did the control cells. Compared with control rats, glands from large rats (400 g) contained more somatotrophs (44 percent compared with 37 percent in control rats); small rats (200 g) showed no difference. No major differences were found in the somatotroph ultrastructure (by TEM) or in the pattern of the immunoactive GH variants. However, high-performance liquid chromatography fractionation of culture media indicated that flight cells released much less of a biologically active high-molecular weight GH variant, suggesting that space flight may lead to secretory dysfunction.

  12. Synthesis and release of luteinizing hormone in vitro: manipulations of Ca2+ environment

    Energy Technology Data Exchange (ETDEWEB)

    Liu, T.C.; Jackson, G.L.

    1985-08-01

    The authors determined if luteinizing hormone (LH) synthesis is Ca2+ dependent and coupled to LH release. They monitored LH synthesis when LH release was stimulated either by specific (gonadotropin-releasing hormone (GnRH)) or nonspecific stimuli (50 mM K+ and 2 or 20 microM Ca2+ ionophore A23187) and inhibited by Ca2+-reduced medium. LH synthesis was estimated by measuring incorporation of (/sup 3/H)glucosamine (glycosylation) and (/sup 14/C)alanine (translation) into total (cell and medium) immunoprecipitable LH by cultured rat anterior pituitary cells. Both GnRH (1 nM) and 50 mM K+ significantly stimulated LH release and glycosylation, but had no effect on LH translation. A23187 also stimulated LH release, but significantly depressed glycosylation of LH and total protein and (/sup 14/C)alanine uptake. Deletion of Ca2+ from the medium depressed both GnRH-induced LH release and glycosylation. Addition of 0.1 mM EGTA to Ca2+-free medium not only inhibited GnRH-induced release and glycosylation of LH but also uptake of precursors and glycosylation and translation of total protein. Thus, glycosylation and release of LH are Ca2+ dependent. Whether parallel changes in LH release and glycosylation reflect a cause and effect relationship remains to be determined.

  13. Comparison of post-surgical MRI presentation of the pituitary gland and its hormonal function

    Science.gov (United States)

    Bladowska, Joanna; Sokolska, Violetta; Sozański, Tomasz; Bednarek-Tupikowska, Grażyna; Sąsiadek, Marek

    2010-01-01

    Summary Background: Post-surgical evaluation of the pituitary gland in MRI is difficult because of a change of anatomical conditions. It depends also on numerous other factors, including: size and expansion of a tumour before surgery, type of surgical access, quality and volume of filling material used and time of its resorption.The aim of the study was to compare MR image of the pituitary gland after surgery with clinical findings and to establish a correlation between MRI presentation of spared pituitary and its hormonal function. Material/Methods: 124 patients after resection of pituitary adenomas – 409 MRI results in total – were studied. With a 1.5-T unit, T1-weighted sagittal and coronal, enhanced and unenhanced images were obtained. Results: The pituitary gland seemed to be normal in MRI in 11 patients, 8 of them had completely regular pituitary function but in 3 of them we noticed a partial hypopituitarism. In 99 patients only a part of the pituitary gland was recognised, 53 of them had hypopituitarism but 46 of them were endocrinologically healthy. 14 patients seemed to have no persistent pituitary gland in MRI, in comparison to hormonal studies: there was panhypopituitarism in 6 and hypopituitarism in 8 cases. Conclusions: MRI presentation of post – surgical pituitary gland doesn’t necessarily correlate with its hormonal function – there was a significant statistical difference. Some patients with partial pituitary seems normal hormonal function. In some cases the pituitary seem normal in MRI but these patients have hormonal disorders and need substitution therapy. PMID:22802758

  14. Investigation of the serum levels of anterior pituitary hormones in male children with autism.

    Science.gov (United States)

    Iwata, Keiko; Matsuzaki, Hideo; Miyachi, Taishi; Shimmura, Chie; Suda, Shiro; Tsuchiya, Kenji J; Matsumoto, Kaori; Suzuki, Katsuaki; Iwata, Yasuhide; Nakamura, Kazuhiko; Tsujii, Masatsugu; Sugiyama, Toshirou; Sato, Kohji; Mori, Norio

    2011-10-19

    The neurobiological basis of autism remains poorly understood. The diagnosis of autism is based solely on behavioural characteristics because there are currently no reliable biological markers. To test whether the anterior pituitary hormones and cortisol could be useful as biological markers for autism, we assessed the basal serum levels of these hormones in subjects with autism and normal controls. Using a suspension array system, we determined the serum levels of six anterior pituitary hormones, including adrenocorticotropic hormone and growth hormone, in 32 drug-naive subjects (aged 6 to 18 years, all boys) with autism, and 34 healthy controls matched for age and gender. We also determined cortisol levels in these subjects by enzyme-linked immunosorbent assay. Serum levels of adrenocorticotropic hormone, growth hormone and cortisol were significantly higher in subjects with autism than in controls. In addition, there was a significantly positive correlation between cortisol and adrenocorticotropic hormone levels in autism. Our results suggest that increased basal serum levels of adrenocorticotropic hormone accompanied by increased cortisol and growth hormone may be useful biological markers for autism.

  15. Investigation of the serum levels of anterior pituitary hormones in male children with autism

    Directory of Open Access Journals (Sweden)

    Iwata Keiko

    2011-10-01

    Full Text Available Abstract Background The neurobiological basis of autism remains poorly understood. The diagnosis of autism is based solely on behavioural characteristics because there are currently no reliable biological markers. To test whether the anterior pituitary hormones and cortisol could be useful as biological markers for autism, we assessed the basal serum levels of these hormones in subjects with autism and normal controls. Findings Using a suspension array system, we determined the serum levels of six anterior pituitary hormones, including adrenocorticotropic hormone and growth hormone, in 32 drug-naive subjects (aged 6 to 18 years, all boys with autism, and 34 healthy controls matched for age and gender. We also determined cortisol levels in these subjects by enzyme-linked immunosorbent assay. Serum levels of adrenocorticotropic hormone, growth hormone and cortisol were significantly higher in subjects with autism than in controls. In addition, there was a significantly positive correlation between cortisol and adrenocorticotropic hormone levels in autism. Conclusion Our results suggest that increased basal serum levels of adrenocorticotropic hormone accompanied by increased cortisol and growth hormone may be useful biological markers for autism.

  16. [Pituitary hormone secretion induced by optokinetic stimulation (author's transl)].

    Science.gov (United States)

    Mang, W L; Scherer, H; Eversmann, T; Gottsmann, M

    1978-08-01

    A slight optokinetic stimulation induces a significant increase of serum levels of antidiuretic hormone 1,1 +/- 0.8 pg/ml (mean +/- SD) to 3,3 +/- 1,9 pg/ml (mean +/- SD). Serum levels of gGH and cortisol remain unchanged, whereas serum prolactin levels decrease slightly. The ADH secretion seems to be the most sensitive hormonal parameter of the stimulation of the vestibular nuclei induced either by the optokinetic stimulation or by the Coriolis effect.

  17. Corticotropin-releasing hormone: an autocrine hormone that promotes lipogenesis in human sebocytes.

    Science.gov (United States)

    Zouboulis, Christos C; Seltmann, Holger; Hiroi, Naoki; Chen, WenChieh; Young, Maggie; Oeff, Marina; Scherbaum, Werner A; Orfanos, Constantin E; McCann, Samuel M; Bornstein, Stefan R

    2002-05-14

    Sebaceous glands may be involved in a pathway conceptually similar to that of the hypothalamic-pituitary-adrenal (HPA) axis. Such a pathway has been described and may occur in human skin and lately in the sebaceous glands because they express neuropeptide receptors. Corticotropin-releasing hormone (CRH) is the most proximal element of the HPA axis, and it acts as central coordinator for neuroendocrine and behavioral responses to stress. To further examine the probability of an HPA equivalent pathway, we investigated the expression of CRH, CRH-binding protein (CRH-BP), and CRH receptors (CRH-R) in SZ95 sebocytes in vitro and their regulation by CRH and several other hormones. CRH, CRH-BP, CRH-R1, and CRH-R2 were detectable in SZ95 sebocytes at the mRNA and protein levels: CRH-R1 was the predominant type (CRH-R1/CRH-R2 = 2). CRH was biologically active on human sebocytes: it induced biphasic increase in synthesis of sebaceous lipids with a maximum stimulation at 10(-7) M and up-regulated mRNA levels of 3 beta- hydroxysteroid dehydrogenase/Delta(5-4) isomerase, although it did not affect cell viability, cell proliferation, or IL-1 beta-induced IL-8 release. CRH, dehydroepiandrosterone, and 17 beta-estradiol did not modulate CRH-R expression, whereas testosterone at 10(-7) M down-regulated CRH-R1 and CRH-R2 mRNA expression at 6 to 24 h, and growth hormone (GH) switched CRH-R1 mRNA expression to CRH-R2 at 24 h. Based on these findings, CRH may be an autocrine hormone for human sebocytes that exerts homeostatic lipogenic activity, whereas testosterone and growth hormone induce CRH negative feedback. The findings implicate CRH in the clinical development of acne, seborrhea, androgenetic alopecia, skin aging, xerosis, and other skin disorders associated with alterations in lipid formation of sebaceous origin.

  18. Thyrotropin-releasing hormone and its analogs accelerate wound healing.

    Science.gov (United States)

    Nie, Chunlei; Yang, Daping; Liu, Nan; Dong, Deli; Xu, Jin; Zhang, Jiewu

    2014-06-15

    Thyrotropin-releasing hormone (TRH) is a classical hormone that controls thyroid hormone production in the anterior pituitary gland. However, recent evidence suggested that TRH is expressed in nonhypothalamic tissues such as epidermal keratinocytes and dermal fibroblasts, but its function is not clear. This study aimed to investigate the effects of TRH and its analogs on wound healing and explore the underlying mechanisms. A stented excisional wound model was established, and the wound healing among vehicle control, TRH, and TRH analog taltirelin treatment groups was evaluated by macroscopic and histologic analyses. Primary fibroblasts were isolated from rat dermis and treated with vehicle control, TRH or taltirelin, cell migration, and proliferation were examined by scratch migration assay, MTT, and 5-ethynyl-2'- deoxyuridine (EdU) assay. The expression of α-Smooth muscle actin in fibroblasts was detected by Western blot and immunocytochemical analysis. TRH or taltirelin-treated wounds exhibited accelerated wound healing with enhanced granulation tissue formation and increased re-epithelialization and tissue formation. Furthermore, TRH or taltirelin promoted the migration and proliferation of fibroblasts and induced the expression of α-Smooth muscle actin in fibroblasts. TRH is important in upregulating the phenotypes of dermal fibroblasts and plays a role in accelerating wound healing. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. The Spectrum of Hormone Immunoreactivity in Typical and Atypical Pituitary Adenomas

    Directory of Open Access Journals (Sweden)

    Yeşim ERTAN

    2009-09-01

    Full Text Available Objective: We aimed to assess the spectrum of hormone immunoreactivity in our pituitary adenoma cases and discuss the diagnostic parameters of atypical pituitary adenomas.Material and Methods: A total of 166 pituitary adenoma cases diagnosed from 2005 to 2008 in our department were included in the present study. Hematoxylin-eosin stained and immunohistochemistry performed slides (ACTH, PRL, GH, TSH, FSH, LH, Ki-67, and p53 were evaluated. Cases having more than two mitoses on 10 high power fields besides more than 3% Ki-67 index were accepted in the atypical group.Results: Histologically, 159 cases were typical pituitary adenoma and 7 were atypical pituitary adenoma. Of the atypical pituitary adenoma cases, one case was ACTH, one GH and one both GH and prolactin hormone immunoreactive pituitary adenomas. Four cases were hormone immunonegative adenomas. Of the typical pituitary adenoma cases, 39 cases were GH, 19 ACTH, 17 prolactin, 10 FSH, 8 LH and one TSH immunreactive pituitary adenomas. Fourty-seven cases were hormone immunonegative adenomas.Twenty-two of the all pitutary adenoma cases had recurrence. Of these cases, 18 were typical adenoma and four were atypical adenoma.Conclusion: The ratio of prolactin immunoreactive pituitary adenoma cases in the surgical material of neuropathology is decreasing due to medical therapy. Atypical pituitary adenomas are not the sole factor affecting the recurrence mechanism but these tumors have higher recurrence rate compared with typical pituitary adenomas and we think the proliferation index might be the principal approach in the diagnosis of these lesions.

  20. Pituitary glycoprotein hormone a-subunit secretion by cirrhotic patients

    Directory of Open Access Journals (Sweden)

    Oliveira M.C.

    1999-01-01

    Full Text Available Secretion of the a-subunit of pituitary glycoprotein hormones usually follows the secretion of intact gonadotropins and is increased in gonadal failure and decreased in isolated gonadotropin deficiency. The aim of the present study was to determine the levels of the a-subunit in the serum of patients with cirrhosis of the liver and to compare the results obtained for eugonadal cirrhotic patients with those obtained for cirrhotic patients with hypogonadotropic hypogonadism. Forty-seven of 63 patients with cirrhosis (74.6% presented hypogonadism (which was central in 45 cases and primary in 2, 7 were eugonadal, and 9 women were in normal menopause. The serum a-subunit was measured by the fluorimetric method using monoclonal antibodies. Cross-reactivity with LH, TSH, FSH and hCG was 6.5, 1.2, 4.3 and 1.1%, respectively, with an intra-assay coefficient of variation (CV of less than 5% and an interassay CV of 5%, and sensitivity limit of 4 ng/l. The serum a-subunit concentration ranged from 36 to 6253 ng/l, with a median of 273 ng/l. The median was 251 ng/l for patients with central hypogonadism and 198 ng/l for eugonadal patients. The correlation between the a-subunit and basal LH levels was significant both in the total sample (r = 0.48, P<0.01 and in the cirrhotic patients with central hypogonadism (r = 0.33, P = 0.02. Among men with central hypogonadism there was a negative correlation between a-subunit levels and total testosterone levels (r = 0.54, P<0.01 as well as free testosterone levels (r = -0.53, P<0.01. In conclusion, although the a-subunit levels are correlated with LH levels, at present they cannot be used as markers for hypogonadism in patients with cirrhosis of the liver.

  1. The FGFR4-G388R polymorphism promotes mitochondrial STAT3 serine phosphorylation to facilitate pituitary growth hormone cell tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Toru Tateno

    2011-12-01

    Full Text Available Pituitary tumors are common intracranial neoplasms, yet few germline abnormalities have been implicated in their pathogenesis. Here we show that a single nucleotide germline polymorphism (SNP substituting an arginine (R for glycine (G in the FGFR4 transmembrane domain can alter pituitary cell growth and hormone production. Compared with FGFR4-G388 mammosomatotroph cells that support prolactin (PRL production, FGFR4-R388 cells express predominantly growth hormone (GH. Growth promoting effects of FGFR4-R388 as evidenced by enhanced colony formation was ascribed to Src activation and mitochondrial serine phosphorylation of STAT3 (pS-STAT3. In contrast, diminished pY-STAT3 mediated by FGFR4-R388 relieved GH inhibition leading to hormone excess. Using a knock-in mouse model, we demonstrate the ability of FGFR4-R385 to promote GH pituitary tumorigenesis. In patients with acromegaly, pituitary tumor size correlated with hormone excess in the presence of the FGFR4-R388 but not the FGFR4-G388 allele. Our findings establish a new role for the FGFR4-G388R polymorphism in pituitary oncogenesis, providing a rationale for targeting Src and STAT3 in the personalized treatment of associated disorders.

  2. The FGFR4-G388R polymorphism promotes mitochondrial STAT3 serine phosphorylation to facilitate pituitary growth hormone cell tumorigenesis.

    Science.gov (United States)

    Tateno, Toru; Asa, Sylvia L; Zheng, Lei; Mayr, Thomas; Ullrich, Axel; Ezzat, Shereen

    2011-12-01

    Pituitary tumors are common intracranial neoplasms, yet few germline abnormalities have been implicated in their pathogenesis. Here we show that a single nucleotide germline polymorphism (SNP) substituting an arginine (R) for glycine (G) in the FGFR4 transmembrane domain can alter pituitary cell growth and hormone production. Compared with FGFR4-G388 mammosomatotroph cells that support prolactin (PRL) production, FGFR4-R388 cells express predominantly growth hormone (GH). Growth promoting effects of FGFR4-R388 as evidenced by enhanced colony formation was ascribed to Src activation and mitochondrial serine phosphorylation of STAT3 (pS-STAT3). In contrast, diminished pY-STAT3 mediated by FGFR4-R388 relieved GH inhibition leading to hormone excess. Using a knock-in mouse model, we demonstrate the ability of FGFR4-R385 to promote GH pituitary tumorigenesis. In patients with acromegaly, pituitary tumor size correlated with hormone excess in the presence of the FGFR4-R388 but not the FGFR4-G388 allele. Our findings establish a new role for the FGFR4-G388R polymorphism in pituitary oncogenesis, providing a rationale for targeting Src and STAT3 in the personalized treatment of associated disorders.

  3. Characterization of growth hormone and prolactin produced by human pituitary in culture.

    Science.gov (United States)

    Skyler, J S; Rogol, A D; Lovenberg, W; Knazek, R A

    1977-02-01

    Fragments of a pituitary tumor from a patient with acromegaly were grown in tissue culture. The tumor secreted both growth hormone and prolactin,which were recovered in high concentrations. The nonpurified hormones were characterized and compared to their respective counterparts obtained by extraction from normal pituitaries obtained at autopsy. The tissue culture and pituitary extracted hormones were eluted from Sephadex G-100 with the same partition coefficients. Growth hormone from both sources showed parallel dose-response displacement curves, by logit-log transformation, in both specific immunoassay and in a specific lymphocyte binding assay. Prolactin from both sources was compared in specific immunoassay using three different antisera. Parallel logit-log displacement curves were seen with one antiserum, while the other two antisera yielded non-parallel curves, indicating structural differences between prolactin from the two sources. Quantitative polyacrylamide gel electrophoresis was performed using multiphasic buffer systems previously developed for characterization of each hormone. By the criteria of joint 95% confidence envelopes of retardation co-efficient and relative free mobility, tissue culture growth hormone and prolactin were indistinguishable from their pituitary-extracted counterparts. This study demonstrates that, prior to purification, tissue culture derived hormone can be characterized by multiple criteria and compared to a standard preparation. Structural differences can be detected, as in the case of prolactin. When the hormones are indistinguishable, as in the case of growth hormone, it becomes worthwhile to increase the scale of tissue cultured production, with the prospect that tissue culture may serve as a source of hormone for both experimental and therapeutic use.

  4. Chronic Unpredictable Mild Stress Induces Loss of GABA Inhibition in Corticotrophin-Releasing Hormone-Expressing Neurons through NKCC1 Upregulation.

    Science.gov (United States)

    Gao, Yonggang; Zhou, Jing-Jing; Zhu, Yun; Kosten, Therese; Li, De-Pei

    2017-01-01

    Prolonged and repeated stresses cause hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. The corticotrophin-releasing hormone (CRH)-expressing neurons in the hypothalamic paraventricular nucleus (PVN) are an essential component of the HPA axis. Chronic unpredictable mild stress (CUMS) was induced in Sprague-Dawley rats. GABA reversal potentials (EGABA) were determined by using gramicidin-perforated recordings in identified PVN-CRH neurons through expressing enhanced green fluorescent protein driven by the CRH promoter. Plasma corticosterone (CORT) levels were measured in rats implanted with a cannula targeting the lateral ventricles and PVN. Blocking the GABAA receptor in the PVN with gabazine significantly increased plasma CORT levels in unstressed rats but did not change CORT levels in CUMS rats. CUMS caused a depolarizing shift in EGABA in PVN-CRH neurons compared with EGABA in PVN-CRH neurons in unstressed rats. Furthermore, CUMS induced a long-lasting increase in expression levels of the cation chloride cotransporter Na+-K+-Cl--Cl- (NKCC1) in the PVN but a transient decrease in expression levels of K+-Cl--Cl- in the PVN, which returned to the basal level 5 days after CUMS treatment. The NKCC1 inhibitor bumetanide decreased the basal firing activity of PVN-CRH neurons and normalized EGABA and the gabazine-induced excitatory effect on PVN-CRH neurons in CUMS rats. In addition, central administration of bumetanide decreased basal circulating CORT levels in CUMS rats. These data suggest that chronic stress impairs GABAergic inhibition, resulting in HPA axis hyperactivity through upregulation of NKCC1. © 2016 S. Karger AG, Basel.

  5. Childhood lead toxicity and impaired release of thyrotropin-stimulating hormone

    Energy Technology Data Exchange (ETDEWEB)

    Huseman, C.A.; Moriarty, C.M.; Angle, C.R.

    1987-04-01

    Decreased stature of children is epidemiologically associated with increased blood lead independent of multiple socioeconomic and nutritional variables. Since endocrine dysfunction occurs in adult lead workers, they studied two girls, 2 years of age, before and after calcium disodium edetate chelation for blood leads (PbB) of 19-72 ..mu..g/dl. The height of both children had crossed from the 50th to below the 10th percentile during the course of chronic lead toxicity. Basal free T/sub 4/, T/sub 4/, T/sub 3/, cortisol, somatomedin C, and sex steroids were normal. A decrease in the growth hormone response and elevation of basal prolcatin and gonadotropins were noted in one. Both children demonstrated blunted thyrotropin-stimulating hormone (TSH) responses to thyrotropin-releasing hormone (TRH) in six of seven challenges. This prompted in vitro studies of cultured cells from rat pituitarities. After incubation of pituitary cells with 0.1-10 ..mu..M Pb/sup 2 +/ for 2 hr, followed by the addition of TRH, there was a dose-dependent inhibition of TSH release Lead did not interfere with the assay of TSH. To investigate the interaction of lead and calcium, /sup 45/Ca/sup 2 +/ kinetic analyses were done on rat pituitary slices after 1 hr incubation with 1.0 ..mu..M lead. The impaired late efflux was consistent with a decrease in the size and exchangeability of the tightly bound pool of intracellular microsomal or mitochondrial calcium. The rat pituitary cell model provides a model for the decreased TSH release of lead poisoning, supports the biological plausibility of a neuroendocrine effect on growth, and suggests that interference with calcium-mediated intracellular responses is a basic mechanism of lead toxicity.

  6. Growth hormone stimulation test - series (image)

    Science.gov (United States)

    The growth hormone (GH) is a protein hormone released from the anterior pituitary gland under the control of the hypothalamus. In children, GH has growth-promoting effects on the body. It stimulates the ...

  7. Secretion of human parathyroid hormone from rat pituitary cells infected with a recombinant retrovirus encoding preproparathyroid hormone.

    OpenAIRE

    Hellerman, J G; Cone, R C; Potts, J. T.; Rich, A; Mulligan, R C; Kronenberg, H M

    1984-01-01

    In order to study the functions of precursors to secreted proteins, we expressed cloned DNA encoding human preproparathyroid hormone (preproPTH) in rat pituitary cells. We first constructed a recombinant plasmid containing human preproPTH cDNA and retroviral control signals. This recombinant plasmid was transfected into psi-2 cells, a packaging cell line that produces Moloney murine leukemia viral particles containing no retroviral RNA. The transfected psi-2 cells generated helper-free recomb...

  8. Effect of cadmium on sexual hormone secretion from pituitary and ovary

    Institute of Scientific and Technical Information of China (English)

    ZhanWC; WuZR

    2002-01-01

    The objective of this study is to provide the evidence of endocrine disruption induced by Cd.The changes of serum luteinizing hormone(LH),follicle stimulating hormone(FSH),progesterone(P) and estradiol(E2) levels were observed in female rats administrated ac with Cd.Serum FSH or LH was no significant difference between groups for 7-day and for 14-day exposure.But the serum E2 of the high dose group of 7-day exposure,the low dose and high dose group for 14d was significantly lower than that of the control group.Serum P of the low dose group of 7 day exposure was significantly lower than that of the control group.After injection of gonadotropin-release hormones (GnRH) the serum FSH and LH levels increased significantly in each group(Cd 0.5,1.0mg·kg-1,5days a week, for 6 weeks).However,the serum LH was lower significantly in the rats administrated Cd than in the control rats after the injection of GnRH.There was no difference of the number of ovum between groups(0,1.5,3.0mg·kg-1 for 5d) in the super-ovulation test(P>0.05).Cadmium has the distinct adverse effect on the ovary of female rats.But the response function of the ovary to excess gonadotropin was basically normal.Under this experimental conditions.the function of secual hormone secretion of pituitary has been damaged,but the normal level of both FSH and LH could be maintained because of the limited compensative function of pituitary.

  9. Pituitary hormone circadian rhythm alterations in cirrhosis patients with subclinical hepatic encephalopathy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To analyze pituitary hormone and melatonin cir- cadian rhythms, and to correlate hormonal alterations with clinical performance, hepatic disease severity and diagnostic tests used for the detection of hepatic en- cephalopathy in cirrhosis. METHODS: Twenty-six patients with cirrhosis were enrolled in the study. Thirteen patients hospitalized for systemic diseases not affecting the liver were included as controls. Liver disease severity was assessed by the Child-Pugh score. All patients underwent detailed neurological assessment, electroencephalogram (EEG), brain magnetic resonance imaging (MRI), assays of pi- tuitary hormone, cortisol and melatonin, and complete blood chemistry evaluation. RESULTS: Pituitary hormone and melatonin circadian patterns were altered in cirrhosis patients without clinical encephalopathy. Circadian hormone alterations were different in cirrhosis patients compared with con- trois. Although cortisol secretion was not altered in any patient with cirrhosis, the basal cortisol levels were low and correlated with EEG and brain MRI abnormalities. Melatonin was the only hormone associated with the severity of liver insufficiency. CONCLUSION: Abnormal pituitary hormone and mel- atonin circadian patterns are present in cirrhosis before the development of hepatic encephalopathy. These abnormalities may be early indicators of impending hepatic encephalopathy. Factors affecting the human biologic clock at the early stages of liver insufficiency require further study.

  10. Is bursting more effective than spiking in evoking pituitary hormone secretion? A spatiotemporal simulation study of calcium and granule dynamics.

    Science.gov (United States)

    Tagliavini, Alessia; Tabak, Joël; Bertram, Richard; Pedersen, Morten Gram

    2016-04-01

    Endocrine cells of the pituitary gland secrete a number of hormones, and the amount of hormone released by a cell is controlled in large part by the cell's electrical activity and subsequent Ca(2+) influx. Typical electrical behaviors of pituitary cells include continuous spiking and so-called pseudo-plateau bursting. It has been shown that the amplitude of Ca(2+) fluctuations is greater in bursting cells, leading to the hypothesis that bursting cells release more hormone than spiking cells. In this work, we apply computer simulations to test this hypothesis. We use experimental recordings of electrical activity as input to mathematical models of Ca(2+) channel activity, buffered Ca(2+) diffusion, and Ca(2+)-driven exocytosis. To compare the efficacy of spiking and bursting on the same cell, we pharmacologically block the large-conductance potassium (BK) current from a bursting cell or add a BK current to a spiking cell via dynamic clamp. We find that bursting is generally at least as effective as spiking at evoking hormone release and is often considerably more effective, even when normalizing to Ca(2+) influx. Our hybrid experimental/modeling approach confirms that adding a BK-type K(+) current, which is typically associated with decreased cell activity and reduced secretion, can actually produce an increase in hormone secretion, as suggested earlier.

  11. Gonadotropin-releasing hormone in the ovary.

    Science.gov (United States)

    Metallinou, Chryssa; Asimakopoulos, Byron; Schröer, Andreas; Nikolettos, Nikos

    2007-12-01

    Gonadotropin-releasing hormone (GnRH) plays a pivotal role in the physiology of reproduction in mammals. GnRH acts by binding to the GnRH receptor (GnRHR). In humans, only 1 conventional GnRH receptor subtype (type I GnRH receptor) has been found. In the human genome, 2 forms of GnRH have been identified, GnRH-I (mammal GnRH) and GnRH-II (chicken GnRH II). Both forms and their common receptor are expressed, apart from the hypothalamus, in various compartments of the human ovary. Gonadal steroids, gonadotropins, and GnRH itself controls the regulation of the GnRH/GnRHR system gene expression in the human ovary. The 2 types of GnRH acting paracrinally/autocrinally influence ovarian steroidogenesis, decrease the proliferation, and induce apoptosis of ovarian cells. In this review, the biology of GnRH/GnRHR system in humans, the potential roles of GnRH, and the direct effects of GnRH analogues in ovarian cells are discussed.

  12. Transformation of a microprolactinoma into a mixed growth hormone and prolactin-secreting pituitary adenoma

    Directory of Open Access Journals (Sweden)

    CEDRIC eDESSIMOZ

    2012-01-01

    Full Text Available Combined prolactin (PRL and growth hormone (GH secretion by a single pituitary tumor can occur in approximately 5% of cases. However, in all previously reported patients, combined secretion of both hormones was present at the time of diagnosis. Here we describe a patient initially diagnosed with a pure prolactin-secreting microadenoma, who experienced the progressive apparition of symptomatic autonomous GH secretion while on intermittent long term dopamine agonist therapy. She was operated on, and immunohistochemical analysis of tumour tissue confirmed the diagnosis of pituitary adenoma with uniform co-staining of all cells for both GH and PRL. This patient represents the first documented occurrence of asynchronous development of combined GH and PRL secretion in a pituitary adenoma. Although pathogenic mechanisms implicated remain largely speculative, it emphasizes the need for long term hormonal follow up of patients harboring prolactinomas.

  13. Thyroid Hormone and Estrogen Regulate Exercise-Induced Growth Hormone Release

    OpenAIRE

    2015-01-01

    Growth hormone (GH) regulates whole body metabolism, and physical exercise is the most potent stimulus to induce its secretion in humans. The mechanisms underlying GH secretion after exercise remain to be defined. The aim of this study was to elucidate the role of estrogen and pituitary type 1 deiodinase (D1) activation on exercise-induced GH secretion. Ten days after bilateral ovariectomy, animals were submitted to 20 min of treadmill exercise at 75% of maximum aerobic capacity and tissues w...

  14. Both pituitary and placental growth hormone transcripts are expressed in human peripheral blood mononuclear cells (PBMC)

    NARCIS (Netherlands)

    Melen, L; Hennen, G; Dullaart, RPF; Igout, A

    1997-01-01

    The hGH-V gene codes for a variant of human pituitary growth hormone (hGH-N) named placental growth hormone (hPGH). hPGH shares 93% amino acid identity with hGH-N. Until now the hGH-V gene was considered to be exclusively expressed in human placenta, where it replaces maternal circulating hGH-N at t

  15. Effect of Camphor on Pituitary-Gonadal Hormonal Axis and Oogenesis in Adult Female Rats

    OpenAIRE

    Habibollah Johari; Amir Ashkan Mahjoor; Siyamak Fallahi; Hossein Kargar Jahromi; Maryam Abedini; Mohammad Ali Poor Danesh; Zahra Zamani

    2013-01-01

    Background & Objective: Camphor stimulates the nervous system and the circulatory system, reduces lactation, and prevents conception and embryo embedding. We investigated the effects of camphor on the pituitary-gonadal hormonal axis and concentration of steroidal hormones.   Materials & Methods: The parameters investigated were concentrations of LH, FSH, estrogen, progesterone, and testosterone. Forty adult female rats at a mean weight of 180 ± 20 grams were divided into five groups. Camphor ...

  16. cDNA microarray reveals signaling pathways involved in hormones expression of human pituitary.

    Science.gov (United States)

    Ma, Yue-Yun; Qi, Xiao-Fei; Song, Shao-Jun; Zhao, Zhan-Yong; Zhu, Zhi-Dong; Qi, Jia; Zhang, Xin; Xiao, Hua-Sheng; Teng, Yun; Han, Ze-Guang

    2005-09-01

    Pituitary, a master gland of neuroendocrine system, secretes hormones that orchestrate many physiological processes, under the regulation of multiple signaling pathways. To investigate the genes involved in hormones expression of human pituitary, homemade cDNA microarray containing 14,800 human genes/ESTs were used to profile the gene expression in both fetal and adult pituitaries. Seven hundred and twelve known genes changed over 2-fold between the both tissues. Of which, 23 genes were changed with hormones expression in aging were confirmed by RT-PCR, not only the known regulators such as Pit1, GATA4, ESRRA, GABA-A, and EMK, but also LOC55884, DUSP3, PNN, and RCL, which had not been reported to be involved in the hormones expression. Correspondingly, the mRNAs of GH, PRL, POMC, TSH-beta, FSH-beta, and LH-beta, was increased as much as 6- to 20-fold in adult pituitary than those in fetal pituitary, by real-time quantitative RT-PCR assay. In addition, the mRNAs of signaling pathways, such as cAMP-PKA-CREB, PI3K-Akt, and PKA-ERK were further investigated. Of them, it was only cAMP-PKA-CREB pathway, but not PI3K-Akt and PKA-ERK have the same expressing pattern as hormones. It suggested that cDNA microarray is highly advantages to profile the differential expressed genes that were involved in hormones expression of human pituitary, but it might ignore some responding proteins regulated posttranscriptionally.

  17. Gonadotrophin-releasing hormone antagonists for assisted reproductive technology

    NARCIS (Netherlands)

    Al-Inany, Hesham G.; Youssef, Mohamed A.; Ayeleke, Reuben Olugbenga; Brown, Julie; Lam, Wai Sun; Broekmans, Frank J.

    2016-01-01

    Background: Gonadotrophin-releasing hormone (GnRH) antagonists can be used to prevent a luteinizing hormone (LH) surge during controlled ovarian hyperstimulation (COH) without the hypo-oestrogenic side-effects, flare-up, or long down-regulation period associated with agonists. The antagonists direct

  18. Gonadotrophin-releasing hormone antagonists for assisted reproductive technology

    NARCIS (Netherlands)

    Al-Inany, Hesham G.; Youssef, Mohamed A.; Ayeleke, Reuben Olugbenga; Brown, Julie; Lam, Wai Sun; Broekmans, Frank J.

    2016-01-01

    Background: Gonadotrophin-releasing hormone (GnRH) antagonists can be used to prevent a luteinizing hormone (LH) surge during controlled ovarian hyperstimulation (COH) without the hypo-oestrogenic side-effects, flare-up, or long down-regulation period associated with agonists. The antagonists

  19. Role of thyrotropin-releasing hormone in prolactin-producing cell models.

    Science.gov (United States)

    Kanasaki, Haruhiko; Oride, Aki; Mijiddorj, Tselmeg; Kyo, Satoru

    2015-12-01

    Thyrotropin-releasing hormone (TRH) is a hypothalamic hypophysiotropic neuropeptide that was named for its ability to stimulate the release of thyroid-stimulating hormone in mammals. It later became apparent that it exerts a number of species-dependent hypophysiotropic activities that regulate other pituitary hormones. TRH also regulates the synthesis and release of prolactin, although whether it is a physiological regulator of prolactin that remains unclear. Occupation of the Gq protein-coupled TRH receptor in the prolactin-producing lactotroph increases the turnover of inositol, which in turn activates the protein kinase C pathway and the release of Ca(2+) from storage sites. TRH-induced signaling events also include the activation of extracellular signal-regulated kinase (ERK) and induction of MAP kinase phosphatase, an inactivator of activated ERK. TRH stimulates prolactin synthesis through the activation of ERK, whereas prolactin release occurs via elevation of intracellular Ca(2+). We have been investigating the role of TRH in a pituitary prolactin-producing cell model. Rat pituitary somatolactotroph GH3 cells, which produce and release both prolactin and growth hormone (GH), are widely used as a model for the study of prolactin- and GH-secreting cells. In this review, we describe the general action of TRH as a hypophysiotropic factor in vertebrates and focus on the role of TRH in prolactin synthesis using GH3 cells.

  20. Butyrate Increases Intracellular Calcium Levels and Enhances Growth Hormone Release from Rat Anterior Pituitary Cells via the G-Protein-Coupled Receptors GPR41 and 43

    OpenAIRE

    Maria Consolata Miletta; Vibor Petkovic; Andrée Eblé; Ammann, Roland A; Flück, Christa E.; Primus-E Mullis

    2014-01-01

    Butyrate is a short-chain fatty acid (SCFA) closely related to the ketone body ß-hydroxybutyrate (BHB), which is considered to be the major energy substrate during prolonged exercise or starvation. During fasting, serum growth hormone (GH) rises concomitantly with the accumulation of BHB and butyrate. Interactions between GH, ketone bodies and SCFA during the metabolic adaptation to fasting have been poorly investigated to date. In this study, we examined the effect of butyrate, an endogenous...

  1. Butyrate increases intracellular calcium levels and enhances growth hormone release from rat anterior pituitary cells via the G-protein-coupled receptors GPR41 and 43

    OpenAIRE

    Miletta, Maria Consolata; Petkovic, Vibor; Eblé, Andrée; Ammann, Roland; Flück, Christa; Mullis, Primus-Eugen

    2014-01-01

    Butyrate is a short-chain fatty acid (SCFA) closely related to the ketone body ß-hydroxybutyrate (BHB), which is considered to be the major energy substrate during prolonged exercise or starvation. During fasting, serum growth hormone (GH) rises concomitantly with the accumulation of BHB and butyrate. Interactions between GH, ketone bodies and SCFA during the metabolic adaptation to fasting have been poorly investigated to date. In this study, we examined the effect of butyrate, an endogenous...

  2. Prospective hormone study of hypothalamic-pituitary function in patients with nasopharyngeal carcinoma after high dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ming-Shen; Lin, Fang-Jen; Huang, Miau-Ju; Wang, Pei-Wan; Tang, Simon; Leung, Wei-Man; Leung, Wan (Chang-Gung Memorial Hospital, Taipei (Taiwan))

    1989-09-01

    With the aim of evaluating the effect of high dose irradiation (6,500 cGy/36 fractions or higher) to pituitary fossa, a prospective study was carried out in patients with nasopharyngeal cancer by a serial determination of several hormones in the serum, before and after the course of radiation therapy (RT). The radiation treatment field was at least 1 cm above the skull base with bilateral parallel opposing fields. Hormone assays were performed three times on each patient: (1)prior to, (2)one month after, (3)15-18 months after radiation therapy. The study included determination of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), cortisol, growth hormone (GH) and prolactin concentrations and LH-releasing hormone, thyrotrophin-releasing hormone stimulation and insulin tolerance tests were also carried out. Complete profiles were obtained in 24 patients (16 males and 8 females), aged 16-67 years. The results showed a significant decrease in the level of serum peak value of LH in males 18 months after therapy, and also in GH both one month and 18 months after therapy. A significant increase in the peak value of serum TSH was observed after therapy. Decreased serum FSH, cortisol and prolactin levels were noted, but these did not reach statistical significance. The decrease in GH level appeared earlier and was more sensitive than that found for the other hormones, and could prove to be a useful parameter for clinical evaluation. None of the patients showed any clinically recognizable symptoms or signs of hormone deficiency in the 18-33 months following completion of the radiation therapy. (author).

  3. CONTENTS BASAL LEVELS of SEX HORMONES and PITUITARY HORMONES IN PATIENTS DEMODECOSIS

    OpenAIRE

    Bodnya K. I.; Revenko Zh. A.

    2014-01-01

    The regularities of changes in the nature and dynamics of clinical – hormonal parameters are revealed in this research that are not being specific they expand knowledge of the pathogenesis of demodicosis and create certain conditions for the directed correction of compensatory and adaptive capabilities of the host and open up prospect for improvement – pathogenetic treatment of demodicosis and its complications.

  4. Modulations of prolactin and growth hormone gene expression and chromatin structure in cultured rat pituitary cells.

    OpenAIRE

    Levy-Wilson, B

    1983-01-01

    I have measured the effect of hormones and other regulatory factors present in the serum component of the culture medium on the levels of growth hormone and prolactin mRNAs in rat pituitary (GH4) cells. Hybridization of cytoplasmic RNA with growth hormone or prolactin cDNA clones indicate that serum depletion reduces significantly the amount of these two mRNAs. The localization of these two genes in chromatin was also analysed using micrococcal nuclease as a probe. At intermediate levels of d...

  5. Binding properties of solubilized gonadotropin-releasing hormone receptor: role of carboxylic groups

    Energy Technology Data Exchange (ETDEWEB)

    Hazum, E.

    1987-11-03

    The interaction of /sup 125/I-buserelin, a superactive agonist of gonadotropin-releasing hormone (GnRH), with solubilized GnRH receptor was studied. The highest specific binding of /sup 125/I-buserelin to solubilized GnRH receptor is evident at 4/sup 0/C, and equilibrium is reached after 2 h of incubation. The soluble receptor retained 100% of the original binding activity when kept at 4 or 22/sup 0/C for 60 min. Mono- and divalent cations inhibited, in a concentration-dependent manner, the binding of /sup 125/I-buserelin to solubilized GnRH receptor. Monovalent cations require higher concentrations than divalent cations to inhibit the binding. Since the order of potency with the divalent cations was identical with that of their association constants to dicarboxylic compounds, it is suggested that there are at least two carboxylic groups of the receptor that participate in the binding of the hormone. The carboxyl groups of sialic acid residues are not absolutely required for GnRH binding since the binding of /sup 125/I-buserelin to solubilized GnRH receptor was only slightly affected by pretreatment with neuraminidase and wheat germ agglutinin. The finding that polylysines stimulate luteinizing hormone (LH) release from pituitary cell cultures with the same efficacy as GnRH suggest that simple charge interactions can induce LH release. According to these results, the authors propose that the driving force for the formation of the hormone-receptor complex is an ionic interaction between the positively charged amino acid arginine in position 8 and the carboxyl groups in the binding site.

  6. Blood plasma levels of anterior pituitary hormones of rabbits after apricot seed exposure in vivo

    Directory of Open Access Journals (Sweden)

    Katarína MICHALCOVÁ

    2016-12-01

    Full Text Available The present study describes possible changes in plasma levels of anterior pituitary hormones induced by bitter apricot (Prunus armeniaca L. seeds in young female rabbits in vivo. Prunus armeniaca L. is an important medicinal edible plant species commonly known as “apricot”. The apricot is a member of the Rosaceae and subfamily Prunoideae. It is one of the most delicious and commercially traded fruits in the world. Apricot kernel is the inner part of the seed of the apricot fruit. The kernel is used to produce oil and other chemicals used for medicinal purposes. The seeds are potentially useful in human nutrition and for treatment several diseases especially cancer. In the present study apricot seeds were mixed with feed at different doses 0, 60, 300, 420 mg*kg-1 of body weight. ELISA was used to determine the levels of follicle stimulating hormone (FSH, luteinizing hormone (LH and prolactin (PRL. 58-days application of apricot seeds did not affect the concentration (P≥0.05 of PRL, LH in blood plasma. Significant (P≤0.01 inhibition of FSH levels induced by the seeds was found at the dose of 420 mg*kg-1 but not at 60 and 300 mg*kg-1 of body weight. These results are suggesting that the natural substances present in apricot seeds may be involved in mechanisms of ovarian folliculogenesis.

  7. Pituitary adenylate cyclase activating polypeptide (PACAP), stress, and sex hormones.

    Science.gov (United States)

    King, S Bradley; Toufexis, Donna J; Hammack, Sayamwong E

    2017-06-14

    Stressor exposure is associated with the onset and severity of many psychopathologies that are more common in women than men. Moreover, the maladaptive expression and function of stress-related hormones have been implicated in these disorders. Evidence suggests that PACAP has a critical role in the stress circuits mediating stress-responding, and PACAP may interact with sex hormones to contribute to sex differences in stress-related disease. In this review, we describe the role of the PACAP/PAC1 system in stress biology, focusing on the role of stress-induced alterations in PACAP expression and signaling in the development of stress-induced behavioral change. Additionally, we present more recent data suggesting potential interactions between stress, PACAP, and circulating estradiol in pathological states, including PTSD. These studies suggest that the level of stress and circulating gonadal hormones may differentially regulate the PACAPergic system in males and females to influence anxiety-like behavior and may be one mechanism underlying the discrepancies in human psychiatric disorders.

  8. Gonadotropin releasing hormone agonists: Expanding vistas

    Directory of Open Access Journals (Sweden)

    Navneet Magon

    2011-01-01

    Full Text Available Gonadotropin-releasing hormone (GnRH agonists are derived from native GnRH by amino acid substitution which yields the agonist resistant to degradation and increases its half-life. The hypogonadotropic hypogonadal state produced by GnRH agonists has been often dubbed as "pseudomenopause" or "medical oophorectomy," which are both misnomers. GnRH analogues (GnRH-a work by temporarily "switching off" the ovaries. Ovaries can be "switched off" for the therapy and therapeutic trial of many conditions which include but are not limited to subfertility, endometriosis, adenomyosis, uterine leiomyomas, precocious puberty, premenstrual dysphoric disorder, chronic pelvic pain, or the prevention of menstrual bleeding in special clinical situations. Rapidly expanding vistas of usage of GnRH agonists encompass use in sex reassignment of male to female transsexuals, management of final height in cases of congenital adrenal hyperplasia, and preserving ovarian function in women undergoing cytotoxic chemotherapy. Hypogonadic side effects caused by the use of GnRH agonists can be tackled with use of "add-back" therapy. Goserelin, leuprolide, and nafarelin are commonly used in clinical practice. GnRH-a have provided us a powerful therapeutic approach to the treatment of numerous conditions in reproductive medicine. Recent synthesis of GnRH antagonists with a better tolerability profile may open new avenues for both research and clinical applications. All stakeholders who are partners in women′s healthcare need to join hands to spread awareness so that these drugs can be used to realize their full potential.

  9. The relationship of appetitive, reproductive and posterior pituitary hormones to alcoholism and craving in humans.

    Science.gov (United States)

    Kenna, George A; Swift, Robert M; Hillemacher, Thomas; Leggio, Lorenzo

    2012-09-01

    A significant challenge for understanding alcoholism lies in discovering why some, but not other individuals, become dependent on alcohol. Genetic, environmental, cultural, developmental, and neurobiological influences are recognized as essential factors underlying a person's risk for becoming alcohol dependent (AD); however, the neurobiological processes that trigger this vulnerability are still poorly understood. Hormones are important in the regulation of many functions and several hormones are strongly associated with alcohol use. While medical consequences are important, the primary focus of this review is on the underlying confluence of appetitive/feeding, reproductive and posterior pituitary hormones associated with distinct phases of alcoholism or assessed by alcohol craving in humans. While these hormones are of diverse origin, the involvement with alcoholism by these hormone systems is unmistakable, and demonstrates the complexity of interactions with alcohol and the difficulty of successfully pursuing effective treatments. Whether alcohol associated changes in the activity of certain hormones are the result of alcohol use or are the result of an underlying predisposition for alcoholism, or a combination of both, is currently of great scientific interest. The evidence we present in this review suggests that appetitive hormones may be markers as they appear involved in alcohol dependence and craving, that reproductive hormones provide an example of the consequences of drinking and are affected by alcohol, and that posterior pituitary hormones have potential for being targets for treatment. A better understanding of the nature of these associations may contribute to diagnosing and more comprehensively treating alcoholism. Pharmacotherapies that take advantage of our new understanding of hormones, their receptors, or their potential relationship to craving may shed light on the treatment of this disorder.

  10. Progressive pituitary hormone deficiency following radiation therapy in adults; Deficiencia progressiva dos hormonios adeno-hipofisarios apos radioterapia em adultos

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Rafaela A.; Vaisman, Mario [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Servico de Endocrinologia]. E-mail: rafaela_loureiro@hotmail.com

    2004-10-01

    Hypopituitarism can be caused by radiation therapy, even when it is not directly applied on the hypothalamic-pituitary axis, and can lead to anterior pituitary deficiency mainly due to hypothalamic damage. The progressive loss of the anterior pituitary hormones usually occurs in the following order: growth hormone, gonadotropin hormones, adrenocorticotropic hormone and thyroid-stimulating hormone. Although there are several different tests available to confirm anterior pituitary deficiency, this paper will focus on the gold standard tests for patients submitted to radiation therapy. We emphasize that the decline of anterior pituitary function is time- and dose-dependent with some variability among the different axes. Therefore, awareness of the need of a joint management by endocrinologists and oncologists is essential to improve treatment and quality of life of the patients. (author)

  11. Receptors for thyrotropin-releasing hormone, thyroid-stimulating hormone, and thyroid hormones in the macaque uterus: effects of long-term sex hormone treatment.

    Science.gov (United States)

    Hulchiy, Mariana; Zhang, Hua; Cline, J Mark; Hirschberg, Angelica Lindén; Sahlin, Lena

    2012-11-01

    Thyroid gland dysfunction is associated with menstrual cycle disturbances, infertility, and increased risk of miscarriage, but the mechanisms are poorly understood. However, little is known about the regulation of these receptors in the uterus. The aim of this study was to determine the effects of long-term treatment with steroid hormones on the expression, distribution, and regulation of the receptors for thyrotropin-releasing hormone (TRHR) and thyroid-stimulating hormone (TSHR), thyroid hormone receptor α1/α2 (THRα1/α2), and THRβ1 in the uterus of surgically menopausal monkeys. Eighty-eight cynomolgus macaques were ovariectomized and treated orally with conjugated equine estrogens (CEE; n = 20), a combination of CEE and medroxyprogesterone acetate (MPA; n = 20), or tibolone (n = 28) for 2 years. The control group (OvxC; n = 20) received no treatment. Immunohistochemistry was used to evaluate the protein expression and distribution of the receptors in luminal epithelium, glands, stroma, and myometrium of the uterus. Immunostaining of TRHR, TSHR, and THRs was detected in all uterine compartments. Epithelial immunostaining of TRHR was down-regulated in the CEE + MPA group, whereas in stroma, both TRHR and TSHR were increased by CEE + MPA treatment as compared with OvxC. TRHR immunoreactivity was up-regulated, but THRα and THRβ were down-regulated, in the myometrium of the CEE and CEE + MPA groups. The thyroid-stimulating hormone level was higher in the CEE and tibolone groups as compared with OvxC, but the level of free thyroxin did not differ between groups. All receptors involved in thyroid hormone function are expressed in monkey uterus, and they are all regulated by long-term steroid hormone treatment. These findings suggest that there is a possibility of direct actions of thyroid hormones, thyroid-stimulating hormone and thyrotropin-releasing hormone on uterine function.

  12. Growth hormone-secreting pituitary adenoma:clinical and MR imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hong Suk; Chang, Kee Hyun; Han, Moon Hee; Sim, Jung Suk; Lee, Sang Hyun; Song, Jae Uoo; Yoo, In Kyu; Jung, Hee Won; Yeon, Kyung Mo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-10-01

    To describe clinical and MRI findings of growth hormone-secreting pituitary adenoma, to determine if there are any characteristic MRI findings different from those of other pituitary adenomas, to evaluate the relationship between tumor size and serum growth hormone level, and to assess the results of immunohi-stochemical study. We retrospectively analysed clinical and MRI findings of 29 patients with growth hormone-secreting pituitary adenoma confirmed by serum growth hormone level and surgery. We also evaluated the relationship between the tumor volume and serum growth hormone level, and the results of immunohistochemical study. Coronal and sagittal T1-weighted MR images in all patients and gadolinium-enhanced T1-weighted MR images in 28 patients were obtained with 2.0 T(24 cases) and 0.5 T(5 cases) MR imagers. The images were analyzed in terms of tumor size, signal intensity, degree of contrast enhancement, extent of tumor growth and the presence or absence of cystic change, hemorrhage and calcification. Clinical manifestations included facial feature change and soft tissue swelling of hands and feet(n=29), headache(n=12), impaired visual acuity(n=9), symptoms of hyperprolactinemia(n=8), visual field defect(n=5), and others(n=6). On MR images, all of the 29 cases were seen to be macroadenomas and the size of the tumors averaged 2.2cm(1-5.2cm). Supra- and infrasellar extensions were seen in 21 and 22 patients, respectively. Cavernous sinus invasion was noted in seven, and in one this was bilateral. Signal intensity was isointense with cortical grey matter in 26 cases(90%). Cystic change or necrosis was seen in eight cases(28%), hemorrhage in four(14%), and calcification in two(7%). After enhancement, most(25/28) of the tumors enhanced less than normal pituitary in degree. There was no correlation between serum growth hormone level and tumor size. Immunohistochemical study showed positive growth hormone-secreting pituitary adenomas were various and included

  13. CONTENTS BASAL LEVELS of SEX HORMONES and PITUITARY HORMONES IN PATIENTS DEMODECOSIS

    Directory of Open Access Journals (Sweden)

    Bodnya K. I.

    2014-01-01

    Full Text Available The regularities of changes in the nature and dynamics of clinical – hormonal parameters are revealed in this research that are not being specific they expand knowledge of the pathogenesis of demodicosis and create certain conditions for the directed correction of compensatory and adaptive capabilities of the host and open up prospect for improvement – pathogenetic treatment of demodicosis and its complications.

  14. Effects of growth hormone deficiency and recombinant growth hormone therapy on postprandial gallbladder motility and cholecystokinin release.

    NARCIS (Netherlands)

    Moschetta, A.; Twickler, M.; Rehfeld, J.F.; Ooteghem, N.A. van; Castro Cabezas, M.; Portincasa, P.; Berge-Henegouwen, G.P. van; Erpecum, K.J. van

    2004-01-01

    In addition to cholecystokinin, other hormones have been suggested to be involved in regulation of postprandial gallbladder contraction. We aimed to evaluate effects of growth hormone (GH) on gallbladder contractility and cholecystokinin release. Gallbladder and gastric emptying (by ultrasound) and

  15. β-Hydroxybutyric Sodium Salt Inhibition of Growth Hormone and Prolactin Secretion via the cAMP/PKA/CREB and AMPK Signaling Pathways in Dairy Cow Anterior Pituitary Cells

    Directory of Open Access Journals (Sweden)

    Shou-Peng Fu

    2015-02-01

    Full Text Available β-hydroxybutyric acid (BHBA regulates the synthesis and secretion of growth hormone (GH and prolactin (PRL, but its mechanism is unknown. In this study, we detected the effects of BHBA on the activities of G protein signaling pathways, AMPK-α activity, GH, and PRL gene transcription, and GH and PRL secretion in dairy cow anterior pituitary cells (DCAPCs. The results showed that BHBA decreased intracellular cAMP levels and a subsequent reduction in protein kinase A (PKA activity. Inhibition of PKA activity reduced cAMP response element-binding protein (CREB phosphorylation, thereby inhibiting GH and PRL transcription and secretion. The effects of BHBA were attenuated by a specific Gαi inhibitor, pertussis toxin (PTX. In addition, intracellular BHBA uptake mediated by monocarboxylate transporter 1 (MCT1 could trigger AMPK signaling and result in the decrease in GH and PRL mRNA translation in DCAPCs cultured under low-glucose and non-glucose condition when compared with the high-glucose group. This study identifies a biochemical mechanism for the regulatory action of BHBA on GH and PRL gene transcription, translation, and secretion in DCAPCs, which may be one of the factors that regulate pituitary function during the transition period in dairy cows.

  16. Pituitary-Gonadal Axis Hormone and Semen Analysis in Narcotic Dependency

    Directory of Open Access Journals (Sweden)

    Raheleh Assaei

    2013-04-01

    Full Text Available Background: Drug abuse is associated with numerous complications including hormonal disorders of hypothalamic-pituitary-gonadal axis and spermatogenic disorders. We have compared the hormone concentration of pituitary-gonadal axis and the semen analysis in opioid-dependent and non-opioid-dependent men.Materials and Methods: In this case-control study, serum concentration of pituitary- gonadal axis hormones and semen analysis in 48 opioid-dependent men as eligible to participate in the study were compared with those in 12 non-dependent men.Results: Free testosterone concentration in all test groups was significantly less than that in control group. Furthermore, the concentration of Dihydrotestosterone (DHT and Dehydroepiandrosterone Sulfate (DHEAS in all test groups except those addicted to heroin was less than in those in control group. Concentrations of LH, FSH, prolactin, SHBG, progesterone and estradiol, normal and abnormal sperm count in test groups were significantly different from control group. However, in all test groups, sperm motility rate was less than control group. No significant relationship was found between the concentration of sex hormones and the status of sperms motility. Conclusion: Chronic use of opioids will affect testosterone hormone and sperm, and it will cause hypogonadism and impairment of sperm motility.

  17. Fractures in pituitary adenoma patients from the Dutch National Registry of Growth Hormone Treatment in Adults

    NARCIS (Netherlands)

    N.C. Van Varsseveld; C.C. van Bunderen (Christa); A.A.M. Franken (Anton); H.P.F. Koppeschaar (Hans); A-J. van der Lely (Aart-Jan); M.L. Drent (Madeleine)

    2016-01-01

    textabstractPurpose: The effects of growth hormone (GH) replacement therapy on fracture risk in adult GH deficient (GHD) patients with different etiologies of pituitary GHD are not well known, due to limited data. The aim of this study was to investigate characteristics and fracture occurrence at st

  18. Growth hormone receptor expression and function in pituitary adenomas

    DEFF Research Database (Denmark)

    Clausen, Lene R; Kristiansen, Mikkel T; Rasmussen, Lars M

    2004-01-01

    OBJECTIVE AND DESIGN: Hypopituitarism, in particular GH deficiency, is prevalent in patients with clinically nonfunctioning pituitary adenomas (NFPAs) both before and after surgery. The factors regulating the growth of pituitary adenomas in general and residual tumour tissue in particular...

  19. Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas

    Directory of Open Access Journals (Sweden)

    Wang JW

    2014-01-01

    Full Text Available Ji-wen Wang,1,2 Ying Li,3 Zhi-gang Mao,1,2 Bin Hu,1,2 Xiao-bing Jiang,1,2 Bing-bing Song,4 Xin Wang,4 Yong-hong Zhu,4 Hai-jun Wang1,21Department of Neurosurgery and Pituitary Tumor Center, The First Affiliated Hospital, Sun Yat-sen University, 2Key Laboratory of Pituitary Adenoma in Guangdong Province, 3State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 4Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, People's Republic of ChinaAbstract: Excessive growth hormone (GH is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs and GH receptor antagonist; the former consists of lanreotide Autogel (ATG and octreotide long-acting release (LAR, and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4–6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated

  20. Central administration of thyrotropin releasing hormone (TRH) and related peptides inhibits feeding behavior in the Siberian hamster.

    Science.gov (United States)

    Steward, Carolyn A; Horan, Tracey L; Schuhler, Sandrine; Bennett, Geoffrey W; Ebling, Francis J P

    2003-04-15

    Centrally acting thyrotropin releasing hormone (TRH), independent of endocrine action, has been shown to regulate several metabolic and behavioral parameters in rats, including food intake and locomotor activity. The present study investigated and compared the effects of central TRH on feeding behavior in Siberian hamsters exposed to long (LP) or short (SP) photoperiods, which induce natural physiological states of obesity and leanness respectively. The effects of two TRH analogues, RX77368 (a metabolically stable TRH analogue) and TRH-Gly (an endogenous precursor to TRH with putative preferential action at the central TRH receptor, TRH-R2), were also investigated. All peptides were infused via the third ventricle (i.c.v.). Food intake was measured, and the proportion of time spent interacting with food, active or resting was scored. TRH (5 microg) significantly reduced food intake without producing associated changes in activity in hamsters maintained in both LP (p hamsters exposed to SP, indicating that there may be an underlying difference in sensitivity to TRH depending on metabolic state. RX77368 (1 microg) produced substantial hypophagia (p < 0.001) and decreased the proportion of time spent interacting with food, but, unlike TRH, may produce this via an increase in locomotor activity. TRH-Gly (5 microg) produced a small decrease in food intake (p < 0.05), lasting for 6 h. We conclude that TRH and TRH analogues possess anorexigenic capacities in this species, with a likely site of action in the hypothalamus. Increased sensitivity to the hypophagic effects of central TRH may contribute to the long-term catabolic state induced by short photoperiods.

  1. Clinical and Biochemical Characteristics of Growth Hormone-Secreting Pituitary Tumors

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To investigate the difference of biochemical characteristics on gsp-positive and gsp-negative growth hormone (GH)-secreting pituitary tumors, 18 GH-secreting pituitary tumors were examined for their clinical characteristics and gsp oncogenes. All patients received the pituitary function combinative stimulating test. It was found that there were no difference in the sex, age, tumor size, course of disease and plasma basal GH levels with gsp- positive and gsp-negative patients. The plasma levels of PRL were increased in most patients (11/18), and the plasma levels of TSH in gsp-positive patients were higher than those in gsp-negative patients (P<0.05). There was no significant difference in the responses to pituitary combinative stimulating test in gsp-positive and gsp-negative patients. It was concluded that there was little difference in the clinical biochemical characteristics of gsp-positive with gsp-negative GH-secreting pituitary tumors.

  2. Growth hormone (GH) and GH-releasing hormone (GHRH): Co-localization and action in the chicken testis.

    Science.gov (United States)

    Martínez-Moreno, Carlos G; López-Marín, Luz M; Carranza, Martha; Giterman, Daniel; Harvey, Steve; Arámburo, Carlos; Luna, Maricela

    2014-04-01

    Growth hormone (GH) gene expression is not confined to the pituitary gland and occurs in many extrapituitary tissues, including the chicken testis. The regulation and function of GH in extrapituitary tissues is, however, largely unknown. The possibility that chicken testicular GH might be regulated by GH-releasing hormone (GHRH), as in the avian pituitary gland, was investigated in the present study. GHRH co-localized with GH in the germinal epithelium and in interstitial zones within the chicken testes, particularly in the spermatogonia and spermatocytes. In testicular cell cultures, exogenous human GHRH1-44 induced (at 1, 10 and 100nM) a dose-related increase in GH release. Western blot analysis showed a heterogeneous pattern in the GH moieties released during GHRH stimulation. 26kDa monomer GH was the most abundant moiety under basal conditions, but 15 and 17kDa isoforms were more abundant after GHRH stimulation. GHRH treatment also increased the abundance of PCNA (proliferating cell nuclear antigen) immunoreactivity in the testes. This may have been GH-mediated, since exogenous GH similarly increased the incorporation of ((3)H)-thymidine into cultured testicular cells and increased their metabolic activity, as determined by increased MTT reduction. Furthermore, GH and GHRH immunoneutralization blocked GHRH-stimulated proliferative activity. In summary, these results indicate that GHRH stimulates testicular GH secretion in an autocrine or paracrine manner. Data also demonstrate proliferative actions of GHRH on testicular cell number and suggest that this action is mediated by local GH production.

  3. Corticotropin-releasing hormone: Mediator of vertebrate life stage transitions?

    Science.gov (United States)

    Watanabe, Yugo; Grommen, Sylvia V H; De Groef, Bert

    2016-03-01

    Hormones, particularly thyroid hormones and corticosteroids, play critical roles in vertebrate life stage transitions such as amphibian metamorphosis, hatching in precocial birds, and smoltification in salmonids. Since they synergistically regulate several metabolic and developmental processes that accompany vertebrate life stage transitions, the existence of extensive cross-communication between the adrenal/interrenal and thyroidal axes is not surprising. Synergies of corticosteroids and thyroid hormones are based on effects at the level of tissue hormone sensitivity and gene regulation. In addition, in representative nonmammalian vertebrates, corticotropin-releasing hormone (CRH) stimulates hypophyseal thyrotropin secretion, and thus functions as a common regulator of both the adrenal/interrenal and thyroidal axes to release corticosteroids and thyroid hormones. The dual function of CRH has been speculated to control or affect the timing of vertebrate life history transitions across taxa. After a brief overview of recent insights in the molecular mechanisms behind the synergic actions of thyroid hormones and corticosteroids during life stage transitions, this review examines the evidence for a possible role of CRH in controlling vertebrate life stage transitions. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Recruiting of somatotroph cells after combined somatostatin, GHRH and growth hormone (GH) secretagogue stimulation in a study of pituitary GH reserve in prepuberal female rats

    OpenAIRE

    Jiménez Reina, L.; García-Martínez, E.; Rojas, J.P.; Cañete, M.D.; G. Bernal; Cañete, R.

    2006-01-01

    Diagnostic confirmation of growth hormone (GH) deficiency in children and adults is based on stimulation tests designed to assess the pituitary reserve by measuring the amount of GH released into the bloodstream; however, the results obtained by this means cannot provide any direct indication of the amount of GH actually produced by pituitary somatotroph cells. The present paper sought to test the hypothesis that release of GH following administration of sp...

  5. Changes of hypothalamus-pituitary hormones in patients after total removal of craniopharyngiomas

    Institute of Scientific and Technical Information of China (English)

    周忠清; 石祥恩

    2004-01-01

    Background This paper aimed to elucidate the changes of hypothalamus-pituitary hormones in patients after total removal of craniopharyngiomas.Methods A total of 40 patients with craniopharyngiomas received surgery. The levels of triiodothyronine (T3), thyroxine (T4), thyrotropic hormone (TSH), antidiuretic hormone (ADH), and adrenocorticotropin (ACTH) were measureed in the 40 patients before surgery and one week after surgery respectively.Results Twenty-eight patients (70%) had hypothyroidism before surgery, but 38 (95%) had hypothyroidism after surgery (P0.05), whereas those of ACTH were (23.97±2.69) pg/ml and (15.60±1.91) pg/ml respectively (P<0.05).Conclusions Hormone deficits after total removal of craniopharyngioma appear to be the common complication of surgery. Hypothyroidism and diabetes insipidus are more frequent after surgery than before surgery. Thyroxine and glucocorticoids should be administered routinely after total removal of craniopharyngioma.

  6. High prevalence rate of pituitary incidentaloma: is it associated with the age-related decline of the sex hormones levels?

    Science.gov (United States)

    Kastelan, Darko; Korsic, Mirko

    2007-01-01

    Incidental pituitary adenoma is the common finding during brain imaging. According to multistep model of pituitary tumourigenesis genetic alterations provide the initiating event that transforms cells while hormones play a role in promoting cell proliferation. Development of pituitary adenoma in a case of excessive hypophysiotrophic hormones production or reduced feedback suppression by target gland hormones emphasizes the importance of hormonal stimulation in pituitary tumourigenesis. Pituitary hyperplasia has been reported in pregnancy, hypothyroidism and conditions such as CRH or GHRH hypersecretion. Moreover, recent study reported one case of gonadotroph macroadenoma and two cases of gonadotroph cells hyperplasia in patients with Klinefelter syndrome probably due to protracted stimulation of gonadotroph cells because of lack of androgen feedback. Significant changes of the hypothalamic-pituitary-gonadal axis occurred with aging. In females, after menopause, estradiol level decreases by 35-fold and estrone level by 20-fold that results in increased gonadotropins levels. Similarly, FSH, but not LH, level is increased with advancing age in men, too, although the age-related difference in the level is less in comparison with women. Regarding these data, we hypothesised that high prevalence rate of pituitary incidentaloma in the elderly is associated with age-related decline in sex hormones levels and subsequent lack of feedback suppression leading to permanent gonadotrophs stimulation which is the crucial step in the pituitary tumour development. According to previously mentioned multistep model of pituitary tumourigenesis, incidentaloma will develop only in persons with already present intrinsic pituitary cell defects. However, further studies have to answer the questions of whether the incidence of pituitary tumours is more frequent in elderly, whether women with late onset menopause or those taking long-term hormone replacement therapy have lower rate of

  7. Differential gene expression of growth hormone (GH)-releasing hormone (GRH) and GRH receptor in various rat tissues.

    Science.gov (United States)

    Matsubara, S; Sato, M; Mizobuchi, M; Niimi, M; Takahara, J

    1995-09-01

    Growth hormone (GH)-releasing hormone (GRH) acts on specific receptors in the anterior pituitary to stimulate the synthesis and release of GH. Recent reports suggest that GRH is also synthesized in extrahypothalamic tissues. To evaluate the potential roles of extrahypothalamic GRH, we studied the gene expression of GRH and GRH receptors in various rat tissues by reverse transcribed (RT)-polymerase chain reaction (PCR). Total RNA was extracted from twenty-three rat organs and RT-PCR was performed with GRH and GRH receptor primers. Highly-sensitive RT-PCR-Southern blotting showed that GRH and GRH receptor mRNA coexist in the widespread tissues (14 of 25 tissues). GRH mRNA was relatively abundant in the cerebral cortex, brain stem, testis, and placenta, while GRH receptor mRNA was abundant in renal medulla and renal pelvis. Northern blot hybridization using poly A+ RNA indicated that the transcript of GRH receptor gene found in the renal medulla was similar to the longer transcript (about 4 Kb) of pituitary GRH receptor in the size. These results suggest that GRH plays a potential role not only in the neuroendocrine axis, but also in the autocrine and paracrine systems in extrahypothalamic tissues.

  8. Adaptation of the hypothalamic-pituitary hormones during intensive endurance training.

    Science.gov (United States)

    Bobbert, T; Brechtel, L; Mai, K; Otto, B; Maser-Gluth, C; Pfeiffer, A F H; Spranger, J; Diederich, S

    2005-11-01

    Physical activity leads to changes in the hypothalamic-pituitary hormonal system. However, acute and long-term adaptations have not yet been precisely characterized. In this study, the changes of the hormonal system as a result of marathon training and running a marathon were examined. In particular, we focused on adaptations of the hypothalamic-pituitary-adrenocortical (HPA) axis, regarding the activation or inactivation of cortisol to cortisone by the 11beta-hydroxysteroid-dehydrogenase system (11beta-HSD). Patient measurements: 8 healthy women and 11 healthy men volunteered for this study. Blood samples, 24-h urine and a dexamethasone suppression test were analysed for metabolic and hormonal parameters at five different dates 12 weeks around a marathon. Cortisol and ACTH values decreased significantly 2 days after the marathon, whereas the activity of the whole body 11beta-HSD-1 was up-regulated. An increased suppression of cortisol levels was observed in the dexamethasone suppression test after 6 weeks of reduced training levels. Ghrelin was elevated 2 days after the marathon. Only minor changes in the other hypothalamic-pituitary-hormonal axes could be observed. However, the free androgen index increased significantly after 6 weeks of reduced training. The HPA system appeared to become chronically activated by continuous physical training and therefore less sensitive to the dexamethasone suppression test. The acute stress of the marathon led to a central exhaustion of the HPA system with a paracrine counteraction by the activation of the 11beta-HSD system. Changes in the other hypothalamic-pituitary hormonal axes were the result of long-term differences in training levels and were not altered by the marathon.

  9. Dopaminergic regulation of luteinizing hormone-releasing hormone release at the median eminence level: immunocytochemical and physiological evidence in hens.

    Science.gov (United States)

    Contijoch, A M; Gonzalez, C; Singh, H N; Malamed, S; Troncoso, S; Advis, J P

    1992-03-01

    Theoretically, the most effective inhibitory control of hypophysiotropic luteinizing hormone-releasing hormone (LHRH) release might occur through a presynaptic inhibition of LHRH neuronal terminals at the median eminence (ME) level. Since: (a) we have recently reported the existence of synaptic contacts between dopamine- and LHRH-containing processes in the ewe ME, and (b) nutritional deprivation induces an ovulatory failure in both birds and mammals, we have assessed the possibility that the anovulatory state induced by feed withdrawal (FW) in laying hens, might be caused by a dopaminergic inhibition of LHRH release at the ME level. Laying hens at the start (35 weeks old) and end (75 weeks old) of their commercial egg-laying life were killed at 0, 1, 2 and 4 days after FW. Serum luteinizing hormone (LH) and progesterone (P4), in vitro release of LHRH by isolated ME, and LHRH content in ME and preoptic area (POA) were determined by RIA. ME content of dopamine (DA) and its main metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) were assessed by LCED. The distribution of LHRH and tyrosine hydroxylase (TH)-containing processes at the ME level of the hen was determined immunocytochemically. In the hen, LHRH-containing cell bodies are localized in the anterior hypothalamus and medial POA. LHRH-containing axons project toward the ME and infundibulum through the ventral-lateral hypothalamus. TH-containing perikarya are concentrated in the arcuate nucleus and in the adjacent part of the periventricular nucleus, dorsal to the arcuate. TH-containing axons converge toward the ME and descend into the infundibulum. Dense concentrations of TH- and LHRH-containing processes are located in the lateral and mediobasal portions of the external layer of the ME, providing opportunities for synaptic interactions between them. Ovulatory failure and regression of the ovary and reproductive tract occurred 2-3 days after FW at the end, but not at the beginning of the hen's commercial egg

  10. Characterization of pituitary growth hormone and its receptor in the green iguana (Iguana iguana).

    Science.gov (United States)

    Ávila-Mendoza, José; Carranza, Martha; Pérez-Rueda, Ernesto; Luna, Maricela; Arámburo, Carlos

    2014-07-01

    Pituitary growth hormone (GH) has been studied in most vertebrate groups; however, only a few studies have been carried out in reptiles. Little is known about pituitary hormones in the order Squamata, to which the green iguana (gi) belongs. In this work, we characterized the hypophysis of Iguana iguana morphologically. The somatotrophs (round cells of 7.6-10 μm containing 250- to 300-nm secretory granules where the giGH is stored) were found, by immunohistochemistry and in situ hybridization, exclusively in the caudal lobe of the pars distalis, whereas the lactotrophs were distributed only in the rostral lobe. A pituitary giGH-like protein was obtained by immuno-affinity chromatography employing a heterologous antibody against chicken GH. giGH showed molecular heterogeneity (22, 44, and 88 kDa by SDS-PAGE/Western blot under non-reducing conditions and at least four charge variants (pIs 6.2, 6.5, 6.9, 7.4) by isoelectric focusing. The pituitary giGH cDNA (1016 bp), amplified by PCR and RACE, encodes a pre-hormone of 218 aa, of which 190 aa correspond to the mature protein and 28 aa to the signal peptide. The giGH receptor cDNA was also partially sequenced. Phylogenetic analyses of the amino acid sequences of giGH and giGHR homologs in vertebrates suggest a parallel evolution and functional relationship between the GH and its receptor.

  11. Follicle stimulating hormone secreting pituitary adenoma: a challenging diagnosis

    Directory of Open Access Journals (Sweden)

    Madhuri Alap Mehendale

    2015-04-01

    Full Text Available FSH secreting pituitary adenomas are relatively uncommon brain tumours and usually non-functioning. But in rare cases they produce ovarian hyperstimulation. We report a case of a 32 year old female P2L2, with amenorrhoea of 1 year, pain in abdomen and galactorrhoea since 6 months. Initially thought to be a simple prolactinoma with multicystic ovaries, but after thorough investigations to our surprise diagnosed to be a rare case of gonadotropin secreting pituitary adenoma. Patient was successfully managed by excision of the pituitary adenoma. [Int J Reprod Contracept Obstet Gynecol 2015; 4(2.000: 493-496

  12. Overnight Levels of Luteinizing Hormone, Follicle-Stimulating Hormone and Growth Hormone before and during Gonadotropin-Releasing Hormone Analogue Treatment in Short Boys Born Small for Gestational Age

    NARCIS (Netherlands)

    van der Kaay, Danielle C. M.; de Jong, Frank H.; Rose, Susan R.; Odink, Roelof J. H.; Bakker-van Waarde, Willie M.; Sulkers, Eric J.; Hokken-Koelega, Anita C. S.

    2009-01-01

    Aims: To evaluate if 3 months of gonadotropin-releasing hormone analogue (GnRHa) treatment results in sufficient suppression of pubertal luteinizing hormone (LH) and follicle-stimulating hormone (FSH) profile patterns in short pubertal small for gestational age (SGA) boys. To compare growth hormone

  13. Mouse hypothalamic growth hormone-releasing hormone and somatostatin responses to probes of signal transduction systems.

    Science.gov (United States)

    Sato, M; Downs, T R; Frohman, L A

    1993-01-01

    Signal transduction mechanisms involved in mouse growth hormone-releasing hormone (GRH) and somatostatin (SRIH) release were investigated using an in vitro perifusion system. Hypothalamic fragments were exposed to depolarizing agents, protein kinase A and C activators, and a calcium ionophore. The depolarizing agents, KCl (60 mM) and veratridine (50 microM), induced similar patterns of GRH and SRIH release. Somatostatin release in response to both agents was twofold greater than that of GRH. Forskolin (10 microM and 100 microM), an adenylate cyclase activator, stimulated both GRH and SRIH release, though with different secretory profiles. The SRIH response was prolonged and persisted beyond removal of the drug from the system, while the GRH response was brief, ending even prior to forskolin removal. Neither GRH nor SRIH were stimulated by 1,9-dideoxy-forskolin (100 microM), a forskolin analog with cAMP-independent actions. A23187 (5 microM), a calcium ionophore, stimulated the release of SRIH to a much greater extent than that of GRH. The GRH and SRIH secretory responses to PMA (1 microM), a protein kinase C activator, were similar, though delayed. The results suggest that 1) GRH and SRIH secretion are regulated by both protein kinase A and C pathways, and 2) depolarizing agents are important for the release of both hormones.

  14. Failure of growth hormone-suppressing agents to affect TSH-releasing hormone- and LH-releasing hormone-induced growth hormone release in acromegaly.

    Science.gov (United States)

    Nakagawa, K; Obara, T

    1977-01-01

    In patients with acromegaly whose basal plasma GH levels were suppressed with 9 mg/day of dexamethasone for 2 days, TRH-(6 cases) and LHRH-(1 case) induced GH release were unaffected when the responses were compared to the basal levels. Phentolamine infusion, 70 mg in 150 min, or hyperglycemia induced by iv infusion of 700 ml of 50% glucose solution also did not suppress TRH-induced GH release in 2 acromegalic patients whose basal GH levels were lowered with these agents alone. These results seem to indicate that dexamethasone does not affect TRH- or LHRH-induced GH release per se, but affects the basal state which determines the absolute level of response. They also support the concept that TRH and LHRH act directly on pituitary tumor cells to release GH in acromegaly.

  15. Validity of a radioimmunoassay for serum and pituitary prolactin in adult male rats. Effects of bromocriptine and thyrotropin-releasing hormone

    Energy Technology Data Exchange (ETDEWEB)

    Andre, M. Grizard, G.; Boucher, D. (Faculte de Medecine, 63 - Clermont-Ferrand (France))

    1981-01-01

    Validity of a radioimmunoassay for rat prolactin (PRL) in serum and pituitary is analysed in adult male rats. Data are presented bearing on the accuracy, precision and sensitivity of the method. Serum levels and pituitary content are respectively ranged from 2,56 to 28,03 ng PRL RP/sub 2/ ml/sup -1/ and from 7,36 to 21,44 ..mu..g PRL RP/sub 2/ per gland in intact animals. Treatment with bromocriptine (10 days) results in a decrease of serum PRL levels and pituitary PRL contents. In progesterone-estradiol benzoate pretreated rats, serum PRL levels are increased 20 min after the injection of TRH.

  16. SEMICIRCADIAN RHYTHM OF DOPAMINE RELEASE IN THE MEDIOBASAL HYPOTHALAMUS IN AWAKE RATS DURING PSEUDOPREGNANCY - EVIDENCE THAT A THYROTROPIN-RELEASING-HORMONE ANALOG STIMULATES DOPAMINE RELEASE AND THEREBY INHIBITS PROLACTIN SECRETION

    NARCIS (Netherlands)

    TIMMERMAN, W; POELMAN, RT; WESTERINK, BHC; SCHUILING, GA

    1995-01-01

    The release of dopamine (DA) from tuberoinfundibular (TIDA) neurons during prolactin (PRL) surge and nonsurge periods and the effects of the thyrotropin-releasing hormone (TRH) analogue CG 3703 on DA and PRL secretion were studied in awake pseudopregnant (PSP) rats by simultaneous measurement of ext

  17. Partial purification and characterization of a peptide with growth hormone-releasing activity from extrapituitary tumors in patients with acromegaly.

    OpenAIRE

    Frohman, L A; Szabo, M; Berelowitz, M.; Stachura, M E

    1980-01-01

    Growth hormone (GH)-releasing activity has been detected in extracts of carcinoid and pancreatic islet tumors from three patients with GH-secreting pituitary tumors and acromegaly. Bioactivity was demonstrated in 2 N acetic acid extracts of the tumors using dispersed rat adenohypophyseal cells in primary monolayer culture and a rat anterior pituitary perifusion system. The GH-releasing effect was dose responsive and the greatest activity was present in the pancreatic islet tumor. Small amount...

  18. Human rhabdomyosarcoma cells express functional pituitary and gonadal sex hormone receptors: Therapeutic implications

    Science.gov (United States)

    PONIEWIERSKA-BARAN, AGATA; SCHNEIDER, GABRIELA; SUN, WENYUE; ABDELBASET-ISMAIL, AHMED; BARR, FREDERIC G.; RATAJCZAK, MARIUSZ Z.

    2016-01-01

    Evidence has accumulated that sex hormones play an important role in several types of cancer. Because they are also involved in skeletal muscle development and regeneration, we were therefore interested in their potential involvement in the pathogenesis of human rhabdomyosarcoma (RMS), a skeletal muscle tumor. In the present study, we employed eight RMS cell lines (three fusion positive and five fusion negative RMS cell lines) and mRNA samples obtained from RMS patients. The expression of sex hormone receptors was evaluated by RT-PCR and their functionality by chemotaxis, adhesion and direct cell proliferation assays. We report here for the first time that follicle-stimulating hormone (FSH) and luteinizing hormone (LH) receptors are expressed in established human RMS cell lines as well as in primary tumor samples isolated from RMS patients. We also report that human RMS cell lines responded both to pituitary and gonadal sex hormone stimulation by enhanced proliferation, chemotaxis, cell adhesion and phosphorylation of MAPKp42/44 and AKT. In summary, our results indicate that sex hormones are involved in the pathogenesis and progression of RMS, and therefore, their therapeutic application should be avoided in patients that have been diagnosed with RMS. PMID:26983595

  19. Effects of gonadotropin-releasing hormone administration on the pituitary-gonadal axis in male and female dogs before and after gonadectomy

    NARCIS (Netherlands)

    De Gier, J.; Buijtels, J.J.C.W.M.; Albers-Wolthers, C.H.J.; Oei, C.H.Y.; Kooistra, H.S.; Okkens, A.C.

    2012-01-01

    GnRH-stimulation tests were performed in 14 female and 14 male client-owned dogs of several breeds, before and 4 to 5 mo after gonadectomy. The aim of the study was to obtain more insight into the pituitary-gonadal axis in intact and neutered dogs and to establish reference values. Basal plasma lute

  20. Psychoneuromedulator role of corticotrophin releasing hormone in PCOS

    Directory of Open Access Journals (Sweden)

    Farideh Zafari Zangeneh

    2016-10-01

    Full Text Available Background: Polycystic ovary syndrome (PCOS is a common complex condition in women associated with reproductive and metabolic systems and also psychological disorders. There is considerable evidence to suggest that the sympathetic nervous system is involved in PCO and metabolic syndromes. Noradrenalin (NA, corticotrophin releasing hormone (CRH and nerve growth factor (NGF are the strong stimulants for two axes: hypothalamic-pituitary-adrenal (HPA and hypothalamic-pituitary-ovarian (HPO axes which are regulators for the female reproductive system. Following previous studies on sympathetic nervous system over activity in PCOS, the main purpose of this study is to evaluate the role of CRH and NGF as two important findings from the perspective of the psycho-emotional. Methods: This case-control study was conducted in Reproductive Health Research Center of Imam Khomeini Hospital, Tehran, Iran in the September of 2011. 170 women participated in this study. The diagnosis of PCOS was made according to the joint criteria of the European Society of Human Reproduction and Embryology and the American Society of Reproductive Medicine (ESHRE/ASRM. All women have 20-40 years of age and body mass index (BMI of less than 28. Demographic questionnaire was used in this study and blood sample was obtained from all participants before 8AM. All analysis was done in SPSS software, version 19 (IBM SPSS, Armonk, NY, USA. P-value less than 0.05 considered as significant level. Results: Serum levels of CRH and NGF in patients with polycystic ovary was significantly lower than the control group (P< 0.001. This reduction can disrupt two neural axes: the sympathetic nervous system (SAS and hypothalamus-pituitary-adrenal (HPA. These axes have a fundamental role in psycho-emotional reactions in women with PCOS. Moreover, using demographic questionnaire quantitative and qualitative characteristics of the population studied, the results of which are reported in the regression

  1. The FGFR4-G388R Polymorphism Promotes Mitochondrial STAT3 Serine Phosphorylation to Facilitate Pituitary Growth Hormone Cell Tumorigenesis

    OpenAIRE

    Toru Tateno; Asa, Sylvia L.; Lei Zheng; Thomas Mayr; Axel Ullrich; Shereen Ezzat

    2011-01-01

    Pituitary tumors are common intracranial neoplasms, yet few germline abnormalities have been implicated in their pathogenesis. Here we show that a single nucleotide germline polymorphism (SNP) substituting an arginine (R) for glycine (G) in the FGFR4 transmembrane domain can alter pituitary cell growth and hormone production. Compared with FGFR4-G388 mammosomatotroph cells that support prolactin (PRL) production, FGFR4-R388 cells express predominantly growth hormone (GH). Growth promoting eff...

  2. Interaction involving the thymus and the hypothalamus-pituitary axis, immunomodulation by hormones

    Directory of Open Access Journals (Sweden)

    Marković Ljiljana 2

    2004-01-01

    Full Text Available Perfectly projected and impeccably created, the endocrine system precisely regulates the most delicate immune processes. The immune and neuroendocrine systems are two essential physiological components of mammalian organisms important for protection from the infection and disease on one hand, and on the other, for regulation of metabolism and other physiological activities; namely, the evidence has been found indicating that there is active and dynamic collaboration of these systems in the execution of their designated functions [1, 2,4]. These interactions occur at many stages of embryonic and neonatal development, and they are a continual part of normal homeostatic balance necessary to preserve health. There is communication between neuroendocrine and immune system via cytokines, neurotransmitters and peptide hormones which act, in both systems, through the same receptor molecules (Scheme 1. Many investigators have reported the increased thymic weight in experimental animals due to both castration and adrenalectomy [4]. The discovery from 1898 revealing that thymus was enlarged in castrated rabbits has been considered the embryo of hybrid medical discipline, i.e. the immunoendocrinology [1]. In the actual literature, at least in that available to us, it has not been noted that the appearance of the eunuchs, i.e. the castrates, stimulated the analytical approach to this phenomenon. Endocrine influences appear to be a part of bidirectional circuitry, namely, thymic hormones also regulate the release of hormones from the pituitary gland. Physiologically, thymus is under neuroendocrine control. It is apparent that the circulating levels of distinct peptide hormones are necessary to maintain a series of biological functions related both to micro environmental and lymphoid cells of the organ. The neuroendocrine control of the thymus appears to be extremely complex, with apparent presence of complete intrathymic biological circuitry involving the

  3. MR imaging of growth hormone-secreting pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Masayuki; Ueda, Fumiaki; Fujinaga, Yasunari [Kanazawa Univ. (Japan). School of Medicine] (and others)

    2000-11-01

    We evaluated MR imaging of 51 growth hormonesecreting pituitary adenomas. On T1WI, 22 tumors were isointense with gray matter (GM), nine isointense with GM and white matter (WM), 14 isointense with WM, and six more hyperintense than WM. On T2WI of 45 patients, only fifteen tumors showed hypointensity than WM, 10 were isointense with WM, eight isointense with GM and WM, 12 showed in part isointensity with GM, and one was more hyperintense than GM. The dynamic study demonstrated the tumor more clearly than the delayed study in 10, while the opposite was true for two patients. The dynamic study is inevitable for MR imaging of GH-secreting pituitary adenomas. (author)

  4. Interferon-alpha-2a is a potent inhibitor of hormone secretion by cultured human pituitary adenomas

    NARCIS (Netherlands)

    L.J. Hofland (Leo); W.W. de Herder (Wouter); M. Waaijers (Marlijn); J. Zuijderwijk; P. Uitterlinden (Piet); P.M. van Koetsveld (Peter); S.W.J. Lamberts (Steven)

    1999-01-01

    textabstractInterferon-alpha (IFN alpha) may exert direct inhibitory effects on cell proliferation and on the production of different peptide hormones. We investigated the effect of IFN alpha on hormone production by 15 GH-secreting pituitary adenomas, 4 clinically nonf

  5. Comparing stimulation requirements and final outcome between early follicular and mid luteal pituitary suppression in the long gonadotropin releasing hormone agonist protocol.

    Science.gov (United States)

    Sarhan, Abdulmagid; Harira, Mervat; Elshazly, Sherine; Nouh, Ahmad

    2016-05-01

    To compare stimulation requirements and ICSI outcome when agonist treatment is started in the early follicular phase or in mid luteal phase of the cycle. 181 infertile patients were randomly assigned to: group A (N=66) and group B (N=115). GnRH-a (Triptorelin) subcutaneous daily injections started on day 20-22 of the previous cycle till pituitary suppression is achieved where gonadotropins stimulation commenced. In group A, agonist treatment was started on the first or second days of the cycle, in group B it was started on day 20-22 of the cycle. The agonist treatment was continued till the day of (hCG) administration. The stimulation requirements were similar in the two groups. The days of t agonist treatment required to reach pituitary suppression were higher in group A: 12.5±6.4 than in group B, 11±4.5. Days of stimulation (10.4±1.7 and 10.3±1.6) and number of gonadotropin vials (40.1±8.7and 39.3±9.5) did not differ between both groups. The mean number of oocytes retrieved, mean number of embryos produced (11.7±7.4 and 13.3±9.3) (5.9±4.2and 6±5.2) were similar in both groups. The rates of fertilization and cleavage were similar in the two groups. Pregnancy rates were similar in both groups. The clinical pregnancy rates per cycle was 31.8% and 33%, while pregnancy rates per embryo transfer was 36.2 % and 36.5% in groups A and B respectively. Starting pituitary suppression with GnRH agonist in the early follicular phase or mid luteal phase were comparable regarding stimulation requirements and final outcomes.

  6. Does a nonclassical signaling mechanism underlie an increase of estradiol-mediated gonadotropin-releasing hormone receptor binding in ovine pituitary cells?

    Science.gov (United States)

    Davis, Tracy L; Whitesell, Jennifer D; Cantlon, Jeremy D; Clay, Colin M; Nett, Terry M

    2011-10-01

    Estradiol-17beta (E2) is the major regulator of GnRH receptor (GnRHR) gene expression and number during the periovulatory period; however, the mechanisms underlying E2 regulation of the GNRHR gene remain undefined. Herein, we find that E2 conjugated to BSA (E2-BSA) mimics the stimulatory effect of E2 on GnRH binding in primary cultures of ovine pituitary cells. The time course for maximal GnRH analog binding was similar for both E2 and E2-BSA. The ability of E2 and E2-BSA to increase GnRH analog binding was blocked by the estrogen receptor (ER) antagonist ICI 182,780. Also, increased GnRH analog binding in response to E2 and the selective ESR1 agonist propylpyrazole triol was blocked by expression of a dominant-negative form of ESR1 (L540Q). Thus, membrane-associated ESR1 is the likely candidate for mediating E2 activation of the GNRHR gene. As cAMP response element binding protein (CREB) is an established target for E2 activation in gonadotrophs, we next explored a potential role for this protein as an intracellular mediator of the E2 signal. Consistent with this possibility, adenoviral-mediated expression of a dominant-negative form of CREB (A-CREB) completely abolished the ability of E2 to increase GnRH analog binding in primary cultures of ovine pituitary cells. Finally, the presence of membrane-associated E2 binding sites on ovine pituitary cells was demonstrated using a fluorescein isothiocyanate conjugate of E2-BSA. We suggest that E2 regulation of GnRHR number during the preovulatory period reflects a membrane site of action and may proceed through a nonclassical signaling mechanism, specifically a CREB-dependent pathway.

  7. Facilitation of lordosis in rats by a metabolite of luteinizing hormone releasing hormone.

    Science.gov (United States)

    Wu, T J; Glucksman, Marc J; Roberts, James L; Mani, Shaila K

    2006-05-01

    In the female rat, ovulation is preceded by a marked increase in the release of the decapeptide, LHRH, culminating in a preovulatory LH surge, which coincides with a period of sexual receptivity. The decapeptide, LHRH, is processed by a zinc metalloendopeptidase EC 3.4.24.15 (EP24.15) that cleaves the hormone at the Tyr(5)-Gly(6) bond. We have previously reported that the autoregulation of LHRH gene expression can also be mediated by its metabolite, LHRH-(1-5). Given the central function of LHRH in reproduction and reproductive behavior, we examined the role of the metabolite, LHRH-(1-5), in mediation of LHRH-facilitated reproductive behavior. Intracerebroventricular administration of LHRH-(1-5) facilitated sexual behavior responses, similar to those facilitated by the decapeptide LHRH, in ovariectomized estradiol-primed female rats. Furthermore, immunoneutralization of EP24.15 resulted in the inhibition of the LHRH-facilitated lordosis but had no inhibitory effects on LHRH-(1-5)-facilitated lordosis. The LHRH antagonist, Antide, was capable of inhibiting LHRH-facilitated lordosis, without affecting LHRH-(1-5)-facilitated lordosis. Collectively, these results suggest a role for LHRH metabolites in the facilitation of female receptive behavior in rats.

  8. HPA axis dysregulation in mice overexpressing corticotropin releasing hormone.

    NARCIS (Netherlands)

    Groenink, L.; Dirks, A.; Verdouw, P.M.; Schipholt, M.; Veening, J.G.; Gugten, J. van der; Olivier, B.

    2002-01-01

    BACKGROUND: Hypersecretion of corticotropin-releasing hormone (CRH) in the brain has been implicated in stress-related human pathologies. We developed a transgenic mouse line overexpressing CRH (CRH-OE) exclusively in neural tissues to assess the effect of long-term CRH overproduction on regulation

  9. Diagnostic challenges and management of a patient with acromegaly due to ectopic growth hormone-releasing hormone secretion from a bronchial carcinoid tumour

    Science.gov (United States)

    Kyriakakis, Nikolaos; Trouillas, Jacqueline; Dang, Mary N; Lynch, Julie; Belchetz, Paul; Korbonits, Márta

    2017-01-01

    Summary A male patient presented at the age of 30 with classic clinical features of acromegaly and was found to have elevated growth hormone levels, not suppressing during an oral glucose tolerance test. His acromegaly was originally considered to be of pituitary origin, based on a CT scan, which was interpreted as showing a pituitary macroadenoma. Despite two trans-sphenoidal surgeries, cranial radiotherapy and periods of treatment with bromocriptine and octreotide, his acromegaly remained active clinically and biochemically. A lung mass was discovered incidentally on a chest X-ray performed as part of a routine pre-assessment for spinal surgery 5 years following the initial presentation. This was confirmed to be a bronchial carcinoid tumour, which was strongly positive for growth hormone-releasing hormone (GHRH) and somatostatin receptor type 2 by immunohistochemistry. The re-examination of the pituitary specimens asserted the diagnosis of pituitary GH hyperplasia. Complete resolution of the patient’s acromegaly was achieved following right lower and middle lobectomy. Seventeen years following the successful resection of the bronchial carcinoid tumour the patient remains under annual endocrine follow-up for monitoring of the hypopituitarism he developed after the original interventions to his pituitary gland, while there has been no evidence of active acromegaly or recurrence of the carcinoid tumour. Ectopic acromegaly is extremely rare, accounting for <1% of all cases of acromegaly. Our case highlights the diagnostic challenges differentiating between ectopic acromegaly and acromegaly of pituitary origin and emphasises the importance of avoiding unnecessary pituitary surgery and radiotherapy. The role of laboratory investigations, imaging and histology as diagnostic tools is discussed. Learning points: Ectopic acromegaly is rare, accounting for less than 1% of all cases of acromegaly. Ectopic acromegaly is almost always due to extra-pituitary GHRH secretion

  10. Diagnostic challenges and management of a patient with acromegaly due to ectopic growth hormone-releasing hormone secretion from a bronchial carcinoid tumour.

    Science.gov (United States)

    Kyriakakis, Nikolaos; Trouillas, Jacqueline; Dang, Mary N; Lynch, Julie; Belchetz, Paul; Korbonits, Márta; Murray, Robert D

    2017-01-01

    A male patient presented at the age of 30 with classic clinical features of acromegaly and was found to have elevated growth hormone levels, not suppressing during an oral glucose tolerance test. His acromegaly was originally considered to be of pituitary origin, based on a CT scan, which was interpreted as showing a pituitary macroadenoma. Despite two trans-sphenoidal surgeries, cranial radiotherapy and periods of treatment with bromocriptine and octreotide, his acromegaly remained active clinically and biochemically. A lung mass was discovered incidentally on a chest X-ray performed as part of a routine pre-assessment for spinal surgery 5 years following the initial presentation. This was confirmed to be a bronchial carcinoid tumour, which was strongly positive for growth hormone-releasing hormone (GHRH) and somatostatin receptor type 2 by immunohistochemistry. The re-examination of the pituitary specimens asserted the diagnosis of pituitary GH hyperplasia. Complete resolution of the patient's acromegaly was achieved following right lower and middle lobectomy. Seventeen years following the successful resection of the bronchial carcinoid tumour the patient remains under annual endocrine follow-up for monitoring of the hypopituitarism he developed after the original interventions to his pituitary gland, while there has been no evidence of active acromegaly or recurrence of the carcinoid tumour. Ectopic acromegaly is extremely rare, accounting for ectopic acromegaly and acromegaly of pituitary origin and emphasises the importance of avoiding unnecessary pituitary surgery and radiotherapy. The role of laboratory investigations, imaging and histology as diagnostic tools is discussed. Ectopic acromegaly is rare, accounting for less than 1% of all cases of acromegaly.Ectopic acromegaly is almost always due to extra-pituitary GHRH secretion, mainly from neuroendocrine tumours of pancreatic or bronchial origin.Differentiating between acromegaly of pituitary origin and

  11. Spontaneous remission of acromegaly or gigantism due to subclinical apoplexy of pituitary growth hormone adenoma

    Institute of Scientific and Technical Information of China (English)

    WANG Xian-ling; DOU Jing-tao; L(U) Zhao-hui; ZHONG Wen-wen; BA Jian-ming; JIN Du; LU Ju-ming; PAN Chang-yu; MU Yi-ming

    2011-01-01

    Background Subclinical apoplexy of pituitary functional adenoma can cause spontaneous remission of hormone hypersecretion.The typical presence of pituitary growth hormone (GH) adenoma is gigantism and/or acromegaly.We investigated the clinical characteristics of patients with spontaneous partial remission of acromegaly or gigantism due to subclinical apoplexy of GH adenoma.Methods Six patients with spontaneous remission of acromegaly or gigantism were enrolled.The clinical characteristics,endocrinological evaluation and imageological characteristics were retrospectively analyzed.Results In these cases,the initial clinical presences were diabetes mellitus or hypogonadism.No abrupt headache,vomiting,visual function impairment,or conscious disturbance had ever been complained of.The base levels of GH and insulin growth factor-1 (IGF-1) were normal or higher,but nadir GH levels were all still >1 μg/L in 75 g oral glucose tolerance test.Magnetic resonance imaging detected enlarged sella,partial empty sella and compressed pituitary.The transsphenoidal surgery was performed in 2 cases,and the other patients were conservatively managed.All the patients were in clinical remission.Conclusions When the clinical presences,endocrine evaluation,biochemical examination and imageology indicate spontaneous remission of GH hypersecretion in patients with gigantism or acromegaly,the diagnosis of subclinical apoplexy of pituitary GH adenoma should be presumed.To these patients,conservative therapy may be appropriate.

  12. Spontaneous remission of acromegaly or gigantism due to subclinical apoplexy of pituitary growth hormone adenoma.

    Science.gov (United States)

    Wang, Xian-Ling; Dou, Jing-Tao; Lü, Zhao-Hui; Zhong, Wen-Wen; Ba, Jian-Ming; Jin, Du; Lu, Ju-Ming; Pan, Chang-Yu; Mu, Yi-Ming

    2011-11-01

    Subclinical apoplexy of pituitary functional adenoma can cause spontaneous remission of hormone hypersecretion. The typical presence of pituitary growth hormone (GH) adenoma is gigantism and/or acromegaly. We investigated the clinical characteristics of patients with spontaneous partial remission of acromegaly or gigantism due to subclinical apoplexy of GH adenoma. Six patients with spontaneous remission of acromegaly or gigantism were enrolled. The clinical characteristics, endocrinological evaluation and imageological characteristics were retrospectively analyzed. In these cases, the initial clinical presences were diabetes mellitus or hypogonadism. No abrupt headache, vomiting, visual function impairment, or conscious disturbance had ever been complained of. The base levels of GH and insulin growth factor-1 (IGF-1) were normal or higher, but nadir GH levels were all still > 1 µg/L in 75 g oral glucose tolerance test. Magnetic resonance imaging detected enlarged sella, partial empty sella and compressed pituitary. The transsphenoidal surgery was performed in 2 cases, and the other patients were conservatively managed. All the patients were in clinical remission. When the clinical presences, endocrine evaluation, biochemical examination and imageology indicate spontaneous remission of GH hypersecretion in patients with gigantism or acromegaly, the diagnosis of subclinical apoplexy of pituitary GH adenoma should be presumed. To these patients, conservative therapy may be appropriate.

  13. In vivo pharmacological evaluation of a lactose-conjugated luteinizing hormone releasing hormone analogue.

    Science.gov (United States)

    Moradi, Shayli Varasteh; Varamini, Pegah; Steyn, Frederik; Toth, Istvan

    2015-11-10

    In the current study, the efficacy and pharmacokinetic profile of lactose-conjugated luteinizing hormone releasing hormone (LHRH) was examined following oral administration in male rats. A rapid and sensitive liquid chromatography/mass spectrometry technique was developed and applied for measuring the concentration of lactose[Q(1)][w(6)]LHRH (compound 1) in rat plasma in order to allow measurement of pharmacokinetic parameters. LH release was evaluated using a sandwich ELISA. Maximum serum concentration (Cmax = 0.11 μg/ml) was reached at 2h (Tmax) following oral administration of the compound at 10mg/kg. The half-life was determined to be 2.6h. The absolute bioavailability of the orally administered compound was found to be 14%, which was a remarkable improvement compared to zero-to-low oral bioavailability of the native peptide. Compound 1 was effective in stimulating LH release at 20mg/kg after oral administration. The method was validated at a linear range of 0.01-20.0 μg/ml and a correlation coefficient of r(2) ≥ 0.999. The accuracy and precision values showed the reliability and reproducibility of the method for evaluation of the pharmacokinetic parameters. These findings showed that the lactose derivative of LHRH has a therapeutic potential to be further developed as an orally active therapeutics for the treatment of hormone-dependent diseases.

  14. Hypergravity and estrogen effects on avian anterior pituitary growth hormone and prolactin levels

    Science.gov (United States)

    Fiorindo, R. P.; Negulesco, J. A.

    1980-01-01

    Developing female chicks with fractured right radii were maintained for 14 d at either earth gravity (1 g) or a hypergravity state (2 g). The birds at 1 g were divided into groups which received daily injections of (1) saline, (2) 200 micrograms estrone, and (3) 400 micrograms estrone for 14 d. The 2-g birds were divided into three similarly treated groups. All 2-g birds showed significantly lower body weights than did 1-g birds. Anterior pituitary (AP) glands were excised and analyzed for growth hormone and prolactin content by analytical electrophoresis. The 1-g chicks receiving either dose of daily estrogen showed increased AP growth hormone levels, whereas hypergravity alone did not affect growth hormone content. Chicks exposed to daily estrogen and hypergravity displayed reduced growth hormone levels. AP prolactin levels were slightly increased by the lower daily estrogen dose in 1-g birds, but markedly reduced in birds exposed only to hypergravity. Doubly-treated chicks displayed normal prolactin levels. Reduced growth in 2-g birds might be due, in part, to reduced AP levels of prolactin and/or growth hormone.

  15. GH responses to growth hormone releasing factor in depression.

    Science.gov (United States)

    Thomas, R; Beer, R; Harris, B; John, R; Scanlon, M

    1989-01-01

    The growth hormone (GH), thyrotrophin (TSH) and prolactin response to growth hormone releasing factor (GRF) was investigated in 18 patients suffering from major depression with melancholia and in 18 age- and sex-matched normal controls. There was no significant difference in the GH response to GRF stimulation between the patients and controls and in neither subject group was there a demonstrable TSH or prolactin response to GRF. These findings indicate that the pathophysiology underlying the blunted GH response to pharmacological challenge, demonstrated in other studies, must lie at a suprapituitary level.

  16. Growth hormone secretion from chicken adenohypophyseal cells in primary culture: effects of human pancreatic growth hormone-releasing factor, thyrotropin-releasing hormone, and somatostatin on growth hormone release.

    Science.gov (United States)

    Perez, F M; Malamed, S; Scanes, C G

    1987-03-01

    A primary culture of chicken adenohypophyseal cells has been developed to study the regulation of growth hormone (GH) secretion. Following collagenase dispersion, cells were exposed for 2 hr to vehicle (control) or test agents. Human pancreatic (tumor) growth hormone-releasing factor (hpGRF) and rat hypothalamic growth hormone-releasing factor stimulated GH release to similar levels. GH release was increased by the presence of dibutyryl cyclic AMP. Thyrotropin-releasing hormone (TRH) alone did not influence GH release; however, TRH plus hpGRF together exerted a synergistic (greater than additive) effect, increasing GH release by 100 to 300% over the sum of the values for each secretagogue acting alone. These relationships between TRH and hpGRF were further examined in cultured cells exposed to secretagogues for two consecutive 2-hr incubations. TRH pretreatment enhanced subsequent hpGRF-stimulated GH release by about 80% over that obtained if no secretagogue was present during the first incubation. In other experiments, somatostatin (SRIF) alone did not alter GH secretion. However, SRIF reduced hpGRF-stimulated GH release to levels found in controls. Furthermore, GH release stimulated by the presence of both TRH and hpGRF was lowered to control values by SRIF. The results of these studies demonstrate that a primary culture of chicken adenohypophyseal cells is a useful model for the study of GH secretion. Indeed, these results suggest that TRH and hpGRF regulate GH secretion by mechanisms which are not identical.

  17. Highly potent analogues of luteinizing hormone-releasing hormone containing D-phenylalanine nitrogen mustard in position 6

    Energy Technology Data Exchange (ETDEWEB)

    Bajusz, S.; Janaky, T.; Csernus, V.J.; Bokser, L.; Fekete, M.; Srkalovic, G.; Redding, T.W.; Schally, A.V. (Tulane Univ. School of Medicine, New Orleans, LA (USA))

    1989-08-01

    The nitrogen mustard derivatives of 4-phenylbutyric acid and L-phenylalanine, called chlorambucil (Chl) and melphalan (Mel), respectively, have been incorporated into several peptide hormones, including luteinizing hormone-releasing hormone (LH-RH). The alkylating analogues of LH-RH were prepared by linking Chl, as an N-acyl moiety, to the complete amino acid sequence of agonistic and antagonistic analogues. These compounds, in particular the antagonistic analogues, showed much lower potency than their congeners carrying other acyl groups. To obtain highly potent alkylating analogues of LH-RH, the D enantiomer of Mel was incorporated into position 6 of the native hormone and some of its antagonistic analogues. Of the peptides prepared, (D-Mel{sup 6})LH-RH (SB-05) and (Ac-D-Nal(2){sup 1},D-Phe(pCl){sup 2},D-Pal(3){sup 3},Arg{sup 5},D-Mel{sup 6},D-Ala{sup 10})LH-RH (SB-86, where Nal(2) is 3-(2-naphthyl)alanine and Pal(3) is 3-(3-pyridyl)alanine) possessed the expected high agonistic and antagonistic activities, respectively, and also showed high affinities for the membrane receptors of rat pituitary cells, human breast cancer cells, human prostate cancer cells, and rat Dunning R-3327 prostate tumor cells. These two analogues exerted cytotoxic effects on human and rat mammary cancer cells in vitro. Thus these two D-Mel{sup 6} analogues seem to be particularly suitable for the study of how alkylating analogues of LH-RH could interfere with intracellular events in certain cancer cells.

  18. Leucine-enkephalin-like immunoreactivity is localized in luteinizing hormone-producing cells in the axolotl (Ambystoma mexicanum) pituitary.

    Science.gov (United States)

    Suzuki, Hirohumi; Yamamoto, Toshiharu

    2014-02-01

    In this study, we used immunohistochemical techniques to determine the cell type of leucine-enkephalin (Leu-ENK)-immunoreactive cells in the axolotl (Ambystoma mexicanum) pituitary. Immunoreactive cells were scattered throughout the pars distalis except for the dorso-caudal portion. These cells were immuno-positive for luteinizing hormone (LH), but they were immuno-negative for adrenocorticotrophic, growth, and thyroid-stimulating hormones, as well as prolactin. Immunoelectron microscopy demonstrated that Leu-ENK-like substance and LH co-localized within the same secretory granules. Leu-ENK secreted from gonadotrophs may participate in LH secretion in an autocrine fashion, and/or may participate in the release of sex steroids together with LH.

  19. Effect of Valsartan on the hormones of Pituitary-gonadal axis Performance in mature female Wistar Rats

    Directory of Open Access Journals (Sweden)

    Ebrahim Hosseini

    2013-02-01

    Conclusion: Valsartan , as a receptor antagonist of Ang II inhibits the secretion of gonadotropin hormones and accelerates their effect on blocking the follicular cells of the female sex ,causing the reduction of female hormones.

  20. Prospective assessment of pituitary size and shape on MR imaging after suppressive hormonal therapy in central precocious puberty

    Energy Technology Data Exchange (ETDEWEB)

    Beek, J.T. van; Sharafuddin, M.J.A.; Kao, S.C.S. [Department of Radiology-JPP 3889, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52246 (United States); Luisiri, A. [Cardinal Glennon Children' s Hospital, St. Louis, Missouri (United States); Garibaldi, L.R. [Children' s Hospital of New Jersey, Newark Beth Israel Medical Center, Newark, New Jersey (United States); St. Barnabas Medical Center, Livingston, New Jersey (United States)

    2000-07-01

    Objective. The diagnostic significance of an enlarged pituitary gland regarding both shape and size parameters on MR imaging has previously been demonstrated in children with central precocious puberty. This study was designed to assess changes in these parameters following successful suppressive therapy of central precocious puberty with the gonadotropin-releasing hormone (GnRH) analogue. Materials and methods. Twelve girls (mean age 7.3 years) with central precocious puberty were prospectively enrolled in our study protocol. Sagittal and coronal MR images of the pituitary region were obtained in all patients before treatment and after at least 6 months of GnRH analogue therapy (mean 18.0 months). Parameters measured included pituitary gland height, length, width, sagittal cross-sectional area, and volume. Results. All patients had excellent clinical response to treatment with arrest of secondary sexual development, normalization of serum estradiol levels, and complete obliteration of the LH response to diagnostic GnRH stimulation. No significant change occurred in any pituitary size or shape parameter following GnRH analogue therapy. Conclusion. Favorable clinical response to GnRH analogue therapy in central precocious puberty is not accompanied by significant a change in pituitary gland size and shape. (orig.)

  1. Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas

    Science.gov (United States)

    Wang, Ji-wen; Li, Ying; Mao, Zhi-gang; Hu, Bin; Jiang, Xiao-bing; Song, Bing-bing; Wang, Xin; Zhu, Yong-hong; Wang, Hai-jun

    2014-01-01

    Excessive growth hormone (GH) is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF) 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs) and GH receptor antagonist; the former consists of lanreotide Autogel (ATG) and octreotide long-acting release (LAR), and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4–6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated with presurgical SA may be achieved, although controversy of such adjuvant therapy exists. Combination of SA and pegvisomant or cabergoline shows advantages in some specific cases. Thus, an individual treatment program should be established for each patient under a full evaluation of the risks and benefits. PMID:24421637

  2. Effect of androgen on Kiss1 expression and luteinizing hormone release in female rats.

    Science.gov (United States)

    Iwata, Kinuyo; Kunimura, Yuyu; Matsumoto, Keisuke; Ozawa, Hitoshi

    2017-06-01

    Hyperandrogenic women have various grades of ovulatory dysfunction, which lead to infertility. The purpose of this study was to determine whether chronic exposure to androgen affects the expression of kisspeptin (ovulation and follicle development regulator) or release of luteinizing hormone (LH) in female rats. Weaned females were subcutaneously implanted with 90-day continuous-release pellets of 5α-dihydrotestosterone (DHT) and studied after 10 weeks of age. Number of Kiss1-expressing cells in both the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) was significantly decreased in ovary-intact DHT rats. Further, an estradiol-induced LH surge was not detected in DHT rats, even though significant differences were not observed between DHT and non-DHT rats with regard to number of AVPV Kiss1-expressing cells or gonadotrophin-releasing hormone (GnRH)-immunoreactive (ir) cells in the presence of high estradiol. Kiss1-expressing and neurokinin B-ir cells were significantly decreased in the ARC of ovariectomized (OVX) DHT rats compared with OVX non-DHT rats; pulsatile LH secretion was also suppressed in these animals. Central injection of kisspeptin-10 or intravenous injection of a GnRH agonist did not affect the LH release in DHT rats. Notably, ARC Kiss1-expressing cells expressed androgen receptors (ARs) in female rats, whereas only a few Kiss1-expressing cells expressed ARs in the AVPV. Collectively, our results suggest excessive androgen suppresses LH surge and pulsatile LH secretion by inhibiting kisspeptin expression in the ARC and disruption at the pituitary level, whereas AVPV kisspeptin neurons appear to be directly unaffected by androgen. Hence, hyperandrogenemia may adversely affect ARC kisspeptin neurons, resulting in anovulation and menstrual irregularities. © 2017 Society for Endocrinology.

  3. effect of luteinizing hormone-releasing hormone analogue on the sexual behavior of sacalia quadriocellata

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    luteinizing hormone-releasing hormone (lhrh) is known to influence sexual behavior in many vertebrate taxa,but there have been no systematic studies on the role of lhrh in sexual behavior of turtles.we tested the hypotheses that exogenous lhrh analogues would induce sexual behavior of male four-eyed turtle,sacalia quadriocellata.we examined this by challenging males with intramuscular injections of mammalian luteinizing hormone-releasing hormone analogue (lhrh-a),human chorionic gonadotropin (hcg),or a combination of the two,and subsequently exposing them to sexually receptive females for behavioral observation.our data show that the injection of only hcg could not,while that of only lhrh-a could,facilitate sexual behavior along with testicular recrudescence and spermatogenesis in s.quadriocellata.the injection of both lhrh-a and hcg would induce more drastic sexual behavior of the animals than that of lhrh-a alone,indicating hcg enhances the effects of lhrh-a induced sexual behavior.however,different pharmacological dosages of lhrh-a (0.5 μg,1 μg,2 μg per 100 g bodyweight) did not correspond to different activity levels.though the mechanism of lhrh effect was not determined,this study may support that the sexual behavior ofs.quadriocellata which occurs at the beginning of the injection despite regression of the gonads.this is the first report on the exogenous lhrh-a induced sexual behavior for this species.

  4. Growth Hormone Response after Administration of L-dopa, Clonidine, and Growth Hormone Releasing Hormone in Children with Down Syndrome.

    Science.gov (United States)

    Pueschel, Seigfried M.

    1993-01-01

    This study of eight growth-retarded children with Down's syndrome (aged 1 to 6.5 years) found that administration of growth hormone was more effective than either L-dopa or clonidine. Results suggest that children with Down's syndrome have both anatomical and biochemical hypothalamic derangements resulting in decreased growth hormone secretion and…

  5. Effects of spaceflight on hypothalamic peptide systems controlling pituitary growth hormone dynamics

    Science.gov (United States)

    Sawchenko, P. E.; Arias, C.; Krasnov, I.; Grindeland, R. E.; Vale, W.

    1992-01-01

    Possible effects of reduced gravity on central hypophysiotropic systems controlling growth hormone (GH) secretion were investigated in rats flown on Cosmos 1887 and 2044 biosatellites. Immunohistochemical (IHC)staining for the growth hormone-releasing factor (GRF), somatostatin (SS), and other hypothalamic hormones was performed on hypothalami obtained from rats. IHC analysis was complemented by quantitative in situ assessments of mRNAs encoding the precursors for these hormones. Data obtained suggest that exposure to microgravity causes a preferential reduction in GRF peptide and mRNA levels in hypophysiotropic neurons, which may contribute to impared GH secretion in animals subjected to spaceflight. Effects of weightlessness are not mimicked by hindlimb suspension in this system.

  6. Suppression of episodic growth hormone secretion in streptozotocin-induced diabetic mice: time-course studies on the hypothalamic pituitary axis.

    Science.gov (United States)

    Murao, S; Sato, M; Tamaki, M; Niimi, M; Ishida, T; Takahara, J

    1995-10-01

    To elucidate the roles of the hypothalamic peptides, GH-releasing hormone (GRH) and somatostatin (SRIH), potentially responsible for altered GH dynamics in diabetes, we studied the time courses of their changes in level associated with altered GH secretion in streptozotocin (STZ)-induced diabetic mice. Diabetic mice were used at 4, 7, and 14 days after STZ injection for analyses of 1) GH secretion in vivo, 2) hypothalamic GRH and SRIH messenger RNA (mRNA) levels, 3) pituitary GH mRNA and protein contents, and 4) pituitary GH response to GRH in vitro. GH secretion was completely suppressed 7 and 14 days after STZ injection. The hypothalamic GRH mRNA level was reduced to 59.8%, 61.2%, and 48.5% of control values at 4, 7, and 14 days, respectively. In contrast, the hypothalamic SRIH mRNA level was not altered at all of these time points. Pituitary GH mRNA and protein contents were significantly reduced to 70.2% and 61.5% of those in controls, respectively, only at 14 days. Pituitary GH responses to GRH at three doses (10, 50, and 250 nM) in vitro were remarkably increased at 4, 7, and 14 days. These findings indicate that the diabetic state rapidly and primarily inhibits hypothalamic GRH gene expression without affecting SRIH. A persistent decrease in hypothalamic GRH tone has been suggested to result in inhibition of GH synthesis in the pituitary. Enhancement of GH responsiveness to GRH may be due to the up-regulation of GRH receptors in the pituitary.

  7. Effects of a gonadotropin-releasing hormone antagonist on gonadotropin levels in Masu salmon and Sockeye salmon.

    Science.gov (United States)

    Amano, Masafumi; Ikuta, Kazumasa; Kitamura, Shoji

    2007-09-01

    The salmon gonadotropin-releasing hormone (sGnRH) is considered to be involved in gonadal maturation via gonadotropin (GTH) secretion in salmonid fishes. However, there is no direct evidence for endogenous sGnRH-stimulated GTH secretion in salmonids. In this study, to clarify whether endogenous sGnRH stimulates GTH secretion, we examined the effects of the mammalian GnRH (mGnRH) antagonist [Ac-Delta(3)-Pro(1), 4FD-Phe(2), D-Trp(3,6)]-mGnRH on luteinizing hormone (LH) levels in 0-year-old masu salmon Oncorhynchus masou and sockeye salmon Oncorhynchus nerka. First, the effects of the GnRH antagonist on LH release were examined in 0-year-old precocious male masu salmon. GnRH antagonist treatment for 3 hr significantly inhibited an increase in plasma LH levels that was artificially induced by exogenous sGnRH administration, indicating that the GnRH antagonist is effective in inhibiting LH release from the pituitary. Subsequently, we examined the effect of the GnRH antagonist on LH synthesis in 0-year-old immature sockeye salmon that were pretreated with exogenous testosterone for 42 days to increase the pituitary LH contents; the testosterone treatment did not affect the plasma LH levels. GnRH antagonist treatment slightly but significantly inhibited an increase in the testosterone-stimulated pituitary LH content levels. However, no significant differences in the plasma LH levels were observed between the GnRH antagonist-treated and control groups. These results suggest that endogenous sGnRH is involved in LH secretion in salmonid fishes.

  8. Algorithmic complexity of growth hormone release in humans.

    Science.gov (United States)

    Prank, K; Wagner, M; Brabant, G

    1997-01-01

    Most hormones are secreted in an pulsatile rather than in a constant manner. This temporal pattern of pulsatile hormone release plays an important role in the regulation of cellular function and structure. In healthy humans growth hormone (GH) secretion is characterized by distinct pulses whereas patients bearing a GH producing tumor accompanied with excessive secretion (acromegaly) exhibit a highly irregular pattern of GH release. It has been hypothesized that this highly disorderly pattern of GH release in acromegaly arises from random events in the GH-producing tumor under decreased normal control of GH secretion. Using a context-free grammar complexity measure (algorithmic complexity) in conjunction with random surrogate data sets we demonstrate that the temporal pattern of GH release in acromegaly is not significantly different from a variety of stochastic processes. In contrast, normal subjects clearly exhibit deterministic structure in their temporal patterns of GH secretion. Our results support the hypothesis that GH release in acromegaly is due to random events in the GH-producing tumorous cells which might become independent from hypothalamic regulation.

  9. Algorithmic complexity of growth hormone release in humans

    Energy Technology Data Exchange (ETDEWEB)

    Prank, K.; Wagner, M.; Brabant, G. [Medical School Hannover (Germany)

    1996-12-31

    Most hormones are secreted in an pulsatile rather than in a constant manner. This temporal pattern of pulsatile hormone release plays an important role in the regulation of cellular function and structure. In healthy humans growth hormone (GH) secretion is characterized by distinct pulses whereas patients bearing a GH producing tumor accompanied with excessive secretion (acromegaly) exhibit a highly irregular pattern of GH release. It has been hypothesized that this highly disorderly pattern of GH release in acromegaly arises from random events in the GH-producing tumor under decreased normal control of GH secretion. Using a context-free grammar complexity measure (algorithmic complexity) in conjunction with random surrogate data sets we demonstrate that the temporal pattern of GH release in acromegaly is not significantly different from a variety of stochastic processes. In contrast, normal subjects clearly exhibit deterministic structure in their temporal patterns of GH secretion. Our results support the hypothesis that GH release in acromegaly is due to random events in the GH-producing tumorous cells which might become independent from hypothalamic regulation. 17 refs., 1 fig., 2 tabs.

  10. Decapeptides as effective agonists from L-amino acids biologically equivalent to the luteinizing hormone-releasing hormone

    Energy Technology Data Exchange (ETDEWEB)

    Folkers, K.; Bowers, C.Y.; Tang, P.L.; Kubota, M.

    1986-02-01

    Apparently, no agonist has been found that is comparable in potency to the luteinizing hormone-releasing hormone (LHRH) for release of LH and follicle-stimulating hormone (FSH) without substitutions with unnatural or D forms of natural amino acids. Of 139 known agonist analogs of LHRH, two were active in the range of 65%. The four LHRHs known to occur in nature involve a total of six amino acids (Tyr, His, Leu, Trp, Arg, Gln) in positions 5, 7, and 8. There are 16 possible peptides with these six amino acids in positions 5, 7, and 8, of which 4 are the known LHRHs, and 2 more were synthesized. The authors have synthesized the 10 new peptides and assayed 11 in vivo and in vitro, and they found not only 1 but a total of 5 that have activity equivalent to or greater than that of LHRH for the release of LH and/or FSH under at least one assay condition. These five are as follows: (HisV,TrpX,GlnY)LHRH; (HisV,TrpX,LeuY)LHRH; (HisV,TrpX)LHRH; (TrpX)LHRH; (HisV)LHRH. These structures are a basis for the design of antagonists without ArgY toward avoiding histamine release. Complete inhibition of LH and FSH release in vivo may be induced by joint use of ArgY and GlnY or LeuY antagonists. These potent agonists, related to LHRH, may be therapeutically useful in disorders of reproduction, the central nervous system, and for the control of hormone-dependent carcinomas. Radioreceptor assays and radioimmunoassays were utilized.

  11. Diagnostic challenges and management of a patient with acromegaly due to ectopic growth hormone-releasing hormone secretion from a bronchial carcinoid tumour

    Directory of Open Access Journals (Sweden)

    Nikolaos Kyriakakis

    2017-01-01

    Full Text Available A male patient presented at the age of 30 with classic clinical features of acromegaly and was found to have elevated growth hormone levels, not suppressing during an oral glucose tolerance test. His acromegaly was originally considered to be of pituitary origin, based on a CT scan, which was interpreted as showing a pituitary macroadenoma. Despite two trans-sphenoidal surgeries, cranial radiotherapy and periods of treatment with bromocriptine and octreotide, his acromegaly remained active clinically and biochemically. A lung mass was discovered incidentally on a chest X-ray performed as part of a routine pre-assessment for spinal surgery 5 years following the initial presentation. This was confirmed to be a bronchial carcinoid tumour, which was strongly positive for growth hormone-releasing hormone (GHRH and somatostatin receptor type 2 by immunohistochemistry. The re-examination of the pituitary specimens asserted the diagnosis of pituitary GH hyperplasia. Complete resolution of the patient’s acromegaly was achieved following right lower and middle lobectomy. Seventeen years following the successful resection of the bronchial carcinoid tumour the patient remains under annual endocrine follow-up for monitoring of the hypopituitarism he developed after the original interventions to his pituitary gland, while there has been no evidence of active acromegaly or recurrence of the carcinoid tumour. Ectopic acromegaly is extremely rare, accounting for <1% of all cases of acromegaly. Our case highlights the diagnostic challenges differentiating between ectopic acromegaly and acromegaly of pituitary origin and emphasises the importance of avoiding unnecessary pituitary surgery and radiotherapy. The role of laboratory investigations, imaging and histology as diagnostic tools is discussed.

  12. Effects of aqueous extract from Asparagus officinalis L. roots on hypothalamic-pituitary-gonadal axis hormone levels and the number of ovarian follicles in adult rats

    Directory of Open Access Journals (Sweden)

    Hojatollah Karimi Jashni

    2016-02-01

    Full Text Available Background: Asparagus is a plant with high nutritional, pharmaceutical, and industrial values. Objective: The present study aimed to evaluate the effect of aqueous extract of asparagus roots on the hypothalamic-pituitary-gonadal axis hormones and oogenesis in female rats. Materials and Methods: In this experimental study, 40 adult female Wistar rats were divided into five groups, which consist 8 rats. Groups included control, sham and three experimental groups receiving different doses (100, 200, 400 mg/kg/bw of aqueous extract of asparagus roots. All dosages were administered orally for 28 days. Blood samples were taken from rats to evaluate serum levels of Gonadotropin releasing hormone (GnRH, follicular stimulating hormone (FSH, Luteinal hormone (LH, estrogen, and progesterone hormones. The ovaries were removed, weighted, sectioned, and studied by light microscope. Results: Dose-dependent aqueous extract of asparagus roots significantly increased serum levels of GnRH, FSH, LH, estrogen, and progestin hormones compared to control and sham groups. Increase in number of ovarian follicles and corpus luteum in groups treated with asparagus root extract was also observed (p<0.05. Conclusion: Asparagus roots extract stimulates secretion of hypothalamic- pituitary- gonadal axis hormones. This also positively affects oogenesis in female rats.

  13. Reproductive Hormone and Transcriptomic Responses of Pituitary Tissue in Anestrus Gilts Induced by Nutrient Restriction.

    Science.gov (United States)

    Xu, Shengyu; Wang, Dingyue; Zhou, Dongsheng; Lin, Yan; Che, Lianqiang; Fang, Zhengfeng; Wu, De

    2015-01-01

    The onset of estrus is a critical sign of female sexual maturity. The pituitary plays a vital role in this process by the secretion of reproductive hormones. To investigate the effects of nutrient restriction on reproductive function and the underlying mechanisms involved, deep RNA sequencing of pituitary gland tissue was carried out to determine the differentially expressed genes (DEGs) between gilts in normal estrus, and gilts in which anestrus was induced by nutrient restriction. Gilts which had gone through two estrus cycles were fed a normal (CON, 2.86kg/d, n = 10) or nutrient restricted (NR, 1kg/d, n = 10) diet. The NR gilts experienced another three estrus cycles, but did not express estrus symptoms at the anticipated 6th and 7th cycles. Body weight gain in NR gilts was significantly decreased by nutrient restriction. Gilts were considered as anestrus when blood progesterone concentrations lower than 1.0 ng/mL from three consecutive blood samples were recorded. Circulating concentrations of progesterone (interaction", "GnRH signaling pathway" and "immune response system". Our findings provide a new perspective for understanding the nutrient restriction-induced reproductive impairment at the pituitary transcriptional level, and how this is linked to hormone secretion. Moreover, the transcriptomic changes in anestrus gilts associated with nutrient restriction could be a resource for targeted studies of genes and pathways potentially involved in the regulation of reproductive function and animal health.

  14. Overnight levels of luteinizing hormone, follicle-stimulating hormone and growth hormone before and during gonadotropin-releasing hormone analogue treatment in short boys born small for gestational age

    NARCIS (Netherlands)

    D.C.M. van der Kaay (Danielle); F.H. de Jong (Frank); S.R. Rose (Susan); R.J.H. Odink (Roelof); W.M. Bakker-Van Waarde (Willie); E.J. Sulkers (Eric); A.C.S. Hokken-Koelega (Anita)

    2009-01-01

    textabstractAims: To evaluate if 3 months of gonadotropin-releasing hormone analogue (GnRHa) treatment results in sufficient suppression of pubertal luteinizing hormone (LH) and follicle-stimulating hormone (FSH) profile patterns in short pubertal small for gestational age (SGA) boys. To compare gro

  15. Triiodothyronine inhibits transcription from the human growth hormone promoter.

    Science.gov (United States)

    Morin, A; Louette, J; Voz, M L; Tixier-Vidal, A; Belayew, A; Martial, J A

    1990-07-09

    Three DNA constructs, the natural human growth hormone gene (hGH-hGH) its 500 bp promoter linked to the chloramphenicol acetyl transferase reporter gene (hGH-CAT), and its structural part linked to the herpes virus thymidine kinase promoter (TK-hGH) were introduced into rat pituitary GC cells by DEAE-dextran transfection. Transient expression was followed as a function of triiodothyronine (T3) concentration. The hGH-CAT expression was specifically inhibited by T3 following a typical dose-response curve while hGH-GH gene expression was not significantly modified. The transient expression of TK-hGH increased as a function of T3 concentration. These results indicate that T3 exerts two opposite effects on hGH gene expression. First, it down-regulates expression by acting on the promoter; second, it up-regulates expression by acting on the structural part of the gene. These action could be due to regulation of transcription and mRNA stabilization, respectively.

  16. Review: Regulatory mechanisms of gonadotropin-inhibitory hormone (GnIH synthesis and release in photoperiodic animals

    Directory of Open Access Journals (Sweden)

    Kazuyoshi eTsutsui

    2013-04-01

    Full Text Available Gonadotropin-inhibitory hormone (GnIH is a novel hypothalamic neuropeptide that was discovered in quail as an inhibitory factor for gonadotropin release. GnIH inhibits gonadotropin synthesis and release in birds through actions on gonadotropin-releasing hormone (GnRH neurons and gonadotropes, mediated via the GnIH receptor (GnIH-R, GPR147. Subsequently, GnIH was identified in mammals and other vertebrates. As in birds, mammalian GnIH inhibits gonadotropin secretion, indicating a conserved role for this neuropeptide in the control of the hypothalamic-pituitary-gonadal (HPG axis across species. Identification of the regulatory mechanisms governing GnIH expression and release is important in understanding the physiological role of the GnIH system. A nocturnal hormone, melatonin, appears to act directly on GnIH neurons through its receptor to induce expression and release of GnIH in quail, a photoperiodic bird. Recently, a similar, but opposite, action of melatonin on the inhibition of expression of mammalian GnIH was shown in hamsters and sheep, photoperiodic mammals. These results in photoperiodic animals demonstrate that GnIH expression is photoperiodically modulated via a melatonin-dependent process. Recent findings indicate that GnIH may be a mediator of stress-induced reproductive disruption in birds and mammals, pointing to a broad role for this neuropeptide in assessing physiological state and modifying reproductive effort accordingly. This paper summarizes the advances made in our knowledge regarding the regulation of GnIH synthesis and release in photoperiodic birds and mammals. This paper also discusses the neuroendocrine integration of environmental signals, such as photoperiods and stress, and internal signals, such as GnIH, melatonin and glucocorticoids, to control avian and mammalian reproduction.

  17. Ghrelin stimulation of growth hormone-releasing hormone neurons is direct in the arcuate nucleus.

    Directory of Open Access Journals (Sweden)

    Guillaume Osterstock

    Full Text Available BACKGROUND: Ghrelin targets the arcuate nucleus, from where growth hormone releasing hormone (GHRH neurones trigger GH secretion. This hypothalamic nucleus also contains neuropeptide Y (NPY neurons which play a master role in the effect of ghrelin on feeding. Interestingly, connections between NPY and GHRH neurons have been reported, leading to the hypothesis that the GH axis and the feeding circuits might be co-regulated by ghrelin. PRINCIPAL FINDINGS: Here, we show that ghrelin stimulates the firing rate of identified GHRH neurons, in transgenic GHRH-GFP mice. This stimulation is prevented by growth hormone secretagogue receptor-1 antagonism as well as by U-73122, a phospholipase C inhibitor and by calcium channels blockers. The effect of ghrelin does not require synaptic transmission, as it is not antagonized by gamma-aminobutyric acid, glutamate and NPY receptor antagonists. In addition, this hypothalamic effect of ghrelin is independent of somatostatin, the inhibitor of the GH axis, since it is also found in somatostatin knockout mice. Indeed, ghrelin does not modify synaptic currents of GHRH neurons. However, ghrelin exerts a strong and direct depolarizing effect on GHRH neurons, which supports their increased firing rate. CONCLUSION: Thus, GHRH neurons are a specific target for ghrelin within the brain, and not activated secondary to altered activity in feeding circuits. These results support the view that ghrelin related therapeutic approaches could be directed separately towards GH deficiency or feeding disorders.

  18. Linkage of congenital isolated adrenocorticotropic hormone deficiency to the corticotropin releasing hormone locus using simple sequence repeat polymorphisms

    Energy Technology Data Exchange (ETDEWEB)

    Kyllo, J.H.; Collins, M.M.; Vetter, K.L. [Univ. of Iowa College of Medicine, Iowa City, IA (United States)] [and others

    1996-03-29

    Genetic screening techniques using simple sequence repeat polymorphisms were applied to investigate the molecular nature of congenital isolated adrenocorticotropic hormone (ACTH) deficiency. We hypothesize that this rare cause of hypocortisolism shared by a brother and sister with two unaffected sibs and unaffected parents is inherited as an autosomal recessive single gene mutation. Genes involved in the hypothalamic-pituitary axis controlling cortisol sufficiency were investigated for a causal role in this disorder. Southern blotting showed no detectable mutations of the gene encoding pro-opiomelanocortin (POMC), the ACTH precursor. Other candidate genes subsequently considered were those encoding neuroendocrine convertase-1, and neuroendocrine convertase-2 (NEC-1, NEC-2), and corticotropin releasing hormone (CRH). Tests for linkage were performed using polymorphic di- and tetranucleotide simple sequence repeat markers flanking the reported map locations for POMC, NEC-1, NEC-2, and CRH. The chromosomal haplotypes determined by the markers flanking the loci for POMC, NEC-1, and NEC-2 were not compatible with linkage. However, 22 individual markers defining the chromosomal haplotypes flanking CRH were compatible with linkage of the disorder to the immediate area of this gene of chromosome 8. Based on these data, we hypothesize that the ACTH deficiency in this family is due to an abnormality of CRH gene structure or expression. These results illustrate the useful application of high density genetic maps constructed with simple sequence repeat markers for inclusion/exclusion studies of candidate genes in even very small nuclear families segregating for unusual phenotypes. 25 refs., 5 figs., 2 tabs.

  19. Contents of corticotropin-releasing hormone and arginine vasopressin immunoreativity in the spleen and thymus during a chronic inflammatory stress

    DEFF Research Database (Denmark)

    Chowdrey, H.S.; Lightman, S.L.; Harbuz, M.S.;

    1994-01-01

    Corticotropin-releasing hormone, spleen, thymus, immune system, stress, arthritis, arginine vasopressin......Corticotropin-releasing hormone, spleen, thymus, immune system, stress, arthritis, arginine vasopressin...

  20. Fasting Upregulates PPAR Target Genes in Brain and Influences Pituitary Hormone Expression in a PPAR Dependent Manner

    Directory of Open Access Journals (Sweden)

    Bettina König

    2009-01-01

    PPAR target genes implicated in -oxidation of fatty acids (acyl-CoA oxidase, carnitine palmitoyltransferase-1, medium chain acyl-CoA dehydrogenase and ketogenesis (mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase in pituitary gland and partially also in frontal cortex and diencephalon compared to nonfasted animals. These data strongly indicate that fasting activates PPAR in brain and pituitary gland. Furthermore, pituitary prolactin and luteinizing hormone- mRNA concentrations were increased upon fasting in wild-type mice but not in mice lacking PPAR. For proopiomelanocortin and thyrotropin-, genotype-specific differences in pituitary mRNA concentrations were observed. Thus, PPAR seems to be involved in transcriptional regulation of pituitary hormones.

  1. Seasonal plasticity in the peptide neuronal systems: potential roles of gonadotrophin-releasing hormone, gonadotrophin-inhibiting hormone, neuropeptide Y and vasoactive intestinal peptide in the regulation of the reproductive axis in subtropical Indian weaver birds.

    Science.gov (United States)

    Surbhi; Rastogi, A; Rani, S; Kumar, V

    2015-05-01

    Two experiments examined the expression of gonadotrophin-releasing and inhibiting hormones (GnRH-I, GnRH-II and GnIH), neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) in subtropical Indian weaver birds, which demonstrate relative photorefractoriness. Experiment 1 measured peptide expression levels in the form of immunoreactive (-IR) cells, percentage cell area and cell optical density in the preoptic area (GnRH-I), midbrain (GnRH-II), paraventricular nucleus (GnIH), mediobasal hypothalamus [dorsomedial hypothalamus (DMH), infundibular complex (INc), NPY and VIP] and lateral septal organ (VIP) during the progressive, breeding, regressive and nonbreeding phases of the annual reproductive cycle. GnRH-I was decreased in the nonbreeding and VIP was increased in INc in the breeding and regressive states. GnRH-II and NPY levels did not differ between the testicular phases. Double-labelled immunohistochemistry (IHC) revealed a close association between the GnRH/GnIH, GnRH/NPY, GnRH/VIP and GnIH/NPY peptide systems, implicating them interacting and playing roles in the reproductive regulation in weaver birds. Experiment 2 further measured these peptide levels in the middle of day and night in weaver birds that were maintained under short days (8 : 16 h light /dark cycle; photosensitive), exposed to ten long days (16 : 8 h light /dark cycle; photostimulated) or maintained for approximately 2 years on a 16 : 8 h light /dark cycle (photorefractory). Reproductively immature testes in these groups precluded the possible effect of an enhanced gonadal feedback on the hypothalamic peptide expression. There were group differences in the GnRH-I (not GnRH-II), GnIH, NPY and VIP immunoreactivity, albeit with variations in immunoreactivity measures in the present study. These results, which are consistent with those reported in birds with relative photorefractoriness, show the distribution and possibly a complex interaction of key neuropeptides in the regulation of the

  2. Acceleration of wound healing by growth hormone-releasing hormone and its agonists.

    Science.gov (United States)

    Dioufa, Nikolina; Schally, Andrew V; Chatzistamou, Ioulia; Moustou, Evi; Block, Norman L; Owens, Gary K; Papavassiliou, Athanasios G; Kiaris, Hippokratis

    2010-10-26

    Despite the well-documented action of growth hormone-releasing hormone (GHRH) on the stimulation of production and release of growth hormone (GH), the effects of GHRH in peripheral tissues are incompletely explored. In this study, we show that GHRH plays a role in wound healing and tissue repair by acting primarily on wound-associated fibroblasts. Mouse embryonic fibroblasts (MEFs) in culture and wound-associated fibroblasts in mice expressed a splice variant of the receptors for GHRH (SV1). Exposure of MEFs to 100 nM and 500 nM GHRH or the GHRH agonist JI-38 stimulated the expression of α-smooth muscle actin (αSMA) based on immunoblot analyses as well as the expression of an αSMA-β-galactosidase reporter transgene in primary cultures of fibroblasts isolated from transgenic mice. Consistent with this induction of αSMA expression, results of transwell-based migration assays and in vitro wound healing (scratch) assays showed that both GHRH and GHRH agonist JI-38 stimulated the migration of MEFs in vitro. In vivo, local application of GHRH or JI-38 accelerated healing in skin wounds of mice. Histological evaluation of skin biopsies showed that wounds treated with GHRH and JI-38 were both characterized by increased abundance of fibroblasts during the early stages of wound healing and accelerated reformation of the covering epithelium at later stages. These results identify another function of GHRH in promoting skin tissue wound healing and repair. Our findings suggest that GHRH may have clinical utility for augmenting healing of skin wounds resulting from trauma, surgery, or disease.

  3. Gonadotrophin releasing hormone-based vaccine, an effective candidate for prostate cancer and other hormone-sensitive neoplasms.

    Science.gov (United States)

    Junco, Jesús A; Basalto, Roberto; Fuentes, Franklin; Bover, Eddy; Reyes, Osvaldo; Pimentel, Eulogio; Calzada, Lesvia; Castro, Maria D; Arteaga, Niurka; López, Yovisleidis; Hernández, Héctor; Bringas, Ricardo; Garay, Hilda; Peschke, Peter; Bertot, José; Guillén, Gerardo

    2008-01-01

    Prostate growth, development, functions, and neoplastic transformation is androgen dependent. Estrogens have similar effects in the ovary and breast. Previous studies using gonadotrophin releasing hormone (GnRH/LHRH) vaccines have shown the usefulness of immunization against this hormone in prostate (PC) and breast cancer (BC). We have synthesized a peptide mutated at position 6 and attached to the 830-844 tetanic toxoid (TT) helper T cell sequence in the same synthesis process. After repeated pig immunizations, we have demonstrated a vaccine that significantly decreased testes size (p < 0.001), prostate (p < 0.01), seminal vesicles (p < 0.01), and testosterone (T) castration [0.05 nM ml(-1) (p < 0. 01)]. Similar results were obtained in adult male and female healthy dogs and Macaca fascicularis models. These data indicate that this GnRHm1-TT vaccine is safe and able to induce significant tumor growth inhibition in the Dunning R3327-H rat androgen responsive prostate tumor model. In these rats, the immunization induced high anti-GnRH titers concomitant with T castration reduction (p < 0.01) in 90% of the animals tested. In addition, 70% of the responders exhibited tumor growth inhibition (p = 0.02) and a survival rate approximately three times longer that those of untreated rats. These data indicate that GnRHm1-TT vaccine may be a potential candidate in the treatment of PC, BC, and other hormone-dependent cancers.

  4. Rab18 is reduced in pituitary tumors causing acromegaly and its overexpression reverts growth hormone hypersecretion.

    Science.gov (United States)

    Vazquez-Martinez, Rafael; Martinez-Fuentes, Antonio J; Pulido, Marina R; Jimenez-Reina, Luis; Quintero, Ana; Leal-Cerro, Alfonso; Soto, Alfonso; Webb, Susan M; Sucunza, Nuria; Bartumeus, Frederic; Benito-Lopez, Pedro; Galvez-Moreno, Maria A; Castaño, Justo P; Malagon, Maria M

    2008-06-01

    Rab proteins regulate the sequential steps of intracellular membrane transport. Alterations of these GTPases and their associated proteins are emerging as the underlying cause for several human diseases involving dysregulated secretory activities. Herein we investigated the role of Rab18, which negatively regulates hormone secretion by interacting with secretory granules, in relation to the altered functioning of tumoral pituitary somatotropes causing acromegaly. A total of 18 patients diagnosed with pituitary tumors causing acromegaly (nine patients) or nonfunctioning adenomas (nine patients) underwent endoscopic transsphenoidal surgery. Adenomas were subsequently processed to evaluate Rab18 production in relation to GH secretion. We found that somatotropinoma cells are characterized by a high secretory activity concomitantly with a remarkably reduced Rab18 expression (15%) and protein content levels (30%), as compared with cells from nonfunctioning pituitary adenomas derived from patients with normal or reduced GH plasma levels (100%). Furthermore, immunoelectron microscopy revealed that Rab18 association with the surface of GH-containing secretory granules was significantly lower in somatotropes from acromegalies than nonfunctioning pituitary adenomas. Finally, we provide evidence that modulation of Rab18 gene expression can revert substantially the hypersecretory activity of cells because Rab18 overexpression reduced by 40% the capacity of cells from acromegalies to respond to GHRH stimulation. These results suggest that molecular alterations affecting individual components of the secretory granule traffic machinery can contribute to maintain a high level of GH in plasma. Accordingly, Rab18 constitutes a valuable target as a diagnostic, prognostic, and/or therapeutic tool for human acromegaly.

  5. Comparative gene expression of gonadotropins (FSH and LH) and peptide levels of gonadotropin-releasing hormones (GnRHs) in the pituitary of wild and cultured Senegalese sole (Solea senegalensis) broodstocks.

    Science.gov (United States)

    Guzmán, J M; Rubio, M; Ortiz-Delgado, J B; Klenke, U; Kight, K; Cross, I; Sánchez-Ramos, I; Riaza, A; Rebordinos, L; Sarasquete, C; Zohar, Y; Mañanós, E L

    2009-07-01

    The Senegalese sole (Solea senegalensis) is a valuable flatfish for aquaculture, but it presents important reproductive problems in captivity. Spawning is achieved by wild-caught breeders but cultured broodstocks fail to spawn spontaneously and, when they do, eggs are unfertilized. To gain knowledge on the physiological basis underlying this reproductive dysfunction, this study aimed at analyzing comparative hormone levels between wild and cultured broodstocks at the spawning season. The Senegalese sole gonadotropin (GTH) subunits, FSHbeta, LHbeta and GPalpha, were cloned and qualitative (in situ hybridization) and quantitative (real-time PCR) assays developed to analyze pituitary GTH gene expression. In females, FSHbeta and GPalpha mRNA levels were higher in wild than in cultured broodstocks, whereas in males all three subunits were highest in cultured. By ELISA, three GnRH forms were detected in the pituitary, displaying a relative abundance of GnRH2>GnRH1>GnRH3. All GnRHs were slightly more abundant in wild than cultured females, whereas no differences were observed in males. Plasma levels of vitellogenin and sex steroids were also analyzed. Results showed endocrine differences between wild and cultured broodstocks at the spawning period, which could be related to the endocrine failure of the reproductive axis in cultured breeders.

  6. Comparison of response to 2-years' growth hormone treatment in children with isolated growth hormone deficiency, born small for gestational age, idiopathic short stature, or multiple pituitary hormone deficiency

    DEFF Research Database (Denmark)

    Lee, Peter A; Sävendahl, Lars; Oliver, Isabelle

    2012-01-01

    Few studies have compared the response to growth hormone (GH) treatment between indications such as isolated growth hormone deficiency (IGHD), born small for gestational age (SGA), idiopathic short stature (ISS), and multiple pituitary hormone deficiency (MPHD). The aim of this analysis of data......, collected from two large ongoing observational outcome studies, was to evaluate growth and insulin-like growth factor-I (IGF-I) response data for children of short stature with IGHD, MPHD, SGA, or ISS following two years of treatment with the recombinant GH product Norditropin® (Novo Nordisk A/S, Bagsværd...

  7. Neither bovine somatotropin nor growth hormone-releasing factor alters expression of thyroid hormone receptors in liver and mammary tissues.

    Science.gov (United States)

    Capuco, A V; Binelli, M; Tucker, H A

    2011-10-01

    Physiological effects of thyroid hormones are mediated primarily by binding of triiodothyronine to specific nuclear receptors. Organ-specific changes in production of triiodothyronine from its prohormone, thyroxine, have been hypothesized to target the action of thyroid hormones on the mammary gland and play a role in mediating or augmenting a galactopoietic response to bovine somatotropin (bST). Additionally, tissue responsiveness to thyroid hormones may be altered by changes in the number or affinity of nuclear receptors for thyroid hormones. In the present study, effects of bST and bovine growth hormone-releasing factor (bGRF) on thyroid hormone receptors in liver and mammary gland were studied. Lactating Holstein cows received continuous infusions of bST or bGRF for 63 d or served as uninfused controls. Nuclei were isolated from harvested mammary and liver tissues and incubated with [(125)I]-triiodothyronine. Treatments did not alter the capacity or affinity of specific binding sites for triiodothyronine in liver or mammary nuclei. Evaluation of transcript abundance for thyroid hormone receptors showed that isoforms of thyroid hormone receptor or retinoid receptor (which may influence thyroid receptor action) expressed in the mammary gland were not altered by bST or bGRF treatment. Data do not support the hypothesis that administration of bST or bGRF alters sensitivity of mammary tissue by changing expression of thyroid hormone receptors.

  8. Role of corticotropin-releasing hormone in onset of labour.

    Science.gov (United States)

    Grammatopoulos, D K; Hillhouse, E W

    1999-10-30

    Corticotropin-releasing hormone (CRH) derived from the placenta is secreted into the maternal circulation in large amounts during the third trimester of human pregnancy and may have an important role in the onset of labour. Although the biological role of CRH remains enigmatic, the presence of functional CRH receptors in the myometrium suggests that CRH may modulate myometrial contractility and hence parturition. CRH action is mediated via multiple receptor subtypes and pregnancy results in differential receptor expression. These receptors are primarily linked to the adenylate cyclase second messenger system, which would help the intracellular microenvironment to maintain the required myometrial quiescence. CRH can exert further actions such as inhibition of prostaglandin production to prevent contractions. At term under the influence of oxytocin there is a modification in the coupling mechanisms that leads to a decrease in the biological activity of the CRH receptor and in the generation of cyclic adenosine monophosphate which favours myometrial contractions. CRH, via distinct receptor subtypes, is then able to enhance the contractile response of the myometrium. This hypothesis places CRH in a central role in coordinating the smooth transition from a state of relaxation to one of contraction.

  9. Isolation of the gene and hypothalamic of cDNA for the common precursor of gonadotropin-releasing hormone and prolactin release-inhibiting factor in human and rat

    Energy Technology Data Exchange (ETDEWEB)

    Adelman, J.P.; Mason, A.J.; Hayflick, J.S.; Seeburg, P.H.

    1986-01-01

    Cloned cDNAs encoding the precursor protein for gonadotropin-releasing hormone (Gn-RH) and prolactin release-inhibiting factor (PIF) were isolated from libraries derived from human and rat hypothalamic mRNA. Nucleotide sequence analyses predict precursor proteins of 92 amino acids for both species and show identity between the human placental and human hypothalamic precursor proteins. Whereas the Gn-RH peptide structure is completely conserved in human and rat, the PIF domain of the precursor displays 70% interspecies homology. Genomic analyses revealed the presence of a single Gn-RH-PIF gene in human and rat containing sequences corresponding to the cDNA distributed across four exons.

  10. Sleep and Endocrinology: Hypothalamic-pituitary- adrenal axis and growth hormone

    Directory of Open Access Journals (Sweden)

    Ravinder Goswami

    2014-03-01

    Full Text Available The supra-chiasmatic nucleus (SCN is the primarily biological clock determining thecircadian rhythm. The neurons of the nucleus making this clock have inherent rhythmand set in biological day and night. These periods usually corresponds to day/night, andindirectly to sleep-wakefulness cycle, in most individuals. Retino-hypothalamic tractcarrying photic information from the retina provides the most important input tomaintain the inherent rhythm of the SCN. The rhythmic discharges from the SCN tovarious neurons of the central nervous system, including pineal gland andhypothalamus, translate into circadian rhythm characteristic of several hormones andmetabolites such as glucose. As a result there is a pattern of hormonal changesoccurring during cycle of sleep wakefulness. Most characteristic of these changes aresurge of melatonin with biological night, surge of growth hormone-releasing hormone(GHRHat onset of sleep and surge of corticotropin-releasinghormone(CRHduring late part of the sleep. The cause and effect relationship of the hypothalamicreleasing hormones and their target hormones on various phases of sleep includinginitial non rapid eye movement (NREM phase at onset of sleep, and rapid eyemovement (REM phase near awakening, is an upcoming research area. Sleepelectroencephalogram (EEG determining the onset of NREM and REM sleep is animportant tool complimenting the studies assessing relationship between varioushormones and phases of sleep. The slow wave activity (SWA corresponds to theintensity of sleep at its onset during the biological night of an individual. Besides,GHRH and CRH, several other peptide and steroid hormones such as growthhormone (GH, its secretagogues, ghrelin, neuropeptide Y, estrogen anddehydroepiandrosterone sulfate are associated or have the potential to change phases ofsleep including initial slow wave-NREM sleep.

  11. Effects of pituitary hormone deficiency on growth and glucose metabolism of the sheep fetus.

    Science.gov (United States)

    Fowden, A L; Forhead, A J

    2007-10-01

    Pituitary hormones are essential for normal growth and metabolic responsiveness after birth, but their role before birth remains unclear. This study examined the effects of hypophysectomizing fetal sheep on their growth and glucose metabolism during the late normal and extended periods of gestation, and on their metabolic response to maternal fasting for 48 h near term. Fetal hypophysectomy reduced crown rump length (CRL), limb lengths, and body weight but increased ponderal index relative to controls near normal term. It also lowered the daily rate of crown rump length increment uniformly from 35 d before, to 20 d after normal term. Hypophysectomized (HX) fetuses had normal weight-specific rates of umbilical uptake, utilization, and oxidation of glucose but lower rates of umbilical oxygen uptake than controls near term. All these metabolic rates were significantly less in HX fetuses during the extended period of gestation than in HX and intact fetuses near normal term. In contrast to controls, glucogenesis was negligible in HX fetuses during maternal fasting. Consequently, the rate of glucose utilization decreased significantly in fasted HX but not intact fetuses. Conversely, the rate of CO(2) production from glucose carbon decreased in fasted intact but not HX fetuses. Fetal hypophysectomy also prevented the fasting-induced increases in plasma cortisol and norepinephrine concentrations seen in controls. These findings demonstrate that the pituitary hormones are important in regulating the growth rate and adaptive responses of glucose metabolism to undernutrition in fetal sheep. They also suggest that fetal metabolism is altered when gestational length is extended.

  12. Effect of Imatinib on the Oogenesis and Pituitary -Ovary Hormonal Axis in Female Wistar Rat

    OpenAIRE

    Parichehreh Yaghmaei; Kazem Parivar; Fatemeh Jalalvand

    2009-01-01

    Background: Imatinib mesylate, a small-molecular analog of adenosine triphosphate (ATP)that potently inhibits tyrosine kinase activities of Bcr–Abl, PDGFR-β, PDGFR-α, c-Fms, Argand c-kit, is one of the novel molecularly targeted drugs being introduced into cancer therapy.We tested the effect of imatinib on the ovarian histological structure and the concentration ofestrogen and progesterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH)in the serum of female Wistar rats.Mater...

  13. HIV gp120 inhibits the somatotropic axis: A possible GH-releasing hormone receptor mechanism for the pathogenesis of AIDS wasting

    OpenAIRE

    Mulroney, Susan E.; McDonnell, Kevin J.; Pert, Candace B.; Ruff, Michael R.; Resch, Zachary; Samson, Willis K.; Lumpkin, Michael D.

    1998-01-01

    AIDS is often associated with growth retardation in children and wasting in adults. The dissociated envelope protein of the HIV (HIV-1), gp120, can be found in significant concentrations in the parenchyma and cerebrospinal fluid of brains in infected individuals, even in the earliest stages of HIV-1 disease. On the basis of this and the fact that we observed pentapeptide sequence homology between GH-releasing hormone (GHRH) and the V2 receptor-binding region of gp120, we initiated experiments...

  14. Effect of Camphor on Pituitary-Gonadal Hormonal Axis and Oogenesis in Adult Female Rats

    Directory of Open Access Journals (Sweden)

    Habibollah Johari

    2013-06-01

    Full Text Available Background & Objective: Camphor stimulates the nervous system and the circulatory system, reduces lactation, and prevents conception and embryo embedding. We investigated the effects of camphor on the pituitary-gonadal hormonal axis and concentration of steroidal hormones.   Materials & Methods: The parameters investigated were concentrations of LH, FSH, estrogen, progesterone, and testosterone. Forty adult female rats at a mean weight of 180 ± 20 grams were divided into five groups. Camphor solution was prepared in olive oil at 25, 50, and 100 mg/kg doses, and 0.2 cc injections were done intraperitoneally every day for 2 weeks. The control group received no injection. The sham group received olive oil (as solvent of camphor and treatment groups of 1, 2, and 3 received doses of 25, 50, and 100 mg/kg. The treatment groups were sacrificed one day after the last injection, and their hearts were dissected and blood samples were obtained. The concentrations of the hormones were measured by the ELISA test, and the results were evaluated via the t-test, ANOVA, and Duncan.   Results: The results showed a significant decrease in the concentrations of testosterone and progesterone (p value < 0.05 and a significant increase in the concentrations of LH and FSH (p value <0.05.   Conclusion: Camphor augmented oogenesis via effecting a rise in the concentrations of LH and FSH in our rats.

  15. How effective is external pituitary irradiation for growth hormone-secreting pituitary tumours

    Energy Technology Data Exchange (ETDEWEB)

    Feek, C.M.; McLelland, J.; Seth, J.; Toft, A.D.; Irvine, W.J.; Padfield, P.L.; Edwards, C.R.W. (Western General Hospital, Edinburgh (UK); Royal Infirmary, Edinburgh (UK))

    1984-04-01

    Forty-six patients with GH-secreting pituitary tumours were treated with external pituitary irradiation through two opposed fields to a total dose of 3750 cGy over 15 fractions. Thirty-patients received external radiotherapy as primary treatment; 16 received radiotherapy combined with pituitary surgery. The mean (+- SD) serum GH in the former group was 74.3 +- 74.8 mU/l before treatment, falling by 28% per year over 0-5 years and by 16% per year over 0-20 years. The mean (+- SD) serum GH in the latter group was 265.4 +- 209.3 mU/l before treatment, falling by 76% in the first year-a direct result of surgery-then by 30% per year over 1-5 years and 16% per year over 1-20 years. Progressive failure of normal anterior pituitary function developed by 10 years, with variable loss of gonadotrophin, corticotrophin and thyrotrophin function. The respective figures for patients treated with radiotherapy alone were 47.4, 29.6 and 16.0% and for the combined group 70.2, 53.9 and 38.1%. Whilst external pituitary irradiation appears to reduce serum GH concentrations in patients with GH-secreting pituitary tumours the major disadvantages are the time taken to achieve a cure and the high incidence of hypopituitarism.

  16. Stimulation of chicken growth hormone release by phorbol esters.

    Science.gov (United States)

    Perez, F M; Malamed, S; Scanes, C G

    1990-11-01

    Synergism between thyrotropin-releasing hormone (TRH) and human pancreatic growth hormone-releasing factor (hpGRF) has been shown in a primary (48 hr) culture of chicken adenohypophyseal cells established in this laboratory. The purpose of the present study was to determine if phorbol esters acting alone or in concert with TRH or hpGRF affect chicken GH release. Collagenase-dissociated chicken adenohypophyseal cells were treated (2 hr) with combinations of TRH, hpGRF, phorbol esters (activators of protein kinase C; PKC), and pharmacologic agents that increase cAMP. Phorbol myristate acetate (PMA) or phorbol dibutyrate (PDBu) alone stimulated GH release in a dose-dependent manner; either phorbol ester (10(-6) M) increased GH release from 100 to 390% over the value obtained in the absence of test agents (control). Similarly, hpGRF (10(-9) M), 8 Br-cAMP (10(-3) M), forskolin (10(-6) M), or isobutylmethylxanthine (IBMX, 10(-3) M) alone elevated GH release by at least 60% over the control value. The combined effects of phorbol esters (either PMA or PDBu) and hpGRF, 8 Br-cAMP, or forskolin on GH release were additive. Only one combination, phorbol esters with IBMX, exerted synergistic effects on GH release. No synergy was shown between TRH (1.3 x 10(-9) M) and either phorbol ester. These findings are the first to implicate PKC in chicken GH release in vitro. In addition, these studies, together with previous results, suggest that TRH and hpGRF synergy occurs via a pathway that arises prior to activation of PKC.

  17. Gonadotropin-releasing hormone stimulates prolactin release from lactotrophs in photoperiodic species through a gonadotropin-independent mechanism.

    Science.gov (United States)

    Henderson, Helen L; Hodson, David J; Gregory, Susan J; Townsend, Julie; Tortonese, Domingo J

    2008-02-01

    Previous studies have provided evidence for a paracrine interaction between pituitary gonadotrophs and lactotrophs. Here, we show that GnRH is able to stimulate prolactin (PRL) release in ovine primary pituitary cultures. This effect was observed during the breeding season (BS), but not during the nonbreeding season (NBS), and was abolished by the application of bromocriptine, a specific dopamine agonist. Interestingly, GnRH gained the ability to stimulate PRL release in NBS cultures following treatment with bromocriptine. In contrast, thyrotropin-releasing hormone, a potent secretagogue of PRL, stimulated PRL release during both the BS and NBS and significantly enhanced the PRL response to GnRH during the BS. These results provide evidence for a photoperiodically modulated functional interaction between the GnRH/gonadotropic and prolactin axes in the pituitary gland of a short day breeder. Moreover, the stimulation of PRL release by GnRH was shown not to be mediated by the gonadotropins, since immunocytochemical, Western blotting, and PCR studies failed to detect pituitary LH or FSH receptor protein and mRNA expressions. Similarly, no gonadotropin receptor expression was observed in the pituitary gland of the horse, a long day breeder. In contrast, S100 protein, a marker of folliculostellate cells, which are known to participate in paracrine mechanisms within this tissue, was detected throughout the pituitaries of both these seasonal breeders. Therefore, an alternative gonadotroph secretory product, a direct effect of GnRH on the lactotroph, or another cell type, such as the folliculostellate cell, may be involved in the PRL response to GnRH in these species.

  18. Cysteamine, zinc, and thiols modify detectability of rat pituitary prolactin: a comparison with effects on bovine prolactin suggests differences in hormone storage

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, L.S.; Lorenson, M.Y.

    1986-03-01

    Little is known about the structure of prolactin (PRL) within secretory granules. Evidence from our previous studies in bovine tissue preparations suggests that control of secretion may reside, in part, in the conversion of storage hormone to releasable PRL. The conversion can be monitored by measuring changes in immunodetectability since the oligomeric, storage form is poorly recognized by antisera raised against monomeric PRL. Since many investigators use rats to study the secretory process and changes in detectability of rat pituitary PRL occur during lactation (depletion-transformation), we undertook the present immunodetectability studies to gain insight into the storage structure of rat (r) PRL. Cysteamine and zinc inhibited tissue PRL immunoassayability in male rat pituitary homogenates and also in partially purified secretory granules as they had inhibited bovine (b) PRL; however, zinc inhibited the rodent hormone less potently than the bovine. In vitro incubation of rat tissue samples without additions resulted in increases in rPRL detectability of up to 84% after 180 minutes; such incubation of bovine samples had no significant effect. A striking additional difference between the species was that exposure to reduced glutathione (GSH), cysteine, homocysteine, mercaptoethanol, and dithiothreitol inhibited rPRL by up to 44%. This compared to thiol stimulation of bPRL by as much as 450%. The inhibitory GSH effect on rPRL was abolished when 0.5% sodium dodecyl sulfate (SDS) was included; in contrast, the stimulatory GSH effect on bPRL did not change with added SDS. SDS alone had no effect on rat homogenate PRL, and only increased rat granule rPRL by 23% compared to its ability to increase bPRL assayability by 44%.

  19. Biosynthesis and the conjugation of magnetite nanoparticles with luteinizing hormone releasing hormone (LHRH).

    Science.gov (United States)

    Obayemi, J D; Dozie-Nwachukwu, S; Danyuo, Y; Odusanya, O S; Anuku, N; Malatesta, K; Soboyejo, W O

    2015-01-01

    This paper presents the results of an experimental study of the biosynthesis of magnetite nanoparticles (BMNPs) with particle sizes between 10 nm and 60 nm. The biocompatible magnetic nanoparticles are produced from Magnetospirillum magneticum (M.M.) bacteria that respond to magnetic fields. M.M. bacteria were cultured and used to synthesize magnetite nanoparticles. This was done in an enriched magnetic spirillum growth medium (EMSGM) at different pH levels. The nanoparticle concentrations were characterized with UV-Visible (UV-Vis) spectroscopy, while the particle shapes were elucidated via transmission electron microscopy (TEM). The structure of the particles was studied using X-ray diffraction (XRD), while the hydrodynamic radii, particle size distributions and polydispersity of the nanoparticles were characterized using dynamic light scattering (DLS). Carbodiimide reduction was also used to functionalize the BMNPs with a molecular recognition unit (luteinizing hormone releasing hormone, LHRH) that attaches specifically to receptors that are over-expressed on the surfaces of most breast cancer cell types. The resulting nanoparticles were examined using Fourier Transform Infrared (FTIR) spectroscopy and quantitative image analysis. The implications of the results are then discussed for the potential development of magnetic nanoparticles for the specific targeting and treatment of breast cancer.

  20. Growth hormone-releasing hormone (GHRH polymorphisms associated with carcass traits of meat in Korean cattle

    Directory of Open Access Journals (Sweden)

    Cheong Il-Cheong

    2006-06-01

    Full Text Available Abstract Background Cold carcass weight (CW and longissimus muscle area (EMA are the major quantitative traits in beef cattle. In this study, we found several polymorphisms of growth hormone-releasing hormone (GHRH gene and examined the association of polymorphisms with carcass traits (CW and EMA in Korean native cattle (Hanwoo. Results By direct DNA sequencing in 24 unrelated Korean cattle, we identified 12 single nucleotide polymorphisms within the 9 kb full gene region, including the 1.5 kb promoter region. Among them, six polymorphic sites were selected for genotyping in our beef cattle (n = 428 and five marker haplotypes (frequency > 0.1 were identified. Statistical analysis revealed that -4241A>T showed significant associations with CW and EMA. Conclusion Our findings suggest that polymorphisms in GHRH might be one of the important genetic factors that influence carcass yield in beef cattle. Sequence variation/haplotype information identified in this study would provide valuable information for the production of a commercial line of beef cattle.

  1. Basic understanding of gonadotropin-releasing hormone-agonist triggering.

    Science.gov (United States)

    Casper, Robert F

    2015-04-01

    A single bolus of human chorionic gonadotropin (hCG) at midcycle has been the gold standard for triggering final oocyte maturation and ovulation in assisted reproductive technology cycles. More recently, gonadotropin-releasing hormone (GnRH)-agonist (GnRH-a) triggering has been introduced. The GnRH-a trigger may allow a more physiologic surge of both luteinizing hormone (LH) and follicle-stimulating hormone, although whether the combined surge will result in improved oocyte and embryo quality remains to be seen. However, the short duration of the LH surge with the GnRH-a trigger (approximately 34 hours) has been shown to be beneficial for preventing ovarian hyperstimulation syndrome in GnRH antagonist in vitro fertilization (IVF) cycles when compared with the prolonged elevation of hCG (≥6 days) after exposure to an hCG bolus. This review discusses the physiologic basis for the use of a GnRH-a trigger in IVF cycles.

  2. High Population Density of Juvenile Chum Salmon Decreased the Number and Sizes of Growth Hormone Cells in the Pituitary

    OpenAIRE

    Salam, Md. Abdus; Ota, Yuki; Ando, Hironori; Fukuwaka, Masa-aki; Kaeriyama, Masahide; Urano, Akihisa

    1999-01-01

    Juveniles of chum salmon (Oncorhynchus keta) held at high population density were apparently smaller than those held at medium and low population densities. The effects of high population density on pituitary growth hormone (GH) cells in juvenile chum salmon were examined using immunocytochemical and in situ hybridization techniques. The ratio of GH-immunoreactive (ir) area to the whole pituitary was almost constant in all of the high, medium and low population density groups, although the nu...

  3. Growth Hormone

    Science.gov (United States)

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Growth Hormone Share this page: Was this page helpful? Also known as: GH; Human Growth Hormone; HGH; Somatotropin; Growth Hormone Stimulation Test; Growth ...

  4. Long-term mortality in the United States cohort of pituitary-derived growth hormone recipients.

    Science.gov (United States)

    Mills, James L; Schonberger, Lawrence B; Wysowski, Diane K; Brown, Paul; Durako, Stephen J; Cox, Christopher; Kong, Fanhui; Fradkin, Judith E

    2004-04-01

    Patients who received pituitary-derived growth hormone (GH) are at excess risk of mortality from Creutzfeldt-Jakob disease. We investigated whether they were at increased risk of death from other conditions, particularly preventable conditions. A cohort (N=6107) from known US pituitary-derived GH recipients (treated 1963-1985) was studied. Deaths were identified by reports from physicians and parents and the National Death Index. Rates were compared with the expected rates for the US population standardized for race, age, and sex. There were 433 deaths versus 114 expected (relative risk [RR], 3.8; 95% confidence interval [CI], 3.4-4.2; Pderived GH recipients was almost four times the expected rate. Replacing pituitary-derived GH with recombinant GH has eliminated only the risk of Creutzfeldt-Jakob disease. Hypoglycemia and adrenal insufficiency accounted for far more mortality than Creutzfeldt-Jakob disease. The large number of potentially preventable deaths in patients with adrenal insufficiency and hypoglycemia underscores the importance of early intervention when infection occurs in patients with adrenal insufficiency, and aggressive treatment of panhypopituitarism.

  5. Growth hormone (GH-releasing hormone and GH secretagogues in normal aging: Fountain of Youth or Pool of Tantalus?

    Directory of Open Access Journals (Sweden)

    Elizabeth C Hersch

    2008-03-01

    Full Text Available Elizabeth C Hersch, George R MerriamVA Puget Sound Health Care System and University of Washington School of Medicine, Tacoma and Seattle, Washington USAAbstract: Although growth hormone (GH is primarily associated with linear growth in childhood, it continues to have important metabolic functions in adult life. Adult GH deficiency (AGHD is a distinct clinical entity, and GH replacement in AGHD can improve body composition, strength, aerobic capacity, and mood, and may reduce vascular disease risk. While there are some hormone-related side effects, the balance of benefits and risks is generally favorable, and several countries have approved GH for clinical use in AGHD. GH secretion declines progressively and markedly with aging, and many age-related changes resemble those of partial AGHD. This suggests that replacing GH, or stimulating GH with GH-releasing hormone or a GH secretagogue could confer benefits in normal aging similar to those observed in AGHD – in particular, could reduce the loss of muscle mass, strength, and exercise capacity leading to frailty, thereby prolonging the ability to live independently. However, while most GH studies have shown body composition effects similar to those in AGHD, functional changes have been much less inconsistent, and older adults are more sensitive to GH side effects. Preliminary reports of improved cognition are encouraging, but the overall balance of benefits and risks of GH supplementation in normal aging remains uncertain.Keywords: growth hormone, growth hormone-releasing hormone, growth hormone secretagogues, aging, sarcopenia, frailty

  6. Serum gonadotropins after gonadotropin-releasing hormone injection in bulls subjected to spacial restriction.

    Science.gov (United States)

    Gwazdauskas, F C; Bindas, E M; Anderson, G W; McGilliard, M L

    1984-12-01

    Response patterns of luteinizing hormone, follicle-stimulating hormone, and testosterone after injection of gonadotropin-releasing hormone were investigated in bulls grouped by weight (250 to 459 kg body weight) and confined five per pen in 9.2 or 6.4 m2 space per bull in two replicates. Blood samples were collected for 1 h prior to injection of 100 micrograms gonadotropin releasing hormone and 5 h after injection at 15-min intervals. Overall mean luteinizing hormone concentrations were not affected by spacial restriction or replicate. Interaction of treatment by time revealed that luteinizing hormone response curves were not similar. Restricted bulls had a higher response of luteinizing hormone to gonadotropin-releasing hormone. Follicle-stimulating hormone increased in all groups within 15 min and peaked at 219.4 ng/ml at 45 min. Both gonadotropin responses returned to preinjection concentrations by 4 h. Testosterone was affected by treatment, replicate, and time of sampling. Testosterone was higher in restricted bulls and higher in replicate 2. Mean testosterone peak following gonadotropin-releasing hormone was 3.86 ng/ml and occurred between 105 and 120 min which was approximately 90 min after the gonadotropin peaks. It appears that hormone responses to gonadotropin-releasing hormone were not depressed by spacial restriction, and additional spacial restriction of young bulls could be used commercially.

  7. Changes in plasma melanocyte-stimulating hormone, ACTH, prolactin, GH, LH, FSH, and thyroid-stimulating hormone in response to injection of sulpiride, thyrotropin-releasing hormone, or vehicle in insulin-sensitive and -insensitive mares.

    Science.gov (United States)

    Valencia, N Arana; Thompson, D L; Mitcham, P B

    2013-05-01

    Six insulin-sensitive and 6 insulin-insensitive mares were used in a replicated 3 by 3 Latin square design to determine the pituitary hormonal responses (compared with vehicle) to sulpiride and thyrotropin-releasing hormone (TRH), 2 compounds commonly used to diagnose pituitary pars intermedia dysfunction (PPID) in horses. Mares were classified as insulin sensitive or insensitive by their previous glucose responses to direct injection of human recombinant insulin. Treatment days were February 25, 2012, and March 10 and 24, 2012. Treatments were sulpiride (racemic mixture, 0.01 mg/kg BW), TRH (0.002 mg/kg BW), and vehicle (saline, 0.01 mL/kg BW) administered intravenously. Blood samples were collected via jugular catheters at -10, 0, 5, 10, 20, 30, 45, 60, 90, and 120 min relative to treatment injection. Plasma ACTH concentrations were variable and were not affected by treatment or insulin sensitivity category. Plasma melanocyte-stimulating hormone (MSH) concentrations responded (P sulpiride and TRH injection and were greater (P sulpiride and TRH injection, and the response was greater (P sulpiride; no effect of insulin sensitivity was observed. Plasma thyroid-stimulating hormone (TSH) concentrations responded (P sulpiride and TRH in insulin-insensitive mares were similar to, but not as exaggerated as, those observed by others for PPID horses. In addition, the reduced TSH concentrations in insulin-insensitive mares are consistent with our previous observation of elevated plasma triiodothyronine concentrations in hyperleptinemic horses (later shown to be insulin insensitive as well).

  8. Long-term effects of human growth hormone-releasing hormone and photoperiod on hormone release and puberty in dairy heifers.

    Science.gov (United States)

    Ringuet, H; Pelletier, G; Brazeau, P; Gaudreau, P; Guilbault, L A; Morisset, J; Couture, Y; Petitclerc, D

    1994-10-01

    Forty-eight Holstein dairy heifers (98.9 kg BW; 3 mo old) were subjected for 246 d to twice-daily s.c. injections of saline (CTL) or human growth hormone-releasing hormone (GRH; 5 micrograms/kg BW) and to photoperiods of 8 h of light (L): 16 h of dark (D) or 16L:8D according to a 2 x 2 factorial arrangement of treatments. Jugular blood samples were collected from 16 heifers at 3, 4, 8, and 11 mo of age to monitor prolactin, growth hormone, and estradiol-17 beta. Plasma progesterone concentrations were monitored weekly in all heifers as an index of puberty (> 1 ng/mL). Growth hormone release was induced by GRH (P GRH heifers. However, GRH-induced GH response was less (P GRH, photoperiod, and days of treatment on GRH-induced GH response; AUC was greater in GRH-16L:8D than in GRH-8L:16D heifers at 3 mo but less at 8 mo of age. The PRL concentrations were similar for both photoperiods at 3 mo (36.4 vs 41.7 ng/mL) and 8 mo (16.2 vs 12.8 ng/mL) of age but were greater in 16L:8D vs 8L:16D heifers at 4 mo (18.4 vs 39.3 ng/mL) and 11 mo (26.3 vs 44.1 ng/mL) of age (photoperiod x day interaction, P GRH-treated heifers (271 vs 284 kg BW; GRH x photoperiod interaction, P = .10). In conclusion, GH response is maintained throughout 8 mo of GRH treatment, and a 16L:8D photoperiod will reduce age and weight at puberty in heifers. Furthermore, refractoriness to photoperiod-induced PRL changes was detected.

  9. A new pathway mediating social effects on the endocrine system: female presence acting via norepinephrine release stimulates gonadotropin-inhibitory hormone in the paraventricular nucleus and suppresses luteinizing hormone in quail.

    Science.gov (United States)

    Tobari, Yasuko; Son, You Lee; Ubuka, Takayoshi; Hasegawa, Yoshihisa; Tsutsui, Kazuyoshi

    2014-07-16

    Rapid effects of social interactions on transient changes in hormonal levels are known in a wide variety of vertebrate taxa, ranging from fish to humans. Although these responses are mediated by the brain, neurochemical pathways that translate social signals into reproductive physiological changes are unclear. In this study, we analyzed how a female presence modifies synthesis and/or release of various neurochemicals, such as monoamines and neuropeptides, in the brain and downstream reproductive hormones in sexually active male Japanese quail. By viewing a female bird, sexually active males rapidly increased norepinephrine (NE) release in the paraventricular nucleus (PVN) of the hypothalamus, in which gonadotropin-inhibitory hormone (GnIH) neuronal cell bodies exist, increased GnIH precursor mRNA expression in the PVN, and decreased luteinizing hormone (LH) concentration in the plasma. GnIH is a hypothalamic neuropeptide that inhibits gonadotropin secretion from the pituitary. It was further shown that GnIH can rapidly suppress LH release after intravenous administration in this study. Centrally administered NE decreased plasma LH concentration in vivo. It was also shown that NE stimulated the release of GnIH from diencephalic tissue blocks in vitro. Fluorescence double-label immunohistochemistry indicated that GnIH neurons received noradrenergic innervations, and immunohistochemistry combined with in situ hybridization have further shown that GnIH neurons expressed α2A-adrenergic receptor mRNA. These results indicate that a female presence increases NE release in the PVN and stimulates GnIH release, resulting in the suppression of LH release in sexually active male quail.

  10. orlistat improves release of gut hormones increasing satiety in obese women

    OpenAIRE

    2014-01-01

    Orlistat, which reduces fat absorption by inhibiting intestinal lipase is a registered drug for obesity pharmacotherapy. Meta-analyzes indicate various positive metabolic effects of orlistat, including improvements in glucose and lipid metabolism, lowering both systolic and diastolic blood pressure. It is assumed that orlistat can reduce postprandial satiety by inhibiting the release of intestinal hormones (incretins), especially glucagon-like peptide-1 (GLP-1). Impact analysis of the secreti...

  11. Effect of ghrelin and thyrotropin-releasing hormone on prolactin secretion in normal women.

    Science.gov (United States)

    Messini, C I; Dafopoulos, K; Chalvatzas, N; Georgoulias, P; Anifandis, G; Messinis, I E

    2010-03-01

    It is known that ghrelin stimulates the secretion of prolactin in women. The aim of this study was to examine the effect of exogenous thyrotropin-releasing hormone (TRH) on ghrelin-induced prolactin release. Ten healthy normally cycling women were studied in four menstrual cycles. The women were injected intravenously in late follicular phase (follicle size 16-17 mm) with a single dose of normal saline (cycle 1), ghrelin (1 microg/kg) (cycle 2), thyrotropin-releasing hormone (200 microg) (cycle 3), and ghrelin plus thyrotropin-releasing hormone (cycle 4). Blood samples in relation to saline or drugs injection (time 0) were taken at -15, 0, 15, 30, 45, 60, 75, 90, and 120 min. The prolactin and growth hormone responses were assessed. After ghrelin administration (cycles 2 and 4), plasma ghrelin, serum prolactin, and growth hormone levels increased rapidly, peaking at 15-30 min (psecretion markedly (pGhrelin induced a smaller prolactin increase than thyrotropin-releasing hormone (pghrelin and thyrotropin-releasing hormone induced a similar increase in prolactin levels as with thyrotropin-releasing hormone alone. No changes in growth hormone and prolactin levels were seen after saline injection. These results demonstrate that the stimulating effect of ghrelin on prolactin secretion is not additive with that of thyrotropin-releasing hormone.

  12. Reproductive Hormone and Transcriptomic Responses of Pituitary Tissue in Anestrus Gilts Induced by Nutrient Restriction.

    Directory of Open Access Journals (Sweden)

    Shengyu Xu

    Full Text Available The onset of estrus is a critical sign of female sexual maturity. The pituitary plays a vital role in this process by the secretion of reproductive hormones. To investigate the effects of nutrient restriction on reproductive function and the underlying mechanisms involved, deep RNA sequencing of pituitary gland tissue was carried out to determine the differentially expressed genes (DEGs between gilts in normal estrus, and gilts in which anestrus was induced by nutrient restriction. Gilts which had gone through two estrus cycles were fed a normal (CON, 2.86kg/d, n = 10 or nutrient restricted (NR, 1kg/d, n = 10 diet. The NR gilts experienced another three estrus cycles, but did not express estrus symptoms at the anticipated 6th and 7th cycles. Body weight gain in NR gilts was significantly decreased by nutrient restriction. Gilts were considered as anestrus when blood progesterone concentrations lower than 1.0 ng/mL from three consecutive blood samples were recorded. Circulating concentrations of progesterone (< 1.0 ng/mL vs. 2.1 ng/mL and estradiol (208.6 ng/mL vs. 371.8 ng/mL were significantly lower in the NR gilts than in the CON gilts. Between 5,360,000 and 5,370,000 sequence reads per sample from the CON and NR gilts' pituitaries were obtained and mapped to the porcine genome. Analysis of read counts revealed 185 DEGs. Expression of selected genes was validated by the use of quantitative real-time RT-PCR. Bioinformatic analysis identified that the genes identified were enriched in the GO terms "neuroactive ligand-receptor interaction", "GnRH signaling pathway" and "immune response system". Our findings provide a new perspective for understanding the nutrient restriction-induced reproductive impairment at the pituitary transcriptional level, and how this is linked to hormone secretion. Moreover, the transcriptomic changes in anestrus gilts associated with nutrient restriction could be a resource for targeted studies of genes and pathways

  13. Secondary amenorrhea in a woman with spinocerebellar degeneration treated with thyrotropin-releasing hormone: a case report and in vitro analysis

    Directory of Open Access Journals (Sweden)

    Kanasaki Haruhiko

    2011-12-01

    Full Text Available Abstract Introduction While thyrotropin-releasing hormone is known to be a prolactin-release stimulating factor, thyrotropin-releasing hormone-tartrate and its derivative, taltirelin hydrate, are used for the treatment of spinocerebellar degeneration, a degenerative disease characterized mainly by motor ataxia. We report the case of a patient being treated with a thyrotropin-releasing hormone preparation for spinocerebellar degeneration who developed amenorrhea after a dose increase. Her hormonal background was analyzed and the effect of prolonged exposure to thyrotropin-releasing hormone on pituitary prolactin-producing cells was examined in vitro. Case presentation Our patient was a 36-year-old Japanese woman who experienced worsening of gait disturbance at around 23 years of age, and was subsequently diagnosed as having spinocerebellar degeneration. She had been treated with thyrotropin-releasing hormone-tartrate for four years. Taltirelin hydrate was added to the treatment seven months prior to her presentation, followed by an improvement in gait disturbance. Around the same period, she started lactating and subsequently developed amenorrhea three months later. Taltirelin hydrate was discontinued and she was referred to our hospital. She was found to have normal sex hormone levels. A thyrotropin-releasing hormone provocation test showed a normal response of thyroid-stimulating hormone level and an over-response of prolactin at 30 minutes (142.7 ng/mL. Resumption of menstruation was noted three months after dose reduction of thyrotropin-releasing hormone. In our in vitro study, following long-term exposure to thyrotropin-releasing hormone, cells from the rat pituitary prolactin-producing cell line GH3 exhibited an increased basal prolactin promoter activity but showed a marked decrease in responsiveness to thyrotropin-releasing hormone. Conclusions Physicians should be aware of hyperprolactinemia-associated side effects in patients receiving

  14. Melatonin improves memory acquisition under stress independent of stress hormone release

    OpenAIRE

    Rimmele, U; Spillmann, M; Bärtschi, C; Wolf, O.T.; Weber, C S; Ehlert, Ulrike; Wirtz, P H

    2009-01-01

    RATIONALE: Animal studies suggest that the pineal hormone melatonin influences basal stress hormone levels and dampens hormone reactivity to stress. OBJECTIVES: We investigated whether melatonin also has a suppressive effect on stress-induced catecholamine and cortisol release in humans. As stress hormones affect memory processing, we further examined a possible accompanying modulation of memory function. MATERIALS AND METHODS: Fifty healthy young men received a single oral dose of either 3...

  15. Reproductive characteristics of grass-fed, luteinizing hormone-releasing hormone-immunocastrated Bos indicus bulls.

    Science.gov (United States)

    Hernandez, J A; Zanella, E L; Bogden, R; de Avila, D M; Gaskins, C T; Reeves, J J

    2005-12-01

    Two field trials were conducted in Brazil to evaluate LHRH immunocastration of Bos indicus bulls (d 0 = 2 yr of age). In Study I, 72 bulls were assigned randomly to one of three treatment groups: LHRH0-immunized, castrated, and intact. Immunized animals (n = 25) received a primary and two booster injections of ovalbumin-LHRH-7 and thioredoxin-LHRH-7 fusion proteins on d 0, 141, and 287. Twenty-three bulls were surgically castrated on d 141, and 24 served as intact controls. All animals were slaughtered on d 385, at approximately 3 yr of age. In Study II, 216 bulls were assigned randomly to the same three treatments as in Study I; however, because of a drought in the area, bulls were kept on pasture an additional year, and a fourth treatment was added, in which one-half the LHRH-immunized bulls received an additional booster on d 639 (fourth immunization). All animals in Study II were slaughtered on d 741 (4 yr of age). Luteinizing hormone-releasing hormone antibodies increased following each immunization for immunized bulls, but they were not detectable in castrate or intact animals in either study. Consequently, scrotal circumference was suppressed in immunized bulls compared with intact controls in both studies. By d 287, serum concentrations of testosterone in LHRH-immunized bulls were decreased compared with intact controls (P bulls (173 +/- 22 and 26 +/- 2 g, respectively) and fourth immunization bulls (78 +/- 23 and 20 +/- 2 g, respectively; Study II). At the end of each study, BW was greater (P bulls than for castrated and LHRH-immunized animals. In these two studies, the efficacy of the LHRH fusion proteins to induce an effect similar to that of surgical castration was considered 92 and 93%, respectively. These data support the concept that immunocastration of bulls at 2 yr of age was successful and that it has practical application as a tool for producing grass-fattened bulls in Brazil.

  16. Biosynthesis and the conjugation of magnetite nanoparticles with luteinizing hormone releasing hormone (LHRH)

    Energy Technology Data Exchange (ETDEWEB)

    Obayemi, J.D. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Department of Materials Science and Engineering, Kwara State University, Malete, Kwara State (Nigeria); Dozie-Nwachukwu, S. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Sheda Science and Technology Complex (SHESTCO) Abuja, Federal Capital Territory (Nigeria); Danyuo, Y. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Department of Electronics and Electricals Engineering, Nigerian Turkish Nile University, Abuja (Nigeria); Odusanya, O.S. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Sheda Science and Technology Complex (SHESTCO) Abuja, Federal Capital Territory (Nigeria); Anuku, N. [Department of Chemistry, Bronx Community College, New York, NY 10453 (United States); Princeton Institute of Science and Technology of Materials (PRISM), Princeton, NJ 08544 (United States); Malatesta, K. [Princeton Institute of Science and Technology of Materials (PRISM), Princeton, NJ 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, NJ 08544 (United States); Soboyejo, W.O., E-mail: soboyejo@princeton.edu [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Princeton Institute of Science and Technology of Materials (PRISM), Princeton, NJ 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, NJ 08544 (United States)

    2015-01-01

    This paper presents the results of an experimental study of the biosynthesis of magnetite nanoparticles (BMNPs) with particle sizes between 10 nm and 60 nm. The biocompatible magnetic nanoparticles are produced from Magnetospirillum magneticum (M.M.) bacteria that respond to magnetic fields. M.M. bacteria were cultured and used to synthesize magnetite nanoparticles. This was done in an enriched magnetic spirillum growth medium (EMSGM) at different pH levels. The nanoparticle concentrations were characterized with UV–Visible (UV–Vis) spectroscopy, while the particle shapes were elucidated via transmission electron microscopy (TEM). The structure of the particles was studied using X-ray diffraction (XRD), while the hydrodynamic radii, particle size distributions and polydispersity of the nanoparticles were characterized using dynamic light scattering (DLS). Carbodiimide reduction was also used to functionalize the BMNPs with a molecular recognition unit (luteinizing hormone releasing hormone, LHRH) that attaches specifically to receptors that are over-expressed on the surfaces of most breast cancer cell types. The resulting nanoparticles were examined using Fourier Transform Infrared (FTIR) spectroscopy and quantitative image analysis. The implications of the results are then discussed for the potential development of magnetic nanoparticles for the specific targeting and treatment of breast cancer. - Highlights: • Biosynthesis of MNPs with clinically relevant sizes between 10 and 60 nm. • New insights into the effects of pH and processing time on nanoparticle shapes and sizes. • Successful conjugation of biosynthesized magnetite nanoparticles to LHRH ligands. • Conjugated BMNPs that are monodispersed with potential biomedical relevance. • Magnetic properties of biosynthesized MNPs suggest potential for MRI enhancement.

  17. Effects of Cypermethrin on Sexual Behaviour and Plasma Concentrations of Pituitary-Gonadal Hormones

    Directory of Open Access Journals (Sweden)

    Jalal Solati

    2010-01-01

    Full Text Available Background: Pyrethroids are commonly used as insecticides for both household and agriculturalapplications, and have recently been linked to endocrine disruption. Cypermethrin is a type Пpyrethroid which is used widely throughout the world. The present study was aimed to investigatethe effects of cypermethrin on the sexual behaviour and plasma level of pituitary-gonadal hormonesof adult male mice.Materials and Methods: Research methodology comprised injecting mice daily with cypermethrin(10, 15, 20 mg/kg i.p. or DMSO (0.2 ml for five weeks. Receptive female mice were used totest male sexual behaviors (sniffing, following, mounting, and coupling. Plasma concentrationsof testosterone, luteinizing hormone (LH and follicle stimulation hormone (FSH were measuredafter five weeks treatment using the ELISA method.Results: The results of the present study showed that cypermethrin-treated groups exhibited reducedsexual behavior when compared with the control group. Assay results demonstrate significantlyreduced serum testosterone levels (p<0.05 versus the control group, whereas FSH and LH valuesincreased significantly.Conclusion: This study demonstrates that cypermethrin reduces plasma testosterone concentrationsand thus is able to disrupt sexual behaviours.

  18. The role of thyroid hormone in sleep deprivation.

    Science.gov (United States)

    Pereira, José Carlos; Andersen, Mônica Levy

    2014-03-01

    Sleep deprivation is a stressful condition, as the subject experiences feelings of inadequate well-being and exhibits impairments in his/her functioning. However, in some circumstances sleep deprivation may be crucial for survival of the individual. Most likely, complex neural circuits and hormones play a role in allowing sleep deprivation to occur. For instance, thyroid hormone activity sharply increases when an individual is in a state of sleep deprivation. We believe that this increase is central to sleep deprivation physiology. During sleep deprivation, the hypothalamic-pituitary-thyroid axis initially increases as a consequence of increased release of thyroid stimulating hormone from the pituitary. Subsequently, as sleep deprivation continues, the sympathetic nervous system is recruited through its anatomical connection with the thyroid gland. While thyroid stimulating hormone levels markedly increase during sleep deprivation, it has been suggested that these increases are secondary to sleep deprivation. However, there is little evidence to support this assumption. We believe that the physiology of the thyroid axis during sleep deprivation and the actions of the effector hormone thyroid hormone suggest that thyroid hormone inhibits sleep and not the contrary. To our knowledge, few studies have addressed the possible neural functions that enable sleep deprivation. In this article, we discuss the hypothesis that an augmentation in the thyroid hormone axis is central to a subject's ability to curtail sleep.

  19. The reciprocal regulation of stress hormones and GABAA receptors

    Directory of Open Access Journals (Sweden)

    Istvan eMody

    2012-01-01

    Full Text Available Stress-derived steroid hormones regulate the expression and function of GABAA receptors (GABAARs. Changes in GABAAR subunit expression have been demonstrated under conditions of altered steroid hormone levels, such as stress, as well as following exogenous steroid hormone administration. In addition to the effects of stress-derived steroid hormones on GABAAR subunit expression, stress hormones can also be metabolized to neuroactive derivatives which can alter the function of GABAARs. Neurosteroids allosterically modulate GABAARs at concentrations comparable to those during stress. In addition to the actions of stress-derived steroid hormones on GABAARs, GABAARs reciprocally regulate the production of stress hormones. The stress response is mediated by the hypothalamic-pituitary-adrenal (HPA axis, the activity of which is governed by corticotropin releasing hormone (CRH neurons. The activity of CRH neurons is largely controlled by robust GABAergic inhibition. Recently, it has been demonstrated that CRH neurons are regulated by neurosteroid-sensitive, GABAAR δ subunit-containing receptors representing a novel feedback mechanism onto the HPA axis. Further, it has been demonstrated that neurosteroidogenesis and neurosteroid actions on GABAAR δ subunit-containing receptors on CRH neurons are necessary to mount the physiological response to stress. Here we review the literature describing the effects of steroid hormones on GABAARs as well as the importance of GABAARs in regulating the production of steroid hormones. This review incorporates what we currently know about changes in GABAARs following stress and the role in HPA axis regulation.

  20. Synchronous esthesioneuroblastoma and growth-hormone-secreting pituitary macroadenoma: combined open and endoscopic management.

    Science.gov (United States)

    Valdes, Costanza J; Tewfik, Marc A; Guiot, Marie-Christine; Di Maio, Salvatore

    2014-12-01

    Background Esthesioneuroblastoma is an uncommon malignant neoplasm that arises from the olfactory neuroepithelium. In this article we report a case of esthesioneuroblastoma presenting concomitantly with a growth-hormone (GH)-secreting pituitary macroadenoma. Results A 52 year old woman underwent surgery for suspected nasal polyps. Intralesional debulking of an intranasal tumor disclosed a low-grade esthesioneuroblastoma. Magnetic resonance imaging (MRI) demonstrated a large nasal and intracranial tumor, in addition to a separate sellar and suprasellar tumor. The patient was frankly acromegalic. She underwent a first-stage gross total resection of the esthesioneuroblastoma via a combined extended subfrontal and extended endonasal approach, followed by focused radiation therapy. She then returned for endoscopic removal of the GH-secreting pituitary macroadenoma. Conclusion The combined open and endoscopic management of this patient is described and a review of the literature presented. To our knowledge this is the first case of synchronous esthesioneuroblastoma and macroadenoma, in this case GH secreting, described in the literature.

  1. Gene Regulation System of Vasopressin and Corticotoropin-Releasing Hormone

    Directory of Open Access Journals (Sweden)

    Masanori Yoshida

    2008-01-01

    Full Text Available The neurohypophyseal hormones, arginine vasopressin and corticotropin-releasing hormone (CRH, play a crucial role in the physiological and behavioral response to various kinds of stresses. Both neuropeptides activate the hypophysialpituitary-adrenal (HPA axis, which is a central mediator of the stress response in the body. Conversely, they receive the negative regulation by glucocorticoid, which is an end product of the HPA axis. Vasopressin and CRH are closely linked to immune response; they also interact with pro-inflammatory cytokines. Moreover, as for vasopressin, it has another important role, which is the regulation of water balance through its potent antidiuretic effect. Hence, it is conceivable that vasopressin and CRH mediate the homeostatic responses for survival and protect organisms from the external world. A tight and elaborate regulation system of the vasopressin and CRH gene is required for the rapid and flexible response to the alteration of the surrounding environments. Several important regulatory elements have been identified in the proximal promoter region in the vasopressin and CRH gene. Many transcription factors and intracellular signaling cascades are involved in the complicated gene regulation system. This review focuses on the current status of the basic research of vasopressin and CRH. In addition to the numerous known facts about their divergent physiological roles, the recent topics of promoter analyses will be discussed.

  2. Five gonadotrophin-releasing hormone receptors in a teleost fish: isolation, tissue distribution and phylogenetic relationships.

    Science.gov (United States)

    Moncaut, Natalia; Somoza, Gustavo; Power, Deborah M; Canário, Adelino V M

    2005-06-01

    Gonadotrophin-releasing hormone (GnRH) is the main neurohormone controlling gonadotrophin release in all vertebrates, and in teleost fish also of growth hormone and possibly of other adenohypophyseal hormones. Over 20 GnRHs have been identified in vertebrates and protochoordates and shown to bind cognate G-protein couple receptors (GnRHR). We have searched the puffer fish, Fugu rubripes, genome sequencing database, identified five GnRHR genes and proceeded to isolate the corresponding complementary DNAs in European sea bass, Dicentrachus labrax. Phylogenetic analysis clusters the European sea bass, puffer fish and all other vertebrate receptors into two main lineages corresponding to the mammalian type I and II receptors. The fish receptors could be subdivided in two GnRHR1 (A and B) and three GnRHR2 (A, B and C) subtypes. Amino acid sequence identity within receptor subtypes varies between 70 and 90% but only 50-55% among the two main lineages in fish. All European sea bass receptor mRNAs are expressed in the anterior and mid brain, and all but one are expressed in the pituitary gland. There is differential expression of the receptors in peripheral tissues related to reproduction (gonads), chemical senses (eye and olfactory epithelium) and osmoregulation (kidney and gill). This is the first report showing five GnRH receptors in a vertebrate species and the gene expression patterns support the concept that GnRH and GnRHRs play highly diverse functional roles in the regulation of cellular functions, besides the "classical" role of pituitary function regulation.

  3. Effect of a long-acting somatostatin analogue (SMS 201-995 on a growth hormone and thyroid stimulating hormone-producing pituitary tumor.

    Directory of Open Access Journals (Sweden)

    Hirasawa,Ryoto

    1991-04-01

    Full Text Available A 46-year-old woman with acromegaly and hyperthyroidism due to a pituitary adenoma. She had high serum thyroid-stimulating hormone (TSH levels and very high serum growth hormone (GH levels. Transsphenoidal removal of the tumor, post-operative irradiation, frontal craniotomy for removal of residual tumor and large-dose bromocriptine therapy were carried out consecutively. After therapy, serum GH levels gradually decreased, but not to the normal range, and serum TSH levels remained at inappropriately normal levels. Using immunoperoxidase techniques, GH-, TSH- and follicle-stimulating hormone (FSH-containing cells were demonstrated in the adenoma. A long-acting somatostatin analogue (SMS 201-995, 600 micrograms/day suppressed the serum GH level to the normal range with a concomitant suppression of TSH. Furthermore, the paradoxical serum GH responses to TRH and LH-RH were slightly improved. No important subjective side-effects were noted. Therefore, SMS 201-995 appeared to be a very effective drug in this patient with a GH- and TSH-producing pituitary tumor.

  4. Classification of pituitary growth hormone producing adenomas according to SIPAP: application in clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Sofie (Dept. of Radiology, Lund Univ. and Skaane Univ. Hospital, Lund (Sweden)), email: Sofie.Meyer@skane.se; Valdemarsson, Stig (Dept. of Endocrinology, Lund Univ. and Skaane Univ. Hospital, Lund (Sweden)); Larsson, Elna-Marie (Dept. of Radiology, Uppsala Univ. Hospital, Uppsala (Sweden))

    2011-09-15

    Background: In 1997, the SIPAP classification was introduced, a guide designed for MRI, to characterize pituitary adenomas with emphasis on extrasellar extensions and impact on adjacent structures. To our knowledge no previous evaluation of the inter-observer agreement of the SIPAP classification has been performed. Purpose: To evaluate the inter-observer agreement of the SIPAP classification. Material and Methods: Sixty patients operated on for growth hormone producing pituitary adenomas at Lund Univ. Hospital 1991-2007 had an assessable preoperative MRI scan. Forty-five of them also had an assessable postoperative MRI scan. The mean time between surgery and postoperative MRI scans was 11 months. Two observers evaluated all the MRI scans independently. The outcome of the evaluation is presented as the percentage of concordance in each of the evaluated directions and the degree of discrepancy for each of the directions evaluated. Results: In 284 (79%) of 360 preoperative gradings both observers agreed completely. In 17 of the 60 preoperative MRI scans, both observers made identical assessments according to the SIPAP classification in all the six different directions of tumor extension. In 76 gradings the results differed between the observers. The difference was 1 grade (or less) in 69 cases. In 230 (85%) of 270 postoperative gradings the results were identical for both observers. In 18 of the 45 postoperative MRI scans, both observers made the same assessments according to the SIPAP classification in all the six different directions of tumor extension. In 40 gradings the results differed between the observers. The difference was 1 grade (or less) in all 40 cases. Conclusion: We found a relatively high inter-observer agreement both pre- and postoperatively, supporting the usefulness and easy applicability of the SIPAP system for grading of pituitary adenomas pre- as well as postoperatively

  5. Effects of the Hormone Kisspeptin on Reproductive Hormone Release in Humans

    Directory of Open Access Journals (Sweden)

    Joanne L. Calley

    2014-01-01

    Full Text Available The kisspeptins are a family of neuropeptides which act as upstream stimulators of gonadotrophin releasing hormone (GnRH neurons. Kisspeptin signalling is prerequisite to establishing the normal human reproductive phenotype; loss of function mutations in the KISS1 or KISS1R gene produces normosmic hypogonadotrophic hypogonadism in humans and mice, whilst increased activation of KISS1R causes precocious puberty. Administration of exogenous kisspeptin to human subjects stimulates an acute gonadotrophin rise. Serum kisspeptin levels also markedly increase during pregnancy. The identification of kisspeptin has been one of the biggest discoveries in the field of reproductive endocrinology, since the isolation and sequencing of GnRH in 1977, and has generated a novel research avenue which has received much attention over the past decade. This research has delineated many properties of the KISS1-KISS1R system, but there is still further work to do. Understanding kisspeptin’s role throughout our reproductive lifetime should help us better understand—and therefore treat—disorders of reproductive function. Promisingly, the current data supports the potential to develop kisspeptin based therapies. As an outlook article this paper focusses predominantly on our groups recent investigations into the effects of kisspeptin administration to humans and the potential therapeutic role of kisspeptin.

  6. High prevalence of chronic pituitary and target-organ hormone abnormalities after blast-related mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Charles W. Wilkinson

    2012-02-01

    Full Text Available Studies of traumatic brain injury from all causes have found evidence of chronic hypopituitarism, defined by deficient production of one or more pituitary hormones at least one year after injury, in 25-50% of cases. Most studies found the occurrence of posttraumatic hypopituitarism (PTHP to be unrelated to injury severity. Growth hormone deficiency (GHD and hypogonadism were reported most frequently. Hypopituitarism, and in particular adult GHD, is associated with symptoms that resemble those of PTSD, including fatigue, anxiety, depression, irritability, insomnia, sexual dysfunction, cognitive deficiencies, and decreased quality of life. However, the prevalence of PTHP after blast-related mild TBI (mTBI, an extremely common injury in modern military operations, has not been characterized. We measured concentrations of 12 pituitary and target-organ hormones in two groups of male US Veterans of combat in Iraq or Afghanistan. One group consisted of participants with blast-related mTBI whose last blast exposure was at least one year prior to the study. The other consisted of Veterans with similar military deployment histories but without blast exposure. Eleven of 26, or 42% of participants with blast concussions were found to have abnormal hormone levels in one or more pituitary axes, a prevalence similar to that found in other forms of TBI. Five members of the mTBI group were found with markedly low age-adjusted insulin-like growth factor-I (IGF-I levels indicative of probable GHD, and three had testosterone and gonadotropin concentrations consistent with hypogonadism. If symptoms characteristic of both PTHP and PTSD can be linked to pituitary dysfunction, they may be amenable to treatment with hormone replacement. Routine screening for chronic hypopituitarism after blast concussion shows promise for appropriately directing diagnostic and therapeutic decisions that otherwise may remain unconsidered and for markedly facilitating recovery and

  7. Seasonal differences in the parameters of luteinizing hormone release to exogenous gonadotropin releasing hormone in prepubertal Holstein heifers in Sapporo.

    Science.gov (United States)

    Kadokawa, Hiroya

    2007-02-01

    Stress due to summer heat has adverse effects on reproduction in Holstein dairy cattle. Summer suppression of reproduction of Holsteins can pose an important economic problem, even in Hokkaido prefecture located in the northern region of Japan. Hokkaido is one of the most important dairy farming areas of Japan. This study is an attempt to clarify the seasonal differences in the parameters of luteinizing hormone (LH) response to exogenous gonadotropin releasing hormone (GnRH) in Sapporo, Hokkaido, Japan. A total of 12 prepubertal heifers received an injection with GnRH analogue intramuscularly in either May (n=4, May group), July (n=4, July group), or November (n=4, November group), and serial blood samples were collected to analyze the parameters of the LH response curve after GnRH injection. The parameters were as follows: the basal LH concentration, peak LH concentration, duration from the time of GnRH injection to the time of the peak LH concentration, and area under the LH response curve (AUC). There were no significant differences in the basal and peak LH concentrations or the AUC among the three groups. The July group reached the LH peak significantly (P<0.05) faster than the May group, but there was no significant difference with the November group. Therefore, the results of the present study do not demonstrate an effect of summer heat on the LH response to the exogenous GnRH in Holstein heifers.

  8. From nose to brain: development of gonadotrophin-releasing hormone-1 neurones.

    Science.gov (United States)

    Wray, S

    2010-07-01

    Gonadotrophin-releasing hormone-1 (GnRH-1) is essential for mammalian reproduction, controlling release of gonadotrophins from the anterior pituitary. GnRH-1 neurones migrate from the nasal placode into the forebrain during development. Although first located within the nasal placode, the embryonic origin/lineage of GnRH-1 neurones is still unclear. The migration of GnRH-1 cells is the best characterised example of neurophilic/axophilic migration, with the cells using a subset of olfactory-derived vomeronasal axons as their pathway and numerous molecules to guide their movement into the forebrain. Exciting work in this area is beginning to identify intersecting pathways that orchestrate the movement of these critical neuroendocrine cells into the central nervous system, both spatially and temporally, through a diverse and changing terrain. Once within the forebrain, little is known about how the axons target the median eminence and ultimately secrete GnRH-1 in a pulsatile fashion.

  9. PET/MR imaging in the diagnosis of hormone-producing pituitary micro-adenoma: a prospective pilot study.

    Science.gov (United States)

    Wang, Hao; Hou, Bo; Lu, Lin; Feng, Ming; Zang, Jie; Yao, Shaobo; Feng, Feng; Wang, Renzhi; Li, Fang; Zhu, Zhaohui

    2017-08-03

    Purpose: This study was designed to evaluate positron emission tomography/magnetic resonance (PET/MR), using (18)F-FDG and (68)Ga-DOTATATE as tracers, in the detection of hormone-producing pituitary micro-adenoma, where diagnosis is difficult using magnetic resonance imaging (MRI) alone. Methods: A total of 37 patients with elevated hormone levels were recruited, including 19 patients with undiagnosable primary pituitary tumors and 18 patients with suspected recurrent pituitary adenomas (PAs). Patients underwent (18)F-FDG PET/MR and (68)Ga-DOTATATE PET/MR within one week. Finally, 27 patients underwent transsphenoidal adenomectomy within two weeks, 3 patients underwent sella region radiotherapy, 1 patient underwent somatostatin therapy, and the other 6 patients had a clinical follow-up. The image characteristics and uptake levels were correlated with the surgical findings and pathological results. Receiver-operating-characteristic (ROC) curve analysis was performed to determine an optimal cutoff pituitary to differentiate pituitary adenoma from normal pituitary tissue. The area under the ROC curve was calculated to compare the diagnostic performance. Results: The PET/MR images were in diagnostic quality without obvious image artifacts. The high contrast of PET imaging provided complementary information to the fine anatomy display of MRI. Increased (18)F-FDG uptake was clearly observed in the all patients, whereas enhanced MRI enhanced MRI using 0.05 mmol/kg Gadopentetate dimeglumine had suspicious findings only in 47% primary and 39% recurrent PAs patients, which were 37% and 50%, respectively when using 0.1 mmol/kg Gadopentetate dimeglumine. The maximum standardized uptake values (SUVmax) of (18)F-FDG activity (6.8 ± 3.7) in 16 primary pituitary adenomas who underwent transsphenoidal adenomectomy, was significantly higher than that of the rest of the normal pituitary gland (3.2 ± 1.1, P PET/MR imaging provides an ideal tool for the detection of small hormone

  10. Data on the characterization of follicle-stimulating hormone monoclonal antibodies and localization in Japanese eel pituitary

    Directory of Open Access Journals (Sweden)

    Dae-Jung Kim

    2016-09-01

    In support of our recent publication, "Production and characterization of monoclonal antibodies against recombinant tethered follicle-stimulating hormone from Japanese eel Anguilla japonica" [1], it was important to characterize the specificity of eel follicle-stimulating hormone antibodies. Here, the production and ELISA system of these monoclonal antibodies are presented. The affinity-purified monoclonal antibodies specifically detected eel rec-FSH in ELISA and on western blots of rec-FSH produced from CHO cells. Immunohistochemical analysis revealed that FSH staining was specifically localized in the eel pituitary.

  11. Elevation of plasma gonadotropin concentration in response to mammalian gonadotropin releasing hormone (GRH) treatment of the male brown trout as determined by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Grim, L.W.; Cluett, D.M.

    1974-01-01

    Rapid increase of the plasma gonadotropin concentration as measured by radioimmunoassay has been demonstrated in response to GRH treatment of the sexually mature male brown trout. Peak gonadotropin values were observed within 15 minutes of GRH treatment, however, the return to baseline values was prolonged compared with the mammalian response. These data support the concept that the brain, operating via releasing hormones, plays a role in the control of pituitary hormone secretion in fish.

  12. Neuroendocrine and Cardiovascular Risk Factors in Adults with Pituitary Growth Hormone Deficiency (Literature Review

    Directory of Open Access Journals (Sweden)

    S.I. Ismailov

    2013-06-01

    Full Text Available In this article authors discussed the results of literature review, which has been dedicated to study of different complications of growth hormone deficiency in adults, referring to the literature of the last 10–15 years. Based on this analysis, the authors concluded that in adults with growth hormone deficiency there is an adverse profile of cardiovascular risk. Patients with growth hormone deficiency have an adverse lipid profile, elevated body mass index, increased waist circumference and a high risk of hypertension. These disorders are likely to explain the increased cardiovascular mortality observed in patients with hypopituitarism, regardless of the etiology of growth hormone deficiency in adults.

  13. Dipeptidylpeptidase IV and trypsin-like enzymatic degradation of human growth hormone-releasing hormone in plasma.

    OpenAIRE

    Frohman, L A; Downs, T. R.; Heimer, E P; Felix, A M

    1989-01-01

    The plasma enzyme responsible for primary proteolytic cleavage of growth hormone-releasing hormone (GRH) at the 2-3 amino acid bond was characterized. Native GRH[GRH(1-44)-NH2 and GRH(1-40)-OH], and COOH-terminally shortened fragments [GRH(1-32)-NH2 and GRH(1-29)-NH2] were rapidly cleaved, while GRH(2-32)-NH2 was not degraded at this site. Moreover, degradation to GRH(3-44)-NH2 was unaffected by an aminopeptidase inhibitor, indicating that this metabolite was generated from a single step clea...

  14. Clinical guidelines for management of diabetes insipidus and syndrome of inappropriate antidiuretic hormone secretion after pituitary surgery.

    Science.gov (United States)

    Lamas, Cristina; del Pozo, Carlos; Villabona, Carles

    2014-04-01

    Changes in water metabolism and regulation of vasopressin (AVP) or antidiuretic hormone (ADH) are common complications of pituitary surgery. The scarcity of studies comparing different treatment and monitoring strategies for these disorders and the lack of prior clinical guidelines makes it difficult to provide recommendations following a methodology based on grades of evidence. This study reviews the pathophysiology of diabetes insipidus and inappropriate ADH secretion after pituitary surgery, and is intended to serve as a guide for their diagnosis, differential diagnosis, treatment, and monitoring. Copyright © 2013 SEEN. Published by Elsevier Espana. All rights reserved.

  15. Myogenic expression of an injectable protease-resistant growth hormone-releasing hormone augments long-term growth in pigs

    Science.gov (United States)

    Draghia-Akli, R.; Fiorotto, M. L.; Hill, L. A.; Malone, P. B.; Deaver, D. R.; Schwartz, R. J.

    1999-01-01

    Ectopic expression of a new serum protease-resistant porcine growth hormone-releasing hormone, directed by an injectable muscle-specific synthetic promoter plasmid vector (pSP-HV-GHRH), elicits growth in pigs. A single 10 mg intramuscular injection of pSP-HV-GHRH DNA followed by electroporation in three-week-old piglets elevated serum GHRH levels by twofold to fourfold, enhanced growth hormone secretion, and increased serum insulin-like growth factor-I by threefold to sixfold over control pigs. After 65 days the average body weight of the pigs injected with pSP-HV-GHRH was approximately 37% greater than the placebo-injected controls and resulted in a significant reduction in serum urea concentration, indicating a decrease in amino acid catabolism. Evaluation of body composition indicated a uniform increase in mass, with no organomegaly or associated pathology.

  16. A role for central nervous growth hormone-releasing hormone signaling in the consolidation of declarative memories.

    Directory of Open Access Journals (Sweden)

    Manfred Hallschmid

    Full Text Available Contributions of somatotropic hormonal activity to memory functions in humans, which are suggested by clinical observations, have not been systematically examined. With previous experiments precluding a direct effect of systemic growth hormone (GH on acute memory formation, we assessed the role of central nervous somatotropic signaling in declarative memory consolidation. We examined the effect of intranasally administered growth hormone releasing-hormone (GHRH; 600 µg that has direct access to the brain and suppresses endogenous GHRH via an ultra-short negative feedback loop. Twelve healthy young men learned word-pair associates at 2030 h and were administered GHRH and placebo, respectively, at 2100 h. Retrieval was tested after 11 hours of wakefulness. Compared to placebo, intranasal GHRH blunted GH release within 3 hours after substance administration and reduced the number of correctly recalled word-pairs by ∼12% (both P<0.05. The impairment of declarative memory consolidation was directly correlated to diminished GH concentrations (P<0.05. Procedural memory consolidation as examined by the parallel assessment of finger sequence tapping performance was not affected by GHRH administration. Our findings indicate that intranasal GHRH, by counteracting endogenous GHRH release, impairs hippocampal memory processing. They provide first evidence for a critical contribution of central nervous somatotropic activity to hippocampus-dependent memory consolidation.

  17. Regulation of endometrial cancer cell growth by luteinizing hormone (LH) and follicle stimulating hormone (FSH)

    OpenAIRE

    Davies, S.; Bax, C M R; Chatzaki, E; Chard, Tim; Iles, Ray K.

    2000-01-01

    Gonadotrophin releasing hormone analogues (GnRHa) have been used to treat recurrent endometrial cancer. However, the mode of action is uncertain. Our previous studies showed no direct effect of GnRHa on endometrial cancer cell growth in vitro. We have now examined the effect of luteinizing hormone (LH) and follicle stimulating hormone (FSH) on endometrial cancer cell growth. The aim was to determine whether suppression of pituitary LH and FSH by GnRHa could explain the tumour regression seen ...

  18. Human pituitary and placental hormones control human insulin-like growth factor II secretion in human granulosa cells

    Energy Technology Data Exchange (ETDEWEB)

    Ramasharma, K.; Li, C.H.

    1987-05-01

    Human granulosa cells cultured with calf serum actively proliferated for 18-20 generations and secreted progesterone into the medium; progesterone levels appeared to decline with increase in generation number. Cells cultured under serum-free conditions secreted significant amounts of progesterone and insulin-like growth factor II (IGF-II). The progesterone secretion was enhanced by the addition of human follitropin, lutropin, and chorionic gonadotropin but not by growth hormone. These cells, when challenged to varying concentrations of human growth hormone, human chorionic somatomammotropin, human prolactin, chorionic gonadotropin, follitropin, and lutropin, secreted IGF-II into the medium as measured by specific IGF-II RIA. Among these human hormones, chorionic gonadotropin, follitropin, and lutropin were most effective in inducing IGF-II secretion from these cells. When synthetic lutropin-releasing hormone and ..cap alpha..-inhibin-92 were tested, only lutropin-releasing hormone was effective in releasing IGF-II. The results described suggest that cultured human granulosa cells can proliferate and actively secrete progesterone and IGF-II into the medium. IGF-II production in human granulosa cells was influenced by a multi-hormonal complex including human growth hormone, human chorionic somatomammotropin, and prolactin.

  19. The Relationship of Appetitive, Reproductive and Posterior Pituitary Hormones to Alcoholism and Craving in Humans

    OpenAIRE

    2012-01-01

    A significant challenge for understanding alcoholism lies in discovering why some, but not other individuals, become dependent on alcohol. Genetic, environmental, cultural, developmental, and neurobiological influences are recognized as essential factors underlying a person's risk for becoming alcohol dependent (AD); however, the neurobiological processes that trigger this vulnerability are still poorly understood. Hormones are important in the regulation of many functions and several hormone...

  20. Relative sparing of anterior pituitary function in patients with growth hormone-secreting macroadenomas: comparison with nonfunctioning macroadenomas.

    Science.gov (United States)

    Greenman, Y; Tordjman, K; Kisch, E; Razon, N; Ouaknine, G; Stern, N

    1995-05-01

    Pre- and postoperative anterior pituitary function was assessed in 26 subjects with nonfunctioning macroadenoma (NFMA) and in 15 acromegalic subjects with macroadenomas. Preoperatively, NFMA patients had a higher prevalence of secondary hypogonadism (78% vs. 40%; P < 0.05), hypothyroidism (23% vs. 0%; P = 0.06), and hypoadrenalism (43% vs. 7%; P = 0.02) compared to individuals with GH-secreting macroadenoma (GHMA). Patients with NFMA also had a higher prevalence of more severe pituitary failure compared with acromegalic patients; 56% of the patients in this group had more than one pituitary hormone axis impaired compared to only 8% in the acromegalic group. These differences could not be accounted for by tumor grade and/or stage. Transsphenoidal pituitary surgery led to a significant improvement in anterior pituitary function in the NFMA group. Nevertheless, the prevalence of pituitary deficiency postoperatively was still significantly greater in NFMA patients than in the acromegalic group (68% vs. 17%, respectively; P < 0.04). The results suggest that anterior pituitary function is better preserved in GHMA than in NFMA and that this difference is independent of tumor size. The mechanism underlying the lower rate of hypopituitarism in acromegalics with macroadenomas remains to be elucidated.

  1. Effects of inorganic and organic manganese supplementation on gonadotropin-releasing hormone-I and follicle-stimulating hormone expression and reproductive performance of broiler breeder hens.

    Science.gov (United States)

    Xie, Jingjing; Tian, Chuanhuan; Zhu, Yongwen; Zhang, Liyang; Lu, Lin; Luo, Xugang

    2014-04-01

    Manganese is an essential microelement. Manganese deficiency affects reproduction performance and reproductive hormones in layers. However, little is known about its effects and the possible mechanism in regulating reproduction in broiler breeder hens. In the current study, broiler breeder hens at peak production were fed with diets supplemented with 0, 120, or 240 mg of Mn/kg as MnSO4 or Mn proteinate for 13 wk. Manganese supplementation did not alter egg laying rate, egg weight, fertility, hatchability, or hatchling weight over a 13-wk trial period. However, 240 mg of Mn/kg supplementation significantly increased serum Mn (P Manganese supplements increased the eggshell breaking strength (P < 0.05) without affecting the eggshell thickness. There was no difference in serum cholesterol and estradiol. Expression of follicle-stimulating hormone) and gonadotropin-releasing hormone-I (GnRH-I) genes was significantly elevated by 240 mg of Mn/kg (P < 0.05). Furthermore, inorganic Mn supplementation doubled GnRH-I expression compared with supplementation with the organic form (P < 0.05), although serum Mn was comparable between these 2 supplements. No obvious difference was shown in gene expression of luteinizing hormone, prolactin, GnRH-I receptor, inducible NO synthase, and dopamine receptor D1 in the pituitary as well as tyrosine hydroxylase and inducible NO synthase in the hypothalamus. This suggests that dietary Mn supplementation could improve eggshell quality in the long term. The central mechanism of nontoxic high doses of Mn suggested the transcriptional activation of GnRH-I and follicle-stimulating hormone genes. The central effect of inorganic Mn activating GnRH-I genes compared with the reduced effect by organic Mn could possibly be due to a decreased capacity of the latter passing through the blood-brain barrier.

  2. Differential sensitivity of growth hormone-releasing hormone and somatostatin release from perifused mouse hypothalamic fragments in response to glucose deficiency.

    Science.gov (United States)

    Sato, M; Frohman, L A

    1993-06-01

    The effects of glucose deficiency on growth hormone (GH)-releasing hormone (GRH) and somatostatin (SRIH) release from mouse hypothalamic fragments were investigated using an in vitro perifusion system. Fragments were perifused with Krebs-Ringer bicarbonate solution (KRB) containing 5.6 mM glucose for 3 h followed by reduced glucose concentrations in KRB for the next 2 h. GRH release was simulated by 0.7-2.8 mM glucose in an inverse concentration-dependent manner. In contrast, SRIH release was not stimulated by glucose at concentrations of 2.8 and 1.4 mM; only at 0.7 mM was there a modest stimulation of SRIH release that was comparable to the effect of 2.8 mM glucose on GRH release. The maximal stimulation of GRH and SRIH release by 0.7 mM glucose was 221 and 150%, respectively, of controls. Glucose concentrations of 11.2 and 22.4 mM inhibited GRH release but did not alter SRIH release. The glucose analog 2-deoxy-D-glucose (2-DG; 5.6-39.2 mM) also stimulated GRH release in a dose-dependent manner, and SRIH release was less sensitive to 2-DG than was GRH. The maximal stimulation of GRH and SRIH release by 39.2 mM 2-DG was 190 and 147%, respectively, of controls. Increases in GRH and SRIH release stimulated by 30 mM KCl 1 h after exposure to low glucose or 2-DG were not significantly different from those after exposure to 5.6 mM glucose. However, the SRIH response to K(+)-induced depolarization was much greater than that of GRH. The glucose intermediate pyruvate (4.9 and 9.8 mM) partially inhibited both GRH and SRIH release induced by 0.7 mM glucose.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Progesterone treatment inhibits and dihydrotestosterone (DHT) treatment potentiates voltage-gated calcium currents in gonadotropin-releasing hormone (GnRH) neurons.

    Science.gov (United States)

    Sun, Jianli; Moenter, Suzanne M

    2010-11-01

    GnRH neurons are central regulators of fertility, and their activity is modulated by steroid feedback. In normal females, GnRH secretion is regulated by estradiol and progesterone (P). Excess androgens present in hyperandrogenemic fertility disorders may disrupt communication of negative feedback signals from P and/or independently stimulate GnRH release. Voltage-gated calcium channels (VGCCs) are important in regulating excitability and hormone release. Estradiol alters VGCCs in a time-of-day-dependent manner. To further elucidate ovarian steroid modulation of GnRH neuron VGCCs, we studied the effects of dihydrotestosterone (DHT) and P. Adult mice were ovariectomized (OVX) or OVX and treated with implants containing DHT (OVXD), estradiol (OVXE), estradiol and DHT (OVXED), estradiol and P (OVXEP), or estradiol, DHT, and P (OVXEDP). Macroscopic calcium current (I(Ca)) was recorded in the morning or afternoon 8-12 d after surgery using whole-cell voltage-clamp. I(Ca) was increased in afternoon vs. morning in GnRH neurons from OVXE mice but this increase was abolished in cells from OVXEP mice. I(Ca) in cells from OVXD mice was increased regardless of time of day; there was no additional effect in OVXED mice. P reduced N-type and DHT potentiated N- and R-type VGCCs; P blocked the DHT potentiation of N-type-mediated current. These data suggest P and DHT have opposing actions on VGCCs in GnRH neurons, but in the presence of both steroids, P dominates. VGCCs are targets of ovarian steroid feedback modulation of GnRH neuron activity and, more specifically, a potential mechanism whereby androgens could activate GnRH neuronal function.

  4. Excitatory and inhibitory effects of prolactin release activated by nerve stimulation in rat anterior pituitary

    Directory of Open Access Journals (Sweden)

    Gao Li-Zhi

    2009-12-01

    Full Text Available Abstract Background A series of studies showed the presence of substantial amount of nerve fibers and their close relationship with the anterior pituitary gland cells. Our previous studies have suggested that aside from the classical theory of humoral regulation, the rat anterior pituitary has direct neural regulation on adrenocorticotropic hormone release. In rat anterior pituitary, typical synapses are found on every type of the hormone-secreting cells, many on lactotrophs. The present study was aimed at investigating the physiological significance of this synaptic relationship on prolactin release. Methods The anterior pituitary of rat was sliced and stimulated with electrical field in a self-designed perfusion chamber. The perfusate was continuously collected in aliquots and measured by radioimmunoassay for prolactin levels. After statistic analysis, differences of prolactin concentrations within and between groups were outlined. Results The results showed that stimulation at frequency of 2 Hz caused a quick enhancement of prolactin release, when stimulated at 10 Hz, prolactin release was found to be inhibited which came slower and lasted longer. The effect of nerve stimulation on prolactin release is diphasic and frequency dependent. Conclusions The present in vitro study offers the first physiological evidence that stimulation of nerve fibers can affect prolactin release in rat anterior pituitary. Low frequency stimulation enhances prolactin release and high frequency mainly inhibits it.

  5. Pituitary hormone responses to meta-chlorophenylpiperazine in panic disorder and healthy control subjects.

    Science.gov (United States)

    Kahn, R S; Wetzler, S; Asnis, G M; Kling, M A; Suckow, R F; van Praag, H M

    1991-04-01

    The present study reports adrenocorticotropic hormone (ACTH) and prolactin responses after oral administration of 0.25 mg/kg of the serotonin agonist, meta-chlorophenylpiperazine (MCPP), in patients with panic disorder (PD) and in healthy subjects. MCPP blood levels were similar for the two groups, but almost twice as high in males as in females. Female patients had augmented ACTH and prolactin release as compared to healthy females, while ACTH and prolactin release in male patients was similar to that of male controls. These results suggest that female PD patients have hypersensitive serotonin receptors. Moreover, they indicate that pharmacokinetic gender differences may affect challenge studies, and that different doses may be required to study neuroendocrine responses in males and females.

  6. The Nutrient and Energy Sensor Sirt1 Regulates the Hypothalamic-Pituitary-Adrenal (HPA) Axis by Altering the Production of the Prohormone Convertase 2 (PC2) Essential in the Maturation of Corticotropin-releasing Hormone (CRH) from Its Prohormone in Male Rats.

    Science.gov (United States)

    Toorie, Anika M; Cyr, Nicole E; Steger, Jennifer S; Beckman, Ross; Farah, George; Nillni, Eduardo A

    2016-03-11

    Understanding the role of hypothalamic neuropeptides and hormones in energy balance is paramount in the search for approaches to mitigate the obese state. Increased hypothalamic-pituitary-adrenal axis activity leads to increased levels of glucocorticoids (GC) that are known to regulate body weight. The axis initiates the production and release of corticotropin-releasing hormone (CRH) from the paraventricular nucleus (PVN) of the hypothalamus. Levels of active CRH peptide are dependent on the processing of its precursor pro-CRH by the action of two members of the family of prohormone convertases 1 and 2 (PC1 and PC2). Here, we propose that the nutrient sensor sirtuin 1 (Sirt1) regulates the production of CRH post-translationally by affecting PC2. Data suggest that Sirt1 may alter the preproPC2 gene directly or via deacetylation of the transcription factor Forkhead box protein O1 (FoxO1). Data also suggest that Sirt1 may alter PC2 via a post-translational mechanism. Our results show that Sirt1 levels in the PVN increase in rats fed a high fat diet for 12 weeks. Furthermore, elevated Sirt1 increased PC2 levels, which in turn increased the production of active CRH and GC. Collectively, this study provides the first evidence supporting the hypothesis that PVN Sirt1 activates the hypothalamic-pituitary-adrenal axis and basal GC levels by enhancing the production of CRH through an increase in the biosynthesis of PC2, which is essential in the maturation of CRH from its prohormone, pro-CRH.

  7. Diagnosis of growth hormone (GH deficiency: comparison of pituitary stalk interruption syndrome and transient GH deficiency

    Directory of Open Access Journals (Sweden)

    Brauner Raja

    2009-05-01

    Full Text Available Abstract Background Most patients with childhood non-organic growth hormone (GH deficiency (GHD produce a normal GH peak as young adults. Our objectives were to better define this transient GHD and evaluate the factors influencing the growth response of patients with pituitary stalk interruption syndrome (PSIS. Methods We studied 72 prepubertal patients with a GH peak Results At diagnosis, 64% of Group 1 and one Group 2 were During the first year of GH treatment, the growth rate was ≥ 2 SDS in 81% Group 1 and 37% Group 2 patients. In Group 1, it was negatively correlated with the GH peak before treatment (P The height gain SDSs between diagnosis and adult height were 1.7 ± 1.2 in Group 1 (n = 30 and 1.08 ± 0.8 in Group 2 (n = 12, P = 0.05. Conclusion The factors of the growth response to GH treatment should be analysed separately for each population: with and without PSIS or other markers.

  8. Blockade of LH release and ovulation in the rabbit with inhibitory analogues of luteinizing hormone releasing hormone.

    Science.gov (United States)

    Phelps, C P; Coy, D H; Schally, A V; Sawyer, C H

    1977-06-01

    Plasma LH levels and ovulation were studied in female rabbits following administration of several inhibitory analogues of luteinizing hormone-releasing hormone (LHRH) before and after mating with experienced males. Administration of (D-Phe2, D-Leu6)-LHRH (1.5 mg/kg sc) to does 30 min before mating did not prevent either LH release or ovulation. However, a single sc injection of (D-Phe2, L-Phe3, D-Phe6y-LHRH (6 mg/kg) given 30 min before mating in 4 rabbits resulted in a 30-60 min delay in the coitus-induced release of LH when compared with post-coital changes in the same animals injected with vehicle; however, all of the does ovulated. When multiple dosages of 4 mg/kg (D-Phe2, L-Phe3, D-Phe6)-LHRH were administered 3-5 times at half-hourly intervals beginning 30 min prior to mating there was a considerable reduction in plasma LH elevations at 0.5, 1.0, 2.0 and 4.0 h after mating and 3/5 treated rabbits showed partial or complete blockade of ovulation. Quite similar results were obtained with the same dosage of (D-Phe2, D-Trp3, D-Phe6)-LHRH. An early sharp peak in LH release and full ovulation were stimulated in 6 out of 6 does by a single iv injection of synthetic LHRH (500 ng/kg). However, in another experiment, three half-hourly sc injections (4 mg/kg) of (D-Phe2, L-Phe3, D-Phe6)-LHRH beginning 30 min before administering LHRH markedly reduced the rise in plasma LH (P less than 0.01) and completely blocked ovulation in all of the same 6 animals. An unsuccessful attempt was made to provide a test animal for LHRH analogue investigations by implanting 4 cm of silastic tubing filled with crystalline estradiol (E2) sc in ovariectomized (OVX) AND INTACT DOES. In OVX does the silastic E2 implants resulted in a progressive decline in the ability to release LH in response to mating at 6 and at 20 days after implantation. With ovaries present, the E2 implant permitted post-coital LH release and ovulation at 4 d but not at 30 d post-implantation. At 30 d after removal of

  9. Negative Feedback Governs Gonadotrope Frequency-Decoding of Gonadotropin Releasing Hormone Pulse-Frequency

    OpenAIRE

    2009-01-01

    The synthesis of the gonadotropin subunits is directed by pulsatile gonadotropin-releasing hormone (GnRH) from the hypothalamus, with the frequency of GnRH pulses governing the differential expression of the common alpha-subunit, luteinizing hormone beta-subunit (LHbeta) and follicle-stimulating hormone beta-subunit (FSHbeta). Three mitogen-activated protein kinases, (MAPKs), ERK1/2, JNK and p38, contribute uniquely and combinatorially to the expression of each of these subunit genes. In this...

  10. Molecular Imaging of Pituitary Pathology.

    Science.gov (United States)

    de Herder, Wouter W

    2016-01-01

    The presence of large numbers and/or the high affinity of dopamine D2 and/or somatostatin receptors on pituitary adenomas may enable their visualization with radionuclide-coupled receptor agonists or antagonists. However, the role of these imaging modalities in the differential diagnosis of or therapeutic purposes for pituitary lesions is very limited. Only in very specific cases might these molecular imaging techniques become helpful. These include the differential diagnosis of pituitary lesions, ectopic production of pituitary hormones, such as adrenocorticotrophic hormone, growth hormone (GH) or their releasing hormones (corticotropin-releasing hormone and GH-releasing hormone), and the localization of metastases from pituitary carcinomas.

  11. Cutaneous induction of corticotropin releasing hormone by Propionibacterium acnes extracts.

    Science.gov (United States)

    Isard, Olivia; Knol, Anne-Chantal; Castex-Rizzi, Nathalie; Khammari, Amir; Charveron, Marie; Dréno, Brigitte

    2009-03-01

    The skin commensal bacillus Propionibacterium acnes is known to play a major role in the development of acne vulgaris and it is established that this bacteria is involved both in the induction and maintenance of the inflammatory phase of acne. The corticotropin releasing hormone (CRH), a neuropeptide originally isolated from the hypothalamus, is also produced by the skin. CRH has been reported to play a role in the inflammation, the production of sebum and finally the differentiation of keratinocytes. At the therapeutic level, zinc is known to act specifically on inflammatory lesions with still partially known mechanisms and thus could play an important role in the development of inflammatory acne lesions. Our objective was to study the modulation of CRH expression by keratinocytes induced by P. acnes extracts. CRH expression was examined using immunohistochemistry technique on deep-frozen sections of normal human skin explants incubated with two different extracts of P. acnes and with or without zinc salts. We observed that the membrane fraction (FM) of P. acnes increased the CRH expression in the epidermis. This result indicates that P. acnes, by stimulating the production of CRH, can both modulate the differentiation of keratinocytes and increase the local inflammation, arguing that this bacterium plays a role not only in the development of inflammatory acne lesions but also in the formation of the microcomedo in the early stages of acne.

  12. Natriuresis and diuretic hormone synergism in R. prolixus upper Malpighian tubules is inhibited by the anti-diuretic hormone, RhoprCAPA-α2.

    Science.gov (United States)

    Paluzzi, Jean-Paul V; Naikkhwah, Wida; O'Donnell, Michael J

    2012-04-01

    Insects contain an array of hormones that coordinate the actions of the excretory system to achieve osmotic and ionic balance. In the hematophagous insect, Rhodnius prolixus, two diuretic hormones have been identified, serotonin (5HT) and a corticotropin releasing factor-related peptide (RhoprDH), and both lead to an increase in fluid secretion by Malpighian tubules (MTs). However, only 5HT activates reabsorption by the lower MTs to recover K(+) and Cl(-). An anti-diuretic hormone (RhoprCAPA-α2) is believed to coordinate the cessation of the rapid diuresis following blood meal engorgement. However, the role of RhoprCAPA-α2 on fluid secretion by MTs stimulated by RhoprDH was previously unknown. Here we demonstrate that, unlike the inhibitory effect on 5HT-stimulated secretion by MTs, RhoprCAPA-α2 does not inhibit secretion stimulated by RhoprDH although it does abolish the synergism that occurs between the two diuretic hormones. In addition, we show that the natriuresis elicited by either diuretic hormone is reduced by RhoprCAPA-α2. Using electrophysiological tools, we investigate the possible mechanism by which this complex regulatory pathway is achieved. Analysis of the pH of secreted fluid as well as the triphasic response in transepithelial potential in MTs treated with diuretic hormones, suggests that RhoprCAPA-α2 does not inhibit the V-type H(+) ATPase. Taken together, these results indicate that RhoprCAPA-α2 functions to reduce the rapid diuresis following blood feeding, and in addition, it inhibits the natriuresis associated with diuretic hormone stimulated MTs. This may reflect an important regulatory mechanism related to the slow diuresis that occurs as the K(+)-rich blood cells are digested.

  13. Information for People Treated with Human Growth Hormone (Summary)

    Science.gov (United States)

    ... NHPP): Information for People Treated with Pituitary Human Growth Hormone (Summary) How did Creutzfeldt-Jakob disease (CJD) occur in people treated with pituitary human growth hormone (hGH)? From 1963 to 1985, the National Hormone ...

  14. Antiproliferative effect of growth hormone-releasing hormone (GHRH antagonist on ovarian cancer cells through the EGFR-Akt pathway

    Directory of Open Access Journals (Sweden)

    Varga Jozsef

    2010-05-01

    Full Text Available Abstract Background Antagonists of growth hormone-releasing hormone (GHRH are being developed for the treatment of various human cancers. Methods MTT assay was used to test the proliferation of SKOV3 and CaOV3. The splice variant expression of GHRH receptors was examined by RT-PCR. The expression of protein in signal pathway was examined by Western blotting. siRNA was used to block the effect of EGFR. Results In this study, we investigated the effects of a new GHRH antagonist JMR-132, in ovarian cancer cell lines SKOV3 and CaOV3 expressing splice variant (SV1 of GHRH receptors. MTT assay showed that JMR-132 had strong antiproliferative effects on SKOV3 and CaOV3 cells in both a time-dependent and dose-dependent fashion. JMR-132 also induced the activation and increased cleaved caspase3 in a time- and dose-dependent manner in both cell lines. In addition, JMR-132 treatments decreased significantly the epidermal growth factor receptor (EGFR level and the phosphorylation of Akt (p-Akt, suggesting that JMR-132 inhibits the EGFR-Akt pathway in ovarian cancer cells. More importantly, treatment of SKOV3 and CaOV3 cells with 100 nM JMR-132 attenuated proliferation and the antiapoptotic effect induced by EGF in both cell lines. After the knockdown of the expression of EGFR by siRNA, the antiproliferative effect of JMR-132 was abolished in SKOV3 and CaOV3 cells. Conclusions The present study demonstrates that the inhibitory effect of the GHRH antagonist JMR-132 on proliferation is due, in part, to an interference with the EGFR-Akt pathway in ovarian cancer cells.

  15. Inhibitory effects of antagonists of growth hormone-releasing hormone on growth and invasiveness of PC3 human prostate cancer.

    Science.gov (United States)

    Muñoz-Moreno, Laura; Arenas, M Isabel; Schally, Andrew V; Fernández-Martínez, Ana B; Zarka, Elías; González-Santander, Marta; Carmena, María J; Vacas, Eva; Prieto, Juan C; Bajo, Ana M

    2013-02-15

    New approaches are needed to the therapy of advanced prostate cancer. This study determined the effect of growth hormone-releasing hormone (GHRH) antagonists, JMR-132 and JV-1-38 on growth of PC3 tumors as well as on angiogenesis and metastasis through the evaluation of various factors that contribute largely to the progression of prostate cancer. Human PC3 androgen-independent prostate cancer cells were injected subcutaneously into nude mice. The treatment with JMR-132 (10 μg/day) or JV-1-38 (20 μg/day) lasted 41 days. We also evaluated the effects of JMR-132 and JV-1-38 on proliferation, cell adhesion and migration in PC-3 cells in vitro. Several techniques (Western blot, reverse transcription polymerase chain reaction, immunohistochemistry, ELISA and zymography) were used to evaluate the expression levels of GHRH receptors and its splice variants, GHRH, vascular endothelial growth factor (VEGF), hypoxia inducible factor (HIF)-1α, metalloproteinases (MMPs) -2 and -9, β-catenin and E-cadherin. GHRH antagonists suppressed the proliferation of PC-3 cells in vitro and significantly inhibited growth of PC3 tumors. After treatment with these analogues, we found an increase in expression of GHRH receptor accompanied by a decrease of GHRH levels, a reduction in both VEGF and HIF-1α expression and in active forms of MMP-2 and MMP-9, a significant increase in levels of membrane-associated β-catenin and a significant decline in E-cadherin. These results support that the blockade of GHRH receptors can modulate elements involved in angiogenesis and metastasis. Consequently, GHRH antagonists could be considered as suitable candidates for therapeutic trials in the management of androgen-independent prostate cancer.

  16. Effect of Imatinib on the Oogenesis and Pituitary -Ovary Hormonal Axis in Female Wistar Rat

    Directory of Open Access Journals (Sweden)

    Parichehreh Yaghmaei

    2009-01-01

    Full Text Available Background: Imatinib mesylate, a small-molecular analog of adenosine triphosphate (ATPthat potently inhibits tyrosine kinase activities of Bcr–Abl, PDGFR-β, PDGFR-α, c-Fms, Argand c-kit, is one of the novel molecularly targeted drugs being introduced into cancer therapy.We tested the effect of imatinib on the ovarian histological structure and the concentration ofestrogen and progesterone, luteinizing hormone (LH and follicle stimulating hormone (FSHin the serum of female Wistar rats.Materials and Methods: Two groups of rats (180 ± 15 grams were gavaged with doses of 50and 100 mg/kg body weight imatinib dissolved in distilled water for 14 days. The control groupreceived sterile water. On day 7, after termination of the treatment, blood serum concentrationwas measured with the radioimmunoassay (RIA method. Also, sections (5 μm thick of ovariesstained with hematoxylin and eosin (H&E were investigated histologically.Results: Progesterone concentration in the experimental groups was increased (p<0.001,estrogen and FSH concentrations were decreased (p<0.01, and the LH concentration decreasedbut was not statistically different in comparison with the control group. The weight of ovaries andnumber of atretic follicles in the experimental groups was increased compared with the controlgroup (p<0.05. The diameter of corpus lutea were increased but the number of corpus luteadecreased in both experimental groups (p<0.01.Conclusion: These findings suggest that administration of imatinib may have profound effects onfemale fertility.

  17. Effects of cold stress on hypothalamic corticotrophin-releasing and thyrotropin-releasing hormone messenger RNA levels in chickens

    Institute of Scientific and Technical Information of China (English)

    WANG Jintao; XU Shiwen

    2007-01-01

    There is increasing evidence that stress can activate the hypothalamic-pituitary-adrenal-axis and hypothalamic-pituitarythyroid-axis, and further affect the synthesis and secretion of corticotrophin-releasing hormone (CRH) and thyrotropin-releasing hormone (TRH). To evaluate the effect of cold stress on the hypothalamic CRH and TRH messenger RNA (mRNA) levels in Yisha chickens, male Yisha chickens were subjected to acute (1, 6, 12 h) and chronic (5, 10, 20 d) cold stress (12±1)℃. Hypothalami were collected for assessment of mRNA levels by semi-quantitative RT-PCR. Acute stress resulted in a significant decrease of CRH mRNA levels at 6 and 12 h, and a significant increase of TRH mRNA levels at every stress time point. Chronic cold stress resulted in a significant increase of CRH mRNA levels and a significant decrease of TRH mRNA levels compared with the control group at every stress time point. The results suggest that the two genes differently respond to cold stress at the mRNA levels. And the different degrees of cold stress will produce different effects on the identical gene.

  18. Fluorochemicals used in food packaging inhibit male sex hormone synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Rosenmai, A.K., E-mail: akjro@food.dtu.dk [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Nielsen, F.K. [Section of Toxicology, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen (Denmark); Pedersen, M. [Division of Food Chemistry, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Hadrup, N. [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Trier, X. [Division of Food Chemistry, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Christensen, J.H. [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, DK-1871 Frederiksberg C. (Denmark); Vinggaard, A.M. [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark)

    2013-01-01

    Polyfluoroalkyl phosphate surfactants (PAPS) are widely used in food contact materials (FCMs) of paper and board and have recently been detected in 57% of investigated materials. Human exposure occurs as PAPS have been measured in blood; however knowledge is lacking on the toxicology of PAPS. The aim of this study was to elucidate the effects of six fluorochemicals on sex hormone synthesis and androgen receptor (AR) activation in vitro. Four PAPS and two metabolites, perfluorooctanoic acid (PFOA) and 8:2 fluorotelomer alcohol (8:2 FTOH) were tested. Hormone profiles, including eight steroid hormones, generally showed that 8:2 diPAPS, 8:2 monoPAPS and 8:2 FTOH led to decreases in androgens (testosterone, dehydroepiandrosterone, and androstenedione) in the H295R steroidogenesis assay. Decreases were observed for progesterone and 17-OH-progesterone as well. These observations indicated that a step prior to progestagen and androgen synthesis had been affected. Gene expression analysis of StAR, Bzrp, CYP11A, CYP17, CYP21 and CYP19 mRNA showed a decrease in Bzrp mRNA levels for 8:2 monoPAPS and 8:2 FTOH indicating interference with cholesterol transport to the inner mitochondria. Cortisol, estrone and 17β-estradiol levels were in several cases increased with exposure. In accordance with these data CYP19 gene expression increased with 8:2 diPAPS, 8:2 monoPAPS and 8:2 FTOH exposures indicating that this is a contributing factor to the decreased androgen and the increased estrogen levels. Overall, these results demonstrate that fluorochemicals present in food packaging materials and their metabolites can affect steroidogenesis through decreased Bzrp and increased CYP19 gene expression leading to lower androgen and higher estrogen levels. -- Highlights: ► Fluorochemicals found in 57% of paper and board food packaging were tested. ► Collectively six fluorochemicals were tested for antiandrogenic potential in vitro. ► Three out of six tested fluorochemicals inhibited

  19. Growth hormone-releasing factor stimulates proliferation of somatotrophs in vitro

    DEFF Research Database (Denmark)

    Billestrup, Nils; Swanson, L W; Vale, W

    1986-01-01

    The mitogenic effect of the hypothalamic peptides growth hormone-releasing factor (GRF) and somatostatin on cultured growth hormone (GH)-producing cells (somatotrophs) was studied. Using autoradiographic detection of [3H]thymidine uptake and immunocytochemical identification of GH-producing cells...

  20. Comparison of the effects of human and chicken ghrelin on chicken ovarian hormone release.

    Science.gov (United States)

    Sirotkin, Alexander V; Harrath, Abdel Halim; Grossmann, Roland

    2016-11-01

    The aim of the present experiments was to examine the species-specific and cell-specific effects of ghrelin on chicken ovarian hormone release. For this purpose, we compared the effects of chicken and human ghrelin on the release of estradiol (E), testosterone (T), progesterone (P) and arginine-vasotocin (AVT) by cultured fragments of chicken ovarian follicles and on the release of T and AVT by cultured ovarian granulosa cells. In cultured chicken ovarian fragments, both human and chicken ghrelin promoted E release. T output was stimulated by chicken ghrelin but not by human ghrelin. No effect of either human or chicken ghrelin on P release was observed. Human ghrelin promoted but chicken ghrelin suppressed AVT release by chicken ovarian fragments. In cultured ovarian granulosa cells, human ghrelin inhibited while chicken ghrelin stimulated T release. Both human and chicken ghrelin suppressed AVT output by chicken granulosa cells. These data confirm the involvement of ghrelin in the control of ovarian secretory activity and demonstrate that the effect of ghrelin is species-specific. The similarity of avian ghrelin on avian ovarian granulosa cells and ovarian fragments (containing both granulosa and theca cells) suggests that ghrelin can influence chicken ovarian hormones primarily by acting on granulosa cells.

  1. NR4A1 (Nur77 mediates thyrotropin-releasing hormone-induced stimulation of transcription of the thyrotropin β gene: analysis of TRH knockout mice.

    Directory of Open Access Journals (Sweden)

    Yasuyo Nakajima

    Full Text Available Thyrotropin-releasing hormone (TRH is a major stimulator of thyrotropin-stimulating hormone (TSH synthesis in the anterior pituitary, though precisely how TRH stimulates the TSHβ gene remains unclear. Analysis of TRH-deficient mice differing in thyroid hormone status demonstrated that TRH was critical for the basal activity and responsiveness to thyroid hormone of the TSHβ gene. cDNA microarray and K-means cluster analyses with pituitaries from wild-type mice, TRH-deficient mice and TRH-deficient mice with thyroid hormone replacement revealed that the largest and most consistent decrease in expression in the absence of TRH and on supplementation with thyroid hormone was shown by the TSHβ gene, and the NR4A1 gene belonged to the same cluster as and showed a similar expression profile to the TSHβ gene. Immunohistochemical analysis demonstrated that NR4A1 was expressed not only in ACTH- and FSH- producing cells but also in thyrotrophs and the expression was remarkably reduced in TRH-deficient pituitary. Furthermore, experiments in vitro demonstrated that incubation with TRH in GH4C1 cells increased the endogenous NR4A1 mRNA level by approximately 50-fold within one hour, and this stimulation was inhibited by inhibitors for PKC and ERK1/2. Western blot analysis confirmed that TRH increased NR4A1 expression within 2 h. A series of deletions of the promoter demonstrated that the region between bp -138 and +37 of the TSHβ gene was responsible for the TRH-induced stimulation, and Chip analysis revealed that NR4A1 was recruited to this region. Conversely, knockdown of NR4A1 by siRNA led to a significant reduction in TRH-induced TSHβ promoter activity. Furthermore, TRH stimulated NR4A1 promoter activity through the TRH receptor. These findings demonstrated that 1 TRH is a highly specific regulator of the TSHβ gene, and 2 TRH mediated induction of the TSHβ gene, at least in part by sequential stimulation of the NR4A1-TSHβ genes through a PKC and

  2. Effect of alcohol and glucose infusion on pituitary-gonadal hormones in normal females

    DEFF Research Database (Denmark)

    Becker, U; Gluud, C; Bennett, Patrick

    1988-01-01

    During 1 h, median 976 mmol ethanol in 5.5% glucose was administered i.v. to six healthy female volunteers (aged 26-37 years) in the luteal phase of the menstrual cycle. The median maximal blood ethanol concentration was median 33.5 mmol/l and serum ethanol concentrations of 2 mmol/l were reached...... and dehydroepiandrosterone-sulphate levels decreased 6-48%, while testosterone levels did not change significantly. Prolactin concentrations were reduced by 41-51% of basal values and luteinizing hormone concentrations by 37-68% Follicle stimulating hormone levels did not change significantly. Stress factors...... or haemodilution are not likely explanations of the observed changes in hormone concentrations. A circadian rhythm could not explain changes in hormones of non-adrenal origin....

  3. Semaphorin Signaling in the Development and Function of the Gonadotropin Hormone-Releasing Hormone (GnRH System

    Directory of Open Access Journals (Sweden)

    Andrea eMessina

    2013-09-01

    Full Text Available The semaphorin proteins are among the best-studied families of guidance cues, contributing to morphogenesis and homeostasis in a wide range of tissue types. The major semaphorin receptors are plexins and neuropilins, however other receptors and co-receptors are capable to mediate signaling by semaphorins. These guidance proteins were originally identified as growth cone collapsing factors or as inhibitory signals, crucial for nervous system development. Since those seminal discoveries, the list of functions of semaphorins has rapidly grown. Over the past few years, a growing body of data indicates that semaphorins are involved in the regulation of the immune and vascular systems, in tumor growth/cancer cell metastasis and in neural circuit formation. Recently there has been increasing emphasis on research to determine the potential influence of semaphorins on the development and homeostasis of hormone systems and how circulating reproductive hormones regulate their expression and functions. Here, we focus on the emerging role of semaphorins in the development, differentiation and plasticity of unique neurons that secrete gonadotropin-releasing hormone (GnRH, which are essential for the acquisition and maintenance of reproductive competence in all vertebrates. Genetic evidence is also provided showing that insufficient semaphorin signaling contributes to some forms of reproductive disorders in humans, characterized by the reduction or failure of sexual competence.Finally, we will review some studies with the goal of highlighting how the expression of semaphorins and their receptors might be regulated by gonadal hormones in physiological and pathological conditions.

  4. [Role of the Periaqueductal Gray Matter of the Midbrain in Regulation of Somatic Pain Sensitivity During Stress: Participation of Corticotropin-Releasing Factor and Glucocorticoid Hormones].

    Science.gov (United States)

    Yarushkina, N I; Filaretova, L P

    2015-01-01

    Periaqueductal gray matter of the midbrain (PAGM) plays a crucial role in the regulation of pain sensitivity under stress, involving in the stress-induced analgesia. A key hormonal system of adaptation under stress is the hypothalamic-pituitary-adrenocortical (HPA) axis. HPA axis's hormones, corticotropin-releasing factor (CRF) and glucocorticoids, are involved in stress-induced analgesia. Exogenous hormones of the HPA axis, similarly to the hormones produced under stress, may cause an analgesic effect. CRF-induced analgesia may be provided by glucocorticoid hormones. CRF and glucocorticoids-induced effects on somatic pain sensitivity may be mediated by PAGM. The aim of the review was to analyze the data of literature on the role of PAGM in the regulation of somatic pain sensitivity under stress and in providing of CRF and glucocorticoid-induced analgesia.

  5. Pituitary-gonadal and pituitary-thyroid axis hormone concentrations before and during a hypoglycemic clamp after sleep deprivation in healthy men.

    Directory of Open Access Journals (Sweden)

    Kamila Jauch-Chara

    Full Text Available Total sleep deprivation (TSD exerts strong modulatory effects on the secretory activity of endocrine systems that might be related to TSD-induced challenges of cerebral glucose metabolism. Here, we investigate whether TSD affects the course of male pituitary-gonadal and pituitary-thyroid axis related hormones during a subsequent 240-min hypoglycemic clamp. Ten healthy men were tested on 2 different conditions, TSD and 7-hour regular sleep. Circulating concentrations of total testosterone, prolactin (PRL, thyroid stimulating hormone (TSH, free triiodothyronine (fT3, and free thyroxin (fT4 were measured during baseline and a subsequent hypoglycemic clamp taking place in the morning. Basal, i.e. at 07:00 am measured, concentrations of total testosterone (P = 0.05 and PRL (P<0.01 were lower while the values of TSH (P = 0.02, fT3 (P = 0.08, and fT4 (P = 0.04 were higher after TSD as compared to regular sleep. During the subsequent hypoglycemic clamp (all measurements from baseline to the end of the clamp analyzed total testosterone concentrations in the regular sleep (P<0.01 but not in the TSD condition (P = 0.61 decreased, while PRL levels increased (P = 0.05 irrespectively of the experimental condition (P = 0.31. TSH concentrations decreased during hypoglycemia (P<0.01, with this decrease being more pronounced after TSD (P = 0.04. However, at the end of the hypoglycemic clamp concentrations all of the above mentioned hormones did not differ between the two sleep conditions. Our data indicate a profound influence of TSD on male pituitary-gonadal and pituitary-thyroid axis hormones characterized by reduced basal testosterone and PRL levels and increased TSH levels. However, since concentrations of these hormones measured at the end of the 240-min hypoglycemic clamp were not affected by TSD it can be speculated that the influence of TSD on the two endocrine axes is rather short lived or does not interact in an additive

  6. Evaluation of the association between placental corticotrophin-releasing hormone and postpartum depressive symptoms.

    Science.gov (United States)

    Glynn, Laura M; Sandman, Curt A

    2014-06-01

    Postpartum depression (PPD) represents a significant threat to maternal-child health. Although PPD is common, with an estimated prevalence of 10% to 15%, critical questions concerning its etiology remain unanswered. Existing studies seem to provide conflicting evidence regarding the relation between placental corticotrophin-releasing hormone (pCRH) and the development of PPD. The purpose of the present investigation was to determine whether maternal prepartum hypothalamic-pituitary-adrenal and placental dysregulation, in particular elevated midgestational pCRH, represent markers of risk for the development of PPD symptoms. One hundred seventy adult women with singleton, term pregnancies were recruited during the first trimester and participated in study visits at 15, 19, 25, 31, and 36+ weeks' gestation and at 3 and 6 months postpartum. At each prenatal visit, blood samples were obtained and assayed to determine maternal cortisol, adrenocorticotropic hormone, and pCRH concentrations. Depressive symptoms were assessed at all visits. Depressive symptoms at 3 months postpartum were associated with elevated midgestational pCRH (partial r = 0.26; p < .01) and also accelerated trajectories of pCRH (B values ranged from 6.9 to 8.3, p < .05). Placental CRH was not predictive of PPD symptoms at 6 months postpartum. Furthermore, prepartum cortisol and corticotrophin profiles were not associated with PPD symptoms. The current prospective study provides results that reconcile both the positive and negative findings in the existing literature and identifies elevated pCRH as a marker of risk for the development of PPD symptoms.

  7. Enzymatic tracer damage during the gonadotropin releasing hormone radioimmunoassay: analytical and immunological assessment

    Energy Technology Data Exchange (ETDEWEB)

    O' Conner, J.L.; Lapp, C.A.; Clary, A.R.

    1985-09-23

    Hypothalamic supernatants from 60 day female rats were fractionated from Sephadex G-200 columns. The radioimmunoassay (RIA) for gonadotropin releasing hormone (GnRH) detected an apparently cross-reacting high molecular weight substance. The substance caused apparent displacement of iodinated GnRH binding in dose response fashion; however, no biological activity was observed in pituitary cell cultures. In order to determine whether the depressed binding might be caused by enzymatic degradation of iodinated GnRH during the RIA incubation, iodinated GnRH was preincubated under RIA conditions with either buffer or increasing concentrations of the GnRH cross-reacting material. Aliquots were subjected to polyacrylamide gel electrophoresis (PAGE) and the gels slices counted. Identical aliquots were subsequently used as iodinated hormone in the RIA of known quantities of synthetic GnRH. Tracer damage during the RIA-like preincubation period was reflected in the subsequent PAGE studies as decreased counts per minute in the intact GnRH peak and in the RIA studies as over-estimated quantification of the GnRH standards. This report describes such damage during the GnRH RIA and the data misinterpretations which result. 30 references, 6 figures, 1 table.

  8. Corticotropin releasing hormone in colonic mucosa in patients with ulcerative colitis.

    Science.gov (United States)

    Kawahito, Y; Sano, H; Mukai, S; Asai, K; Kimura, S; Yamamura, Y; Kato, H; Chrousos, G P; Wilder, R L; Kondo, M

    1995-01-01

    Corticotropin releasing hormone (CRH) is a key hormone in integrated response to stress, acting as the major regulator of the hypothalamic-pituitary-adrenal axis. Recently, local production of CRH has been detected in normal human colonic enterochromaffin cells. CRH is locally secreted in granulomatous and arthritic tissues in rats and humans, where it seems to act as a local proinflammatory agent. To find out if CRH is present in colonic tissues of patients with ulcerative colitis, this study examined the expression of this peptide in the large bowel of patients with ulcerative colitis. Colonic tissues of patients with ulcerative colitis obtained by endoscopic biopsy were immunostained with anti-CRH antibody. CRH messenger (m) RNA was also examined in biopsy specimens of ulcerative colitis by the reverse transcribed polymerase chain reaction method and by in situ hybridisation. Considerably enhanced expression of immunoreactive CRH was found in mucosal inflammatory cells. Intense staining with anti-CRH antibody was also shown in mucosal macrophages. CRH mRNA was expressed in mucosal epithelial cells. The expression of immunoreactive CRH in colonic mucosal epithelial cells of ulcerative colitis slightly increased, but not significantly, compared with normal colonic mucosal epithelial cells. These results suggest that CRH may play a part in the modulation of intestinal immune and inflammatory system, and as a modulator in the pathogenesis of ulcerative colitis. Images Figure 1 Figure 2 Figure 4A Figure 4B-4C Figure 5 PMID:7489943

  9. Hyperpolarization of the Membrane Potential Caused by Somatostatin in Dissociated Human Pituitary Adenoma Cells that Secrete Growth Hormone

    Science.gov (United States)

    Yamashita, Naohide; Shibuya, Naohiko; Ogata, Etsuro

    1986-08-01

    Membrane electrical properties and the response to somatostatin were examined in dissociated human pituitary adenoma cells that secrete growth hormone (GH). Under current clamp condition with a patch electrode, the resting potential was -52.4 ± 8.0 mV, and spontaneous action potentials were observed in 58% of the cells. Under voltage clamp condition an outward K+ current, a tetrodotoxin-sensitive Na+ current, and a Ca2+ current were observed. Cobalt ions suppressed the Ca2+ current. The threshold of Ca2+ current activation was about -60 mV. Somatostatin elicited a membrane hyperpolarization associated with increased membrane permeability in these cells. The reversal potential of somatostatin-induced hyperpolarization was -78.4 ± 4.3 mV in 6 mM K+ medium and -97.2 ± 6.4 mV in 3 mM K+ medium. These reversal potential values and a shift with the external K+ concentration indicated that membrane hyperpolarization was caused by increased permeability to K+. The hyperpolarized membrane potential induced by somatostatin was -63.6 ± 5.9 mV in the standard medium. This level was subthreshold for Ca2+ and Na+ currents and was sufficient to inhibit spontaneous action potentials. Hormone secretion was significantly suppressed by somatostatin and cobalt ions. Therefore, we suggest that Ca2+ entering the cell through voltage-dependent channels are playing an important role for GH secretion and that somatostatin suppresses GH secretion by blocking Ca2+ currents. Finally, we discuss other possibilities for the inhibitory effect of somatostatin on GH secretion.

  10. Effects of growth hormone over-expression on reproduction in the common carp Cyprinus carpio L.

    Science.gov (United States)

    Cao, Mengxi; Chen, Ji; Peng, Wei; Wang, Yaping; Liao, Lanjie; Li, Yongming; Trudeau, Vance L; Zhu, Zuoyan; Hu, Wei

    2014-01-01

    To study the complex interaction between growth and reproduction we have established lines of transgenic common carp (Cyprinus carpio) carrying a grass carp (Ctenopharyngodon idellus) growth hormone (GH) transgene. The GH-transgenic fish showed delayed gonadal development compared with non-transgenic common carp. To gain a better understanding of the phenomenon, we studied body growth, gonad development, changes of reproduction related genes and hormones of GH-transgenic common carp for 2years. Over-expression of GH elevated peripheral gh transcription, serum GH levels, and inhibited endogenous GH expression in the pituitary. Hormone analyses indicated that GH-transgenic common carp had reduced pituitary and serum level of luteinizing hormone (LH). Among the tested genes, pituitary lhβ was inhibited in GH-transgenic fish. Further analyses in vitro showed that GH inhibited lhβ expression. Localization of ghr with LH indicates the possibility of direct regulation of GH on gonadotrophs. We also found that GH-transgenic common carp had reduced pituitary sensitivity to stimulation by co-treatments with a salmon gonadotropin-releasing hormone (GnRH) agonist and a dopamine antagonist. Together these results suggest that the main cause of delayed reproductive development in GH transgenic common carp is reduced LH production and release.

  11. Growth Hormone Deficiency in Children

    Science.gov (United States)

    Fact Sheet Growth Defici H e o n r c m y one in Children What is growth hormone deficiency? Growth hormone deficiency (GHD) is a rare condition in which the body does not make enough growth hormone (GH). GH is made by the pituitary ...

  12. Endocrine disrupting effects of dichlorodiphenyltrichloroethane analogues on gonadotropin hormones in pituitary gonadotrope cells.

    Science.gov (United States)

    Zhou, Jinghua; Yang, Ye; Xiong, Kang; Liu, Jing

    2014-05-01

    It has been shown that exposure to dichlorodiphenyltrichloroethane (DDT) analogues leads to disharmony of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). However, the effects and mechanisms of DDT analogues on the expression of gonadotropin genes (FSHβ, LHβ and Cgα), which is the rate-limiting step of FSH and LH biosynthesis, remain unknown. In this study, we assessed the effects of p,p'-DDT, o,p'-DDT, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and methoxychlor (MXC) on gonadotropin genes expression and hormones synthesis in gonadotrope cells. p,p'-DDT and MXC at test concentrations ranging from 10(-9) to 10(-7)mol/L, stimulated gonadotropin genes expression and hormones synthesis in a dose-dependent manner. The activation of extracellular signal-regulated kinase (ERK) was required for the induction of gonadotropin genes expression and hormones synthesis by p,p'-DDT or MXC exposure. This study showed for the first time that p,p'-DDT and MXC regulated gonadotropin genes expression and hormones synthesis through ERK pathway in gonadotrope cells.

  13. Inhibition effects of parathyroid hormone on human medullary thyroid carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Yaqiong Ni; Qinjiang Liu; Shihong Ma; Ruihui Chen

    2014-01-01

    Objective:The purpose of the study was to investigate the ef ects of parathyroid hormone and parathyroid hor-mone receptor monoclonal antibody on in vitro growth and proliferation of human medul ary thyroid carcinoma celllines. Methods:The medul ary thyroid carcinoma cellline was cultured in vitro, with parathyroid hormone and parathyroid hormone receptor monoclonal antibody treatment intervention, the growth of the cells was observed under an inverted contrast micro-scope, the MTT assay was used to detect the cellgrowth inhibition rate. Results:Under the inverted contrast microscope, the cells changed significantly, the parathyroid hormone and parathyroid hormone receptor monoclonal antibodies can ef ectively inhibit the proliferation of medul ary thyroid cancer cells in a time and dose dependent. When parathyroid hormone concentra-tion reached a concentration of 2.0μmol/L, the parathyroid hormone receptor monoclonal antibody reached a concentration of 1.0μmol/L, the cellgrowth was most significantly inhibited (P<0.05). Conclusion:Parathyroid hormone and parathyroid hormone receptor monoclonal antibody were able to inhibit the proliferation of medul ary thyroid carcinoma cells and signifi-cantly reduce the proliferation index.

  14. Optimizing subcutaneous injection of the gonadotropin-releasing hormone receptor antagonist degarelix.

    Science.gov (United States)

    Barkin, Jack; Burton, Shelley; Lambert, Carole

    2016-02-01

    The gonadotropin-releasing hormone (GnRH) receptor antagonist degarelix has several unique characteristics compared to luteinizing hormone-releasing hormone (LHRH) analogs used in the management of prostate cancer. Notable differences of GnRH receptor antagonists include no flare reaction, and a more rapid suppression of testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) and prostate-specific antigen (PSA) compared to LHRH analogs. Despite emerging evidence supporting the use of GnRH receptor antagonists over the more widely used LHRH analogs in the management of prostate cancer, physicians may be reluctant to prescribe degarelix. They may be concerned about patient complaints about injection-site reactions (ISRs). The subcutaneous injection of degarelix has been associated with a higher rate of ISRs compared with the intramuscular injections of LHRH analogs. This "How I Do It" article describes techniques and strategies that have been developed by physicians and nurses to reduce the discomfort associated with the subcutaneous delivery of degarelix.

  15. Negative feedback governs gonadotrope frequency-decoding of gonadotropin releasing hormone pulse-frequency.

    Directory of Open Access Journals (Sweden)

    Stefan Lim

    Full Text Available The synthesis of the gonadotropin subunits is directed by pulsatile gonadotropin-releasing hormone (GnRH from the hypothalamus, with the frequency of GnRH pulses governing the differential expression of the common alpha-subunit, luteinizing hormone beta-subunit (LHbeta and follicle-stimulating hormone beta-subunit (FSHbeta. Three mitogen-activated protein kinases, (MAPKs, ERK1/2, JNK and p38, contribute uniquely and combinatorially to the expression of each of these subunit genes. In this study, using both experimental and computational methods, we found that dual specificity phosphatase regulation of the activity of the three MAPKs through negative feedback is required, and forms the basis for decoding the frequency of pulsatile GnRH. A fourth MAPK, ERK5, was shown also to be activated by GnRH. ERK5 was found to stimulate FSHbeta promoter activity and to increase FSHbeta mRNA levels, as well as enhancing its preference for low GnRH pulse frequencies. The latter is achieved through boosting the ultrasensitive behavior of FSHbeta gene expression by increasing the number of MAPK dependencies, and through modulating the feedforward effects of JNK activation on the GnRH receptor (GnRH-R. Our findings contribute to understanding the role of changing GnRH pulse-frequency in controlling transcription of the pituitary gonadotropins, which comprises a crucial aspect in regulating reproduction. Pulsatile stimuli and oscillating signals are integral to many biological processes, and elucidation of the mechanisms through which the pulsatility is decoded explains how the same stimulant can lead to various outcomes in a single cell.

  16. Negative feedback governs gonadotrope frequency-decoding of gonadotropin releasing hormone pulse-frequency.

    Science.gov (United States)

    Lim, Stefan; Pnueli, Lilach; Tan, Jing Hui; Naor, Zvi; Rajagopal, Gunaretnam; Melamed, Philippa

    2009-09-29

    The synthesis of the gonadotropin subunits is directed by pulsatile gonadotropin-releasing hormone (GnRH) from the hypothalamus, with the frequency of GnRH pulses governing the differential expression of the common alpha-subunit, luteinizing hormone beta-subunit (LHbeta) and follicle-stimulating hormone beta-subunit (FSHbeta). Three mitogen-activated protein kinases, (MAPKs), ERK1/2, JNK and p38, contribute uniquely and combinatorially to the expression of each of these subunit genes. In this study, using both experimental and computational methods, we found that dual specificity phosphatase regulation of the activity of the three MAPKs through negative feedback is required, and forms the basis for decoding the frequency of pulsatile GnRH. A fourth MAPK, ERK5, was shown also to be activated by GnRH. ERK5 was found to stimulate FSHbeta promoter activity and to increase FSHbeta mRNA levels, as well as enhancing its preference for low GnRH pulse frequencies. The latter is achieved through boosting the ultrasensitive behavior of FSHbeta gene expression by increasing the number of MAPK dependencies, and through modulating the feedforward effects of JNK activation on the GnRH receptor (GnRH-R). Our findings contribute to understanding the role of changing GnRH pulse-frequency in controlling transcription of the pituitary gonadotropins, which comprises a crucial aspect in regulating reproduction. Pulsatile stimuli and oscillating signals are integral to many biological processes, and elucidation of the mechanisms through which the pulsatility is decoded explains how the same stimulant can lead to various outcomes in a single cell.

  17. DYNAMIC BEHAVIOR OF A DELAY-DIFFERENTIAL EQUATION MODEL FOR THE HORMONAL REGULATION OF THE MENSTRUAL CYCLE

    Science.gov (United States)

    During the menstrual cycle, pituitary hormones stimulate the growth and development of ovarian follicles and the release of an ovum to be fertilized. The ovarian follicles secrete hormones during the cycle that regulate the production of the pituitary hormones creating positi...

  18. DYNAMIC BEHAVIOR OF A DELAY-DIFFERENTIAL EQUATION MODEL FOR THE HORMONAL REGULATION OF THE MENSTRUAL CYCLE

    Science.gov (United States)

    During the menstrual cycle, pituitary hormones stimulate the growth and development of ovarian follicles and the release of an ovum to be fertilized. The ovarian follicles secrete hormones during the cycle that regulate the production of the pituitary hormones creating positi...

  19. In vivo multiplex quantitative analysis of 3 forms of alpha melanocyte stimulating hormone in pituitary of prolyl endopeptidase deficient mice

    Directory of Open Access Journals (Sweden)

    Perroud Bertrand

    2009-06-01

    Full Text Available Abstract Background In vitro reactions are useful to identify putative enzyme substrates, but in vivo validation is required to identify actual enzyme substrates that have biological meaning. To investigate in vivo effects of prolyl endopeptidase (PREP, a serine protease, on alpha melanocyte stimulating hormone (α-MSH, we developed a new mass spectrometry based technique to quantitate, in multiplex, the various forms of α-MSH. Methods Using Multiple Reaction Monitoring (MRM, we analyzed peptide transitions to quantify three different forms of α-MSH. Transitions were first confirmed using standard peptides. Samples were then analyzed by mass spectrometry using a triple quadrupole mass spectrometer, after elution from a reverse phase C18 column by a gradient of acetonitrile. Results We first demonstrate in vitro that PREP digests biological active alpha melanocyte stimulating hormone (α-MSH1–13, by cleaving the terminal amidated valine and releasing a truncated alpha melanocyte stimulating hormone (α-MSH1–12 product – the 12 residues α-MSH form. We then use the technique in vivo to analyze the MRM transitions of the three different forms of α-MSH: the deacetylated α-MSH1–13, the acetylated α-MSH1–13 and the truncated form α-MSH1–12. For this experiment, we used a mouse model (PREP-GT in which the serine protease, prolyl endopeptidase, is deficient due to a genetrap insertion. Here we report that the ratio between acetylated α-MSH1–13 and α-MSH1–12 is significantly increased (P-value = 0.015, N = 6 in the pituitaries of PREP-GT mice when compared to wild type littermates. In addition no significant changes were revealed in the relative level of α-MSH1–13 versus the deacetylated α-MSH1–13. These results combined with the demonstration that PREP digests α-MSH1–13 in vitro, strongly suggest that α-MSH1–13 is an in vivo substrate of PREP. Conclusion The multiplex targeted quantitative peptidomics technique we

  20. EFFECT OF PREOPERATIVE USE OF LONG-ACTING OCTREOTIDE ON GROWTH HORMONE SECRETING PITUITARY ADENOMA AND TRANSSPHENOIDAL SURGERY

    Institute of Scientific and Technical Information of China (English)

    Jian Yin; Chang-bao Su; Zhi-qin Xu; Yi Yang; Wen-bin Ma; Wei Tao; Zhong Yang; Xue-wei Xia

    2005-01-01

    Objective To investigate whether somatostatin analog octreotide long acting release (LAR) shrinks growth hormone (GH) secreting adenomas, and improves the results of subsequent transsphenoidal surgery.Methods Seventeen previously untreated active acromegalic patients with pituitary adenomas were treated with LAR (30 mg intramuscular injection every 28 days) for 3 months prior to transsphenoidal surgery. Clinical reaction, mean GH secretion, and tumor volume were measured under basal conditions and after LAR treatment.Results Presurgical treatment improved acromegaly symptoms and induced a significant reduction of GH under the 5 ng/mL limit in microadenoma (P < 0.05), while only 18.2% (2/11) in macroadenoma. Meanwhile, tumor shrinkage occurred in 58.8% (10/17) patients, with 1 case in the microadenoma group. All marked shrinkage (> 25%) occurred in the macroadenoma group. Statistical analysis showed tumor shrinkage caused by LAR was greater in macroadenoma group than that in microadenoma group (P < 0.05). During operation, adenoma was soft in 15 cases, with the exception of 2cases in which the soft rumor was divided by fibrous septa, but all tumor removal was smooth.Conclusions A short term administration of preoperative LAR may induce a significant decrease in GH-secretion level and adenoma volume. Presurgical use of octreotide LAR improves surgical results especially in macroadenomas.

  1. Gonadotropin-releasing hormone: regulation of the GnRH gene.

    Science.gov (United States)

    Lee, Vien H Y; Lee, Leo T O; Chow, Billy K C

    2008-11-01

    As the key regulator of reproduction, gonadotropin-releasing hormone (GnRH) is released by neurons in the hypothalamus, and transported via the hypothalamo-hypophyseal portal circulation to the anterior pituitary to trigger gonadotropin release for gonadal steroidogenesis and gametogenesis. To achieve appropriate reproductive function, mammals have precise regulatory mechanisms; one of these is the control of GnRH synthesis and release. In the past, the scarcity of GnRH neurons and their widespread distribution in the brain hindered the study of GnRH gene expression. Until recently, the development of GnRH-expressing cell lines with properties similar to those of in vivo GnRH neurons and also transgenic mice facilitated GnRH gene regulation research. This minireview provides a summary of the molecular mechanisms for the control of GnRH-I and GnRH-II gene expression. These include basal transcription regulation, which involves essential cis-acting elements in the GnRH-I and GnRH-II promoters and interacting transcription factors, and also feedback control by gonadotropins and gonadal sex steroids. Other physiological stimuli, e.g. insulin and melatonin, will also be discussed.

  2. Metabolic impact of adult-onset, isolated, growth hormone deficiency (AOiGHD due to destruction of pituitary somatotropes.

    Directory of Open Access Journals (Sweden)

    Raul M Luque

    Full Text Available Growth hormone (GH inhibits fat accumulation and promotes protein accretion, therefore the fall in GH observed with weight gain and normal aging may contribute to metabolic dysfunction. To directly test this hypothesis a novel mouse model of adult onset-isolated GH deficiency (AOiGHD was generated by cross breeding rat GH promoter-driven Cre recombinase mice (Cre with inducible diphtheria toxin receptor mice (iDTR and treating adult Cre(+/-,iDTR(+/- offspring with DT to selectively destroy the somatotrope population of the anterior pituitary gland, leading to a reduction in circulating GH and IGF-I levels. DT-treated Cre(-/-,iDTR(+/- mice were used as GH-intact controls. AOiGHD improved whole body insulin sensitivity in both low-fat and high-fat fed mice. Consistent with improved insulin sensitivity, indirect calorimetry revealed AOiGHD mice preferentially utilized carbohydrates for energy metabolism, as compared to GH-intact controls. In high-fat, but not low-fat fed AOiGHD mice, fat mass increased, hepatic lipids decreased and glucose clearance and insulin output were impaired. These results suggest the age-related decline in GH helps to preserve systemic insulin sensitivity, and in the context of moderate caloric intake, prevents the deterioration in metabolic function. However, in the context of excess caloric intake, low GH leads to impaired insulin output, and thereby could contribute to the development of diabetes.

  3. Metabolic impact of adult-onset, isolated, growth hormone deficiency (AOiGHD) due to destruction of pituitary somatotropes.

    Science.gov (United States)

    Luque, Raul M; Lin, Qing; Córdoba-Chacón, José; Subbaiah, Papasani V; Buch, Thorsten; Waisman, Ari; Vankelecom, Hugo; Kineman, Rhonda D

    2011-01-19

    Growth hormone (GH) inhibits fat accumulation and promotes protein accretion, therefore the fall in GH observed with weight gain and normal aging may contribute to metabolic dysfunction. To directly test this hypothesis a novel mouse model of adult onset-isolated GH deficiency (AOiGHD) was generated by cross breeding rat GH promoter-driven Cre recombinase mice (Cre) with inducible diphtheria toxin receptor mice (iDTR) and treating adult Cre(+/-),iDTR(+/-) offspring with DT to selectively destroy the somatotrope population of the anterior pituitary gland, leading to a reduction in circulating GH and IGF-I levels. DT-treated Cre(-/-),iDTR(+/-) mice were used as GH-intact controls. AOiGHD improved whole body insulin sensitivity in both low-fat and high-fat fed mice. Consistent with improved insulin sensitivity, indirect calorimetry revealed AOiGHD mice preferentially utilized carbohydrates for energy metabolism, as compared to GH-intact controls. In high-fat, but not low-fat fed AOiGHD mice, fat mass increased, hepatic lipids decreased and glucose clearance and insulin output were impaired. These results suggest the age-related decline in GH helps to preserve systemic insulin sensitivity, and in the context of moderate caloric intake, prevents the deterioration in metabolic function. However, in the context of excess caloric intake, low GH leads to impaired insulin output, and thereby could contribute to the development of diabetes.

  4. Prolactin, thyrotropin, and growth hormone release during stress associated with parachute jumping.

    Science.gov (United States)

    Noel, G L; Dimond, R C; Earll, J M; Frantz, A G

    1976-05-01

    Prolactin, growth hormone, and thyrotropin (TSH) release during the stress of parachute jumping has been evaluated in 14 male subjects. Subjects were studied at several times before and immediately after their first military parachute jump. All three hormones had risen significantly 1 to 14 min after the jump, compared to mean levels measured immediately beforehand. Earlier studies of physical exercise by ourselves and others would suggest that emotional stress played a role in producing changes of this magnitude. We conclude that prolactin, TSH, and growth hormone are released in physiologically significant amounts in association with the stress of parachute jumping.

  5. Alpha-adrenergic regulation of growth hormone release after electroconvulsive therapy in man.

    Science.gov (United States)

    Vigas, M; Wiedermann, V; Németh, S; Jurcovicová, J; Zigo, L

    1976-01-01

    When electroshcok therapy was administered to male psychiatric patients without anticonvulsive premedication, serum growth hormone (GH) increased; the increase was not prevented by an infusion of 20% glucose (5 ml per min) 20 min prior to electroshock. Therefore, the GH rise is not caused by muscle exercise during convulsions. Infusing 30 mg of phentolamine 40 min prior to electroshcok inhibited the GH response. Phentolamine's effect shows that the stress-induced GH release that follows electroconvulsive therapy is mediated by alpha-adrenergic neurons.

  6. Molecular Mechanisms of Gonadotropin-Releasing Hormone Signaling: Integrating Cyclic Nucleotides into the Network

    Directory of Open Access Journals (Sweden)

    Craig Alexander McArdle

    2013-11-01

    Full Text Available Gonadotropin-releasing hormone (GnRH is the primary regulator of mammalian reproductive function in both males and females. It acts via G-protein coupled receptors on gonadotropes to stimulate synthesis and secretion of the gonadotropin hormones luteinizing hormone and follicle-stimulating hormone. These receptors couple primarily via G-proteins of the Gq/11 family, driving activation of phospholipase C and mediating GnRH effects on gonadotropin synthesis and secretion. There is also good evidence that GnRH causes activation of other heterotrimeric G-proteins (Gs and Gi with consequent effects on cyclic AMP production, as well as for effects on the soluble and particulate guanylyl cyclases that generate cGMP. Here we provide an overview of these pathways. We emphasise mechanisms underpinning pulsatile hormone signaling and the possible interplay of GnRH and autocrine or paracrine regulatory mechanisms in control of cyclic nucleotide signaling.

  7. Gender difference in age-related number of corticotropin-releasing hormone-expressing neurons in the human hypothalamic paraventricular nucleus and the role of sex hormones

    NARCIS (Netherlands)

    Bao, A.-M.; Swaab, D.F.

    2007-01-01

    Previous studies have shown that the total number of corticotropin-releasing hormone (CRH)-stained neurons in the human hypothalamic paraventricular nucleus (PVN) increases with age. To determine whether this age-related change depends on gender and whether circulating sex hormones play a role, we

  8. Inhibition by female sex hormones of collagen degradation by corneal fibroblasts.

    Science.gov (United States)

    Zhou, Hongyan; Kimura, Kazuhiro; Orita, Tomoko; Nishida, Teruo; Sonoda, Koh-Hei

    2011-01-01

    Corneal fibroblasts contribute to collagen remodeling in the corneal stroma in part by mediating collagen degradation. Given that corneal structure is influenced by sex hormone status, we examined the effects of sex hormones on collagen degradation by corneal fibroblasts. Rabbit corneal fibroblasts were cultured in three-dimensional collagen gels with or without sex hormones including 17β-estradiol, progesterone, testosterone, and dehydroepiandrosterone (DHEA). Collagen degradation was determined by measurement of hydroxyproline after acid hydrolysis. The expression and activity of matrix metalloproteinases (MMPs) were evaluated by immunoblot analysis and gelatin zymography. The phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-kappa B (NF-κB) inhibitor NF kappa B Inhibitor-alpha (IκB-α) in corneal fibroblasts was examined by immunoblot analysis. Cell proliferation and viability were evaluated by measurement of bromodeoxyuridine incorporation and the release of lactate dehydrogenase, respectively. 17β-Estradiol and progesterone each inhibited interleukin (IL)-1β-induced collagen degradation by corneal fibroblasts in a concentration-dependent manner, whereas testosterone and DHEA had no such effect. MMP expression and activation in corneal fibroblasts exposed to IL-1β were also inhibited by 17β-estradiol and progesterone. These female sex hormones did not affect cell proliferation or viability. Both 17β-estradiol and progesterone inhibited the IL-1β-induced phosphorylation of p38 MAPK without affecting that of the MAPKs extracellular Signal-regulated Kinase (ERK) or c-jun N-terminal kinase (JNK). 17β-Estradiol also inhibited the IL-1β-induced phosphorylation of IκB-α. 17β-Estradiol and progesterone inhibited MMP expression and activity in IL-1β-stimulated corneal fibroblasts and thereby suppressed collagen degradation by these cells.

  9. Changes of growth hormone-releasing hormone and somatostatin neurons in the rat hypothalamus induced by genistein: a stereological study.

    Science.gov (United States)

    Trifunović, Svetlana; Manojlović-Stojanoski, Milica; Ristić, Nataša; Nestorović, Nataša; Medigović, Ivana; Živanović, Jasmina; Milošević, Verica

    2016-12-01

    Genistein is a plant-derived estrogenic isoflavone commonly found in dietary and therapeutic supplements, due to its potential health benefits. Growth hormone-releasing hormone (GHRH) and somatostatin (SS) are neurosecretory peptides synthesized in neurons of the hypothalamus and regulate the growth hormone secretion. Early reports indicate that estrogens have highly involved in the regulation of GHRH and SS secretions. Since little is known about the potential effects of genistein on GHRH and SS neurons, we exposed rats to genistein. Genistein were administered to adult rats in dose of 30 mg/kg, for 3 weeks. The estradiol-dipropionate treatment was used as the adequate controls to genistein. Using applied stereology on histological sections of hypothalamus, we obtained the quantitative information on arcuate (Arc) and periventricular (Pe) nucleus volume and volume density of GHRH neurons and SS neurons. Image analyses were used to obtain GHRH and SS contents in the median eminence (ME). Administration of estradiol-dipropionate caused the increase of Arc and Pe nucleus volume, SS neuron volume density, GHRH and SS staining intensity in the ME, when compared with control. Genistein treatment increased: Arc nucleus volume and the volume density of GHRH neurons (by 26%) and SS neurons (1.5 fold), accompanied by higher GHRH and SS staining intensity in the ME, when compared to the orhidectomized group. These results suggest that genistein has a significant effect on hypothalamic region, involved in the regulation of somatotropic system function, and could contribute to the understanding of genistein as substance that alter the hormonal balance.

  10. Responsiveness of adenylate cyclase to pituitary gonadotropins and evidence of a hormone-induced desensitization in the lizard ovary.

    Science.gov (United States)

    Borrelli, L; De Stasio, R; Bovenzi, V; Parisi, E; Filosa, S

    1997-07-01

    Gonadotropins (FSH and LH) affect several mammalian gonadal functions. In particular, FSH stimulates oogonial proliferation and oocyte growth, while LH regulates ovulation and progesterone secretion. In lacertilian reptiles, gonadal function is also regulated by pituitary gonadotropins, but which hormone controls ovarian activities and the mechanisms of action are unknown. The present study aimed to clarify mechanisms of action of pituitary gonadotropins on the ovary of Podarcis sicula (Lacertilia). The data demonstrate that mammalian gonadotropins FSH and LH produce a threefold stimulation of adenylate cyclase activity in follicular membranes, while hCG and TSH are less effective, causing a twofold increase in adenylate cyclase activity. Neurotransmitters such as dopamine, serotonin, and catecholamines have no effect on enzyme activity. The action of mammalian FSH and LH on the ovary mimics the effect of homologous hormones: in lizard ovaries incubated in vitro in the presence of isolated homologous pituitary glands, the intracellular cAMP level increased by 50% with respect to control ovaries. Mammalian gonadotropins appear homologous to lizard gonadotropin(s): Southern blot analyses show that the lizard genome contains nucleotide sequences homologous to those encoding for mammalian beta FSH and beta LH. Both homologous and heterologous desensitization of adenylate cyclase activity occurs in the lizard ovary. In fact, responsiveness of adenylate cyclase to gonadotropin stimulation is abolished in animals 2 hr after in vivo treatment with FSH. Sensitivity to gonadotropin stimulation is restored 2 weeks after the beginning of the in vivo treatment. Desensitization was also observed in ovaries incubated in vitro with mammalian FSH or with isolated pituitary glands.

  11. Stress hormone release is a key component of the metabolic response to lipopolysaccharide: studies in hypopituitary and healthy subjects.

    Science.gov (United States)

    Bach, Ermina; Møller, Andreas B; Jørgensen, Jens O L; Vendelbo, Mikkel H; Jessen, Niels; Pedersen, Steen B; Nielsen, Thomas S; Møller, Niels

    2016-11-01

    Acute and chronic inflammatory and metabolic responses are generated by lipopolysaccharide (LPS) during acute illness and in the pathogenesis of the metabolic syndrome, type 2 diabetes and cardiovascular disease, but whether these responses depend on intact pituitary release of hormones are not clearly identified. We compared the metabolic effects of LPS in hypopituitary patients (HPs) (in the absence of growth hormone (GH) and ACTH responses) and healthy control subjects (CTR) (with normal pituitary hormone responses). Single-blind randomized. We compared the effects of LPS on glucose, protein and lipid metabolism in eight HP and eight matched CTR twice during 4-h basal and 2-h hyperinsulinemic-euglycemic clamp conditions with muscle and fat biopsies in each period during infusion with saline or LPS. LPS increased cortisol and GH levels in CTR but not in HP. Also, it increased whole-body palmitate fluxes (3-fold) and decreased palmitate-specific activity (SA) 40-50% in CTR, but not in HP. G(0)/G(1) Switch Gene 2 (G0S2 - an inhibitor of lipolysis) adipose tissue (AT) mRNA was decreased in CTR. Although LPS increased phenylalanine fluxes significantly more in CTR, there was no difference in glucose metabolism between groups and intramyocellular insulin signaling was unaltered in both groups. LPS increased indices of lipolysis and amino acid/protein fluxes significantly more in CTR compared with HP and decreased adipocyte G0S2 mRNA only in CTR. Thus, in humans intact pituitary function and appropriate cortisol and GH release are crucial components of the metabolic response to LPS. © 2016 European Society of Endocrinology.

  12. [Women, immunity and sexual hormones].

    Science.gov (United States)

    Denenberg, R

    1995-01-01

    How a weakened immune system affects the female's reproductive system is explained. The female's endocrine system controls the menstrual and reproductive systems, and the immune system attacks harmful substances and organisms. The hypothalamus stimulates the pituitary gland to produce the hormones FSH and LH, which in turn signal the ovaries to produce estrogen and progesterone. These hormones cause a mature egg to be released. If fertilized, the egg remains within the uterus; if not, menstruation occurs. HIV-positive females often complain of menstrual cycle changes, such as irregular periods, depression, or pain. The virus, other complications, or medications, such as AZT, may cause these symptoms. Estrogen therapy may help those with suppressed immune systems who have premature menopause. Oral contraceptives offer protection against pregnancy, but not HIV. It is not known if the pill reacts adversely with AIDS treatment drugs. Lists are provided showing the pros and cons of oral contraceptives and hormone therapy.

  13. Apoptotic death of prostate cancer cells by a gonadotropin-releasing hormone-II antagonist.

    Directory of Open Access Journals (Sweden)

    Sumi Park

    Full Text Available Gonadotropin-releasing hormone-I (GnRH-I has attracted strong attention as a hormonal therapeutic tool, particularly for androgen-dependent prostate cancer patients. However, the androgen-independency of the cancer in advanced stages has spurred researchers to look for new medical treatments. In previous reports, we developed the GnRH-II antagonist Trp-1 to inhibit proliferation and stimulate the autophagic death of various prostate cancer cells, including androgen-independent cells. We further screened many GnRH-II antagonists to identify molecules with higher efficiency. Here, we investigated the effect of SN09-2 on the growth of PC3 prostate cancer cells. SN09-2 reduced the growth of prostate cancer cells but had no effect on cells derived from other tissues. Compared with Trp-1, SN09-2 conspicuously inhibited prostate cancer cell growth, even at low concentrations. SN09-2-induced PC3 cell growth inhibition was associated with decreased membrane potential in mitochondria where the antagonist was accumulated, and increased mitochondrial and cytosolic reactive oxygen species. SN09-2 induced lactate dehydrogenase release into the media and annexin V-staining on the PC3 cell surface, suggesting that the antagonist stimulated prostate cancer cell death by activating apoptotic signaling pathways. Furthermore, cytochrome c release from mitochondria to the cytosol and caspase-3 activation occurred in a concentration- and time-dependent manner. SN09-2 also inhibited the growth of PC3 cells xenotransplanted into nude mice. These results demonstrate that SN09-2 directly induces mitochondrial dysfunction and the consequent ROS generation, leading to not only growth inhibition but also apoptosis of prostate cancer cells.

  14. Growth hormone modulation of arginine-induced glucagon release: studies of isolated growth hormone deficiency and acromegaly.

    Science.gov (United States)

    Seino, Y; Taminato, T; Goto, Y; Inoue, Y; Kadowaki, S; Hattori, M; Mori, K; Kato, Y; Matsukura, S; Imura, H

    1978-12-01

    Plasma glucagon and insulin responses to L-arginine were compared in normal controls and patients with isolated growth hormone deficiency and acromegaly. Patients with isolated growth hormone deficiency were characterized by high plasma glucagon response and low plasma insulin response, whereas acromegalic patients showed exaggerated plasma glucagon response and almost normal insulin response. These results suggest that growth hormone is probably required for optimum function of the islets, and since hyperglucagonaemia was observed in both growth hormone deficiency and acromegaly, metabolic disturbances stemming from the respective primary diseases may affect glucagon secretion.

  15. The Decreased Growth Hormone Response to Growth Hormone Releasing Hormone in Obesity Is Associated to Cardiometabolic Risk Factors

    Directory of Open Access Journals (Sweden)

    Fernando Cordido

    2010-01-01

    Premenopausal obese women, aged 35–52 years, were studied. GH secretion, IGF-I, serum cardiovascular risk markers, insulin, leptin, mid-waist and hip circumference, total body fat, and truncal fat were measured. Subjects were classified as meeting the criteria for GH deficiency (GHD when peak GH after stimulation with GHRH was ≤3 μg/L. Mean total and LDL cholesterol, fasting insulin, and HOMA-IR were all higher, in subjects who would have been classified as GH-deficient compared with GH-sufficient. Peak GH secretion after stimulation was inversely associated with fasting insulin (R=−0.650, P=.012, HOMA-IR (R=−0.846, P=.001, total cholesterol (R=−0.532, P=.034, and LDL cholesterol (R=−0.692, P=.006 and positively associated with HDL cholesterol (R=0.561, P=.037. These data strongly suggest a role for insulin resistance in the decreased GH secretion of obesity and that the blunted GH secretion of central obesity could be the pituitary expression of the metabolic syndrome.

  16. The estrogen myth: potential use of gonadotropin-releasing hormone agonists for the treatment of Alzheimer's disease.

    Science.gov (United States)

    Casadesus, Gemma; Garrett, Matthew R; Webber, Kate M; Hartzler, Anthony W; Atwood, Craig S; Perry, George; Bowen, Richard L; Smith, Mark A

    2006-01-01

    Estrogen and other sex hormones have received a great deal of attention for their speculative role in Alzheimer's disease (AD), but at present a direct connection between estrogen and the pathogenesis of AD remains elusive and somewhat contradictory. For example, on one hand there is a large body of evidence suggesting that estrogen is neuroprotective and improves cognition, and that hormone replacement therapy (HRT) at the onset of menopause reduces the risk of developing AD decades later. However, on the other hand, studies such as the Women's Health Initiative demonstrate that HRT initiated in elderly women increases the risk of dementia. While estrogen continues to be investigated, the disparity of findings involving HRT has led many researchers to examine other hormones of the hypothalamic-pituitary-gonadal axis such as luteinising hormone (LH) and follicle-stimulating hormone. In this review, we propose that LH, rather than estrogen, is the paramount player in the pathogenesis of AD. Notably, both men and women experience a 3- to 4-fold increase in LH with aging, and LH receptors are found throughout the brain following a regional pattern remarkably similar to those neuron populations affected in AD. With respect to disease, serum LH level is increased in women with AD relative to non-diseased controls, and levels of LH in the brain are also elevated in AD. Mechanistically, we propose that elevated levels of LH may be a fundamental instigator responsible for the aberrant reactivation of the cell cycle that is seen in AD. Based on these aforementioned aspects, clinical trials underway with leuprolide acetate, a gonadotropin-releasing hormone agonist that ablates serum LH levels, hold great promise as a ready means of treatment in individuals afflicted with AD.

  17. Obtaining growth hormone from calf blood

    Science.gov (United States)

    Kalchev, L. A.; Ralchev, K. K.; Nikolov, I. T.

    1979-01-01

    The preparation of a growth hormone from human serum was used for the isolation of the hormone from calf serum. The preparation was biologically active - it increased the quantity of the free fatty acids released in rat plasma by 36.4 percent. Electrophoresis in Veronal buffer, ph 8.6, showed the presence of a single fraction having mobility intermediate between that of alpha and beta globulins. Gel filtration through Sephadex G 100 showed an elutriation curve identical to that obtained by the growth hormone prepared from pituitary glands.

  18. Exocytosis sensitivity to growth hormone-releasing hormone in subsets of GH cells in rats under different corticosterone conditions. Ultrastructural study using microwave irradiation for fixation and immunocytochemistry.

    Science.gov (United States)

    Ozawa, Hitoshi; Han, Fang; Kawata, Mitsuhiro

    2004-12-01

    Growth hormone (GH) cells in the rat anterior pituitary have been morphologically classified into three subtypes: type I (mature) containing large secretory granules about 350 nm in diameter, type II (intermediate) containing a mixture of large and small granules, and type III (immature) containing small granules about 150 nm in diameter. However, the functional implications of morphological heterogeneity, especially the different sensitivities to growth hormone-releasing hormone (GRH) under different corticosteroid conditions have not been elucidated to date. In the present study, by application of microwave irradiation (MWI) for fixation and immunocytochemistry, new findings of the exocytotic response have been revealed among the subsets of GH cells following adrenalectomy (ADX), corticosterone treatment and/or GRH treatment. The MWI gave effective results for fixation, especially for the permeability of the fixative, and showed good results for immunoelectron microscopy using the protein-A gold method. Moreover, the use of MWI greatly shortened the fixation, processing and immunolabeling times without compromising the quality of ultrastructural preservation and the specificity of labeling. The number of exocytotic figures was low in all subtypes of GH cells in the sham-operated control rats. GRH treatment induced a significant increase in exocytosis in each subtype of GH cells, particularly in type I (mature) and type II (intermediate) GH cells in the control rats. GRH injection to rats for 4 days after ADX also showed an increase in exocytosis, but the degree was significantly less in comparison with the GRH injection in the control group. Corticosterone replacement given to ADX rats induced a clear recovery of the exocytotic response to GRH to the control level. Serum GH content measured by radioimmunoassay correlated with these morphological results. These results suggest that the secretion of GH stimulated by GRH is closely related to corticosteroids, and

  19. An intronic SNP in the thyroid hormone receptor β gene is associated with pituitary cell-specific over-expression of a mutant thyroid hormone receptor β2 (R338W in the index case of pituitary-selective resistance to thyroid hormone

    Directory of Open Access Journals (Sweden)

    Cochran Craig

    2011-08-01

    Full Text Available Abstract Background The syndrome of resistance to thyroid hormone (RTH is caused by mutations in the thyroid hormone receptor β gene (THRB. The syndrome varies from asymptomatic to diffuse hypothyroidism, to pituitary-selective resistance with predominance of hyperthyroid signs and symptoms. The wide spectrum of clinical presentation is not completely attributable to specific THRB mutations. The THRB gene encodes two main isoforms, TR β1 which is widely distributed, and TR β2, whose expression is limited to the cochlea, retina, hypothalamus, and pituitary. Recent data demonstrated that in mice an intron enhancer region plays a critical role in the pituitary expression of the β2 isoform of the receptor. We thus hypothesized that polymorphisms in the human homologous region could modulate the pituitary expression of the mutated gene contributing to the clinical presentation of RTH. Methods Screening and in vitro characterization of polymorphisms of the intron enhancer region of the THRB gene in the index case of pituitary-selective RTH. Results The index case of pituitary-selective resistance is characterized by the missense R338W exon 9 mutation in cis with two common SNPs, rs2596623T and rs2596622C, located in the intron enhancer region of the THRB gene. Reporter gene assay experiments in GH3 pituitary-derived cells indicate that rs2596623T generates an increased pituitary cell-specific activity of the TR β2 promoter suggesting that rs2596623T leads to pituitary over-expression of the mutant allele. Conclusions The combined coding mutation and non-coding SNP therefore generate a tissue-specific dominant-negative condition recapitulating the patient's peculiar phenotype. This case illustrates the role of regulatory regions in modifying the clinical presentation of genetic diseases.

  20. Changes in Plasma Prolactin and Growth Hormone Level and Visual Problem after radiation Therapy(RT) of Pituitary Adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Sei Chul; Kwon, Hyung Chul; Oh, Yoon Kyeong; Bahk, Yong Whee; Son, Ho Young; Kang, Joon Ki; Song, Jin Un [Catholic Medical College, Seoul (Korea, Republic of)

    1985-06-15

    Twenty-four cases of pituitary adenoma, 13 males and 11 females with the age ranging from 11 to 65 years, received radiation therapy(RT) on the pituitary area with 6MV linear accelerator during past 25 months at the Division of Radiation Therapy, Kangnam St. Mary Hospital, Catholic Medical College. Of 24 case of RT, 20 were postoperative and 4 primary. To evaluate the effect of RT, we analyzed the alteration of the endocrinological tests, neurologic abnormalities, major clinical symptoms, endocrinological changes and improvement in visual problems after RT. The results were as follows ; 1. Major clinical symptoms were headache, visual defects, diabetes insipidus, hypogonadisms and general weakness in decreasing order of frequency. 2. All but the one with Nelson syndrome showed abnormal neuroradiologic changes in the sella turcica with an invasive tumor mass around supra and para-sellar area. 3. Endocrinological classifications of the patient were 11 prolactinoma, 4 growth hormonesecreting tumors, 3 ACTH-secreting tumors consisting of one Cushing disease and two Nelson syndrome, and 6 nonfunctioning tumors. 4. Eleven of 14 patients, visual problems were improved after treatment but remaining 3 were unchanged. 5. Seven of 11 prolactinomas returned to normal hormonal level after postoperative and primary RT and 3 patients are being treated with bromocriptine (BMCP) but on lost case. 6. Two of 4 growth hormone-secreting tumor returned to normal level after RT but the remaining 2 are being treated with BMCP, as well.

  1. Hormone Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hormones quantified from marine mammal and sea turtle tissue provide information about the status of each animal sampled, including its sex, reproductive status and...

  2. Mink aging is associated with a reduction in ovarian hormone release and the response to FSH and ghrelin.

    Science.gov (United States)

    Sirotkin, Alexander V; Mertin, Dušan; Süvegová, Karina; Lauričik, Jozef; Morovič, Martin; Harrath, Abdel Halim; Kotwica, Jan

    2016-09-15

    The endocrine mechanisms of mink ovarian hormones release and reproductive aging are poorly investigated. The aims of our study were to: (1) identify hormones produced by mink ovaries (the steroids progesterone [P] and estradiol [E], the peptide hormone oxytocin [OT], and the prostaglandin F [PGF] and prostaglandin E [PGE]); (2) examine the effect of FSH and ghrelin on the release of the hormones listed previously; and (3) understand whether these hormones can be involved in the control of mink reproductive aging, i.e., whether aging can be associated with changes (a) in the basal release of P, E, OT, PGF, or PGE and (b) their response to FSH and ghrelin. Fragments of ovaries of young (yearlings) and old (3-5 years of age) minks were cultured with and without FSH and ghrelin (0, 1, 10, or 100 ng/mL), and the release of hormones was analyzed by EIA/RIA. We found that isolated ovaries were able to release P, E, OT, PGF, and PGE, and the levels of P produced in the ovaries of old animals were lower than those produced in the ovaries of young animals, whereas the levels of other hormones did not differ. FSH was able to stimulate P and E and suppress OT and PGF and did not affect PGE release. Aging was associated with the inhibition of the effect of FSH on ovarian P and E, the appearance of the inhibitory action of FSH on OT, and the disappearance of this action on ovarian PGF. PGE was not affected by FSH, irrespective of animal age. Ghrelin was able to promote E (but not P) and suppress OT, PGF, and PGE output. Aging was associated with the appearance of an inhibitory influence of ghrelin on ovarian OT and PGE and with the disappearance of this influence on PGF output. Aging did not affect the action of ghrelin on ovarian P and E. Our observations (1) confirm the production of P and E and show that OT, PGF, and PGE are released from mink ovaries, (2) confirm the involvement of FSH and demonstrate the involvement of ghrelin in the control of mink ovarian hormone

  3. Influence of age on pulsatile luteinizing hormone release and responsiveness of the gonadotrophs to sex hormone feedback in men.

    Science.gov (United States)

    Deslypere, J P; Kaufman, J M; Vermeulen, T; Vogelaers, D; Vandalem, J L; Vermeulen, A

    1987-01-01

    The influence of aging on serum LH and testosterone (T) pulse frequency and gonadotroph sensitivity to androgen and estrogen feedback was studied in young (less than 55 yr old) and elderly (greater than 65 yr) Trappist monks. LH pulse frequency (sampling interval, 20 min) was significantly lower [0.25 +/- 0.03 (+/- SEM) vs. 0.38 +/- 0.02 pulses/h; P less than 0.01] in elderly (n = 21) than in young monks (n = 27); the pulse amplitudes were similar. Similarly, T pulse frequency was lower in the elderly than in the young monks (0.13 +/- 0.04 vs. 0.23 +/- 0.02 pulses/h; P less than 0.01). In elderly men, the hypothalamo-pituitary complex was more sensitive to 5 alpha-androstan-17 beta-ol-3-one feedback, as determined by the decrease in serum LH and T levels. Moreover, during 5 alpha-androstan-17 beta-ol-3-one (125 mg/day, percutaneously, for 10 days) administration, the LH response to LHRH (100 micrograms, iv) was significantly higher in the elderly men compared to the pretreatment response. During estradiol (1.5 mg/day, percutaneously for 10 days) administration, the LH response to LHRH was decreased in the elderly men, but unchanged in the young men, suggesting greater responsiveness to estradiol in the elderly men. We conclude that in aged men, decreased testicular androgen secretion is not exclusively the consequence of a primary testicular alteration, but that important changes occur in hypothalamo-pituitary function, specifically decreased LH pulse frequency and increased LH responsiveness to sex hormone feedback.

  4. Thyroid-stimulating hormone-secreting pituitary adenoma presenting with recurrent hyperthyroidism in post-treated Graves’ disease: a case report

    Directory of Open Access Journals (Sweden)

    Ogawa Yoshikazu

    2013-01-01

    Full Text Available Abstract Introduction The coexistence of autoimmune hyperthyroid disease and thyroid-stimulating hormone-secreting pituitary adenoma is rare. The simple presumption of coincidence of these two diseases has a calculated incidence of less than one/several hundred million, and only four cases with histological confirmation have been reported. A rapid decrease in thyroid-stimulating hormone level after pituitary tumor removal may induce subsequent activation of autoimmune responses against the thyroid gland. We report the first case of a sequential and paradoxical occurrence of Graves’ disease and a thyroid-stimulating hormone-secreting pituitary adenoma. Case presentation A 32-year-old Japanese woman had recurrent hyperthyroidism. She had a history of Graves’ hyperthyroidism, which had been successfully treated with propylthiouracil. A head magnetic resonance imaging showed a less enhanced area in the left lateral wing of her sella turcica. Transsphenoidal surgery was performed, and the diagnosis was established as thyroid-stimulating hormone-secreting plurihormonal adenoma. A rapid reduction in thyroid hormone levels was achieved, and her blood pressure was normalized after the operation. Conclusion Although incidental occurrence is the most probable etiology, long and repeated followup examinations of both thyroid and pituitary gland should be performed in patients with an atypical clinical course.

  5. Aging influences steroid hormone release by mink ovaries and their response to leptin and IGF-I

    Directory of Open Access Journals (Sweden)

    Alexander V. Sirotkin

    2016-02-01

    Full Text Available The aim of our study was to understand whether ovarian steroid hormones, and their response to the metabolic hormones leptin and IGF-I leptin, could be involved in the control of mink reproductive aging via changes in basal release of ovarian progesterone and estradiol. For this purpose, we compared the release of progesterone and estradiol by ovarian fragments isolated from young (yearlings and old (3-5 years of age minks cultured with and without leptin and IGF-I (0, 1, 10 or 100 ng/ml. We observed that isolated ovaries of older animals produced less progesterone but not less estradiol than the ovaries of young animals. Leptin addition stimulated estradiol release by the ovarian tissue of young animals but inhibited it in older females. Leptin did not influence progesterone output by the ovaries of either young or older animals. IGF-I inhibited estradiol output in young but not old animals, whereas progesterone release was inhibited by IGF-I irrespective of the animal age. Our observations demonstrate the involvement of both leptin and IGF-I in the control of mink ovarian steroid hormones release. Furthermore, our findings suggest that reproductive aging in minks can be due to (a reduction in basal progesterone release and (b alterations in the response of estradiol but not of progesterone to leptin and IGF-I.

  6. Aging influences steroid hormone release by mink ovaries and their response to leptin and IGF-I.

    Science.gov (United States)

    Sirotkin, Alexander V; Mertin, Dušan; Süvegová, Karin; Harrath, Abdel Halim; Kotwica, Jan

    2016-01-21

    The aim of our study was to understand whether ovarian steroid hormones, and their response to the metabolic hormones leptin and IGF-I leptin, could be involved in the control of mink reproductive aging via changes in basal release of ovarian progesterone and estradiol. For this purpose, we compared the release of progesterone and estradiol by ovarian fragments isolated from young (yearlings) and old (3-5 years of age) minks cultured with and without leptin and IGF-I (0, 1, 10 or 100 ng/ml). We observed that isolated ovaries of older animals produced less progesterone but not less estradiol than the ovaries of young animals. Leptin addition stimulated estradiol release by the ovarian tissue of young animals but inhibited it in older females. Leptin did not influence progesterone output by the ovaries of either young or older animals. IGF-I inhibited estradiol output in young but not old animals, whereas progesterone release was inhibited by IGF-I irrespective of the animal age. Our observations demonstrate the involvement of both leptin and IGF-I in the control of mink ovarian steroid hormones release. Furthermore, our findings suggest that reproductive aging in minks can be due to (a) reduction in basal progesterone release and (b) alterations in the response of estradiol but not of progesterone to leptin and IGF-I.

  7. Evaluation of growth hormone release and human growth hormone treatment in children with cranial irradiation-associated short stature

    Energy Technology Data Exchange (ETDEWEB)

    Romshe, C.A.; Zipf, W.B.; Miser, A.; Miser, J.; Sotos, J.F.; Newton, W.A.

    1984-02-01

    We studied nine children who had received cranial irradiation for various malignancies and subsequently experienced decreased growth velocity. Their response to standard growth hormone stimulation and release tests were compared with that in seven children with classic GH deficiency and in 24 short normal control subjects. With arginine and L-dopa stimulation, six of nine patients who received radiation had a normal GH response (greater than 7 ng/ml), whereas by design none of the GH deficient and all of the normal children had a positive response. Only two of nine patients had a normal response to insulin hypoglycemia, with no significant differences in the mean maximal response of the radiation and the GH-deficient groups. Pulsatile secretion was not significantly different in the radiation and GH-deficient groups, but was different in the radiation and normal groups. All subjects in the GH-deficient and radiation groups were given human growth hormone for 1 year. Growth velocity increased in all, with no significant difference in the response of the two groups when comparing the z scores for growth velocity of each subject's bone age. We recommend a 6-month trial of hGH in children who have had cranial radiation and are in prolonged remission with a decreased growth velocity, as there is no completely reliable combination of GH stimulation or release tests to determine their response.

  8. Neither bST nor Growth Hormone Releasing Factor Alter Expression of Thyroid Hormone Receptors in Liver and Mammary Tissues

    Science.gov (United States)

    Physiological effects of thyroid hormones are mediated primarily by binding of triiodothyronine, to specific nuclear receptors. It has been hypothesized that organ-specific changes in production of triiodothyronine from its prohormone, thyroxine, target the action of thyroid hormones to the mammary...

  9. Molecular cloning of pituitary glycoprotein alpha-subunit and follicle stimulating hormone and chorionic gonadotropin beta-subunits from New World squirrel monkey and owl monkey.

    Science.gov (United States)

    Scammell, Jonathan G; Funkhouser, Jane D; Moyer, Felricia S; Gibson, Susan V; Willis, Donna L

    2008-02-01

    The goal of this study was to characterize the gonadotropins expressed in pituitary glands of the New World squirrel monkey (Saimiri sp.) and owl monkey (Aotus sp.). The various subunits were amplified from total RNA from squirrel monkey and owl monkey pituitary glands by reverse transcription-polymerase chain reaction and the deduced amino acid sequences compared to those of other species. Mature squirrel monkey and owl monkey glycoprotein hormone alpha-polypeptides (96 amino acids in length) were determined to be 80% homologous to the human sequence. The sequences of mature beta subunits of follicle stimulating hormone (FSHbeta) from squirrel monkey and owl monkey (111 amino acids in length) are 92% homologous to human FSHbeta. New World primate glycoprotein hormone alpha-polypeptides and FSHbeta subunits showed conservation of all cysteine residues and consensus N-linked glycosylation sites. Attempts to amplify the beta-subunit of luteinizing hormone from squirrel monkey and owl monkey pituitary glands were unsuccessful. Rather, the beta-subunit of chorionic gonadotropin (CG) was amplified from pituitaries of both New World primates. Squirrel monkey and owl monkey CGbeta are 143 and 144 amino acids in length and 77% homologous with human CGbeta. The greatest divergence is in the C terminus, where all four sites for O-linked glycosylation in human CGbeta, responsible for delayed metabolic clearance, are predicted to be absent in New World primate CGbetas. It is likely that CG secreted from pituitary of New World primates exhibits a relatively short half-life compared to human CG.

  10. GnRH在青年摩杂一代水牛下丘脑-垂体-卵巢轴的免疫组化定位%Distribution of Gonadotropin (GnRH) Releasing Hormone in Hypothalamus-pituitary-ovary Axis of Youth Murrah Hybrid Water Buffalo

    Institute of Scientific and Technical Information of China (English)

    凌泽继; 李瑞明; 谢莹雪; 周辰瑜; 黎金秀; 秦津; 潘堂峰; 宋小白; 杨柄壮; 许典新; 韩涛; 潘琼

    2009-01-01

    [Objective] The research aimed to study the distribution of gonadotropin (GnRH) releasing hormone in hypothalamus-pituitary-ovary axis of youth murrah hybrid water buffalo.[Method] The immunohistochemistry SuperPicTureTM two step method was used to detect the distribution of GnRH in hypothalamus-pituitary-ovary axis of five femal murrah hybrid water buffalos.The association of GnRH 's distribution in hypothalamus, pituitary and ovary, and understand how the GnRH secrete releasing in hypothalamus, pituitary and ovary.[Result] The GnRH was first discovered in singulorum link of hypothalamus-pituitary-ovary axis of murrah hybrid water bufflo.The GnRH immunoreactive neurons were first discovered in every main nucleus of murrah hybrid water bufflo hypothalamus, especially distributed in supraoptic nucleus, preoptic nucleus, paraventricular nucleus most.The GnRH immunoactive productions were first discovered only in murrah hybrid water bufflo adenohypophysis for pituitary.The GnRH immunoactive productions were first discovered in the germinal epithelium cells, granulosa cells and lutein cells of murrah hybrid water bufflo.[Conclusion] The test results could provide morphological basis for the study of the GnRH's synthesis and mechanism of action, and could play reference and directions part in breeding murrah hybrid water bufflo.%[目的]研究促性腺激素释放激素(GnRH)在青年摩杂一代水牛下丘脑-垂体-卵巢轴的免疫组化定位.[方法]采用免疫组织化学SuperPicTureTM二步法检测5头青年摩杂一代水牛下丘脑、垂体和卵巢中GnRH的分布情况,研究GnRH在下丘脑、垂体及卵巢的分布上的联系,进而了解GnRH在下丘脑、垂体及卵巢三者之间分泌释放的途径.[结果]GnRH存在于青年摩杂一代水牛下丘脑-垂体-卵巢轴的各个环节.青年摩杂一代水牛下丘脑中各主要核团都有GnRH免疫阳性神经元的分布,尤其以视上核、视前核、室旁核分布较多.对于垂体,Gn

  11. The regulation and function of fibroblast growth factor 8 and its function during gonadotropin-releasing hormone neuron development

    Directory of Open Access Journals (Sweden)

    Wilson CJ Chung

    2016-09-01

    Full Text Available Over the last few years, numerous studies solidified the hypothesis that fibroblast growth factor (FGF signaling regulates neuroendocrine progenitor cell proliferation, fate-specification, and cell survival, and therefore is critical for the regulation and maintenance of homeostasis of the body. One important example that underscores the involvement of FGF signaling during neuroendocrine cell development is gonadotropin-releasing hormone (GnRH neuron ontogenesis. Indeed, transgenic mice with reduced olfactory placode (OP Fgf8 expression do not have GnRH neurons. This observation indicates the requirement of FGF8 signaling for the emergence of the gonadotropin-releasing hormone (GnRH neuronal system in the embryonic OP, the putative birth place of GnRH neurons. Mammalian reproductive success depends on the presence of GnRH neurons to stimulate gonadotropin secretion from the anterior pituitary, which activates gonadal steroidogenesis and gametogenesis. Together, these observations are critical for understanding the function of GnRH neurons and their control of the hypothalamus-pituitary-gonadal (HPG axis to maintain fertility. Taken together, these studies illustrate that GnRH neuron emergence, and hence HPG-function is vulnerable to genomic and molecular signals that abnormally modify Fgf8 expression in the developing mouse OP. In this short review, we focus on research that is aimed at unraveling how androgen, all-trans retinoic acid and epigenetic modifies control mouse OP Fgf8 transcription in the context of GnRH neuronal development, and mammalian reproductive success.

  12. Negative regulation of human growth hormone gene expression by insulin is dependent on hypoxia-inducible factor binding in primary non-tumor pituitary cells.

    Science.gov (United States)

    Vakili, Hana; Jin, Yan; Cattini, Peter A

    2012-09-28

    Insulin controls growth hormone (GH) production at multiple levels, including via a direct effect on pituitary somatotrophs. There are no data, however, on the regulation of the intact human (h) GH gene (hGH1) by insulin in non-tumor pituitary cells, but the proximal promoter region (nucleotides -496/+1) responds negatively to insulin in transfected pituitary tumor cells. A DNA-protein interaction was also induced by insulin at nucleotides -308/-235. Here, we confirmed the presence of a hypoxia-inducible factor 1 (HIF-1) binding site within these sequences (-264/-259) and investigated whether HIF-1 is associated with insulin regulation of "endogenous" hGH1. In the absence of primary human pituitary cells, transgenic mice expressing the intact hGH locus in a somatotroph-specific manner were generated. A significant and dose-dependent decrease in hGH and mouse GH RNA levels was detected in primary pituitary cell cultures from these mice with insulin treatment. Increasing HIF-1α availability with a hypoxia mimetic significantly decreased hGH RNA levels and was accompanied by recruitment of HIF-1α to the hGH1 promoter in situ as seen with insulin. Both inhibition of HIF-1 DNA binding by echinomycin and RNA interference of HIF-1α synthesis blunted the negative effect of insulin on hGH1 but not mGH. The insulin response is also sensitive to histone deacetylase inhibition/trichostatin A and associated with a decrease in H3/H4 hyperacetylation in the proximal hGH1 promoter region. These data are consistent with HIF-1-dependent down-regulation of hGH1 by insulin via chromatin remodeling specifically in the proximal promoter region.

  13. Evaluation of Hydro-alcoholic Extract of Peganum harmala on Pituitary-thyroid Hormones in Adult Male Rats

    Directory of Open Access Journals (Sweden)

    E HOssini

    2010-01-01

    Full Text Available Introduction & Objectives: Peganum harmala from the Jigo Phalluses family has compounds such as: alkaloid,saponine steroid and lignin which is used as a traditional medicine witht antibacterial, anti tumor, inhibition of MAO enzyme, and stimulation of the nerve system. It also serves as a modulator to endocrine activities. The aim of the present study was to evaluate the effect of the hydro-alcoholic extract of Peganum harmala on plasma levels of pituitary-thyroid’s hormones of adult rats. Materials & Methods: In this experimental study, which was conducted at Yasuj University of Medical sciences in 2009, 50 adult Mala rats with the approximate weight of 260+30 grams were divided into 5 groups: the control group, the sham group, and 3 experimental groups. The control group did not take any medicine. The sham group received 1 mL of distilled water daily for 17 consecutive days. The experimental groups took 90 mg/kg, 180mg/kg, or 270 mg/kg of Peganum harmala extract daily respectively for 17 consecutive days. In the 18th day, by collecting the blood samples of the animals, plasma level of TSH, T4, and T3 was measured using radioimmunoassay method. Collected data were analyzed using SPSS software. Results: This study revealed that the minimum and maximum dose of the Peganum harmala extract reduces the TSH level and average and maximum dose of the extract significantly reduces the level of T4 and T3 in rats. Conclusion: results of this study indicate that by further study the Peganum harmala extract might be used for treatment hyperthyroidism. However further study is needed to explore this concept.

  14. Estrogenic effects of the new opioid antagonist naltrexone-estrone azine on pituitary luteinizing hormone secretion in ovariectomized rats.

    Science.gov (United States)

    Armeanu, M C; van Dieten, J A; Kolb, V M; Schoemaker, J; de Koning, J

    1992-01-01

    The effect of the new opioid antagonist naltrexone-estrone azine (EH-NX) on pituitary luteinizing hormone (LH) secretion in the ovariectomized rat was studied. EH-NX is a hybrid between the steroid component estrone and the opioid antagonist naltrexone (NX). It is a potent and long-acting opioid antagonist in vitro and in vivo, but its effect upon in vivo LH secretion has not been tested before. The aims of the study were to investigate whether, unlike naltrexone, EH-NX can stimulate LH secretion without the need of additional estrogen pretreatment and whether EH-NX has peripheral estrogenic effects upon the uterine weight, when administered chronically to long-term ovariectomized rats. Female rats were injected subcutaneously with EH-NX 21 days after ovariectomy. The effects of EH-NX injections on LH secretion were compared to the effects of NX and estrone hydrazone (EH) alone, or in combination, with or without estradiol-benzoate (EB) pretreatment. Inhibition of LH secretion and uterine proliferation were observed in rats treated chronically with EH-NX in dosages of 0.250 mg/kg bw and higher. These effects were similar to those caused by EH and EB. In short-term OVX rats EH-NX appeared to act faster than EH. In contrast to NX, no stimulatory effect on LH secretion was seen with EH-NX in EB primed OVX rats. These results surprisingly demonstrate that EH-NX behaves like an estrogen and not like an opioid antagonist. The unexpected pharmacological profile of this new drug may open up doors for several medical applications.

  15. orlistat improves release of gut hormones increasing satiety in obese women

    Directory of Open Access Journals (Sweden)

    Teona Albertovna Shvangiradze

    2014-12-01

    Full Text Available Orlistat, which reduces fat absorption by inhibiting intestinal lipase is a registered drug for obesity pharmacotherapy. Meta-analyzes indicate various positive metabolic effects of orlistat, including improvements in glucose and lipid metabolism, lowering both systolic and diastolic blood pressure. It is assumed that orlistat can reduce postprandial satiety by inhibiting the release of intestinal hormones (incretins, especially glucagon-like peptide-1 (GLP-1. Impact analysis of the secretion of incretins, with prolonged use of orlistat was conducted. The aim of the study M.Olszanecka-Glinianowicz et al. was to evaluate the effect of 8 weeks of treatment with orlistat as part of a weight loss program for preprandialnye levels of peptide YY and GLP-1.

  16. Parathyroid hormone and calcitonin interactions in bone: Irradiation-induced inhibition of escape in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Krieger, N.S.; Tashjian, A.H. Jr.; Feldman, R.S.

    1982-01-01

    Calcitonin (CT) inhibits hormonally stimulated bone resorption only transiently in vitro. This phenomenon has been termed ''escape,'' but the mechanism for the effect is not understood. One possible explanation is that bone cell differentiation and recruitment of specific precursor cells, in response to stimulators of resorption, lead to the appearance of osteoclasts that are unresponsive to CT. To test this hypothesis, cell proliferation in neonatal mouse calvaria in organ culture was inhibited by irradiation from a cobalt-60 source. At a dose of 6000 R, (/sup 3/H)thymidine incorporation into intact calvaria was inhibited approximately 90%. Irradiation had no effect on the resorptive response to 0.1 U/ml parathyroid hormone (PTH). However, irradiation induced a dose-dependent inhibition of the escape response which was maximal at 6000 R. A dose of 6000 R did not affect the binding of /sup 125/I-salmon CT to calvaria and decreased PTH stimulation of cyclic AMP release from bone without affecting the cyclic AMP response to CT. Although irradiation caused a dose-dependent inhibition of DNA synthesis, the dose-response curves for that effect and inhibition of escape were not superimposable. A morphologic study of hormonally treated calvaria demonstrated that irradiation prevented the early increase in number of osteoclasts in PTH-treated calvaria that had been observed previously in unirradiated bones. Autoradiography showed that irradiation also prevented the PTH-stimulated recruitment of newly divided mononuclear cell precursors into osteoclasts. This may be correlated with the effect of irradiation to prevent the loss of responsiveness to CT in the presence of PTH.

  17. Combined Dexamethasone Suppression-Corticotropin-Releasing Hormone Stimulation Test in Studies of Depression, Alcoholism, and Suicidal Behavior

    Directory of Open Access Journals (Sweden)

    Leo Sher

    2006-01-01

    Full Text Available The hypothalamic-pituitary-adrenal (HPA axis controls the secretion of corticotropin-releasing hormone (CRH, corticotropin (adrenocorticotropic hormone, ACTH, and cortisol. The dexamethasone suppression test (DST is the most frequently used test to assess HPA system function in psychiatric disorders. Patients who have failed to suppress plasma cortisol secretion, i.e., who escape from the suppressive effect of dexamethasone, have a blunted glucocorticoid receptor response. After CRH became available for clinical studies, the DST was combined with CRH administration. The resulting combined dexamethasone suppression-corticotropin-releasing hormone stimulation (DST–CRH test proved to be more sensitive in detecting HPA system changes than the DST. There is a growing interest in the use of the DEX-CRH test for psychiatric research. The DEX-CRH test has been used to study different psychiatric conditions. Major depression, alcoholism, and suicidal behavior are public health problems around the world. Considerable evidence suggests that HPA dysregulation is involved in the pathogenesis of depressive disorders, alcoholism, and suicidal behavior. Over the past 2 decades, there has been a shift from viewing excessive HPA activity in depression as an epiphenomenon to its having specific effects on symptom formation and cognition. The study of HPA function in depression, alcoholism, and suicidal behavior may yield new understanding of the pathophysiolgy of these conditions, and suggest new approaches for therapeutic interventions. The combined DEX-CRH test may become a useful neuroendocrinological tool for evaluating psychiatric patients.

  18. A Recessive Mutation Resulting in a Disabling Amino Acid Substitution (T194R) in the LHX3 Homeodomain Causes Combined Pituitary Hormone Deficiency

    OpenAIRE

    Bechtold-Dalla Pozza, Susanne; Hiedl, Stefan; Roeb, Julia; Lohse, Peter; Malik, Raleigh E.; Park, Soyoung; Duran-Prado, Mario; Rhodes, Simon J.

    2012-01-01

    Background/Aims: Recessive mutations in the LHX3 homeodomain transcription factor gene are associated with developmental disorders affecting the pituitary and nervous system. We describe pediatric patients with combined pituitary hormone deficiency (CPHD) who harbor a novel mutation in LHX3. Methods: Two female siblings from related parents were examined. Both patients had neonatal complications. The index patient had CPHD featuring deficiencies of GH, LH, FSH, PRL, and TSH, with later onset ...

  19. Gonadotropin releasing hormone in the primitive vertebrate family Myxinidae: reproductive neuroanatomy and evolutionary aspects.

    Science.gov (United States)

    Sills, Eric Scott; Palermo, Gianpiero D

    2013-01-01

    The family Myxinidae embraces all hagfish species, and occupies an evolutionary niche intermediate between ancestral vertebrates and the gnathostomes (jawed vertebrates). Gonadotropin releasing hormone (GnRH) modulates neuroendocrine activity in vertebrates and works in the context of the hypothalamic-pituitary (H-P) axis. The appearance of this neuroendocrine axis marks one of the most crucial developmental achievements in vertebrate evolution, because it enabled further diversification in general growth, metabolism, osmoregulation and reproduction as jawed vertebrates evolved. GnRH studies in hagfish draw attention because such work may be considered as providing proxy data for similar investigations conducted upon long extinct species. Indeed, the fossil record reveals little anatomical difference between those hagfish living 300 million years ago and their modern descendants. Accordingly, the hagfish can offer important evolutionary lessons as they have some highly unusual characteristics not seen in any other vertebrate; they retain many representative features of an ancestral state from which all vertebrates originated. Indeed, because central control of reproduction is perhaps the most basic function of the vertebrate H-P axis, and given the importance of GnRH in this network, research on GnRH in hagfish can help elucidate the early evolution of the H-P system itself. Like all vertebrates, hagfish have a functional hypothalamic area and a pituitary gland, constituting a basic H-P axis. But what role does GnRH play in the reproductive system of this "living fossil"? How can understanding GnRH in hagfish help advance the knowledge of vertebrate neuroendocrinology? Here, information on neuroendocrine function and the role of GnRH specifically in this very basal vertebrate is reviewed.

  20. Thyroid hormone and the heart.

    Science.gov (United States)

    Moolman, J A

    2002-01-01

    Thyroid hormone has important cardiovascular effects, and abnormalities of its production cause cardiovascular morbidity. The role of both excessive and insufficient thyroid hormone production in the pathogenesis of clinical cardiac diseases can be deduced from thyroid hormone-induced molecular changes. Thyroid hormone regulates the expression of myocardial genes regulating the handling of calcium, which affects both systolic and diastolic myocardial function. Thyroid hormone also has indirect and direct effects on peripheral vascular smooth muscle tone, and alters the coupling of the left ventricle and arterial system. Excessive production of thyroid hormone results in an increased cardiac output as well as increased cardiac work efficiency, but reduced cardiac reserve. Amiodarone therapy for cardiac rhythm can cause both hyper- and hypothyroidism. Amiodarone-induced thyrotoxicosis (AIT) can be due to either excessive thyroid hormone production (type I AIT) or thyroid hormone release due to an inflammatory condition (type II AIT). Classification of AIT is helpful in guiding therapy. Amiodarone causes changes in the thyroid function tests of euthyroid patients on therapy--it inhibits the conversion of T(4) and T(3), which results in decreased T(3) and slightly increased T(4) serum levels in euthyroid patients. Baseline thyroid functions should therefore be determined before starting amiodarone therapy, and at 6-monthly intervals thereafter.

  1. Growth hormone releasing hormone (GHRH) signaling modulates intermittent hypoxia-induced oxidative stress and cognitive deficits in mouse.

    Science.gov (United States)

    Nair, Deepti; Ramesh, Vijay; Li, Richard C; Schally, Andrew V; Gozal, David

    2013-11-01

    Intermittent hypoxia (IH) during sleep, such as occurs in obstructive sleep apnea (OSA), leads to degenerative changes in the hippocampus, and is associated with spatial learning deficits in adult mice. In both patients and murine models of OSA, the disease is associated with suppression of growth hormone (GH) secretion, which is actively involved in the growth, development, and function of the central nervous system (CNS). Recent work showed that exogenous GH therapy attenuated neurocognitive deficits elicited by IH during sleep in rats. Here, we show that administration of the Growth Hormone Releasing Hormone (GHRH) agonist JI-34 attenuates IH-induced neurocognitive deficits, anxiety, and depression in mice along with reduction in oxidative stress markers such as MDA and 8-hydroxydeoxyguanosine, and increases in hypoxia inducible factor-1α DNA binding and up-regulation of insulin growth factor-1 and erythropoietin expression. In contrast, treatment with a GHRH antagonist (MIA-602) during intermittent hypoxia did not affect any of the IH-induced deleterious effects in mice. Thus, exogenous GHRH administered as the formulation of a GHRH agonist may provide a viable therapeutic intervention to protect IH-vulnerable brain regions from OSA-associated neurocognitive dysfunction. Sleep apnea, characterized by chronic intermittent hypoxia (IH), is associated with substantial cognitive and behavioral deficits. Here, we show that administration of a GHRH agonist (JI-34) reduces oxidative stress, increases both HIF-1α nuclear binding and downstream expression of IGF1 and erythropoietin (EPO) in hippocampus and cortex, and markedly attenuates water maze performance deficits in mice exposed to intermittent hypoxia during sleep.

  2. Differential involvement of signaling pathways in the regulation of growth hormone release by somatostatin and growth hormone-releasing hormone in orange-spotted grouper (Epinephelus coioides).

    Science.gov (United States)

    Wang, Bin; Qin, Chaobin; Zhang, Cong; Jia, Jirong; Sun, Caiyun; Li, Wensheng

    2014-02-15

    Somatostatin is the most effective inhibitor of GH release, and GHRH was recently identified as one of the primary GH-releasing factors in teleosts. In this study, we analyzed the possible intracellular transduction pathways that are involved in the mechanisms induced by SRIF and GHRH to regulate GH release. Using a pharmacological approach, the blockade of the PLC/IP/PKC pathway reversed the SRIF-induced inhibition of GH release but did not affect the GHRH-induced stimulation of GH release. Furthermore, SRIF reduced the GH release induced by two PKC activators. Inhibitors of the AC/cAMP/PKA pathway reversed both the SRIF- and GHRH-induced effects on GH release. Moreover, the GH release evoked by forskolin and 8-Br-cAMP were completely abolished by SRIF. The blockade of the NOS/NO pathway attenuated the GHRH-induced GH release but had minimal effects on the inhibitory actions of SRIF. In addition, inhibitors of the sGC/cGMP pathway did not modify the SRIF- or GHRH-induced regulation of GH release. Taken together, these findings indicate that the SRIF-induced inhibition of GH release is mediated by both the PLC/IP/PKC and the AC/cAMP/PKA pathways and not by the NOS/NO/sGC/cGMP pathway. In contrast, the GHRH-induced stimulation of GH secretion is mediated by both the AC/cAMP/PKA and the NOS/NO pathways and is independent of the sGC/cGMP pathway and the PLC/IP/PKC system.

  3. Inhibition of somatotroph growth and growth hormone biosynthesis by activin in vitro

    DEFF Research Database (Denmark)

    Billestrup, Nils; González-Manchón, C; Potter, E

    1990-01-01

    ]methionine-labeled cells, could be observed after 24 h of activin treatment, and maximal (70%) inhibition of GH biosynthesis was observed after 3 days. Activin inhibited basal as well as GH-releasing factor (GRF)-, glucocorticoid-, and thyroid hormone-stimulated GH biosynthesis. Inhibin, which is known to reverse...... the effect of activin on FSH secretion, did not reverse the effect of activin on GH biosynthesis. Treatment of somatotrophs with activin for 3 days completely inhibited the growth-promoting effect of GRF on somatotrophs. However, no effect of activin on GRF-stimulated expression of the c-fos protooncogene...... was observed. These data demonstrate that activin, in addition to its stimulatory effect on FSH secretion, is able to inhibit both expression of GH and growth of somatotropic cells....

  4. Primary hypothyroidism mimicking a pituitary macroadenoma: regression after thyroid hormone replacement therapy

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Ki Seong; Kim, Jong Moon; Kim, Tae Young [Wonkwang University School of Medicine, Department of Neurosurgery, Iksan (Korea); See-Sung, Choi [Wonkwang University School of Medicine, Department of Radiology, Iksan (Korea); Kim, Jong Duck [Wonkwang University School of Medicine, Department of Pediatrics, Iksan (Korea)

    2009-02-15

    We report a 9-year-old girl with pituitary hyperplasia due to primary hypothyroidism. She presented with growth arrest, abnormal thyroid function studies, and a pituitary mass on MRI. With thyroxine therapy, the pituitary mass regressed and her symptoms resolved. Primary hypothyroidism should be considered in the differential diagnosis of solid mass lesions of the pituitary gland. (orig.)

  5. Influence of ascorbic acid on in vivo amidation of alpha-melanocyte stimulating hormone in guinea pig pituitary

    DEFF Research Database (Denmark)

    Fenger, M; Hilsted, L

    1988-01-01

    The effect of ascorbic acid depletion on the amidation of alphamelanocyte stimulating hormone (alpha MSH) was studied in vivo in guinea pig pituitary. After four weeks, the concentration of ascorbic acid was 1.20 +/- 0.11 mumol/g tissue (mean +/- SD) in the pituitary and 0.34 +/- 0.07 mumol....../g tissue in the cerebral cortex from the depleted animals versus 7.58 +/- 0.08 and 1.51 +/- 0.32 mumol/g tissue, respectively, in the control animals. In the pituitaries from the animals depleted of ascorbate (N = 4), the relative amount of alpha MSH was reduced to approximately half the values obtained......-39) immunoreactivity was observed in the depleted guinea pigs. Gel chromatography and reversed-phase high-performance luquid chromatography showed that the alpha MSH and ACTH (1-14) immunoreactivity was of low molecular weight and partly mono- or diacetylated. Depletion of ascorbic acid had no influence on the degree...

  6. DNA methylation of pituitary growth hormone is involved in male growth superiority of Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Zhong, Huan; Xiao, Jun; Chen, Wenzhi; Zhou, Yi; Tang, Zhanyang; Guo, Zhongbao; Luo, Yongju; Lin, Zhengbao; Gan, Xi; Zhang, Ming

    2014-05-01

    Growth hormone (GH) and its receptors are critical regulators of somatic growth and metabolism. It has been shown in mammals that the methylation of cytosines within the GH promoter plays a key role in regulating transcripts expression. In the present study, the GH, GHR1 and GHR2 proximal promoters were identified and the methylation levels of these genes in corresponding tissues were assayed. The results suggested that significant arising of GH putative promoter methylation levels in pituitary was observed in females compared with males. However, no such sex-specific changes were found in GHR1 and GHR2 promoters. The GH mRNA expression also was influenced by GH promoter methylation levels in pituitary, which resulted in the higher growth rate of Nile tilapia males. Meanwhile, the methylation levels of GH putative promoter were negatively correlated with growth rate as well as mRNA expression of GH. Furthermore, the methylation of specific E-Box CpG site is also negatively related to the mRNA expression of GH in pituitary. Taken together, our data provide an epigenetic mechanism of explicating the sex duality in phenotypic plasticity of growth rate in male and female of Nile tilapia.

  7. Human chorionic somatomammotropin and growth hormone gene expression in rat pituitary tumor cells is dependent on proximal promoter sequences

    Energy Technology Data Exchange (ETDEWEB)

    Nachtigal, M.W.; Nickel, B.E.; Klassen, M.E.; Cattini, P.A. (Univ. of Manitoba, Winnipeg (Canada)); Zhang, Wengang; Eberhardt, N.L. (Univ. of California, San Francisco (USA))

    1989-06-12

    Human placental chorionic somatomammotropin (hCS-A or hCS-B) and pituitary growth hormone (hGH-N) are related by structure and function. The hCS-A gene is expressed in rat pituitary tumor (GC) cells after gene transfer. Deletion of hCS-A 5{prime}-flanking DNA reveals repressor activity upstream of nucleotide {minus}132, and a region essential for expression in GC cells between nucleotides {minus}94 and {minus}61. The sequences in this region differ from the equivalent hGH-N gene DNA by one nucleotide, and include the binding site for a pituitary-specific factor (GHF-1), required for hGH-N expression in GC cells. Exchange of hGH-N with hCS-A gene DNA in this region maintains expression in GC cells. By contrast, modification of these sequences blocks expression. These data indicate that proximal promoter sequences, equivalent to those bound by GHF-1 on the hGH-N gene, are required for hCS-A expression in GC cells.

  8. Interaction of growth hormone overexpression and nutritional status on pituitary gland clock gene expression in coho salmon, Oncorhynchus kisutch.

    Science.gov (United States)

    Kim, Jin-Hyoung; White, Samantha L; Devlin, Robert H

    2015-02-01

    Clock genes are involved in generating a circadian rhythm that is integrated with the metabolic state of an organism and information from the environment. Growth hormone (GH) transgenic coho salmon, Oncorhynchus kisutch, show a large increase in growth rate, but also attenuated seasonal growth modulations, modified timing of physiological transformations (e.g. smoltification) and disruptions in pituitary gene expression compared with wild-type salmon. In several fishes, circadian rhythm gene expression has been found to oscillate in the suprachiasmatic nucleus of the hypothalamus, as well as in multiple peripheral tissues, but this control system has not been examined in the pituitary gland nor has the effect of transgenic growth modification been examined. Thus, the daily expression of 10 core clock genes has been examined in pituitary glands of GH transgenic (T) and wild-type coho salmon (NT) entrained on a regular photocycle (12L: 12D) and provided either with scheduled feeding or had food withheld for 60 h. Most clock genes in both genotypes showed oscillating patterns of mRNA levels with light and dark cycles. However, T showed different amplitudes and patterns of expression compared with wild salmon, both in fed and starved conditions. The results from this study indicate that constitutive expression of GH is associated with changes in clock gene regulation, which may play a role in the disrupted behavioural and physiological phenotypes observed in growth-modified transgenic strains.

  9. Modulation of Sleep Homeostasis by Corticotropin Releasing Hormone in REM Sleep-Deprived Rats

    Directory of Open Access Journals (Sweden)

    Ricardo Borges Machado

    2010-01-01

    Full Text Available Studies have shown that sleep recovery following different protocols of forced waking varies according to the level of stress inherent to each method. Sleep deprivation activates the hypothalamic-pituitary-adrenal axis and increased corticotropin-releasing hormone (CRH impairs sleep. The purpose of the present study was to evaluate how manipulations of the CRH system during the sleep deprivation period interferes with subsequent sleep rebound. Throughout 96 hours of sleep deprivation, separate groups of rats were treated i.c.v. with vehicle, CRH or with alphahelical CRH9−41, a CRH receptor blocker, twice/day, at 07:00 h and 19:00 h. Both treatments impaired sleep homeostasis, especially in regards to length of rapid eye movement sleep (REM and theta/delta ratio and induced a later decrease in NREM and REM sleep and increased waking bouts. These changes suggest that activation of the CRH system impact negatively on the homeostatic sleep response to prolonged forced waking. These results indicate that indeed, activation of the HPA axis—at least at the hypothalamic level—is capable to reduce the sleep rebound induced by sleep deprivation.

  10. Correlation of expression of preprothyrotropin-releasing hormone and receptor with rat testis development

    Institute of Scientific and Technical Information of China (English)

    李臻; 张远强; 刘新平; 许若军

    2002-01-01

    Objective To investigate the expression regulation of thyrotrophin-releasing hormone (TRH) and TRH receptor (TRH-R), and their role in the development of rat testis.Methods Oligonucleotide primers were designed from the sequences of rat hypothalamus prepro TRH (ppTRH) and pituitary TRH-R cDNA for reverse transcription polymerase chain reaction (RT-PCR). Specific fragments of ppTRH and TRH-R cDNA were cloned and sequenced. Expression plasmids containing ppTRH and TRH-R genes were then constructed, and expression was found in E.coli DH5-α. ppTRH and TRH-R mRNA in the testis was quantitated in RNA samples prepared from rats at different developmental stages by real time quantitative RT-PCR.Results The quantitative analyses demonstrated that no ppTRH and TRH mRNA could be detected at the earliest stage (day 8). ppTRH and TRH mRNA signals were detected on day 15 and increased progressively on days 20, 35, 60 and 90. Conclusion Our results suggest that rat testis could specifically express TRH and TRH-R, and the transcriptions of ppTRH and TRH-R genes in the rat testis were development-dependent. The acquirement of expressed products for ppTRH and TRH-R can be used for further research on the physiological significance of TRH and TRH-R expression in rat testis.

  11. Genetics Home Reference: isolated growth hormone deficiency

    Science.gov (United States)

    ... Genetic Testing (4 links) Genetic Testing Registry: Ateleiotic dwarfism Genetic Testing Registry: Autosomal dominant isolated somatotropin deficiency ... in my area? Other Names for This Condition dwarfism, growth hormone deficiency dwarfism, pituitary growth hormone deficiency ...

  12. Consensus statement on the use of gonadotropin-releasing hormone analogs in children

    DEFF Research Database (Denmark)

    Carel, Jean-Claude; Eugster, Erica A; Rogol, Alan;

    2009-01-01

    OBJECTIVE: Gonadotropin-releasing hormone analogs revolutionized the treatment of central precocious puberty. However, questions remain regarding their optimal use in central precocious puberty and other conditions. The Lawson Wilkins Pediatric Endocrine Society and the European Society...... for Pediatric Endocrinology convened a consensus conference to review the clinical use of gonadotropin-releasing hormone analogs in children and adolescents. PARTICIPANTS: When selecting the 30 participants, consideration was given to equal representation from North America (United States and Canada) and Europe...... assembly for final review. If consensus could not be reached, conclusions were based on majority vote. All participants approved the final statement. CONCLUSIONS: The efficacy of gonadotropin-releasing hormone analogs in increasing adult height is undisputed only in early-onset (girls

  13. MULTIPLE STABLE PERIODIC SOLUTIONS IN A MODEL FOR THE HORMONAL REGULATION OF THE MENSTRUAL CYCLE

    Science.gov (United States)

    ABSTRACTThe pituitary hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and the ovarian hormones, estradiol (E2), progesterone (P4), and inhibin (Ih), are five hormones important for the regulation and maintenance of the human menstrual cycle. The...

  14. MULTIPLE STABLE PERIODIC SOLUTIONS IN A MODEL FOR THE HORMONAL REGULATION OF THE MENSTRUAL CYCLE

    Science.gov (United States)

    ABSTRACTThe pituitary hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and the ovarian hormones, estradiol (E2), progesterone (P4), and inhibin (Ih), are five hormones important for the regulation and maintenance of the human menstrual cycle. The...

  15. Effects of growth hormone-releasing hormone on visceral fat, metabolic, and cardiovascular indices in human studies.

    Science.gov (United States)

    Stanley, Takara L; Grinspoon, Steven K

    2015-04-01

    Increased visceral adipose tissue (VAT) is associated with reductions in endogenous GH secretion, possibly as a result of hyperinsulinemia, increased circulating free fatty acid, increased somatostatin tone, and reduced ghrelin. Reduced GH may, in turn, further exacerbate visceral fat accumulation because of decreased hormone-sensitive lipolysis in this depot. Data from multiple populations demonstrate that both reduced GH and increased VAT appear to contribute independently to dyslipidemia, increased systemic inflammation, and increased cardiovascular risk. The reductions in GH in states of visceral adiposity are characterized by reduced basal and pulsatile GH secretion with intact pulse frequency. Treatment with GH-releasing hormone (GHRH) provides a means to reverse these abnormalities, increasing endogenous basal and pulsatile GH secretion without altering pulse frequency. This review describes data from HIV-infected individuals and individuals with general obesity showing that treatment with GHRH significantly reduces visceral fat, ameliorates dyslipidemia, and reduces markers of cardiovascular risk. Further research is needed regarding the long-term efficacy and safety of this treatment modality. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Structural and functional divergence of growth hormone-releasing hormone receptors in early sarcopterygians: lungfish and Xenopus.

    Directory of Open Access Journals (Sweden)

    Janice K V Tam

    Full Text Available The evolutionary trajectories of growth hormone-releasing hormone (GHRH receptor remain enigmatic since the discovery of physiologically functional GHRH-GHRH receptor (GHRHR in non-mammalian vertebrates in 2007. Interestingly, subsequent studies have described the identification of a GHRHR(2 in chicken in addition to the GHRHR and the closely related paralogous receptor, PACAP-related peptide (PRP receptor (PRPR. In this article, we provide information, for the first time, on the GHRHR in sarcopterygian fish and amphibians by the cloning and characterization of GHRHRs from lungfish (P. dolloi and X. laevis. Sequence alignment and phylogenetic analyses demonstrated structural resemblance of lungfish GHRHR to their mammalian orthologs, while the X. laevis GHRHR showed the highest homology to GHRHR(2 in zebrafish and chicken. Functionally, lungfish GHRHR displayed high affinity towards GHRH in triggering intracellular cAMP and calcium accumulation, while X. laevis GHRHR(2 was able to react with both endogenous GHRH and PRP. Tissue distribution analyses showed that both lungfish GHRHR and X. laevis GHRHR(2 had the highest expression in brain, and interestingly, X. laevis(GHRHR2 also had high abundance in the reproductive organs. These findings, together with previous reports, suggest that early in the Sarcopterygii lineage, GHRHR and PRPR have already established diverged and specific affinities towards their cognate ligands. GHRHR(2, which has only been found in xenopus, zebrafish and chicken hitherto, accommodates both GHRH and PRP.

  17. Role of growth hormone-releasing hormone in sleep and growth impairments induced by upper airway obstruction in rats.

    Science.gov (United States)

    Tarasiuk, A; Berdugo-Boura, N; Troib, A; Segev, Y

    2011-10-01

    Upper airway obstruction (UAO) can lead to abnormal growth hormone (GH) homeostasis and growth retardation but the mechanisms are unclear. We explored the effect of UAO on hypothalamic GH-releasing hormone (GHRH), which has a role in both sleep and GH regulation. The tracheae of 22-day-old rats were narrowed; UAO and sham-operated animals were sacrificed 16 days post-surgery. To stimulate slow-wave sleep (SWS) and GH secretion, rats were treated with ritanserin (5-HT(2) receptor antagonist). Sleep was measured with a telemetric system. Hypothalamic GHRH, hypothalamic GHRH receptor (GHRHR) and GH receptor, and orexin were analysed using ELISA, real-time PCR and Western blot. UAO decreased hypothalamic GHRH, GHRHR and GH receptor levels, while orexin mRNA increased (psleep and slow-wave activity was reduced (pgrowth impairment (pgrowth retardation in UAO is associated with a reduction in hypothalamic GHRH content. Our findings show that abnormalities in the GHRH/GH axis underlie both growth retardation and SWS-disorder UAO.

  18. Extracellular signal-regulated kinase mediates gonadotropin subunit gene expression and LH release responses to endogenous gonadotropin-releasing hormones in goldfish.

    Science.gov (United States)

    Klausen, Christian; Booth, Morgan; Habibi, Hamid R; Chang, John P

    2008-08-01

    The possible involvement of extracellular signal-regulated kinase (ERK) in mediating the stimulatory actions of two endogenous goldfish gonadotropin-releasing hormones (salmon (s)GnRH and chicken (c)GnRH-II) on gonadotropin synthesis and secretion was examined. Western blot analysis revealed the presence of ERK and phosphorylated (p)ERK in goldfish brain, pituitary, liver, ovary, testis and muscle tissue extracts, as well as extracts of dispersed goldfish pituitary cells and HeLa cells. Interestingly, a third ERK-like immunoreactive band of higher molecular mass was detected in goldfish tissue and pituitary cell extracts in addition to the ERK1-p44- and ERK2-p42-like immunoreactive bands. Incubation of primary cultures of goldfish pituitary cells with either a PKC-activating 4beta-phorbol ester (TPA) or a synthetic diacylglycerol, but not a 4alpha-phorbol ester, elevated the ratio of pERK/total (t)ERK for all three ERK isoforms. The stimulatory effects of TPA were attenuated by the PKC inhibitor GF109203X and the MEK inhibitor PD98059. sGnRH and cGnRH-II also elevated the ratio of pERK/tERK for all three ERK isoforms, in a time-, dose- and PD98059-dependent manner. In addition, treatment with PD98059 reduced the sGnRH-, cGnRH-II- and TPA-induced increases in gonadotropin subunit mRNA levels in Northern blot studies and sGnRH- and cGnRH-II-elicited LH release in cell column perifusion studies with goldfish pituitary cells. These results indicate that GnRH and PKC can activate ERK through MEK in goldfish pituitary cells. More importantly, the present study suggests that GnRH-induced gonadotropin subunit gene expression and LH release involve MEK/ERK signaling in goldfish.

  19. Stress hormone release is a key component of the metabolic response to lipopolysaccharide (LPS): studies in hypopituitary and healthy subjects

    DEFF Research Database (Denmark)

    Bach, Ermina; Møller, Andreas Buch; Jørgensen, Jens Otto Lunde

    2016-01-01

    of stress hormones. We compared the metabolic effects of LPS in hypopituitary patients (HP) (in the absence of pituitary stress hormone responses) and healthy control subjects (CTR) (with normal pituitary stress hormone responses). DESIGN: Single blind randomized. METHODS: We compared effects of LPS...... but not in HP. LPS increased whole body palmitate fluxes (3-fold) and decreased palmitate specific activity 40-50 % in CTR, but not in HP. G(0)/G(1) Switch Gene 2 (G0S2 - an inhibitor of lipolysis) adipose tissue mRNA was decreased in CTR. LPS increased phenylalanine fluxes significantly more in CTR, whereas...... on glucose, protein and lipid metabolism in eight HP and eight matched CTR twice during 4-h basal and 2-h hyperinsulinemic euglycemic clamp conditions with muscle biopsies and fat biopsies in each period during infusion with saline or LPS. RESULTS: LPS increased cortisol and growth hormone (GH) levels in CTR...

  20. Comparison of response to 2-years’ growth hormone treatment in children with isolated growth hormone deficiency, born small for gestational age, idiopathic short stature, or multiple pituitary hormone deficiency: combined results from two large observational studies

    Directory of Open Access Journals (Sweden)

    Lee Peter A

    2012-07-01

    Full Text Available Abstract Background Few studies have compared the response to growth hormone (GH treatment between indications such as isolated growth hormone deficiency (IGHD, born small for gestational age (SGA, idiopathic short stature (ISS, and multiple pituitary hormone deficiency (MPHD. The aim of this analysis of data, collected from two large ongoing observational outcome studies, was to evaluate growth and insulin-like growth factor-I (IGF-I response data for children of short stature with IGHD, MPHD, SGA, or ISS following two years of treatment with the recombinant GH product Norditropin® (Novo Nordisk A/S, Bagsværd, Denmark. Methods Analysis of auxologic data from two ongoing prospective observational studies, NordiNet® International Outcomes Study (NordiNet® IOS and NovoNet®/American Norditropin® Studies: Web-enabled Research (ANSWER Program®. Results 4,582 children aged p = 0.047; p  0.001 vs. IGHD, respectively. Height gain was comparable between IGHD and MPHD. In pre-pubertal children vs. total population, height SDS change after two years was: IGHD, +1.24 vs. +0.97; SGA, +1.17 vs. +1.03; ISS, +1.04 vs. +0.84; and MPHD, +1.16 vs. +0.99 (all p  Conclusions After two years’ GH treatment, change in height SDS was greater in SGA and less in ISS, compared with IGHD; the discrepancy in responses may be due to the disease nature or confounders (i.e. age. Height SDS increase was greatest in pre-pubertal children, supporting early treatment initiation to optimize growth outcomes.

  1. Prevalence of pituitary hormone dysfunction, metabolic syndrome, and impaired quality of life in retired professional football players: a prospective study.

    Science.gov (United States)

    Kelly, Daniel F; Chaloner, Charlene; Evans, Diana; Mathews, Amy; Cohan, Pejman; Wang, Christina; Swerdloff, Ronald; Sim, Myung-Shin; Lee, Jihey; Wright, Mathew J; Kernan, Claudia; Barkhoudarian, Garni; Yuen, Kevin C J; Guskiewicz, Kevin

    2014-07-01

    Hypopituitarism is common after moderate and severe traumatic brain injury (TBI). Herein, we address the association between mild TBI (mTBI) and pituitary and metabolic function in retired football players. Retirees 30-65 years of age, with one or more years of National Football League (NFL) play and poor quality of life (QoL) based on Short Form 36 (SF-36) Mental Component Score (MCS) were prospectively enrolled. Pituitary hormonal and metabolic syndrome (MetS) testing was performed. Using a glucagon stimulation test, growth hormone deficiency (GHD) was defined with a standard cut point of 3 ng/mL and with a more stringent body mass index (BMI)-adjusted cut point. Subjects with and without hormonal deficiency (HD) were compared in terms of QoL, International Index of Erectile Function (IIEF) scores, metabolic parameters, and football career data. Of 74 subjects, 6 were excluded because of significant non-football-related TBIs. Of the remaining 68 subjects (mean age, 47.3±10.2 years; median NFL years, 5; median NFL concussions, 3; mean BMI, 33.8±6.0), 28 (41.2%) were GHD using a peak GH cutoff of <3 ng/mL. However, with a BMI-adjusted definition of GHD, 13 of 68 (19.1%) were GHD. Using this BMI-adjusted definition, overall HD was found in 16 (23.5%) subjects: 10 (14.7%) with isolated GHD; 3 (4.4%) with isolated hypogonadism; and 3 (4.4%) with both GHD and hypogonadism. Subjects with HD had lower mean scores on the IIEF survey (p=0.016) and trended toward lower scores on the SF-36 MCS (p=0.113). MetS was present in 50% of subjects, including 5 of 6 (83%) with hypogonadism, and 29 of 62 (46.8%) without hypogonadism (p=0.087). Age, BMI, median years in NFL, games played, number of concussions, and acknowledged use of performance-enhancing steroids were similar between HD and non-HD groups. In summary, in this cohort of retired NFL players with poor QoL, 23.5% had HD, including 19% with GHD (using a BMI-adjusted definition), 9% with hypogonadism, and 50% had Met

  2. Effects of ionizing radiation and pretreatment with (D-Leu6,des-Gly10) luteinizing hormone-releasing hormone ethylamide on developing rat ovarian follicles

    Energy Technology Data Exchange (ETDEWEB)

    Jarrell, J.; YoungLai, E.V.; McMahon, A.; Barr, R.; O' Connell, G.; Belbeck, L.

    1987-10-01

    To assess the effects of a gonadotropin-releasing hormone agonist, (D-Leu6,des-Gly10) luteinizing hormone-releasing hormone ethylamide, in ameliorating the damage caused by ionizing radiation, gonadotropin-releasing hormone agonist was administered to rats from day 22 to 37 of age in doses of 0.1, 0.4, and 1.0 microgram/day or vehicle and the rats were sacrificed on day 44 of age. There were no effects on estradiol, progesterone, luteinizing, or follicle-stimulating hormone, nor an effect on ovarian follicle numbers or development. In separate experiments, rats treated with gonadotropin-releasing hormone agonist in doses of 0.04, 0.1, 0.4, or 1.0 microgram/day were either irradiated or sham irradiated on day 30 and all groups sacrificed on day 44 of age. Irradiation produced a reduction in ovarian weight and an increase in ovarian follicular atresia. Pretreatment with the agonist prevented the reduction in ovarian weight and numbers of primordial and preantral follicles but not healthy or atretic antral follicles. Such putative radioprotection should be tested on actual reproductive performance.

  3. Central administration of growth hormone-releasing hormone triggers downstream movement and schooling behavior of chum salmon (Oncorhynchus keta) fry in an artificial stream.

    Science.gov (United States)

    Ojima, Daisuke; Iwata, Munehico

    2009-03-01

    Anadromous salmonids migrate downstream to the ocean (downstream migration). The neuroendocrine mechanism of triggering the onset of downstream migration is not well known. We investigated the effects of 14 chemicals, including neuropeptides, pineal hormones, neurotransmitters, and neuromodulators (growth hormone-releasing hormone: GHRH, thyrotropin-releasing hormone, corticotropin-releasing hormone: CRH, gonadotropin-releasing hormone, melatonin, N-acetyl serotonin, serotonin, beta-endorphin, enkephalin, dopamine, norepinephrine, epinephrine, acetylcholine, and histamine) on the onset of downstream migration in chum salmon (Oncorhynchus keta) fry. We defined downstream migration as a downstream movement (negative rheotaxis) with schooling behavior and counted the number of downstream movements and school size in experimental circulation tanks. An intracerebroventricular injection of GHRH, CRH, melatonin, N-acetyl serotonin, or serotonin stimulated the number of downstream movements. However, GHRH was the only chemical that also stimulated an increase in schooling behavior. These results suggest that CRH, melatonin, N-acetyl serotonin, and serotonin are involved in the stimulation of downstream movement in chum salmon, while GHRH stimulates both downstream movement and schooling behavior.

  4. Anophthalmia, hearing loss, abnormal pituitary development and response to growth hormone therapy in three children with microdeletions of 14q22q23.

    Science.gov (United States)

    Brisset, Sophie; Slamova, Zuzana; Dusatkova, Petra; Briand-Suleau, Audrey; Milcent, Karen; Metay, Corinne; Simandlova, Martina; Sumnik, Zdenek; Tosca, Lucie; Goossens, Michel; Labrune, Philippe; Zemankova, Elsa; Lebl, Jan; Tachdjian, Gerard; Sedlacek, Zdenek

    2014-02-28

    Microdeletions of 14q22q23 have been associated with eye abnormalities and pituitary defects. Other phenotypic features in deletion carriers including hearing loss and response to growth hormone therapy are less well recognized. We studied genotype and phenotype of three newly identified children with 14q22q23 deletions, two girls and one boy with bilateral anophthalmia, and compared them with previously published deletion patients and individuals with intragenic defects in genes residing in the region. The three deletions were de novo and ranged in size between 5.8 and 8.9 Mb. All three children lacked one copy of the OTX2 gene and in one of them the deletion involved also the BMP4 gene. All three patients presented partial conductive hearing loss which tended to improve with age. Analysis of endocrine and growth phenotypes showed undetectable anterior pituitary, growth hormone deficiency and progressive growth retardation in all three patients. Growth hormone therapy led to partial catch-up growth in two of the three patients but just prevented further height loss in the third. The pituitary hypoplasia, growth hormone deficiency and growth retardation associated with 14q22q23 microdeletions are very remarkable, and the latter appears to have an atypical response to growth hormone therapy in some of the cases.

  5. TRH (thyrotropin-releasing hormone) and BAY K 8644 synergistically stimulate prolactin release but not sup 45 Ca sup 2+ uptake

    Energy Technology Data Exchange (ETDEWEB)

    Pachter, J.A.; Law, G.J.; Dannies, P.S. (Yale Univ. School of Medicine, New Haven, CT (USA))

    1988-11-01

    Thyrotropin-releasing hormone (TRH) and the Ca{sup 2+}-channel agonist BAY K 8644 each induced transient increases in prolactin secretion from primary cultures of rat anterior pituitary cells in perfusion. When BAY K 8644 was added after a TRH-induced secretory peak, the additional effect of BAY K 8644 on prolactin release was approximately twofold greater over a 30-min period than the effect of BAY K 8644 on previously untreated cells. TRH and BAY K 8644 were also synergistic when added in the opposite order or simultaneously. Substitution of other agents for BAY K 8644 revealed that only high K{sup +} was at least additive with TRH in stimulating prolactin secretion; treatment with TRH inhibited, rather than facilitated, subsequent stimulation of prolactin secretion by angiotensin II or the ionophore A23187. The cooperative effect was not specific for TRH because BAY K 8644 also acted synergistically with angiotensin II or 40 mM K{sup +}. In GH{sub 4}C{sub 1} cells, in which TRH and BAY K 8644 were also synergistic in releasing prolactin, measurements with the fluorescent indicator indo-1 showed that TRH and BAY K 8644 could each elevate cytosolic Ca{sup 2+} above the level stimulated by the other. Unexpectedly, TRH was found to inhibit BAY K 8644-stimulated {sup 45}Ca{sup 2+} uptake in both GH{sub 4}C{sub 1} and primary cultured cells. These results indicate that BAY K 8644 and TRH synergistically stimulate prolactin secretion by a mechanism other than a cooperative effect on the activity of dihydropyridine-sensitive Ca{sup 2+} channels.

  6. Ovulation induction with pulsatile gonadotropin-releasing hormone (GnRH) or gonadotropins in a case of hypothalamic amenorrhea and diabetes insipidus.

    Science.gov (United States)

    Georgopoulos, N A; Markou, K B; Pappas, A P; Protonatariou, A; Vagenakis, G A; Sykiotis, G P; Dimopoulos, P A; Tzingounis, V A

    2001-12-01

    Hypothalamic amenorrhea is a treatable cause of infertility. Our patient was presented with secondary amenorrhea and diabetes insipidus. Cortisol and prolactin responded normally to a combined insulin tolerance test (ITT) and thyrotropin-releasing hormone (TRH) challenge, while thyroid-stimulating hormone (TSH) response to TRH was diminished, and no response of growth hormone to ITT was detected. Both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels increased following gonadotropin-releasing hormone (GnRH) challenge. No response of LH to clomiphene citrate challenge was detected. Magnetic resonance imaging findings demonstrated a midline mass occupying the inferior hypothalamus, with posterior lobe not visible and thickened pituitary stalk. Ovulation induction was carried out first with combined human menopausal gonadotropins (hMG/LH/FSH) (150 IU/day) and afterwards with pulsatile GnRH (150 ng/kg/pulse). Ovulation was achieved with both pulsatile GnRH and combine gonadotropin therapy. Slightly better results were achieved with the pulsatile GnRH treatment.

  7. Effects of theophylline infusion on the growth hormone (GH) and prolactin response to GH-releasing hormone administration in acromegaly.

    Science.gov (United States)

    Losa, M; Alba-Lopez, J; Schopohl, J; Sobiesczcyk, S; Chiodini, P G; Müller, O A; von Werder, K

    1988-10-01

    Since theophylline has been shown to blunt the GH response to growth hormone-releasing hormone (GHRH) in normal subjects, we investigated whether the same effect of theophylline administration could be reproduced in patients with active acromegaly. Ten acromegalic patients received on two different days 100 micrograms GHRH iv alone and the same GHRH dose during a constant infusion of theophylline (3.56 mg/min), beginning 2 h before GHRH administration. In the whole group theophylline did not affect basal GH secretion significantly (from a mean of 44.6 +/- 14.4 at 0 min to 41.8 +/- 13.5 ng/ml at 120 min). However, the amount of GH released after GHRH stimulation was lower when theophylline was concomitantly infused (7525 +/- 3709 ng min/ml vs. 12038 +/- 6337 ng min/ml; p less than 0.05). The inhibitory effect of theophylline was not homogeneous, since either marked or minimal reductions of the GHRH-stimulated GH secretion occurred. Serum PRL levels increased after GHRH administration in 6 patients and theophylline infusion had no influence upon this response. Peak GHRH levels were not different in both studies (14.9 +/- 1.7 and 17.1 +/- 4.0 ng/ml, respectively). Free fatty acid levels rose progressively during theophylline administration (from 0.66 +/- 0.10 at 0 min to 1.04 +/- 0.10 mEq/l at 240 min) and were significantly higher than after GHRH stimulation alone from 180 min up to the end of the test. Our results demonstrate that in active acromegaly theophylline blunts the GH response to GHRH, though this effect is not uniformly seen in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Discordant effects of endogenous and exogenous somatostatin on growth hormone-releasing hormone secretion from perifused mouse hypothalami.

    Science.gov (United States)

    Pecori Giraldi, F; Frohman, L A

    1995-05-01

    The role of somatostatin (SRIF) on growth hormone-releasing hormone (GRH) secretion has been controversial because of discordant findings that may be model dependent. We have examined possible explanations for these findings by altering endogenous and exogenous SRIF tone in a mouse hypothalamic perifusion system. Four mediobasal hypothalamic fragments were perifused in a single chamber for 6 h. After a 2-hour equilibration period, test substances were introduced and maintained throughout the perifusion. After an additional 2 h, fragments were submaximally stimulated with 30 mM K+. Depletion of tissue SRIF by 10(-3) M cysteamine increased K(+)-stimulated GRH release 2-fold without altering basal GRH secretion. Removal of endogenous SRIF tone by anti-SRIF serum also augmented the GRH response to K+. Perifusion of SRIF at concentrations ranging from 10(-12) to 10(-8) M significantly increased the GRH response to K+ in a dose-dependent manner. A significant increase was also observed during the perifusion of 10(-9) M octreotide. Simultaneous perifusion with anti-SRIF serum and 10(-9) M octreotide (to which the antibody does not bind) resulted in a response of GRH to K+ that was similar to that observed with anti-SRIF serum alone. Combined perifusion with cysteamine and 10(-9) M SRIF also resulted in a GRH response to K+ that did not differ from the response observed during cysteamine alone. The enhancement of GRH secretion by reduction of endogenous SRIF tone or tissue content implies an inhibitory role of endogenous SRIF on GRH secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Effects of TCDD on thyroid hormone homeostasis in the rat.

    Science.gov (United States)

    Kohn, M C

    2000-02-01

    A physiological dosimetric model was constructed to describe the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on circulating thyroid hormones in the rat and to test the hypothesis that these hormonal changes cause chronically elevated serum thyrotropin (thyroid stimulating hormone, TSH), which mediates growth promotion and may lead to thyroid tumors in TCDD-treated rats. The model included diffusion restricted distribution of TCDD among compartments for liver, kidney, white fat, slowly and rapidly perfused tissues, and the thyroxine-sensitive tissues brown fat, pituitary, and thyroid. Blood was distributed among major vessels and the capillary beds of the tissues. Metabolism of TCDD was limited to the liver. Secretion of 3,5,3'-triiodothyronine (T3) and thyroxine (3,5,3',5'-tetraiodothyronine, T4) from the thyroid was modeled as stimulated by circulating TSH, whose release from the pituitary was regulated by the hypothalamic peptides thyrotropin releasing hormone (activating) and somatostatin (inhibiting). Release of these peptides was represented as inhibited and activated, respectively, by circulating T4. Binding proteins for T3 and T4 and metabolism of the hormones by deiodination were included in thyroxine-sensitive tissues. Induction of hepatic UDP-glucuronosyltransferase-1*6 (UGT), the enzyme which glucuronidates T4, was modeled as induced by the complex formed between TCDD and the aryl hydrocarbon receptor. The computed extent of deiodination, primacy of the thyroid in generating T3 from T4, dependence of liver and kidney on locally produced T3, and export of T3 formed in the pituitary agreed with experimental observations. The model reproduced the observed decrease in circulating T4 and elevated serum TSH following chronic administration of TCDD. The altered levels were attributed to the increased clearance of T4 by the induced UGT and the consequent modification of feedback control of hormone releases. These results are consistent with the

  10. Long-term consequences of growth hormone replacement and cranial radiation on pituitary function

    NARCIS (Netherlands)

    Appelman-Dijkstra, Natasha Mireille

    2015-01-01

    This thesis covers the consequences of cranial irradiation of non-pituitary tumors, eg nasopharyngeal carcinoma, on pituitary function. In chapter 2 we have performed a meta-analysis of available data reported in literature on pituitary function after cranial radiotherapy for head and neck and non-p

  11. How to recognize the desensitization of pituitary-ovarian axis achieved by gonadotropin-releasing hormone analogue-induced down-regulation?%识别促性腺激素释放激素激动剂对垂体-卵巢轴降调节抑制程度及意义

    Institute of Scientific and Technical Information of China (English)

    李洁; 刘倍余

    2011-01-01

    本文通过文献复习讨论促性腺激素释放激素激动剂(GnRH-a)联合促性腺激素(Gn)诱导排卵治疗方案对垂体卵巢轴的降调节作用及意义.广义的降调节作用包括:对血清促性腺激素:卵泡刺激素、黄体生成素(FSH、LH)水平、卵泡周期性发育和类固醇激素合成的影响.临床常见的垂体降调节程度包括过度抑制、部分抑制和未能达到抑制.过度抑制被认为是垂体卵巢轴完全静息状态所需要的,适用于性激素依赖性肿瘤或疾病的治疗.体外受精-胚胎移植(IVF-ET)治疗周期中仅需要达到部分垂体卵巢轴降调节,即保留进入周期募集的卵泡对促性腺激素的反应性和类固醇激素合成.未能达到抑制的垂体卵巢轴伴随着卵泡晚期早发LH峰的风险,与无降调节周期相似.GnRH-a对垂体卵巢轴的降调节作用不仅与其类型、半衰期和患者个体差异有关,并且呈现出剂量与使用时间的依赖性.大部分过度抑制效应的患者可以通过降低GnRH-a剂量逆转,恢复卵巢对外源促性腺激素的反应性.极少数妇女存在降调节的延迟反应,与LH受体变异和受体后缺陷有关.%The review is to discuss how to recognize the desensitization of the pituitary-ovarian axis after gonadotrophin-releasing hormone analogue (GnRH-a) administration, which includes hormone profile, oocytogenesis and steroidogenesis. The original down-regulation is defined as luteinizing hormone (LH) levels <5 U/L, the thickness of endometrium less than 5 mm and follicular diameter pituitary-ovarian axis could be reversed by reducing

  12. Pituitary-specific overexpression of porcine follicle-stimulating hormone leads to improvement of female fecundity in BAC transgenic mice.

    Directory of Open Access Journals (Sweden)

    Mingjun Bi

    Full Text Available Follicle-stimulating hormone (FSH is a pituitary glycoprotein that, together with luteinizing hormone, plays a crucial role in ovarian folliculogenesis and female fertility. We previously found that FSH beta is a major gene controlling high prolificacy of Chinese Erhualian pigs. To directly study the biological effects on reproductive function of porcine FSH (pFSH for polyovulatory species, we generated a novel gain-of-function mouse model using a bacterial artificial chromosome (BAC system to jointly introduce 92 kb and 165 kb genomic fragments comprising the pFSH α- and β-subunit genes. These directed the physiological expression of pFSH with the same temporal and spatial pattern as endogenous FSH in female transgenic (TG mice. Serum levels of biologically active pFSH heterodimers in independent TG lines ranged from 6.36 to 19.83 IU/L. High basal pFSH activity led to a significant reduction of serum LH and testosterone levels in TG females compared to wild-type (WT littermates, yet endogenous FSH and estradiol levels were significantly elevated. Interestingly, ovarian histology showed that the number of corpora lutea was significantly higher at 14 and 28 weeks of age in TG females and breeding curves revealed that mean litter sizes of TG females were obviously larger than for WT littermates before 52 weeks of age. These findings indicate that pituitary-specific overexpression of pFSH within physiological boundaries can increase ovulation rate and litter size, but it does not cause reproductive defects. Therefore, our TG mouse model provides exciting insights for investigating the actions of pFSH in vivo.

  13. Different effects of growth hormone-releasing hormone (GRH) and somatostatin on growth hormone and stable metabolite of prostaglandin E2, 13, 14-dihydro-15-keto-prostaglandin E2 (PGE2-M) in normal subjects.

    Science.gov (United States)

    Zacharieva, S; Muchá, I; Popova, J; Andonova, K

    1992-01-01

    Twenty four healthy subjects were placed in two treatment groups: 1. The first group consisted of twelve subjects in whom growth releasing hormone (GRH) (1 microgram/kg.BW) resulted in a marked and sustained elevation of serum growth hormone (GH) and a slight and delayed increase in plasma prostaglandin E2-M. In the second group, consisting also of twelve subjects, somatostatin infusion (500 micrograms/250 ml) was initiated and maintained for 60 min. Serum GH significantly decreased at 30 and 60 min during infusion and 15 min thereafter. We did not observe any changes in plasma prostaglandin E2-M during or after somatostatin infusion. The results obtained confirm previous in vitro studies and suggest a possible link between growth releasing hormone and prostaglandin E2 in their action on growth hormone secretion. It seems that somatostatin does not play a role in the control of prostaglandin E2 release.

  14. Hormone impostors

    Energy Technology Data Exchange (ETDEWEB)

    Colborn, T.; Dumanoski, D.; Myers, J.P.

    1997-01-01

    This article discusses the accumulating evidence that some synthetic chemicals disrupt hormones in one way or another. Some mimic estrogen and others interfere with other parts of the body`s control or endocrine system such as testosterone and thyroid metabolism. Included are PCBs, dioxins, furans, atrazine, DDT. Several short sidebars highlight areas where there are or have been particular problems.

  15. Gonadotropin-releasing hormone, estradiol, and inhibin regulation of follicle-stimulating hormone and luteinizing hormone surges: implications for follicle emergence and selection in heifers.

    Science.gov (United States)

    Haughian, James M; Ginther, O J; Diaz, Francisco J; Wiltbank, Milo C

    2013-06-01

    Mechanisms regulating gonadotropin surges and gonadotropin requirements for follicle emergence and selection were studied in heifers. Experiment 1 evaluated whether follicular inhibins regulate the preovulatory luteinizing hormone (LH)/follicle-stimulating hormone (FSH) surges elicited by gonadotropin-releasing hormone (GnRH) injection (Hour = 0) and the subsequent periovulatory FSH surge. Treatments included control (n = 6), steroid-depleted bovine follicular fluid (bFF) at Hour -4 (n = 6), and bFF at Hour 6 (n = 6). Gonadotropins in blood were assessed hourly from Hours -6 to 36, and follicle growth tracked by ultrasound. Consistent with inhibin independence, bFF at Hour -4 did not impact the GnRH-induced preovulatory FSH surge, whereas treatment at Hour 6 delayed onset of the periovulatory FSH surge and impeded growth of a new follicular wave. Experiment 2 examined GnRH and estradiol (E2) regulation of the periovulatory FSH surge. Treatment groups were control (n = 8), GnRH-receptor antagonist (GnRHr-ant, n = 8), and E2 + GnRHr-ant (n = 4). GnRHr-ant (acyline) did not reduce the concentrations of FSH during the periovulatory surge and early follicle development (8.0 mm) was prevented by GnRHr-ant. Addition of E2 delayed both the onset of the periovulatory FSH surge and emergence of a follicular wave. Failure to select a dominant follicle in the GnRHr-ant group was associated with reduced concentrations of LH but not FSH. Maximum diameter of F1 in controls (13.3 ± 0.5 mm) was greater than in both GnRHr-ant (7.7 ± 0.3 mm) and E2 + GnRHr-ant (6.7 ± 0.8 mm) groups. Results indicated that the periovulatory FSH surge stems from removal of negative stimuli (follicular E2 and inhibin), but is independent of GnRH stimulation. Emergence and early growth of follicles (until about 8 mm) requires the periovulatory FSH surge but not LH pulses. However, follicular deviation and late-stage growth of a single dominant follicle requires GnRH-dependent LH pulses.

  16. Polymorphisms in luteinizing hormone receptor and hypothalamic gonadotropin-releasing hormone genes and their effects on sperm quality traits in Chinese Holstein bulls.

    Science.gov (United States)

    Sun, Li-Ping; Du, Qing-Zhi; Song, Ya-Pan; Yu, Jun-Na; Wang, Shu-Juan; Sang, Lei; Song, Luo-Wen; Yue, Yao-Min; Lian, Yu-Ze; Zhang, Sheng-Li; Hua, Guo-Hua; Zhang, Shu-Jun; Yang, Li-Guo

    2012-06-01

    Genes of hypothalamic-pituitary-gonadal axis play a key role in male reproductive performance. This study evaluated the polymorphisms of luteinizing hormone receptor (LHR) and hypothalamic gonadotropin-releasing hormone (GnRH) genes and their effects on sperm quality traits including semen volume per ejaculate (VOL), sperm density (SD), fresh sperm motility (FSM), thawed sperm motility (TSM), acrosome integrity rate (AIR), and abnormal sperm rate (ASR) collected from 205 Chinese Hostein bulls. The study bulls consisted of 205 mature Chinese Holstein, 27 Simmental, 28 Charolais, and 14 German yellow cattle. One single nucleotide polymorphism (SNP) (A883G) in exon 2 of GnRH and two SNPs (A51703G and G51656T) in intron 9 of LHR were identified in 274 bulls. Analysis of variance in 205 Chinese Holstein bulls showed that age had significant effect on both SD and FSM (P bulls with AG genotype had higher FSM than bulls with AA and GG genotype in LHR at 51,703 locus (P bulls with GG genotype had higher SD than bulls with TT genotype in LHR at G51656T locus (P < 0.10). Phenotypic correlation among the traits revealed that significant negative correlations were observed between ASR and AIR (r = -0.736, P < 0.01), ASR and AIR (r = -0.500, P < 0.01). There were moderate positive correlations between VOL and SD (r = 0.422, P < 0.01), as well as FSM (r = 0.411, P < 0.01). In conclusion, LHR may be a potential marker for sperm quality of SD and FSM.

  17. Melanin-concentrating hormone (MCH) and gonadotropin-releasing hormones (GnRH) in Atlantic cod, Gadus morhua: tissue distributions, early ontogeny and effects of fasting.

    Science.gov (United States)

    Tuziak, Sarah M; Volkoff, Hélène

    2013-12-01

    Melanin-concentrating hormone (MCH) is classically known for its role in regulating teleost fish skin color change for environmental adaptation. Recent evidence suggests that MCH also has appetite-stimulating properties. The gonadotropin-releasing hormone (GnRH) peptide family has dual roles in endocrine control of reproduction and energy status in fish. Atlantic cod (Gadus morhua) are a commercially important aquaculture species inhabiting the shores of Atlantic Canada. In this study, we examine MCH and GnRH transcript expression profiles during early development as well as in central and peripheral tissues and quantify juvenile Atlantic cod MCH and GnRH hypothalamic mRNA expressions following food deprivation. MCH and GnRH3 cDNAs are maternally deposited into cod eggs, while MCH has variable expression throughout early development. GnRH2 and GnRH3 mRNAs "turn-on" during mid-segmentation once the brain is fully developed. For both MCH and GnRH, highest expression appears during the exogenous feeding stages, perhaps supporting their functions as appetite regulators during early development. MCH and GnRH transcripts are found in brain regions related to appetite regulation (telencephalon/preoptic area, optic tectum/thalamus, hypothalamus), as well as the pituitary gland and the stomach, suggesting a peripheral function in food intake regulation. Atlantic cod MCH mRNA is upregulated during fasting, while GnRH2 and GnRH3 transcripts do not appear to be influenced by food deprivation. In conclusion, MCH might be involved in stimulating food intake in juvenile Atlantic cod, while GnRHs may play a more significant role in appetite regulation during early development.

  18. Hypothalamic-pituitary-adrenal axis response to acute psychosocial stress: Effects of biological sex and circulating sex hormones.

    Science.gov (United States)

    Stephens, Mary Ann C; Mahon, Pamela B; McCaul, Mary E; Wand, Gary S

    2016-04-01

    Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis influences the risk for developing stress-related disorders. Sex-dependent differences in the HPA axis stress response are believed to contribute to the different prevalence rates of stress-related disorders found in men and women. However, studies examining the HPA axis stress response have shown mixed support for sex differences, and the role of endogenous sex hormones on HPA axis response has not been adequately examined in humans. This study utilized the largest sample size to date to analyze the effects of biological sex and sex hormones on HPA axis social stress responses. Healthy, 18- to 30- year-old community volunteers (N=282) completed the Trier Social Stress Test (TSST), a widely used and well-validated stress-induction laboratory procedure. All women (n=135) were tested during the follicular phase of their menstrual cycle (when progesterone levels are most similar to men). Adrenocorticotropic hormone (ACTH) and cortisol measures were collected at multiple points throughout pre- and post-TSST. Testosterone and progesterone (in men) and progesterone and estradiol (in women) were determined pre-TSST. Following the TSST, men had greater ACTH and cortisol levels than women. Men had steeper baseline-to-peak and peak-to-end ACTH and cortisol response slopes than women; there was a trend for more cortisol responders among men than women. Testosterone negatively correlated with salivary cortisol response in men, while progesterone negatively correlated with ACTH and cortisol responses in women. These data confirm that men show more robust activation of the HPA axis response to the TSST than do women in the follicular phase of the menstrual cycle. Testosterone results suggest an inhibitory effect on HPA axis reactivity in men. Progesterone results suggest an inhibitory effect on HPA axis reactivity in women. Future work is needed to explain why men mount a greater ACTH and cortisol response to the

  19. Concentrations of the adrenocorticotropic hormone, corticosterone and sex steroid hormones and the expression of the androgen receptor in the pituitary and adrenal glands of male turkeys (Meleagris gallopavo) during growth and development.

    Science.gov (United States)

    Kiezun, J; Kaminska, B; Jankowski, J; Dusza, L

    2015-01-01

    Androgens take part in the regulation of puberty and promote growth and development. They play their biological role by binding to a specific androgen receptor (AR). The aim of this study was to evaluate the expression of AR mRNA and protein in the pituitary and adrenal glands, to localize AR protein in luteinizing hormone (LH)-producing pituitary and adrenocortical cells, to determine plasma concentrations of adrenocorticotropic hormone (ACTH) and corticosterone and the concentrations of corticosterone, testosterone (T), androstenedione (A4) and oestradiol (E2) in the adrenal glands of male turkeys at the age of 4, 8, 12, 16, 20, 24 and 28weeks. The concentrations of hormones and the expression of AR varied during development. The expression of AR mRNA and protein in pituitary increased during the growth. The increase of AR mRNA levels in pituitary occurred earlier than increase of AR protein. The percentage of pituitary cells expressing ARs in the population of LH-secreting cells increased in week 20. It suggests that AR expression in LH-producing pituitary cells is determined by the phase of development. The drop in adrenal AR mRNA and protein expression was accompanied by an increase in the concentrations of adrenal androgens. Those results could point to the presence of a compensatory mechanism that enables turkeys to avoid the potentially detrimental effects of high androgen concentrations. Our results will expand our knowledge of the role of steroids in the development of the reproductive system of turkeys from the first month of age until maturity. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Effects of Gonadotropin-releasing Hormone (GnRH) and Dopamine on Gonadotropin(GTH) Secretion from in vitro Pituitary Cells of Rainbow Trout%促性腺激素释放激素和多巴胺对虹鳟( Oncorhynchus mykiss )离体脑垂体细胞分泌促性腺激素的影响

    Institute of Scientific and Technical Information of China (English)

    侯亚义

    2001-01-01

    本文研究了不同性腺发育时期淡水饲养的雌雄虹鳟(Oncorhynchus mykiss)血浆促性腺激素(GTH)浓度的变化规律;以及在离体条件下,探讨了促性腺激素释放激素(GnRH)、GnRH拮抗物和多巴胺对虹鳟脑垂体细胞分泌促性腺激素(GTH-Ⅱ)的影响。结果表明:(1)在雄性,血浆中GTH-Ⅱ的水平随性腺发育而逐渐增高;在雌性,仅排卵期血浆中GTH-Ⅱ的水平明显增高。(2)未成熟期和成熟期的雌性虹鳟脑垂体细胞对sGnRH和cGnRH刺激的敏感性表现不尽相同。成熟期和排卵后的脑垂体细胞对GnRH的刺激较为敏感,GTH-Ⅱ的分泌量较多。(3)在没有sGnRH的存在下,GnRH拮抗物对GTH-Ⅱ的分泌不发生作用,而在sGnRH的存在下,GnRH拮抗物对GTH-Ⅱ的分泌表现出浓度依赖的抑制作用。(4)在没有sGnRH的存在下,多巴胺对GTH-Ⅱ的分泌不发生作用,而当多巴胺的浓度一定时,随着sGnRH浓度的增加,GTH-Ⅱ分泌的量增大。另外,不论sGnRH还是cGnRH都不影响不同时期的脑垂体细胞GTH-I的分泌这些结果可为虹鳟的人工催产提供一些理论依据。%Plasma gonadotropin (GTH) levels during immature, mature and ovulated periods and effects of gonadotropin-releasing hormone (GnRH) and dopamine on GTH secretion of in vitro pituitary cells of rainbow trout were investigated. Plasma GTH levels increased with gonadal development. The different effects of sGnRH and cGnRH on GTH- Ⅱ secretions of pituitary cells in vitro from immature, mature and ovulated periods of rainbow trout were observed. GnRH antagonist did not change GTH - Ⅱ contents under the absence of sGnRH while GnRH antagonist suppressed dose-dependently GTH- Ⅱ secretions of pituitary cells in combination with sGnRH.Dopamine also did not affect GTH- Ⅱ levels under the absence of sGnRH, while GTH- Ⅱ secretions of pituitary cells were enhanced when the dosage of sGnRH was increased with the presence of

  1. Neonatal imprinting predetermines the sexually dimorphic, estrogen-dependent expression of galanin in luteinizing hormone-releasing hormone neurons.

    Science.gov (United States)

    Merchenthaler, I; Lennard, D E; López, F J; Negro-Vilar, A

    1993-01-01

    The incidence of colocalization of galanin (GAL) in luteinizing hormone-releasing hormone (LHRH) neurons is 4- to 5-fold higher in female than male rats. This fact and the finding that the degree of colocalization parallels estradiol levels during the estrous cycle suggest that GAL is an estrogen-inducible product in a subset of LHRH neurons. To analyze further this paradigm we evaluated the effects of gonadectomy and steroid replacement therapy in male and female rats. Ovariectomy resulted in a significant decrease in the number of cells colocalizing LHRH and GAL, whereas estradiol replacement to such animals restored the incidence of colocalization to that observed in controls. In males, however, estradiol treatment failed to enhance the incidence of colocalization of GAL and LHRH, indicating, therefore, that the colocalization of these peptides is gender-determined. This possibility--i.e., gender-specific determination of LHRH neurons coexpressing GAL--was evaluated by neonatal manipulation of hypothalamic steroid imprinting. As mentioned above, male rats did not respond to estrogen or testosterone by increasing GAL/LHRH colocalization as females did. Neonatally orchidectomized rats, whose hypothalami have not been exposed to testosterone during the critical period, when treated with estrogen in adulthood showed an increase in colocalization of GAL and LHRH similar to that seen in female animals. These observations indicate that the colocalization of LHRH/GAL is neonatally determined by an epigenetic mechanism that involves the testis. In summary, this sex difference in the incidence of colocalization of GAL and LHRH represents a unique aspect of sexual differentiation in that only certain phenotypic characteristics of a certain cellular lineage are dimorphic. The subpopulation of LHRH neurons that also produces GAL represents a portion of the LHRH neuronal system that is sexually differentiated and programed to integrate, under steroidal control, a network of

  2. Luteinizing Hormone Secretion during Gonadotropin-Releasing Hormone Stimulation Tests in Obese Girls with Central Precocious Puberty

    Science.gov (United States)

    Lee, Hae Sang; Yoon, Jong Seo; Hwang, Jin Soon

    2016-01-01

    Objective: Girls with precocious puberty have high luteinizing hormone (LH) levels and advanced bone age. Obese children enter puberty at earlier ages than do non-obese children. We analyzed the effects of obesity on LH secretion during gonadotropin-releasing hormone (GnRH) tests in girls with precocious puberty. Methods: A total of 981 subjects with idiopathic precocious puberty who had undergone a GnRH stimulation testing between 2008 and 2014 were included in the study. Subjects were divided into three groups based on body mass index (BMI). Auxological data and gonadotropin levels after the GnRH stimulation test were compared. Results: In Tanner stage 2 girls, peak stimulated LH levels on GnRH test were 11.9±7.5, 10.4±6.4, and 9.1±6.1 IU/L among normal-weight, overweight, and obese subjects, respectively (p=0.035 for all comparisons). In Tanner stage 3 girls, peak stimulated LH levels were 14.9±10.9, 12.8±7.9, and 9.6±6.0 IU/L, respectively (p=0.022 for all comparisons). However, in Tanner stage 4 girls, peak stimulated LH levels were not significantly different among normal, overweight, and obese children. On multivariate analysis, BMI standard deviation score was significantly and negatively associated with peak LH (β=-1.178, p=0.001). Conclusion: In girls with central precocious puberty, increased BMI was associated with slightly lower peak stimulated LH levels at early pubertal stages (Tanner stages 2 and 3). This association was not valid in Tanner stage 4 girls. PMID:27215137

  3. Effect of permeation enhancer pretreatment on the iontophoresis of luteinizing hormone releasing hormone (LHRH) through human epidermal membrane (HEM).

    Science.gov (United States)

    Smyth, Hugh D C; Becket, Gordon; Mehta, Samir

    2002-05-01

    A 2 x 2 factorial design was performed to determine the effect of a permeation enhancer (oleic acid/propylene glycol), iontophoresis (2 V), and the combination of the two treatments on the permeation enhancement of a model peptide, LHRH (luteinizing hormone releasing hormone), through human epidermal membrane (HEM). In parallel studies, TEAB (tetraethylammonium bromide, a small ionic solute) and sucrose (an electroosmotic flow marker) were also investigated. Structural changes in the HEM were monitored via conductance measurements, differential scanning calorimetry (DSC), and infrared (IR) spectroscopy experiments. LHRH enhancement due to enhancer in combination with iontophoresis (I + E; 29.5 times passive permeability, P), was greater than during iontophoresis alone (I; 14.3) and enhancer treatment alone (E; 3.5). I + E had an additive effect of I and E, indicating the mechanisms of action of the individual enhancement strategies were likely to be located at different sites in the skin. Also, no synergistic enhancement was observed with I + E for either TEAB or sucrose. For TEAB, permeability enhancement due to I (approximately 1400) was much higher than that due to E (14.9), and no additive effect could be detected. For sucrose, E had no effect on either passive or iontophoretic permeability, eliminating the possibility that electroosmosis could explain increases in LHRH permeability. Evidence of synergy between E and I was found, with conductance measurements indicating that I + E synergistically increased the membrane permeability to conducting ions (Na+ and Cl-). It appears these pathways were not available for transport for the solutes used in the current study. DSC and IR investigations showed significant changes in stratum corneum lipid structure following E treatment but not following I. These findings probably arise from the localized action of iontophoresis compared with the bulk action of enhancer. In summary, increased LHRH delivery through HEM in

  4. Studies on the functional relationship between thyroid, adrenal and gonadal hormones.

    Science.gov (United States)

    Tohei, Atsushi

    2004-02-01

    In order to clarify the functional relationship between thyroid, adrenal and gonadal hormones, hypothyroidism was induced by administration of thiuoracil in adult male and female rats, and the effects of hypothyroidism on the adrenal and the gonadal axes were investigated in the present study. 1. The functional relationship between thyroid and adrenal hormones: Adrenal weights and corticosterone were lowered, whereas the secretion of ACTH, corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) increased in hypothyroid rats compared to euthyroid rats. These results indicate that hypothyroidism causes adrenal dysfunction directly and results in hypersecretion of CRH and AVP from the hypothalamus. 2. The functional relationship between thyroid and gonadal hormones: The pituitary response to LHRH was lowered, whereas the testicular response to hCG was not changed in hypothyroid rats. Hypothyroidism suppressed copulatory behavior in male rats. These results suggest that hypothyroidism probably causes dysfunction in gonadal axis at the hypothalamic-pituitary level in male rats. In adult female rats, hypothyroidism inhibited the follicular development accompanied estradiol secretion, whereas plasma concentrations of progesterone and prolactin (PRL) increased in hypothyroid female rats. Hypothyroidism significantly increased the pituitary content of vasoactive intestinal peptide (VIP) though it did not affect dopamine synthesis. These results suggest that hypothyroidism increases pituitary content of VIP and this increased level of VIP likely affects PRL secretion in a paracrine or autocrine manner. In female rats, inhibition of gonadal function in hypothyroid rats mediated by hyperprolactinemia in addition to hypersecretion of endogenous CRH.

  5. Effects of antagonists of growth hormone-releasing hormone (GHRH) on GH and insulin-like growth factor I levels in transgenic mice overexpressing the human GHRH gene, an animal model of acromegaly.

    Science.gov (United States)

    Kovacs, M; Kineman, R D; Schally, A V; Zarandi, M; Groot, K; Frohman, L A

    1997-11-01

    Transgenic mice overexpressing the human GH-releasing hormone (hGHRH) gene, an animal model of acromegaly, were used to investigate the effects of potent GHRH antagonists MZ-4-71 and MZ-5-156 on the excessive GH and insulin-like growth factor I (IGF-I) secretion caused by overproduction of hGHRH. Because metallothionein (MT)-GHRH mice express the hGHRH transgene in various tissues, including the pituitary and hypothalamus, initial experiments focused on the effectiveness of the GHRH antagonists in blocking basal and stimulated GH secretion from pituitary cells in vitro. Both MZ-4-71 and MZ-5-156 suppressed basal release of GH from superfused MT-GHRH pituitary cells, apparently by blocking the action of endogenously produced hGHRH. In addition, these antagonists effectively eliminated the response to stimulatory action of exogenous hGHRH(1-29)NH2 (30 and 100 nM). To ascertain whether MZ-4-71 and MZ-5-156 could antagonize the effect of hGHRH hyperstimulation in vivo, each antagonist was administered to MT-GHRH transgenic mice in a single iv dose of 10-200 microg. Both compounds decreased serum GH levels in transgenic mice by 39-72% at 1 h after injection. The inhibitory effect of 50 microg MZ-5-156 was maintained for 5 h. Twice daily ip administration of 100 microg MZ-5-156 for 3 days suppressed the highly elevated serum GH and IGF-I concentrations in transgenic mice by 56.8% and 39.0%, respectively. This treatment also reduced IGF-I messenger RNA levels in the liver by 21.8% but did not affect the level of GH messenger RNA in the pituitary. Our results demonstrate that GHRH antagonists MZ-4-71 and MZ-5-156 can inhibit elevated GH levels caused by overproduction of hGHRH. The suppression of circulating GH concentrations induced by the antagonists seems to be physiologically relevant, because both IGF-I secretion and synthesis also were reduced. Our findings, showing the suppression of GH and IGF-I secretion with GHRH antagonists, suggest that this class of analogs

  6. The effect of gonadotropin-releasing hormone agonist-induced down-regulation on pituitary and ovarian function%促性腺激素释放激素激动剂降调对垂体内外的影响

    Institute of Scientific and Technical Information of China (English)

    朱桂金; 徐蓓; 聂睿

    2011-01-01

    catalytic subunit.40%-60% of follicle-stimulating hormone (FSH) secretion is repressed by the immediate action of downregulation,while 90% luteinizing hormone (LH) could be repressed, so downregulation is used to prevent the premature LH surges. Regulation of paracrine secretion by downregulation requires the involvement of FSH and LH and regulatory factors of paracrine secretion have no effect on the promotion of follicular development. The negative feedback of steroid hormone is through the level of hypothalamus and pituitary, while downregulation functions at the level of the gonadotropin-releasing hormone (GnRH) receptors, so the normal positive and negative feedbacks are cancelled by downregulation.There exist GnRH receptors in granulosa cells, theca cells and luteal cells, so it could be presumed theoretically that GnRH may have direct effects on ovary. Both animal experiments and in vitro studiessuggest that GnRH may have a direct action on ovarian granulosa cells through interfering steroid synthesis and follicular development. So except for preventing the premature LH surges and decreasing the detrimental effect of high LH, the effect of GnRH agonist-induced down-regulation increasing pregnancy rate may be also through the immediate action on follicular development, oocyte maturation and endometrial receptivity, but no confirmation has been made by the existing evidence.

  7. Premenstrual Exacerbation of Life-Threatening Asthma: Effect of Gonadotrophin Releasing Hormone Analogue Therapy

    Directory of Open Access Journals (Sweden)

    Alun L Edwards

    1996-01-01

    Full Text Available Variability in the severity of asthma during various phases of the menstrual cycle has been frequently suspected. However, the hormonal changes that might affect mediators of bronchospasm have yet to be elucidated. The case of a 41-year-old woman suffering from longstanding asthma with life-threatening exacerbations is reported. The patient was treated with buserelin, a gonadotropin releasing hormone (GnRH analogue, which created a temporary chemical menopause and thus permitted diagnosis of a premenstrual exacerbation of asthma and offered insight into potential therapy. GnRH analogues may therefore be of value in assessing women with severe asthma suspected to vary with the menstrual cycle. The addition of estrogens and progestins at the same time as treatment with GnRH analogue may be of value in determining the role of these hormones in the pathogenesis of menstrually related exacerbations of asthma.

  8. Influence of season and nutritional status on the direct effects of leptin, orexin-A and ghrelin on luteinizing hormone and growth hormone secretion in the ovine pituitary explant model.

    Science.gov (United States)

    Kirsz, K; Szczesna, M; Dudek, K; Bartlewski, P M; Zieba, D A

    2014-07-01

    The aim of this study was to examine whether leptin (anorexigenic peptide), orexin-A, and ghrelin (orexigenic peptides) could directly (ie, independently of hypothalamic influences) affect the secretion of luteinizing hormone (LH) and growth hormone (GH) by adenohypophyseal (AP) explants obtained from normally fed or fasted (48 h) ewes during the breeding and nonbreeding seasons. In addition, a specific ovine super leptin antagonist (SLAN-3) was used to assess the interactions between leptin and ghrelin and/or orexin-A. Pituitary glands from 16 ovariectomized Polish Longwool ewes that had received estradiol-releasing subcutaneous implants were collected in the breeding (November; n = 8) and nonbreeding (May; n = 8) seasons. The AP explants were incubated for 240 min in a gas-liquid interface and treated with leptin (50 ng/mL), ghrelin (100 ng/mL), orexin-A (100 ng/mL), and SLAN-3 (500 ng/mL) with orexin-A or ghrelin. Treatments with leptin and SLAN-3 + orexin-A increased (P secretion by AP explants from both fasted and fed animals in the breeding season. Ghrelin stimulated (P secretion by AP explants collected from fasted animals in nonbreeding season and from normally fed ewes in both seasons. Leptin decreased (P secretion by AP explants collected from fasted ewes in both seasons and from nonfasted ewes in the breeding season. However, the treatment with SLAN-3 + ghrelin resulted in greater (P ghrelin exerted direct effects on AP secretory function in an ex situ model and both the reproductive season and nutritional status of the animals impinged on the direct effects of the peptides on LH and GH release. Specifically, orexin-A was more potent than leptin in directly stimulating LH secretion in cycling ewes, whereas ghrelin and leptin generally had opposing effects on the secretory function of somatotrophs in sheep.

  9. Central stimulation of hormone release and the proliferative response of lymphocytes in humans.

    Science.gov (United States)

    Juránková, E; Jezová, D; Vigas, M

    1995-01-01

    The central nervous system (CNS) may communicate with the immune system by direct innervation of lymphoid organs and/or by neurotransmitters and changes in neuroendocrine functioning and hormone release. The consequences of selective transient changes in circulating hormones on immune functioning in humans have not yet been studied. To address this problem, the authors evaluated the lymphoproliferative responses to optimal and suboptimal concentrations of phytohemagglutinin (PHA) and pokeweek mitogen (PWM) under selective enhancement of circulating growth hormone, prolactin, or norepinephrine. The authors failed to demonstrate any effect of elevated growth hormone levels after clonidine challenge on the lymphoproliferative response to mitogens. Similarly, the results did not show any effect of elevated prolactin concentrations induced by domperidone administration on the immune test. Exposure of volunteers to cold resulted in elevation of plasma norepinephrine levels without changes in growth hormone, epinephrine, or cortisol secretion. Cold exposure induced elevation of plasma norepinephrine and reduction of the lymphoproliferative response to the suboptimal dosage of PHA. The reduction was significant 180 and 240 min after exposure. These results are indicative of a relationship between norepinephrine and immunity.

  10. Update on the male hormonal contraceptive agents.

    Science.gov (United States)

    Walton, Melanie; Anderson, Richard A

    2004-09-01

    There remains a need for new acceptable and effective male contraceptives to increase the choice for couples throughout the world. There have been no recent advances in available male contraceptive methods although a number of promising approaches have been identified, of which the hormonal approach is currently undergoing clinical investigation. In recent years the pace of research in this area has quickened significantly with increasing interest and now investment by the pharmaceutical industry. This is vital if the work undertaken so far by the public sector is to be transformed into a commercial reality. The hormonal approach is based on suppression of pituitary gonadotropin secretion resulting in a reversible reduction in spermatogenesis with azoospermia in all men being the ultimate aim. Without stimulation by luteinising hormone from the pituitary, testicular testosterone production also ceases. Therefore, androgen administration to restore physiological levels is an essential component of all male hormonal contraceptive regimes. Male hormonal contraceptives can consist of testosterone alone, or either a progestogen or gonadotropin-releasing hormone antagonist with 'add-back' testosterone. This article reviews the current state of progress in this field.

  11. The forkhead transcription factor, Foxd1, is necessary for pituitary luteinizing hormone expression in mice.

    Directory of Open Access Journals (Sweden)

    Jason H Gumbel

    Full Text Available The pituitary gland regulates numerous physiological functions including growth, reproduction, temperature and metabolic homeostasis, lactation, and response to stress. Pituitary organogenesis is dependent on signaling factors that are produced in and around the developing pituitary. The studies described in this report reveal that the forkhead transcription factor, Foxd1, is not expressed in the developing mouse pituitary gland, but rather in the mesenchyme surrounding the pituitary gland, which is an essential source of signaling factors that regulate pituitary organogenesis. Loss of Foxd1 causes a morphological defect in which the anterior lobe of the pituitary gland protrudes through the cartilage plate that is developing ventral to the pituitary at embryonic days (e14.5, e16.5, and e18.5. The number of proliferating pituitary cells is increased at e14.5 and e16.5. Loss of Foxd1 also results in significantly decreased levels of Lhb expression at e18.5. This decrease in Lhb expression does not appear to be due to a change in the number of gonadotrope cells in the pituitary gland. Previous studies have shown that loss of the LIM homeodomain factor, Lhx3, which is activated by the FGF signaling pathway, results in loss of LH production. Although there is a difference in Lhb expression in Foxd1 null mice, the expression pattern of LHX3 is not altered in Foxd1 null mice. These studies suggest that Foxd1 is indirectly required for normal Lhb expression and cartilage formation.

  12. Protective effect of Growth Hormone-Releasing Hormone agonist in bacterial toxin-induced pulmonary barrier dysfunction.

    Directory of Open Access Journals (Sweden)

    Istvan eCzikora

    2014-07-01

    Full Text Available Rationale. Antibiotic treatment of patients infected with G- or G+ bacteria promotes release of the toxins lipopolysaccharide (LPS and pneumolysin (PLY in their lungs. Growth Hormone-releasing Hormone (GHRH agonist JI-34 protects human lung microvascular cells (HL-MVEC, expressing splice variant 1 (SV-1 of the receptor, from PLY-induced barrier dysfunction. We investigated whether JI-34 also blunts LPS-induced hyperpermeability. Since GHRH receptor signaling can potentially stimulate both cAMP-dependent barrier-protective pathways as well as barrier-disruptive protein kinase C pathways, we studied their interaction in GHRH agonist-treated HL-MVEC, in the presence of PLY, by means of siRNA-mediated PKA depletion.Methods. Barrier function measurements were done in HL-MVEC monolayers using Electrical Cell substrate Impedance Sensing (ECIS and VE-cadherin expression by Western blotting. Capillary leak was assessed by Evans Blue dye incorporation. Cytokine generation in broncho-alveolar lavage fluid was measured by multiplex analysis. PKA and PKC-alpha activity were assessed by Western blotting. Results. GHRH agonist JI-34 significantly blunts LPS-induced barrier dysfunction, at least in part by preserving VE-cadherin expression, while not affecting inflammation. In addition to activating PKA, GHRH agonist also increases PKC-alpha activity in PLY-treated HL-MVEC. Treatment with PLY significantly decreases resistance in control siRNA-treated HL-MVEC, but does so even more in PKA-depleted monolayers. Pretreatment with GHRH agonist blunts PLY-induced permeability in control siRNA-treated HL-MVEC, but fails to improve barrier function in PKA-depleted PLY-treated monolayers. Conclusions. GHRH signaling in HL-MVEC protects from both LPS and PLY-mediated endothelial barrier dysfunction and concurrently induces a barrier-protective PKA-mediated and a barrier-disruptive PKC-alpha-induced pathway in the presence of PLY, the former of which dominates the latter.

  13. Histone deacetylases regulate gonadotropin-releasing hormone I gene expression via modulating Otx2-driven transcriptional activity.

    Directory of Open Access Journals (Sweden)

    Lu Gan

    Full Text Available BACKGROUND: Precise coordination of the hypothalamic-pituitary-gonadal axis orchestrates the normal reproductive function. As a central regulator, the appropriate synthesis and secretion of gonadotropin-releasing hormone I (GnRH-I from the hypothalamus is essential for the coordination. Recently, emerging evidence indicates that histone deacetylases (HDACs play an important role in maintaining normal reproductive function. In this study, we identify the potential effects of HDACs on Gnrh1 gene transcription. METHODOLOGY/PRINCIPAL FINDINGS: Inhibition of HDACs activities by trichostatin A (TSA and valproic acid (VPA promptly and dramatically repressed transcription of Gnrh1 gene in the mouse immortalized mature GnRH neuronal cells GT1-7. The suppression was connected with a specific region of Gnrh1 gene promoter, which contains two consensus Otx2 binding sites. Otx2 has been known to activate the basal and also enhancer-driven transcription of Gnrh1 gene. The transcriptional activity of Otx2 is negatively modulated by Grg4, a member of the Groucho-related-gene (Grg family. In the present study, the expression of Otx2 was downregulated by TSA and VPA in GT1-7 cells, accompanied with the opposite changes of Grg4 expression. Chromatin immunoprecipitation and electrophoretic mobility shift assays demonstrated that the DNA-binding activity of Otx2 to Gnrh1 gene was suppressed by TSA and VPA. Overexpression of Otx2 partly abolished the TSA- and VPA-induced downregulation of Gnrh1 gene expression. CONCLUSIONS/SIGNIFICANCE: Our data indicate that HDAC inhibitors downregulate Gnrh1 gene expression via repressing Otx2-driven transcriptional activity. This study should provide an insight for our understanding on the effects of HDACs in the reproductive system and suggests that HDACs could be potential novel targets for the therapy of GnRH-related diseases.

  14. Dehydration-induced drinking decreases Fos expression in hypothalamic paraventricular neurons expressing vasopressin but not corticotropin-releasing hormone.

    Science.gov (United States)

    Wotus, Cheryl; Arnhold, Michelle M; Engeland, William C

    2007-03-01

    Water-restricted (WR) rats exhibit a rapid suppression of plasma corticosterone following drinking. The present study monitored Fos-like immunoreactivity (Fos) to assess the effect of WR-induced drinking on the activity of vasopressin (VP)-positive magnocellular and parvocellular neurons and corticotropin-releasing hormone (CRH)-positive parvocellular neurons in the paraventricular nucleus of the hypothalamus. Adult male rats received water for 30 min (WR) in the post meridiem (PM) each day for 6 days and were killed without receiving water or at 1 h after receiving water for 15 min. In WR rats, Fos increased in VP magnocellular and parvocellular neurons but not CRH neurons. After drinking, Fos was reduced in VP magnocellular and parvocellular neurons but did not change in CRH neurons. To assess the severity of osmotic stress, rats were sampled throughout the final day of WR. Plasma osmolality, hematocrit and plasma VP were increased throughout the day before PM rehydration, and plasma ACTH and corticosterone were elevated at 1230 and 1430, respectively, showing that WR activates hypothalamic-pituitary-adrenal activity during the early PM before the time of rehydration. To determine the effects of WR-induced drinking on CRH neurons activated by acute stress, WR rats underwent restraint. Restraint increased plasma ACTH and corticosterone and Fos in CRH neurons; although rehydration reduced plasma ACTH and Fos expression in VP neurons, Fos in CRH neurons was not affected. These results suggest that inhibition of VP magnocellular and parvocellular neurons, but not CRH parvocellular neurons, contributes to the suppression of corticosterone after WR-induced drinking.

  15. Inhibition of thyroid hormone sulfotransferase activity by brominated flame retardants and halogenated phenolics.

    Science.gov (United States)

    Butt, Craig M; Stapleton, Heather M

    2013-11-18

    Many halogenated organic contaminants (HOCs) are considered endocrine disruptors and affect the hypothalamic-pituitary-thyroid axis, often by interfering with circulating levels of thyroid hormones (THs). We investigated one potential mechanism for TH disruption, inhibition of sulfotransferase activity. One of the primary roles of TH sulfation is to support the regulation of biologically active T3 through the formation of inactive THs. We investigated TH sulfotransferase inhibition by 14 hydroxylated polybrominated diphenyl ethers (OH BDEs), BDE 47, triclosan, and fluorinated, chlorinated, brominated, and iodinated analogues of 2,4,6-trihalogenated phenol and bisphenol A (BPA). A new mass spectrometry-based method was also developed to measure the formation rates of 3,3'-T2 sulfate (3,3'-T2S). Using pooled human liver cytosol, we investigated the influence of these HOCs on the sulfation of 3,3'-T2, a major substrate for TH sulfation. For the formation of 3,3'-T2S, the Michaelis constant (Km) was 1070 ± 120 nM and the Vmax was 153 ± 6.6 pmol min(-1) (mg of protein)(-1). All chemicals investigated inhibited sulfotransferase activity with the exception of BDE 47. The 2,4,6-trihalogenated phenols were the most potent inhibitors followed by the OH BDEs and then halogenated BPAs. The IC50 values for the OH BDEs were primarily in the low nanomolar range, which may be environmentally relevant. In silico molecular modeling techniques were also used to simulate the binding of OH BDE to SULT1A1. This study suggests that some HOCs, including antimicrobial chemicals and metabolites of flame retardants, may interfere with TH regulation through inhibition of sulfotransferase activity.

  16. Association between corticotropin-releasing hormone receptor 1 and 2 (CRHR1 and CRHR2) gene polymorphisms and personality traits.

    Science.gov (United States)

    Ishitobi, Yoshinobu; Nakayama, Shinya; Kanehisa, Masayuki; Higuma, Haruka; Maruyama, Yoshihiro; Okamoto, Shizuko; Inoue, Ayako; Imanaga, Junko; Tanaka, Yoshihiro; Tsuru, Jusen; Hanada, Hiroaki; Akiyoshi, Jotaro

    2013-12-01

    Previous studies have reported that the hypothalamic-pituitary-adrenal axis is involved with personality traits. We examined the association between corticotropin-releasing hormone receptor (CRHR) genes and personality traits. We investigated the 12 single-nucleotide polymorphisms of intron CRHR (six in CRHR1 and six in CRHR2, respectively) in 218 healthy volunteers using TaqMan PCR assays. Personality traits were assessed using the Revised NEO-Personality Inventory, the Temperament and Character Inventory, and the State-Trait Anxiety Inventory. No significant associations were observed between CRHR1 and CRHR2 expression and personality traits. These results fail to provide support for an association of CRHR1 and CRHR2 with personality traits in a Japanese adult population.

  17. Cloning and characterization of mouse growth hormone-releasing hormone (GRH) complementary DNA: increased GRH messenger RNA levels in the growth hormone-deficient lit/lit mouse.

    Science.gov (United States)

    Frohman, M A; Downs, T R; Chomczynski, P; Frohman, L A

    1989-10-01

    We have isolated and cloned the full length cDNA for mouse GH-releasing hormone (mGRH) from mouse hypothalamus using a recently described strategy involving the polymerase chain reaction technique (PCR). Degenerate oligonucleotide primers were selected based on short (six amino acids) conserved regions in the human and rat GRH peptides that would recognize DNA sequences encoding similar amino acids regardless of codon usage. Primer-extended cDNA was amplified by PCR on cDNA templates prepared by reverse transcribing total mouse hypothalamic RNA. After cloning and sequencing the initial product, the 3' and 5' ends of mGRH were generated using a separate PCR strategy (RACE protocol). The mGRH cDNA encodes a 103-amino acid reading frame, structurally similar to the human and rat GRH genes, containing a signal sequence, a 42-residue GRH peptide, and a 31-residue C-terminal region. Although the structures of mouse and rat GRH are highly conserved in the signal peptide and C-terminal region, there is considerable diversity in the GRH region, which exhibits nearly comparable homology with the rat (68%) and human (62%) structures. Differences between mouse and rat GRH were also found in the amino acid cleavage sites at the 5' and 3' ends of the mature peptide and at the polyadenylation signal.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Results of endoscopic transsphenoidal pituitary surgery in 40 patients with a growth hormone-secreting macroadenoma

    NARCIS (Netherlands)

    Wagenmakers, M.A.; Netea-Maier, R.T.; Lindert, E.J. van; Pieters, G.F.F.M.; Grotenhuis, A.J.; Hermus, A.R.M.M.

    2011-01-01

    OBJECTIVE: Transsphenoidal pituitary surgery (TS) is the primary treatment of choice for patients with acromegaly. Macroadenomas (>1 cm) are more difficult to resect than microadenomas (remission rate +/- 50% compared to +/- 90%). Besides the conventional microscopic TS, the more recently introdu

  19. Omnigen-AF reduces basal plasma cortisol, AWA cortisol release to adrencocorticotropic hormone or corticotrophin releasing hormone & vasopressin in lactating dairy cows under thermoneutral or acute heat stress conditions.

    Science.gov (United States)

    Differences in the adrenal cortisol response of OmniGen-AF (OG) supplemented dairy cows to a corticotrophin releasing hormone (CRH) and vasopressin (VP) or an adrenocorticotropic hormone (ACTH) challenge when housed at different temperature-humidity indices (THI) were studied. Holstein cows (n=12; 1...

  20. Receptors of Hypothalamic-Pituitary-Ovarian-Axis Hormone in Uterine Myomas

    Directory of Open Access Journals (Sweden)

    Danuta Plewka

    2014-01-01

    Full Text Available In this study the expression of GnRH, FSH, LH, ER-α, ER-β, and PR receptors was examined in uterine myomas of women in reproductive and perimenopausal age. In cases of GnRH and tropic hormones a membranous and cytoplasmic immunohistochemical reaction was detected, in cases of ER-α and PR the reaction was located in cell nucleus, and in the case of ER-β it manifested also a cytoplasmic location. In some of the examined cases the expression was detected in endometrium, myocytes, and endothelium of blood vessels, in uterine glands and myoma cells. In myometrium the level of GnRH and LH receptors increases with age, whereas the level of progesterone and both estrogen receptors decreases. In myomas of women in reproductive age, independently of their size, expression of GnRH, FSH, and LH receptors was more pronounced than in myometrium. In women of perimenopausal age, independently of myoma size, expression of LH and estrogen α receptors was higher while expression of GnRH receptors was lower than in myometrium. FSH receptor expression was not observed. Expression of estrogen receptor β was not affected by age of the woman or size of myoma. Analysis of obtained results indicates on existing in small myomas local feedback axis between GnRH-LH-progesterone.

  1. Acromegaly caused by a growth hormonereleasing hormone secreting carcinoid tumour of the lung : the effect of octreotide treatment

    NARCIS (Netherlands)

    De Heide, L. J. M.; Van den Berg, G.; Wolthuis, A.; Van Schelven, W. D.

    2007-01-01

    in acromegaly, the overproduction of growth hormone is usually caused by a pituitary adenoma. We report a 74-year-old woman with acromegaly caused by ectopic overproduction of growth hormone-releasing hormone (GHRH), a rare diagnosis. The GHRH appeared to be produced by a carcinoid tumour of the

  2. Acromegaly caused by a growth hormonereleasing hormone secreting carcinoid tumour of the lung : the effect of octreotide treatment

    NARCIS (Netherlands)

    De Heide, L. J. M.; Van den Berg, G.; Wolthuis, A.; Van Schelven, W. D.

    2007-01-01

    in acromegaly, the overproduction of growth hormone is usually caused by a pituitary adenoma. We report a 74-year-old woman with acromegaly caused by ectopic overproduction of growth hormone-releasing hormone (GHRH), a rare diagnosis. The GHRH appeared to be produced by a carcinoid tumour of the lun

  3. Identification of the growth hormone-releasing hormone analogue [Pro1, Val14]-hGHRH with an incomplete C-term amidation in a confiscated product.

    Science.gov (United States)

    Esposito, Simone; Deventer, Koen; Van Eenoo, Peter

    2014-01-01

    In this work, a modified version of the 44 amino acid human growth hormone-releasing hormone (hGHRH(1-44)) containing an N-terminal proline extension, a valine residue in position 14, and a C-terminus amidation (sequence: PYADAIFTNSYRKVVLGQLSARKLLQDIMSRQQGESNQERGARARL-NH2 ) has been identified in a confiscated product by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Investigation of the product suggests also an incomplete C-term amidation. Similarly to other hGHRH analogues, available in black markets, this peptide can potentially be used as performance-enhancing drug due to its growth hormone releasing activity and therefore it should be considered as a prohibited substance in sport. Additionally, the presence of partially amidated molecule reveals the poor pharmaceutical quality of the preparation, an aspect which represents a big concern for public health as well.

  4. Antimullerian hormone: prediction of cumulative live birth in gonadotropin-releasing hormone antagonist treatment for in vitro fertilization

    NARCIS (Netherlands)

    Hamdine, O.; Eijkemans, M.J.; Lentjes, E.G.; Torrance, H.L.; Macklon, N.S.; Fauser, B.C.; Broekmans, F.J.

    2015-01-01

    OBJECTIVE: To assess the accuracy of antimullerian hormone (AMH) in predicting cumulative live birth rate (CLBR) within 1 year after treatment initiation in GnRH antagonist treatment cycles for in vitro fertilization (IVF). DESIGN: Observational (retrospective) substudy as part of an ongoing

  5. Coherence between biosynthesis, storage, and release of adipokinetic hormones

    NARCIS (Netherlands)

    Harthoorn, Leunis Forrinus

    2002-01-01

    In insects, specific parts of the retrocerebral complex are essential for homeostatic control in response to changes in both internal and external environments. Neuroendocrine cells in the glandular part of the coprus cardiacum of Locusta migratoria represent the site of synthesis and release of thr

  6. Pregnancy rates to timed artificial insemination in dairy cows treated with gonadotropin-releasing hormone or porcine luteinizing hormone.

    Science.gov (United States)

    Colazo, M G; Gordon, M B; Rajamahendran, R; Mapletoft, R J; Ambrose, D J

    2009-07-15

    We compared the effects of porcine luteinizing hormone (pLH) versus gonadotropin-releasing hormone (GnRH) on ovulatory response and pregnancy rate after timed artificial insemination (TAI) in 605 lactating dairy cows. Cows (mean+/-SEM: 2.4+/-0.08 lactations, 109.0+/-2.5 d in milk, and 2.8+/-0.02 body condition score) at three locations were assigned to receive, in a 2x2 factorial design, either 100 microg GnRH or 25mg pLH im on Day 0, 500 microg cloprostenol (PGF) on Day 7, and GnRH or pLH on Day 9, with TAI 14 to 18h later. Ultrasonographic examinations were performed in a subset of cows on Days 0, 7, 10, and 11 to determine ovulations, presence of corpus luteum, and follicle diameter and in all cows 32 d after TAI for pregnancy determination. In 35 cows, plasma progesterone concentrations were determined 0, 3, 4, 5, 6, 7, and 12 d after ovulation. The proportion of noncyclic cows and cows with ovarian cysts on Day 0 were 12% and 6%, respectively. Ovulatory response to first treatment was 62% versus 44% for pLH and GnRH and 78% versus 50% for noncyclic and cyclic cows (PpLH or GnRH, cyclic status, presence of an ovarian cyst, and preovulatory follicle size did not affect pregnancy rate. Plasma progesterone concentrations after TAI did not differ among treatments. Pregnancy rate to TAI was greater (PpLH group (42%) than in the other three groups (28%, 30