Abstract:
:Chronic hyperprolactinemia in the rat is associated with suppression of plasma gonadotropin concentrations. The reduction of gonadotropins is considered to be due to either an inhibitory effect of prolactin (PRL) on pituitary gonadotropin secretion and/or suppression of hypothalamic gonadotropin-releasing hormone (GnRH) release. In contrast to the in vivo effects of PRL on hypothalamic GnRH release, it has recently been reported that endogenous hypothalamic PRL exerts a tonic stimulatory effect on GnRH release in vitro. The present study was undertaken to further evaluate the role of PRL on GnRH release. To accomplish this, we set up a static hypothalamic organ culture system which enabled us to evaluate immunoreactive GnRH (iGnRH) release by individually incubated longitudinally halved hypothalami. PRL at the concentrations of 100 and 1,000 nM (2,300 and 23,000 ng/ml) inhibited iGnRH release. This suppressive effect of PRL was apparently specific since growth hormone, a PRL-related molecule, did not have any significant effect on iGnRH release at the concentration of 1,000 nM (21,500 ng/ml) and a PRL antiserum completely suppressed the inhibitory effect of exogenously added PRL. On the other hand, this antiserum had no effect on basal iGnRH release suggesting that hypothalamic PRL does not regulate GnRH release. Based on the observation that PRL exerts a sexually dimorphic effect on plasma gonadotropin levels, we also evaluated the effects of testosterone (T), dihydrotestosterone (DHT), 17 beta-estradiol (E2), and progesterone (P) on PRL-inhibited iGnRH release in vitro. T, DHT and E2 did not have any detectable effect on PRL-suppressed iGnRH release whereas P, at the concentration of 0.1 nM (0.03 ng/ml), completely abolished the effect of PRL.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Calogero AE,Weber RF,D'Agata Rdoi
10.1159/000126355subject
Has Abstractpub_date
1993-01-01 00:00:00pages
152-8issue
1eissn
0028-3835issn
1423-0194journal_volume
57pub_type
杂志文章abstract::The hypothesis was tested that corticotropin-releasing factor (CRF) is involved in the inhibition of gonadotropin secretion during chronic hyperprolactinemia. Two models of hyperprolactinemia were used, namely inoculation with the prolactin (PRL)-secreting tumor 7315b and implantation of isogenic pituitary glands. Gon...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125348
更新日期:1990-03-01 00:00:00
abstract::Serotonin, a biologically active amine, is related to carcinoid syndrome in functioning neuroendocrine tumors (NETs). Telotristat ethyl is a novel inhibitor of the tryptophan hydroxylase (TPH), a key enzyme in the production of serotonin. While its use in patients with carcinoid syndrome and uncontrolled diarrhea unde...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000502200
更新日期:2020-01-01 00:00:00
abstract::Gastric carcinoids are rare neuroendocrine tumors, usually classified as type I, if associated with atrophic body gastritis; type II, if associated with Zollinger-Ellison syndrome and multiple endocrine neoplasia type I, and type III, in the absence of any gastric pathology (sporadic tumors). The pathological features...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000080734
更新日期:2004-01-01 00:00:00
abstract::In pituitary cells, c-fos transcription induced by releasing hormones and growth factors results from enhanced initiation of transcription, and sustained elongation of transcripts beyond the first intron. We studied the regulatory role of the first intron of the mouse c-fos gene for the control of its transcription in...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054606
更新日期:2000-12-01 00:00:00
abstract::Ghrelin is a 28-amino-acid gastric peptide that potently stimulates growth hormone (GH) secretion in vivo and in vitro. Ghrelin-expressing cells have been found in the oxyntic region of the stomach and in the arcuate nucleus of the hypothalamus. The aim of this work was to investigate the regional distribution and dev...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000068653
更新日期:2003-02-01 00:00:00
abstract:UNLABELLED:Opioid peptides are present in both the posterior pituitary (PP) and stalk-median eminence (SME). Their effects on the dopaminergic neurons in the SME are well documented, but little is known concerning their role in the regulation of dopamine (DA) release from the PP. The objectives of this study were (1) t...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125612
更新日期:1990-10-01 00:00:00
abstract::The neuroanatomical distribution and morphology of neurons that produce gonadotropin-releasing hormone (GnRH) in the brain of the postpubertal male Djungarian hamster was studied using light microscopic immunocytochemistry. Analysis of every section from the rostral olfactory tubercle to the medial basal hypothalamus ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125341
更新日期:1990-02-01 00:00:00
abstract::The modulatory actions of ovarian steroids on the norepinephrine (NE) induced alterations in luteinizing hormone (LH) secretion were examined in male and female rats. Long-term (4 weeks) castrated male and female rats bearing chronic third-ventricle cannulae were implanted with intra-atrial catheters. Animals were ble...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124581
更新日期:1986-01-01 00:00:00
abstract::We studied the effect that beta-endorphin (beta END) might have at the median eminence (ME) on luteinizing hormone (LH)-releasing hormone (LHRH) during the ovulatory cycle of domestic hens. Thus, we assessed (a) the immunocytochemical distribution of beta END and LHRH in the hen ME, (b) the temporal changes in ME and ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126381
更新日期:1993-01-01 00:00:00
abstract::Somatotropes and GC cells, a GH-producing cell line, exhibit [Ca(2+)](i) oscillations that result from rhythmic Ca(2+) action potentials. Determination of this operating mode required simultaneous recording of both parameters by fura-2 imaging and patch-clamp techniques. In order to test whether patch recording induce...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054495
更新日期:1999-11-01 00:00:00
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 ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054429
更新日期:1999-04-01 00:00:00
abstract::Neuronal nitric oxide synthase, e.g. NADPH diaphorase (NADPH-d), catalyzes formation of the free radical, nitric oxide (NO), and occurs within brain structures that have functional significance for energy fuel homeostasis. The following studies examined whether populations of NADPH-d-positive neurons in the hypothalam...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054417
更新日期:1999-03-01 00:00:00
abstract::The effect of amphetamine (AMPH) on plasma corticosterone was studied in the conscious, unstressed rat. AMPH (0.5-5.0 mg/kg) produced a dose-dependent increase in plasma corticosterone. This rise in plasma corticosterone was not altered by the adrenergic blocking agents phenoxybenzamine or propranolol. In contrast, th...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122912
更新日期:1979-01-01 00:00:00
abstract:BACKGROUND:Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) express insulin-like growth factor (IGF)-related factors [IGF1, IGF2; insulin receptor (IR)-A, IR-B; IGF-binding protein (IGFBP) 1-3] as well as somatostatin (SSTRs) and dopamine D2 receptors (D2Rs). OBJECTIVES:To (1) compare mRNA expression of IGF-rel...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000444280
更新日期:2016-01-01 00:00:00
abstract:INTRODUCTION:Pituitary neuroendocrine tumors (PitNETs), the most abundant of all intracranial tumors, entail severe comorbidities. First-line therapy is transsphenoidal surgery, but subsequent pharmacological therapy is often required. Unfortunately, many patients are/become unresponsive to available drugs (somatostati...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000505923
更新日期:2020-01-01 00:00:00
abstract:BACKGROUND/AIMS:Both prostaglandin E2 (PGE2) and estradiol stimulate fetal ACTH secretion and augment fetal ACTH responses to stress. We have reported that estradiol increases prostaglandin endoperoxide synthase-2 (PGHS-2), and we have proposed that there is a positive feedback relationship between estrogen and fetal h...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000109664
更新日期:2008-01-01 00:00:00
abstract::The properties of neuronal-type nicotinic acetylcholine receptors (nAChRs) present on the neuroendocrine cells of the porcine pars intermedia of the pituitary were studied in intact single cell using measurements of the free intracellular Ca2+ concentration ([Ca]i) with the calcium-sensitive dye fura 2. Local applicat...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126772
更新日期:1994-10-01 00:00:00
abstract::Immobilization of adult male rats resulted in concomitant, significant releases of prolactin (PRL) and oxytocin (OT). Naloxone (0.2 mg/kg, i.p.) administration 30 min prior to initiation of restraint resulted in a significant diminution of the PRL response to stress. On the other hand, a significant augmentation of OT...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124053
更新日期:1985-01-01 00:00:00
abstract::Normal and castrated male rats implanted with permanent right atrial cannulae were used, and sequential blood samples were taken every 2 min through the cannula. When the rats, both normal and castrated, were exposed to ether for 2 min, the prolactin (Prl) concentration in plasma was immediately and dramatically eleva...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122826
更新日期:1978-01-01 00:00:00
abstract::The capability of the anterior pituitary gland to secrete growth hormone (GH) in response to an intravenous injection of growth hormone-releasing factor, hpGRF-44, was evaluated in male rats ranging from 22 days to 24 months of age. The increase in GH concentrations following a submaximal dose of hpGRF-44 (0.5 microgr...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123594
更新日期:1983-12-01 00:00:00
abstract::Both the pituitary-adrenal axis and the pituitary-gonadal axis are under the tonic inhibitory control of endogenous opioid peptides in man. However, the precise opioid receptor involved in the modulation of these hormones remains unknown. The effect of a dose of intravenous naloxone on serum levels of luteinising horm...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124463
更新日期:1986-01-01 00:00:00
abstract::It has been well documented that interleukin-1beta (IL-1beta) is a major mediator for recruiting the hypothalamo-pituitary-adrenal (HPA) axis following infectious disease. The recent localization of IL-1beta receptors in neurons of the hippocampus provides further support for the role of IL-1beta as a neurotransmitter...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054405
更新日期:1999-02-01 00:00:00
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...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126940
更新日期:1996-01-01 00:00:00
abstract::The effects of hepatic vagotomy upon the circadian rhythm of lipogenesis and body fat store levels were tested in seasonally obese Syrian hamsters. Lipogenesis was studied 8 weeks after surgery by measuring the incorporation of label into epididymal and retroperitoneal fat pad lipid in animals killed 30 min after intr...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125531
更新日期:1990-07-01 00:00:00
abstract::Rats bearing transplanted prolactin-secreting tumors are known to have very high prolactin levels in the serum, reduced hypothalamic opiate concentrations, increasing hypothalamic dopamine synthesis and increased hypophyseal portal blood dopamine levels. Further, it has been shown that incubation in 3H-leucine of ante...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123211
更新日期:1981-08-01 00:00:00
abstract::Pulsatile gonadotropin-releasing hormone (GnRH) release from the median eminence is critical for the appropriate function of the pituitary gonadotropes and for the generation of a preovulatory gonadotropin surge. The mechanisms by which many GnRH axon terminals are synchronized to release GnRH in a coordinated fashion...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054304
更新日期:1998-02-01 00:00:00
abstract:BACKGROUND/AIMS:Abuse of toluene products (e.g., glue-sniffing) primarily occurs during adolescence and has been associated with appetite suppression and weight impairments. However, the metabolic phenotype arising from adolescent inhalant abuse has never been fully characterised, and its persistence during abstinence ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000493686
更新日期:2018-01-01 00:00:00
abstract::We have previously reported that luteinizing hormone releasing hormone (LH-RH) levels in the medial basal hypothalamus (MBH) of adult male rats castrated for 2 weeks can be raised by testosterone (T) or estradiol (E2) treatment for 3-4 days. The present study was undertaken to determine the time after castration when ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124188
更新日期:1985-09-01 00:00:00
abstract::The functions of oxytocin in the female are thought to be confined to the processes of milk ejection and parturition. In this study the role of oxytocin in the body's response to stressful stimuli has been examined. Physical immobilization of rats and forced swimming caused large increases in the secretion of the horm...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123566
更新日期:1983-10-01 00:00:00
abstract::Glucocorticoid hormones have important effects on brain function in the context of acute and chronic stress. Many of these are mediated by the glucocorticoid receptor (GR). GR has transcriptional activity which is highly context-specific and differs between tissues and even between cell types. The outcome of GR-mediat...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000499659
更新日期:2019-01-01 00:00:00