Abstract：
:Although glutamate is the predominant excitatory amino acid in the vertebrate central nervous system (CNS) where it affects a variety of physiological processes and pathophysiological states, the role that glutamate receptors may play outside the CNS has not been clearly established. In the present study, the effects of N-methyl-D-aspartate (NMDA), alpha-amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazolepropanoic acid (AMPA) kainate, and metabotropic glutamate receptor agonists and antagonists were investigated on neuroendocrine melanotropes of the rat pars intermedia using single-cell dual-wavelength microfluorometry and the Ca(2+)-sensitive probe, fura-2, to monitor changes in [Ca2+]i. Glutamate induced a rapid, concentration-dependent rise in [Ca2+]i with an EC50 of 24 microM that was Mg(2+)-sensitive and dependent on the presence of extracellular Ca2+. NMDA increased [Ca2+]i in a glycine-dependent manner with an EC50 of 83 microM that was blocked by 1 microM MK-801 and 1 mM Mg2+. The non-NMDA receptor agonists kainate, AMPA, and quisqualate increased [Ca2+]i with an EC50 of 124, 5 and 8 microM, respectively. Responses to kainic acid were blocked by 10 microM CNQX and were shown to be sensitive to Mg2+ and dihydropyridine. AMPA stimulation was the most potent, and glutamate stimulation was the most efficacious at mediating increases in [Ca2+]i. The metabotropic receptor-specific agonist, trans-ACPD, failed to induce a change in [Ca2+]i. The glutamate-induced Ca2+ influx was about half of that elicited by a 50 mM K(+)-induced membrane depolarization and activation of voltage-sensitive Ca2+ channels. These results demonstrate the presence of glutamate receptors on rat melanotropes and suggest that glutamate receptors in the intermediate lobe of the pituitary may provide the excitatory counterbalance to the well-described secretoinhibiting input via dopamine and gamma-aminobutyric acid receptors.
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Giovannucci DR,Stuenkel ELdoi
10.1159/000126995subject
Has Abstractpub_date
1995-08-01 00:00:00pages
111-22issue
2eissn
0028-3835issn
1423-0194journal_volume
62pub_type
杂志文章abstract：:The hypothalamic peptide kisspeptin (metastin), the endogenous ligand of the G protein-coupled receptor KISS1R, plays a critical role in controlling GnRH release from hypothalamic GnRH neurons and thereby regulates hypothalamic-pituitary-gonadal functions. Although the therapeutic potential of kisspeptin is attractive...
journal_title：Neuroendocrinology
pub_type： 杂志文章,评审
doi：10.1159/000357809
更新日期：2014-01-01 00:00:00
abstract：:Structural and functional impairment of the skeletal system remains an important cause of morbidity and disability in patients with Cushing's syndrome (CS). Glucocorticoid (GC) excess inhibits bone formation and calcium absorption from the gut, increases bone resorption, and alters the secretion of gonadotropin and gr...
journal_title：Neuroendocrinology
pub_type： 杂志文章,评审
doi：10.1159/000314298
更新日期：2010-01-01 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：:Interleukin-1 (IL-1) and glucocorticoid hormones represent two key mediators involved in the modulation of the neuroimmunoendocrine response to stress. IL-1 is a potent activator of the hypothalamic-pituitary-adrenal (HPA) axis in rodents. In the immune system, glucocorticoids modulate IL-1 production and a number of ...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000126648
更新日期：1994-02-01 00:00:00
abstract：:Glass microknife lesions and immunocytochemistry were used to evaluate luteinizing hormone-releasing hormone (LH-RH)- and somatostatin (SS)-immunoreactive pathways from the preoptic region to the rat median eminence. Cuts were so placed that axons of more caudally located neurons in the periventricular hypothalamic ar...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000123886
更新日期：1984-03-01 00:00:00
abstract：:This study was carried out to clarify the central effects of neuropeptide Y (NPY) on gonadotropin and prolactin (PRL) release in the male rat and to evaluate the hypothesis that it may play a role in negative feedback regulation of gonadotropin secretion in the male. NPY (4 micrograms in 2 microliters 0.9% NaCl) or an...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000126481
更新日期：1993-06-01 00:00:00
abstract：:The effects of ablation of the nucleus medianus on drinking and vasopressin secretion were studied in male Long-Evans rats. The amount of water drunk in 1 h was assessed after subcutaneous injection of 5.8% NaCl (13.34 mosm/kg) or of angiotensin II (1.5 mg/kg). In a separate test with no water available, plasma vasopr...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000123518
更新日期：1983-07-01 00:00:00
abstract：:A consistent group of gonadotropin-releasing hormone (GnRH) cell bodies occurs in the ventral hypothalamic tract at the infundibular lip (IL), just below the arcuate nucleus (ARC), at the site of the so-called GnRH 'pulse generator'. Immunocytochemical studies were performed to examine contacts between these GnRH neur...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000124914
更新日期：1988-03-01 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：:The following fragments of LHRH were administered intraventricularly and tested for their ability to enhance sexual receptivity in ovariectomized, estrogen-primed female rats: LHRH1-6 NH2, Ac-LHRH5-10, des-Tyr5-LHRH and des-Gly10-LHRH. LHRH1-6 NH2 had no effect on sexual behavior compared to saline-infused controls. A...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000123503
更新日期：1983-06-01 00:00:00
abstract：:Activin A immunoreactivity has been localized within the nucleus tractus solitarius and its projections into regions of the hypothalamus such as the paraventricular nucleus. However, the function of activin within the central nervous system is unclear. Because these regions of the brain are involved in the regulation ...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000126399
更新日期：1993-03-01 00:00:00
abstract：:Three control point enzymes of the Embden-Meyerhof pathway, hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK) were measured by quantitative histochemical methods in individual hypothalamic nuclei of adult neonatally androgenized female rats. HK activity was significantly increased in anterior hypotha...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000122715
更新日期：1977-01-01 00:00:00
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...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000082735
更新日期：2004-01-01 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：:The effect of pinealectomy or immunization against melatonin (Mel) and N-acetylserotonin (NAS) on plasma prolactin (Prl) levels was studied in rats following pineal stimulation induced by blinding or exposure to short photoperiods (1 h light and 23 h darkness daily). Blinding alone or together with pinealectomy or imm...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000122650
更新日期：1977-01-01 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：:Gastroenteropancreatic (GEP) endocrine tumors are hypervascular tumors able to synthesize and secrete high amounts of VEGF. We aimed to study the regulation of VEGF production in GEP endocrine tumors and to test whether some of the drugs currently used in their treatment, such as somatostatin analogues and mTOR inhibi...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000289569
更新日期：2010-01-01 00:00:00
abstract：:Avian prolactin (PRL) secretion is regulated by vasoactive intestinal peptide (VIP) neurons residing in the infundibular nuclear complex (INF) of the hypothalamus. This VIPergic activity is modulated by stimulatory dopaminergic inputs. Dynorphin, serotonin (5-HT), dopamine (DA) and VIP all appear to stimulate PRL secr...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000048236
更新日期：2002-03-01 00:00:00
abstract：:Using specific antibodies to corticotrophin-releasing factor (CRF) and arginine vasopressin (AVP) we have immunocytochemically located cells and fibres containing these peptides in sheep fetuses. CRF neurones were first detected, in low frequency, in the paraventricular nuclei of fetuses of 90 days of gestation (term ...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000124860
更新日期：1987-11-01 00:00:00
abstract：:To assess whether gonadotropin-releasing hormone (GnRH) release from the hypothalamus might be altered by hyperprolactinemia in the male rat, we measured in chronically hyperprolactinemic rats the pituitary GnRH receptor content and described the pattern of luteinizing hormone (LH) release during the postcastration ri...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000124844
更新日期：1987-10-01 00:00:00
abstract：:Overt Cushing's syndrome is a rare disorder with an annual incidence of 2-3/million of which benign adrenal adenomas account for 0.6/million. The female:male ratio is 3:1. Preliminary data indicate a high proportion of subclinical Cushing's syndrome in certain risk populations such as patients with type 2 diabetes or ...
journal_title：Neuroendocrinology
pub_type： 杂志文章,评审
doi：10.1159/000314297
更新日期：2010-01-01 00:00:00
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：:Hereditary cases of growth hormone (GH)-secreting tumors have been classified into three clinical entities: the multiple endocrine neoplasia type 1 (MEN1) syndrome, the Carney complex (CNC) and the isolated familial somatotropinomas (IFS). The genomic defects associated with MEN1 are all linked to various mutations of...
journal_title：Neuroendocrinology
pub_type： 杂志文章,评审
doi：10.1159/000095525
更新日期：2006-01-01 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：:The influence of the hypothalamus on the development of the anterior pituitary cells was studied in normal and anencaphalic human fetuses. An immunocytological method was applied to study the quantitative evolution of the size of the cells during gestation. The somatotropic and corticotropic cells appeared at the end ...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000122709
更新日期：1977-01-01 00:00:00
abstract：BACKGROUND/AIM:The mode of action of the somatostatin analog octreotide on neuro-endocrine tumour proliferation is largely unknown. Overexpression of the proto-oncogene Akt/PKB (protein kinase B) has been demonstrated in certain neuro-endocrine tumours: Akt activates downstream proteins including mTOR and p70S6K, which...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000111501
更新日期：2008-01-01 00:00:00
abstract：:Previous reports have shown that dopamine (DA) in the zona incerta (ZI) has a stimulatory effect on gonadotrophin release. We have now investigated the possibility that steroids exert their feedback effects on the release of luteinizing hormone (LH) via catecholamine systems in the ZI. Since the same steroid regimes a...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000125708
更新日期：1991-02-01 00:00:00
abstract：:Pathologies involving the pituitary stalk (PS) are generally revealed by the presence of diabetes insipidus. The availability of MRI provides a major diagnostic contribution by enabling the visualization of the site of the culprit lesion, especially when it is small. However, when only an enlarged PS is found, the eti...
journal_title：Neuroendocrinology
pub_type： 杂志文章,评审
doi：10.1159/000506641
更新日期：2020-01-01 00:00:00
abstract：:Intestinal gluconeogenesis is a recently described function in intestinal glucose metabolism. In particular, the intestine contributes around 20-25% of total endogenous glucose production during fasting. Intestinal gluconeogenesis appears to regulate energy homeostasis via a neurally mediated mechanism linking the ent...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000369070
更新日期：2014-01-01 00:00:00
abstract：:Increases in the level of cAMP stimulate the secretion of GnRH from GT1 GnRH neuronal cells. We hypothesized that cyclic nucleotide phosphodiesterases (PDEs), the enzymes that hydrolyze cAMP, may constitute a negative feedback signaling mechanism for GnRH regulation by decreasing the level of cAMP. GT1 cells were show...
journal_title：Neuroendocrinology
pub_type： 杂志文章
doi：10.1159/000054386
更新日期：1998-12-01 00:00:00
