Abstract:
:In goldfish the two native forms of gonadotropin-releasing hormone (GnRH), salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II), stimulate both gonadotropin-II (GTH-II) and growth hormone (GH) release. Modifications of GnRH structure at positions 1, 2, 3, and 6 often result in an antagonist in goldfish, an observation well documented in mammalian studies. In a preliminary study in goldfish, a mammalian GnRH antagonist, [Ac-D(2)Nal1, 4Cl-D-Phe2, D(3)-Pal3,6, Arg5, D-Ala10]-mGnRH (analog L) weakly stimulated GTH-II release, and strongly inhibited GH release. The objectives of the present study were to study the dose-related actions of analog L on GTH-II and GH release in the goldfish, the specificity of inhibition of native GnRH actions, and to test whether analog L can act directly on goldfish pituitary cells. In a goldfish pituitary fragments perifusion system, analog L at different concentrations, given as 2-min pulses or as 30-min prolonged treatments, stimulated GTH-II and inhibited GH release in a dose-dependent manner. Analog L at 2 microM concentration (45 min) significantly suppressed sGnRH- and cGnRH-II-stimulated GTH-II as well as GH release. Analog L specifically inhibited GnRH-stimulated GH release, without having any significant effects on the GH release induced by either SKF38393, a dopamine D1 receptor agonist, or thyrotropin-releasing hormone. The GTH-II stimulatory and GH-inhibitory actions of analog L were significantly suppressed by a 'true' GnRH antagonist (Ac-delta 3-Pro1, 4FD-Phe2, D-Trp3,6)-mGnRH. Further, analog L stimulated GTH-II release and suppressed GH release from the enzymatically dispersed goldfish pituitary cells, indicating the direct actions of analog L at the pituitary cell level. Analog L also displaced 125I-(D-Arg6, Pro9 NHEt)-sGnRH bound to crude goldfish pituitary membrane preparations in a dose-related manner. In conclusion, contrary to its action as a potent GnRH antagonist in mammals, analog L has GTH-II stimulatory action in goldfish. Analog L by acting via GnRH receptors at the pituitary cell level differentially acts on GTH-II and GH release, suggesting functional differences in the properties of the GnRH receptors on GTH and GH cells. Analog L also specifically inhibits sGnRH and cGnRH-II actions on GTH-II and GH release.
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Murthy CK,Turner RJ,Wong AO,Rao PD,Rivier JE,Peter REdoi
10.1159/000126706subject
Has Abstractpub_date
1994-06-01 00:00:00pages
561-71issue
6eissn
0028-3835issn
1423-0194journal_volume
59pub_type
杂志文章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 ...
journal_title:Neuroendocrinology
pub_type: 杂志文章,多中心研究
doi:10.1159/000472717
更新日期:2018-01-01 00:00:00
abstract::In the present study we demonstrated that TLQP-21, a biologically active peptide derived from the processing of the larger pro-VGF granin, plays a role in mammotrophic cell differentiation. We used an established in vitro model, the GH3 cell line, which upon treatment with epidermal growth factor develops a mammotroph...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000339855
更新日期:2013-01-01 00:00:00
abstract::To study the eyes' role in maintaining the circadian rhythm in pituitary-adrenal function, 24-h patterns of corticosterone levels were compared in intact and blinded adult female rats. Rats were blinded by optic enucleation at approximately 80 days of age. Nonstress plasma corticosterone levels were determined fluorom...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122495
更新日期:1976-01-01 00:00:00
abstract::This study examines the neural lobe of the pituitary gland for the presence of receptors for pituitary adenylate cyclase-activating polypeptide (PACAP) and their possible involvement in the regulation of neurosecretion. The presence of PACAP receptors of type I was revealed in the neural lobe, as well as in anterior a...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127113
更新日期:1996-08-01 00:00:00
abstract:BACKGROUND/AIMS:Cervical stimulation induces a circadian rhythm of prolactin secretion and antiphase dopamine release. The suprachiasmatic nucleus (SCN) controls this rhythm, and we propose that it does so through clock gene expression within the SCN. METHODS:To test this hypothesis, serial blood samples were taken fr...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000254379
更新日期:2010-01-01 00:00:00
abstract::The pineal gland in the rat exhibits a diurnal rhythm in activity of the enzyme serotonin N-acetyltransferase (N-AT) with peak values during the dark period of a diurnal lighting schedule approximately 100-fold those during the light period. After blinding the rhythm becomes free-running. It is abolished by partial hy...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122489
更新日期:1976-01-01 00:00:00
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...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125138
更新日期:1989-04-01 00:00:00
abstract::Leptin, the product of the obese gene, is a protein that is secreted primarily from adipocytes. Leptin can influence the function of the pituitary gland through its action on the hypothalamus, but it can also directly act at the level of the pituitary gland. The ability of leptin to induce an increase in intracellular...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000081843
更新日期:2004-01-01 00:00:00
abstract::Visual average evoked responses (AERs) to 4 intensities of light were studied in 5 patients with adrenal cortical insufficiency. Patients were tested off all medications, on ACTH while off all medications, and during replacement with carbohydrate-active steroids. Off treatment, when steroid levels were low, AERs were ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122452
更新日期:1975-01-01 00:00:00
abstract::Studies were undertaken to investigate the nature of receptors involved in the prolactin-releasing action of histamine in male rats. The increase of plasma prolactin levels induced by third-ventricle injection of histamine was blocked by intraventricular injection of ranitidine, an H2-antagonist, but not by systemic a...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123495
更新日期:1983-06-01 00:00:00
abstract::The involvement of histaminergic transmission in the rapid and sustained plasma ACTH and corticosterone (CORT) responses induced in conscious rats by intra-arterial infusions of 25 micrograms.kg-1 Escherichia coli lipopolysaccharide (LPS) was investigated. LPS challenge produced a rapid and transient increase (+ 62%) ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126961
更新日期:1996-03-01 00:00:00
abstract::Unlike rats, but similar to primates, guinea pigs exhibit prolonged function of the corpus luteum and elevated progesterone secretion after ovulation. The gonadotropins, estrogen (E) and progesterone (P) have been examined throughout the guinea pig estrous cycle. However, neither prolactin secretion nor its regulation...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126897
更新日期:1995-06-01 00:00:00
abstract::Delta-sleep-inducing peptide (DSIP) colocalizes within gonadotropin-releasing-hormone (GnRH)-containing neurons in adult hypothalamus and could play a role in the regulation of hypothalamic-pituitary axis in adults. To support the possibility that DSIP also participates in fetal neuroendocrine events and to demonstrat...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126098
更新日期:1992-01-01 00:00:00
abstract::The concentrations in plasma of the biologically active endogenous peptide Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) have not been measured during development or in female rats. By radioimmunoassay, we found that Tyr-MIF-1-like immunoreactivity (Tyr-MIF-1-LI) was first consistently detectable in plasma when the rat was 5 days o...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126322
更新日期:1992-12-01 00:00:00
abstract::Oxytocin receptors are regulated during parturition and lactation. Gonadal steroids are thought to be key players in this regulation. It is not well documented how oxytocin receptor gene expression is regulated in the CNS. In this study we analyzed potential estrogen effects on the oxytocin receptor mRNA levels in som...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127160
更新日期:1997-01-01 00:00:00
abstract::The timing of the episodic secretion of luteinizing hormone (LH) in ovariectomized ewes was investigated with respect to an ultradian rest-activity cycle. Individual sheep were enclosed in a chamber where their physical activity was continuously monitored, and blood samples for LH analysis were collected at 5-min inte...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123187
更新日期:1981-06-01 00:00:00
abstract:BACKGROUND/AIMS:Stress exacerbates neuron loss in many CNS injuries via the actions of adrenal glucocorticoid (GC) hormones. For some injuries, this GC endangerment of neurons is accompanied by greater immune cell activation in the CNS, a surprising outcome given the potent immunosuppressive properties of GCs. METHODS...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000367849
更新日期:2014-01-01 00:00:00
abstract::Using a high-performance liquid chromatography (HPLC) system coupled with an electrochemical detector, the concentrations of dopamine (DA) and 5-hydroxytryptamine (5-HT) and their major specific metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole-3-acetic acid (5-HIAA), respectively, were measured i...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125111
更新日期:1989-02-01 00:00:00
abstract::We have investigated the effects of exposure to short-term constant light (LL) on the spontaneous, proestrous luteinizing hormone (LH) surge in the female rat. Exposure to LL during the 3 days preceding proestrus delayed and reduced the magnitude of the LH surge which was measured in blood samples taken from conscious...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123225
更新日期:1981-09-01 00:00:00
abstract::After in vivo treatment, progesterone initially decreases tyrosine hydroxylase (TH) activity in the TIDA neurons, but subsequently increases TH activity with prolonged treatment. In order to explore the cellular mechanism for progesterone's effect, this study examined the acute inhibitory action of progesterone on TH ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000057336
更新日期:2002-05-01 00:00:00
abstract::During adult-onset peripheral hypothyroidism, the brain maintains normal levels of thyroid hormone for some time through a mechanism of 'central homeostasis'. Although onset, duration, and termination of such a homeostatic phenomenon have been recently evaluated in rat models, the mechanism behind remains unknown. Dur...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000107580
更新日期:2007-01-01 00:00:00
abstract::To examine the role of excitatory amino acid neurotransmitters in the regulation of LH and FSH secretion in ovariectomized (ovx) adult rats treated with estradiol and progesterone, we measured the release rates of the excitatory amino acid neurotransmitters, glutamate and aspartate, as well as the neurally inactive am...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126673
更新日期:1994-04-01 00:00:00
abstract::In the present study the effects of intravenously administered corticotropin-releasing hormone (CRH) on the release of proopiomelanocortin (POMC) derivatives such as adrenocorticotropic hormone (ACTH), beta-lipotropin (beta-LPH) and beta-endorphin (beta-END) as well as direct effects of CRH on pain sensitivity were ex...
journal_title:Neuroendocrinology
pub_type: 杂志文章,随机对照试验
doi:10.1159/000091980
更新日期:2005-01-01 00:00:00
abstract::Pituitary adenylate cyclase-activating polypeptide (PACAP) receptors were characterized and their function investigated in mouse pituitary neurointermediate lobe explants. We show that mouse neurointermediate lobes can be maintained for up to 1 month in defined medium. After 8 days in culture, these explants are devoi...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127091
更新日期:1996-07-01 00:00:00
abstract::Chronic exposure to Delta(9)-tetrahydrocannabinol (Delta(9)-THC) increases corticotropin-releasing hormone (CRH) and proopiomelanocortin (POMC) gene expression in the rat hypothalamus. The levels of circulating gonadal steroids concurrently modulate both neuropeptides in male and female rats. However, it remains unkno...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054685
更新日期:2001-09-01 00:00:00
abstract:INTRODUCTION:Acromegaly is commonly complicated by arthropathy and skeletal fragility with high risk of vertebral fractures (VFs). OBJECTIVE:This study aimed to assess whether VFs may be associated with sagittal spine deformities, arthropathy, impaired quality of life (QoL), pain and disability. METHODS:Thirty-eight ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000511811
更新日期:2020-09-25 00:00:00
abstract::Studies were performed to determine the role of thyroid hormone in the suppression of thyrotropin (TSH) by opiates. Serum samples were collected by decapitation 1, 3, 6, 12, 24, or 48 h after rats were implanted with 1 sustained-release morphine (75 mg) or placebo pellet. Morphine decreased TSH by 44% at 1 h and by 83...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125602
更新日期:1990-09-01 00:00:00
abstract::In man and other mammals, starvation is accompanied by a severe suppression of luteinizing hormone-releasing hormone (LHRH) and luteinizing-hormone (LH) secretion, which is caused by unknown alterations in hypothalamic functions. Prostaglandin E2 (PGE2), endorphins and testosterone (T) are know to be strongly involved...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124034
更新日期:1984-12-01 00:00:00
abstract::The aim of this study was to examine the occurrence of endogenous oscillations of Per1, Per2, Bmal1 and Rev-erbα genes in rat pineal explants and to investigate their regulation by adrenergic ligands. Our results show a significant and sustained rhythm of Per2,Bmal1 and Rev-erbα gene expression for up to 48 h in cultu...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000327430
更新日期:2011-01-01 00:00:00
abstract::The effects of adrenalectomy (ADX) and dexamethasone (DEX) treatment on brain dopamine (DA) receptors of ovariectomized (OVX) rats were investigated by autoradiography using binding of the D1 and D2 antagonists ligands [3H]SCH 23390 and [3H]spiperone, respectively. Fourteen days after ADX, D1 receptors decreased in th...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126158
更新日期:1992-04-01 00:00:00