Differential regulation of the two forms of gonadotropin-releasing hormone (mGnRH and cGnRH-II) by sex steroids in the European female silver eel (Anguilla anguilla).


:The effect of steroids on the two gonadotropin-releasing hormone (GnRH) forms present in the eel (mammalian GnRH, mGnRH and chicken GnRH-II, cGnRH-II), as well as on gonadotropin (GTH), was studied using specific radioimmunoassays. Female silver eels received chronic treatments with various steroids (estradiol, testosterone, androstenedione, 5 alpha-androstane-3 beta, 17 beta-diol). Estradiol or the combination of estradiol and androgens induced increases in brain and pituitary mGnRH levels and pituitary GTH level, whereas androgens given alone had no significant effect. In contrast, androgens or their combination with estradiol reduced brain cGnRH-II levels (this form remaining undetectable in the pituitary), estradiol given alone having no significant effect. This work demonstrates that the two forms of GnRH undergo a differential regulation by steroids, with a positive estrogen-dependent feedback on mGnRH (as well as on GTH) and a negative androgen-dependent feedback on cGnRH-II. These data are in agreement with previous results obtained in experimentally matured female eels (induced by a gonadotropic treatment which stimulates the production of both estrogens and androgens) showing increases in mGnRH and GTH levels, as well as a decrease in cGnRH-II [1]. The positive feedback of steroids on the mGnRH-GTH axis adds credence to the hypothesis according to which mGnRH would be the main form involved in the control of the gonadotropic function. This positive feedback would play an important role, amplifying pubertal stimulation of the gonadotropic axis, in this fish species.






Montero M,Le Belle N,King JA,Millar RP,Dufour S




Has Abstract


1995-05-01 00:00:00












  • Effect of insulin on LHRH release by perifused hypothalamic fragments.

    abstract::Insulin-deficient states are associated with an impaired function of the hypothalamic-pituitary-gonadal axis, but the mechanisms underlying hypothalamic alterations in experimental diabetes are still unknown. We investigated the effect of glucose concentrations, in the presence and absence of insulin, on LHRH release ...


    pub_type: 杂志文章


    authors: Arias P,Rodríguez M,Szwarcfarb B,Sinay IR,Moguilevsky JA

    更新日期:1992-09-01 00:00:00

  • Rat interleukin-1 beta binding sites in rat hypothalamus and pituitary gland.

    abstract::In this study, radiolabeled recombinant rat interleukin-1 beta (r125I-IL-1 beta) was used to localize and characterize IL-1 beta binding in rat hypothalamus and pituitary gland by quantitative autoradiography. The ability of this ligand to bind to type I IL-1 receptor was first tested on murine lymphoma cells (EL-4). ...


    pub_type: 杂志文章


    authors: Marquette C,Van Dam AM,Ban E,Lanièce P,Crumeyrolle-Arias M,Fillion G,Berkenbosch F,Haour F

    更新日期:1995-10-01 00:00:00

  • Fos expression in the female rat brain during the proestrous prolactin surge and following mating.

    abstract::A prolactin (PRL) surge occurs in the female rat during proestrus in response to elevated estradiol levels. The elevated release of ovarian steroids on the day of proestrus is also associated with sexual receptivity. Mating triggers twice-daily PRL surges that supplant the proestrous PRL surge and are responsible for ...


    pub_type: 杂志文章


    authors: Yang S,Lee Y,Voogt JL

    更新日期:1999-04-01 00:00:00

  • 17 beta-estradiol and progesterone positively modulate spinal cord dynorphin: relevance to the analgesia of pregnancy.

    abstract::Pregnancy and parturition are associated with opioid-mediated elevations in maternal pain thresholds. This analgesia is subserved by a spinal cord dynorphin/kappa-opiate receptor system. During gestation, elevated pain thresholds are paralleled by a significant increase in the content of dynorphin (1-17 and 1-8) in th...


    pub_type: 杂志文章


    authors: Medina VM,Dawson-Basoa ME,Gintzler AR

    更新日期:1993-09-01 00:00:00

  • Osmotic mechanisms regulating cerebrospinal fluid vasopressin and oxytocin in the conscious rat.

    abstract::The effect of intraventricular and intravenous (i.v.) hypertonic saline on plasma and perfusate arginine vasopressin (AVP) and oxytocin (OT) levels was determined. A push-pull technique was used to sample third ventricular cerebrospinal fluid (CSF) in the conscious unrestrained rat. Intraventricular perfusion of hyper...


    pub_type: 杂志文章


    authors: Morris M,Barnard RR Jr,Sain LE

    更新日期:1984-11-01 00:00:00

  • Differential neuroendocrine and behavioral responses to cocaine in Lewis and Fischer rats.

    abstract::Lewis (LEW) and Fischer 344 (F344) rats differ in responsiveness of the hypothalamo-pituitary-adrenocortical (HPA) axis as well as in their behavioral responses to drugs of abuse. The present experiments were conducted to compare hypothalamic corticotropin-releasing factor (CRF), plasma adrenocorticotropic hormone (AC...


    pub_type: 杂志文章


    authors: Simar MR,Saphier D,Goeders NE

    更新日期:1996-01-01 00:00:00

  • Regulation of His-dTrp-Ala-Trp-dPhe-Lys-NH2 (GHRP-6)-induced GH secretion in the rat.

    abstract::His-dTrp-Ala-Trp-dPhe,Lys-NH2(GHRP-6) is a synthetic compound that releases GH in a dose-response and specific manner in several species and that may well be related to an endogenous compound of similar structure. The aim of this study was to investigate the in vivo GH responses to GHRP-6 in pentobarbital anesthetized...


    pub_type: 杂志文章


    authors: Mallo F,Alvarez CV,Benitez L,Burguera B,Coya R,Casanueva FF,Dieguez C

    更新日期:1993-01-01 00:00:00

  • The long form of the leptin receptor (OB-Rb) is widely expressed in the human brain.

    abstract::Leptin exerts important effects on the regulation of food intake and energy expenditure by acting in the brain. Leptin action is mediated by the interaction with a receptor that is alternatively spliced, resulting in at least five different isoforms. The long form (OB-Rb) has a long intracellular domain that is essent...


    pub_type: 杂志文章


    authors: Burguera B,Couce ME,Long J,Lamsam J,Laakso K,Jensen MD,Parisi JE,Lloyd RV

    更新日期:2000-03-01 00:00:00

  • Modulation of pancreatic neuroendocrine neoplastic cell fate by autophagy mediated death.

    abstract::Introduction Autophagic cell death in cancer cells can be mediated by inhibition of deacetylases. Although extensive studies have focused on the autophagic process in cancer, little is known about the role of autophagy in degrading cytosolic and nuclear components of pancreatic neuroendocrine neoplastic (pNEN) cells l...


    pub_type: 杂志文章


    authors: Matrood S,de Prisco N,Wissniowski T,Wiese D,Jabari S,Griesmann H,Wanzel M,Stiewe T,Neureiter D,Klieser E,Mintziras I,Buchholz M,Bartsch DK,Gennarino V,Di Fazio P

    更新日期:2020-10-27 00:00:00

  • Correlations between the hypothalamic density of 3H-clonidine-binding sites and plasma testosterone levels in mice.

    abstract::Correlations between the specific binding of radiolabelled adrenoligands in frontal cortex and hypothalamus, and plasma testosterone levels were investigated in inbred mouse strains. Binding values were structure and genotype dependent. There were significant negative intrastrain and interstrain correlations between h...


    pub_type: 杂志文章


    authors: Shishkina GT,Naumenko EV

    更新日期:1995-06-01 00:00:00

  • Glucocorticoid and mineralocorticoid receptors are involved in the facilitation of anxiety-like response induced by restraint.

    abstract::In previous studies, we have shown that male Wistar rats exposed to a single inescapable stressor session (15 min restraint) exhibited 24 h later an anxiogenic-like behavior in the elevated plus-maze (EPM), which was reversed by inhibition of corticosterone (CS) synthesis with metyrapone (75 mg/kg i.p.) 3 h before str...


    pub_type: 杂志文章


    authors: Calvo N,Volosin M

    更新日期:2001-04-01 00:00:00

  • Modulation of the neonatal pituitary and adrenocortical responses to stress by thyroid hormones in the rat: effects of hypothyroidism and hyperthyroidism.

    abstract::Neonatal rats exhibit a period of diminished pituitary and adrenocortical responses to stress during the first 2 weeks of life. Since thyroid hormones are known to affect brain development, modulation of these responses to stress by alterations in thyroid hormone status have been investigated in hypothyroid (Hypo) and...


    pub_type: 杂志文章


    authors: Walker CD,Sizonenko PC,Aubert ML

    更新日期:1989-09-01 00:00:00

  • A role for agouti-related protein in appetite regulation in a species with continuous nutrient delivery.

    abstract::Knowledge of specific neurotransmitters as well as the pathways and mechanisms regulating appetite in ruminants that continually graze, such as sheep, is incomplete. Although fundamentally agouti-related protein (AGRP) has a similar function across species to increase food intake, the regulation of AGRP may vary acros...


    pub_type: 杂志文章


    authors: Wagner CG,McMahon CD,Marks DL,Daniel JA,Steele B,Sartin JL

    更新日期:2004-01-01 00:00:00

  • Corticosterone decreases 3H-glutamate binding in rat hippocampal formation.

    abstract::The effect of in vivo corticosterone manipulation on binding sites for the excitatory neurotransmitter glutamate was determined using radioligand binding to rat brain cryostat sections and crude synaptic membranes. 3H-glutamate binding to regions of the dorsal hippocampal formation was significantly decreased in adren...


    pub_type: 杂志文章


    authors: Halpain S,McEwen BS

    更新日期:1988-09-01 00:00:00

  • Autoradiographic analyses of the effects of restraint-induced stress on 5-HT1A, 5-HT1C and 5-HT2 receptors in the dorsal hippocampus of male and female rats.

    abstract::Quantitative autoradiography was used to evaluate the effects of sex and either 1 or 5 daily 2-hour sessions of restraint stress on binding at 5-HT1A, 5-HT1C and 5-HT2 receptors in the rat dorsal hippocampus. Neither sex nor restraint stress were found to have effects on binding at 5-HT1C or 5-HT2 receptors. However, ...


    pub_type: 杂志文章


    authors: Mendelson SD,McEwen BS

    更新日期:1991-11-01 00:00:00

  • Novel ligand specificity of pituitary vasopressin receptors in the rat.

    abstract::The ligand specificities of sites binding tritium-labeled arginine vasopressin (3H-AVP) were investigated in membrane preparations of rat anterior pituitary gland and liver. Labeled AVP interacted with high-affinity, low-capacity binding sites in liver as well as in pituitary membrane fractions. Binding displacement s...


    pub_type: 杂志文章


    authors: Antoni FA

    更新日期:1984-08-01 00:00:00

  • 68Gallium DOTANOC-PET Imaging in Lung Carcinoids: Impact on Patients' Management.

    abstract:BACKGROUND:68Gallium DOTA-PET imaging is preferable to standard somatostatin receptor scintigraphy where available; however, its role in the management of lung carcinoid tumours (LC) remains unclear. METHODS:All consecutive patients with histologically confirmed LC from two ENETS Centres of Excellence were identified ...


    pub_type: 杂志文章,多中心研究


    authors: Lamarca A,Pritchard DM,Westwood T,Papaxoinis G,Nonaka D,Vinjamuri S,Valle JW,Manoharan P,Mansoor W

    更新日期:2018-01-01 00:00:00

  • Age-dependent changes in the mechanisms controlling prolactin secretion and phosphatidylinositol turnover in male rats: effect of phosphatidylserine.

    abstract::The present study was undertaken in order to better characterize the functional state of anterior pituitary gland in young and old rats by using prolactin secretion and incorporation of radioactive phosphate into phosphatidylinositol (PI) as markers. The in vitro incorporation of radiolabeled phosphate into anterior p...


    pub_type: 杂志文章


    authors: Bonetti AC,Bellini F,Calderini G,Galbiati E,Toffano G

    更新日期:1987-02-01 00:00:00

  • Pre- and postnatal influence of an estrogen antagonist and an androgen antagonist on differentiation of the sexually dimorphic nucleus of the preoptic area in male and female rats.

    abstract::The volume of the sexually dimorphic nucleus in the preoptic area (SDN-POA) of the rat brain is severalfold larger in adult male rats than in adult females. This sex difference in brain structure was previously shown to develop under the influence of androgenic and estrogenic hormones during the perinatal period. We t...


    pub_type: 杂志文章


    authors: Döhler KD,Coquelin A,Davis F,Hines M,Shryne JE,Sickmöller PM,Jarzab B,Gorski RA

    更新日期:1986-01-01 00:00:00

  • Thymic Neuroendocrine Neoplasms: Biological Behaviour and Therapy.

    abstract::Thymic neuroendocrine neoplasms are rare tumours, but their management can often be highly problematic. While previously assumed to be essentially variants of bronchopulmonary (lung) carcinoids, they are generally more aggressive and more difficult to treat. Some 25% are associated with multiple endocrine neoplasia-1,...


    pub_type: 杂志文章,评审


    authors: Jia R,Sulentic P,Xu JM,Grossman AB

    更新日期:2017-01-01 00:00:00

  • Cerebrospinal fluid levels of acetylcholinesterase, monoamines and oxytocin during labour, parturition, vaginocervical stimulation, lamb separation and suckling in sheep.

    abstract::Acetylcholinesterase (AChE) activity, and concentrations of monoamines, monoamine metabolites and oxytocin (OT) were measured in the cerebrospinal fluid (CSF) of sheep during late pregnancy, labour, parturition, vaginocervical stimulation, lamb separation and suckling. Concentrations of AChE, 4-hydroxy-3 methoxyphenyl...


    pub_type: 杂志文章


    authors: Kendrick KM,Keverne EB,Baldwin BA,Sharman DF

    更新日期:1986-01-01 00:00:00

  • Diurnal rhythmicity of gonadotropin-releasing hormone gene expression in the rat.

    abstract::The release of the decapeptide gonadotropin-releasing hormone (GnRH) from neuroterminals in the median eminence varies depending upon the stage of development, time of day, reproductive season, and day of the ovarian cycle. With respect to the biosynthetic events responsible for such alterations in GnRH release, we ha...


    pub_type: 杂志文章


    authors: Gore AC

    更新日期:1998-10-01 00:00:00

  • Seasonal regulation of neuroendocrine activity in male Turkish hamsters (Mesocricetus brandti): role of the hypothalamic paraventricular nucleus.

    abstract::Male Turkish hamsters received horizontal knife cuts within the hypothalamus to investigate the role of afferent and efferent projections of the paraventricular nucleus (PVN) in seasonal regulation of endocrine function. Following surgery, the animals were exposed to either a long (16 h light/8 h dark) or a short (8 h...


    pub_type: 杂志文章


    authors: Badura LL,Goldman BD

    更新日期:1992-04-01 00:00:00

  • Coexistence of growth hormone releasing factor-like and tyrosine hydroxylase-like immunoreactivities in neurons of the rat arcuate nucleus.

    abstract::Neurons synthesizing growth hormone releasing factor were detected by immunocytochemistry with specific antiserum against synthetic rat hypothalamic growth hormone releasing factor. Growth hormone releasing factor immunoreactive neurons which also showed tyrosine hydroxylase immunoreactivity were located in the ventro...


    pub_type: 杂志文章


    authors: Okamura H,Murakami S,Chihara K,Nagatsu I,Ibata Y

    更新日期:1985-08-01 00:00:00

  • Olfactory bulbs influence testosterone feedback on gonadotropin secretion in male hamsters on long or short photoperiod.

    abstract::Previous studies have shown that prepubertal olfactory bulbectomy will prevent the testicular regression associated with short photoperiod in golden hamsters. The gonadal regression which normally occurs in hamsters on short photoperiod is known to be due in part to an increased responsiveness of the reproductive neur...


    pub_type: 杂志文章


    authors: Pieper DR,Unthank PD,Shuttie DA,Lobocki CA,Swann JM,Newman S,Subramanian MG

    更新日期:1987-10-01 00:00:00

  • Morphology of luteinizing hormone-releasing hormone neurons as a function of age and hormonal condition in the male rat.

    abstract::Previous work in many laboratories has shown that luteinizing hormone-releasing hormone (LHRH) neurons display a range of shapes from smooth-contoured to extremely irregular or 'thorny'. To determine if these forms reflect or can be modified by the gonadal steroid milieu, the morphology of LHRH neurons was examined in...


    pub_type: 杂志文章


    authors: Witkin JW

    更新日期:1989-04-01 00:00:00

  • Postnatal morphological changes in rat LHRH neurons correlated with sexual maturation.

    abstract::The postnatal development of the luteinizing hormone-releasing hormone (LHRH) system in male and female rats was investigated using light microscopic immunocytochemistry. An identical number of immunoreactive LHRH cells (about 1,300) was observed for males and females throughout development. Two LHRH cell types, based...


    pub_type: 杂志文章


    authors: Wray S,Hoffman G

    更新日期:1986-01-01 00:00:00

  • MC4R dimerization in the paraventricular nucleus and GHSR/MC3R heterodimerization in the arcuate nucleus: is there relevance for body weight regulation?

    abstract::The worldwide obesity epidemic is increasing, yet at this time, no long-acting and specific pharmaceutical therapies are available. Peripheral hormonal signals communicate metabolic status to the hypothalamus by activating their corresponding receptors in the arcuate nucleus (ARC). In this brain region, a variety of G...


    pub_type: 杂志文章,评审


    authors: Rediger A,Piechowski CL,Habegger K,Grüters A,Krude H,Tschöp MH,Kleinau G,Biebermann H

    更新日期:2012-01-01 00:00:00

  • A detailed characterization of prolactin secretion patterns during daylight in individual cycling and pseudopregnant rats.

    abstract::In order to characterize plasma prolactin (Prl) patterns during the estrous cycle and pseudopregnancy (PSP), I collected sequential blood samples between 8.00 and 19.00 h at 1-hour, 1.5-min or 1-min intervals from conscious, unrestrained female rats. During the afternoon of proestrus and estrus a single Prl surge was ...


    pub_type: 杂志文章


    authors: Wiersma J

    更新日期:1981-11-01 00:00:00

  • Effect of spinal cord transection on the endocrine and blood pressure responses to intravenous clonidine.

    abstract::To determine whether the inhibitory effect of clonidine (CLON) on renin secretion is due in part to a direct action on the kidneys or due entirely to an action on the brain, the drug was administered intravenously in a dose of 30 microgram/kg to dogs in which the spinal cord had been transected in the cervical region....


    pub_type: 杂志文章


    authors: Ganong WF,Wise BL,Reid IA,Holland J,Kaplan S,Shackelford R,Boryczka AT

    更新日期:1978-01-01 00:00:00